Attachment 1 20160613 Dr Nick Kim report.pdf

Technical commentary and opinion relating to the nature, health significance
and persistence of trace of methamphetamine on indoor surfaces.
Report 1: nature and health significance.
13 June 2016
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Author:

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Dr Nick D Kim, Senior Lecturer, School of Public Health, College of Health, Massey University,
PO Box 756, Wellington 6140: [email address]

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School of Public Health, College of Health, P O Box 756, Wellington 6140, New Zealand.

1. Background
1.1 Nature of the engagement

Housing New Zealand have indicated that they would value some background technical
commentary and opinion on the following:

1.  The nature of the recommended clean-up guideline (0.5 µg/100 cm2) for
methamphetamine residues from surfaces.
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2.  Any information about surface methamphetamine loadings that might be linked to
potential for adverse health effects.
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3.  Expected natural rates of loss of methamphetamine residues on surfaces over time.

Statement relating to free provision and non-exclusivity of the information

I  am  happy  to  provide  this  information  to  Housing  New  Zealand  and  other  agencies  or
private  individuals  as  part  of  my  public  service  function  as  a  University  academic,  and  am
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also preparing a series of shorter briefing notes relating to aspects of the same issue.

Statement confirming absence of personal financial interest

To compensate for time taken in preparing these comments Housing New Zealand has kindly
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offered  to  pay  Massey  University  up  to  $8,100  by  way  of  a  short-form  contract,  with  the
exact sum depending on hours spent.  This will be invoiced at a future date.   None of this
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money  will  be  paid  to  me  personally.    After  deduction  of  overheads  by  the  University  for
contract administration, the balance of any funds received will be used in support of Massey
University  postgraduate  research  projects  within  the  School  of  Public  Health,  within  the
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College  of  Health.    This  is  my  standard  practice  for  external  contracts  through  Massey
University; they are a means of obtaining research funding for postgraduate students that I
am supervising or co-supervising.  Within the tertiary education sector it is usually necessary
to  seek  such  additional  funding  for  postgraduate  research  students  by  way  of  research
grants,  scholarships or  contracts.    Supplementary funds of  this type  typically  help  to  cover
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costs  of  laboratory  consumables,  external  analytical  tests,  and  other  advanced  forms  of
computational analysis, to allow masters and PhD students to complete their thesis work to
a suitable academic standard.

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1.2 Overview of expertise

This document contains expert opinion relating to traces of methamphetamine residues on
surfaces.  It is appropriate for me to first outline my areas of expertise to establish the basis
upon which I feel qualified to offer technical commentary in this area.  In later sections I will
identify significant technical documents and outline the reasoning upon which my opinions
are based.  I have prepared an outline of my background and areas of expertise in ‘brief of
evidence’ format, as Appendix 1.
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In  overview  form,  my  core  area  of  professional  expertise  is  the  technical  appraisal,  risk
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assessment and management of chemical contamination issues.

My  academic  qualifications  are  a  BSc(Hons)(First  Class)  in  Chemistry  (1987)  and  a  PhD  in
Environmental  Analytical  Chemistry  (1990).    My post-qualification  experience  includes  one
year in postdoctoral research, 11 years as a chemistry lecturer at the University of Waikato,
and 10 years with the Waikato Regional Council in regional government, and 4.5 years as a
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senior  lecturer  at  Massey  University  in  Wellington.    My  role  with  the  Waikato  Regional
Council was as a technical specialist in chemical contamination issues across the board (air,
land, water, etc.), including contaminated sites. My responsibilities ranged from provision of
scientific advice through to coordination of specific research programmes.
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My  academic  teaching  and  research  have  covered  two  main  areas:  (a)  environmental
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chemistry and risk assessment, particularly in relation to chemical contamination issues, and
(b) analytical chemistry method development, including new methods in forensic science.  I
am currently the ‘major leader’ for the Massey University’s Environmental Health teaching
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programme, and teach in chemistry and toxicology.

At  national  level  I  have  contributed  to  New  Zealand  policy  and  legislation  development  in
the  areas  of  contaminated  land,  hazardous  substances,  and  air  quality,  gained  experience
with  hazardous  emergency  management,  and  served  as  an  expert  witness  in  legal
proceedings, and as an independent hearings commissioner.
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In relation to this evidence it is relevant that I provided technical input into and peer review
of the Guidelines for the Remediation of Clandestine Methamphetamine Laboratory Sites [1].
This  document  was  published  by  the  Ministry  of  Health  in  2010  and  (in  the  absence  of
further  guidance)  has  been  used  since  then  (2010-2016)  as  the  New  Zealand  standard
reference  document  by  practitioners  involved  in  investigating  methamphetamine
contamination and remediating contaminated properties.
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In addition I was a member of Ministry for the Environment technical advisory groups that
oversaw  development  of  technical  documents  that  support  the  ‘Resource  Management
(National  Environmental  Standard  for  Assessing  and  Managing  Contaminants  in  Soil  to
Protect  Human  Health)  Regulations  2011’  *2]  which  are  also  referred  to  as  the  NESCS
regulations.    The  two  documents  of  most  relevance  here  are:  ‘Methodology  for  Deriving
Standards  for  Contaminants  in  Soil  to  Protect  Human  Health’  *3]  and  Toxicological  Intake
Values for Priority Contaminants in Soil.’ *4+.  The ‘Methodology’ document sets out a New
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Zealand exposure-risk model for determination of numeric guidelines for contaminants from
toxicological reference values, and is incorporated into the NESCS regulations by reference.
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Although  the  context  of  the  methodology  document  is  soil  contamination,  the  adopted
exposure-pathway risk methodology provides a general guide to the New Zealand approach
to determining risk-based guideline values.

1.3 Documents referred to in this assessment

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As part of this assessment I will refer to a number of documents by name and/or number in
the text, at points where they inform my commentary or opinions.  The identities of these
are  provided  in  a  single  reference  list  in  Section  4  of  this  report.    The  first  and  most
frequently referenced of these (reference [1]) is:
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  Ministry of Health (2010). Guidelines for the Remediation of Clandestine Methamphetamine
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Laboratory Sites. Wellington: Ministry of Health.

For simplicity, this document will be referred to as the NZ Methamphetamine Guidelines.

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2.0 Nature of current clean-up target  for surface methamphetamine
2.1  Identity, regulatory status and intended context

The  current  remediation  guideline  for  methamphetamine  residues  from  surfaces,  as
recommended by the Ministry of Health in the NZ Methamphetamine Guidelines [1] is 0.5
µg/100 cm2:

“The  Ministry  of  Health  currently  recommends  that  surface  wipes  for  methamphetamine  not
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exceed a concentration of 0.5 μg/100 cm2 as the acceptable post-remediation re-occupancy level
for a dwelling that has been used as a clan meth lab.”
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In  words,  this  figure  is  half  a  millionth  of  a  gram  of  methamphetamine  for  each  100  cm2
area of wall.  An example of 100 cm2 is a square patch of dimensions 10 cm wide by 10 cm
high.

This figure is not a mandatory clean-up target, or a standard that has (yet) been adopted in
any New Zealand statute, regulation or New Zealand Standard.  As such it carries no intrinsic
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weight  but  instead  exists  as  a  ‘recommended-practice’  reference  point,  which  gains
regulatory  solidity  only  when  adopted  operationally  by  public  agencies  (such  as  territorial
authorities) who have a say in re-habitation of a residence after a meth lab clean-up.   The
numeric  remediation  guideline  is  also  presented  as  being  open  to  future  modification,
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through  use  of  the  word  ‘currently’  in  the  excerpt  cited  above.    To  emphasize  the  non-
mandatory  status  of  the  remediation  guideline  it  is  worth  noting  the  first  sentence  of  the
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disclaimer in its parent document, the NZ Methamphetamine Guidelines [1], which reads:

“These guidelines have no statutory effect and are of an advisory nature only.”

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The  first  excerpt  above  is  the  only  written  statement  in  the  NZ  Methamphetamine
Guidelines [1] which explicitly links the Ministry of Health to the recommended remediation
guideline 0.5 µg/100 cm2.  With this in mind it is worth noting that the same statement also
specifies that the intended context of its use was for “a dwelling that has been used as a clan
meth  lab.”    This  specific  phrasing  reflects  that  fact  that  during  the  development  of  the NZ
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Methamphetamine Guidelines [1] it was not anticipated that the recommended remediation
guideline  for  methamphetamine  may  also  be  applied  to  a  multitude  of  cases  where
methamphetamine had merely been smoked within the walls of a dwelling.   The front page
title  of  the  NZ  Methamphetamine  Guidelines  [1]  also  make  it  clear  that  their  intended
context was the remediation of methamphetamine laboratories.

The majority of potential health risks associated with buildings used as meth labs are linked
to  inhalation  risks  of  the  higher-volume  and  toxic  chemicals  that  are  used  in  the
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manufacturing process, in particular, various solvents.  It is possible that the authors of the
NZ  Methamphetamine  Guidelines  [1]  may  have  opted  for  a  higher  remediation  target  (a)
had the potential relevance of smoking been foreseen, and/or (b) if representative data had
been  available  describing  the  ordinary  prevalence  and  concentrations  of  traces  of
methamphetamine on the interior walls of ordinary residential properties and hotel/motel
units.

The  Australian  guidelines  [5]  (published  in  2011)  do  explicitly  accommodate  both  options
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(manufacture  and  smoking)  in  the  same  remediation  target  for  methamphetamine  on
surfaces; however  with experience  and  ordinary  prevalence data  (see  Section 2.3.2 of this
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report) it is possible that the Australian guidance may be open to future modification.

2.2 What the guideline is and what that means
2.2.1 Overview

The numeric remediation guideline for methamphetamine can be referred to in two ways:
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  In New Zealand it qualifies as a ‘risk-based  guideline  value’ adopted from an overseas
jurisdiction,  as  defined  in  reference  [6]  (Ministry  for  the  Environment  (2003,  revised
2011).
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  In  some  overseas  jurisdictions,  it  would  be  regarded  as  a  ‘technology-based’  clean-up
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target, as the term is used by Hammon and Griffin (2007) [7].

Although  it  may  be  referred  to  as  ‘risk-based’,  the  remediation  guideline  does  not  denote
the onset of either a quantifiable health risk, or a sharp transition from ‘benign’ to ‘harmful.’
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As will be outlined below, the term ‘risk-based’ refers to the nature of the process that was
followed when a guideline is developed, and not the consequences of one being exceeded.
For reasons that will be outlined below, the existence of either minor or significant health
risks  can  not  be  inferred  from  a  simple  exceedance  of  the  0.5  µg/100  cm2  remediation
guideline.
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2.2.2  How risk-based guidelines are developed and what they represent

Risk-based  guidelines  are  numeric  limits  have  been  developed  to  define  tolerable
concentrations  or  loadings  of toxic  substances  in  various  media,  including  water, food,  air,
soil, and for some contaminants such as methamphetamine, surfaces.

The first step in developing any risk-based guideline is to determine and agree a toxicological
reference  dose  (RfD)  which  can  also  be  referred  to  as  a  tolerable  daily  intake  (TDI).    In
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general a reference dose is:

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“an estimate of a daily exposure to the human population (including sensitive subgroups) that is
likely to be without an appreciable risk of harmful effects during a lifetime.” *7]

In most cases the reference dose is based on the lowest dose at (or just above) which the
very  beginning  of  a  potential  health  effect  occurs,1  which  is  then  divided  by  uncertainty
factors to create a substantially lower number still.

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The combined uncertainty factor can range from 10 to 1000 but is commonly 100.  A factor
of 100 is designed to allow for differences in sensitivity between species (e.g. extrapolating
from  rats  to  humans)  and  between  individuals  (i.e.  variation  in  sensitivity  within  a  human
population).    Use  of  the  uncertainty factor  provides  some  assurance  that  the  onset  of any
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effect  is  unlikely  to  occur  in  even  the  most  sensitive  individuals  of  the  most  sensitive
subgroups of the population (e.g. children), even if exposed over the long term.
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Once a toxicological reference dose has been established, risk-based guidelines applicable to
various media (soil, food, water, a surface) can be derived from it.
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The toxicological reference dose (RfD) which sits well behind the NZ [1] methamphetamine
remediation  guideline  is  0.0003  mg/kg  body  weight,  and  was  initially  derived  by  the

1  These ‘minimum onset thresholds’ go by various titles depending on what exactly is being tracked:
  NOEL = no observable effects level (the highest dose at which no effect of any type is
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observed);
  NOAEL = no observable adverse effects level (the highest dose at which no adverse effect is
observed);
  LOEL = lowest observable effects level (the lowest dose at which an effect of any type is
observed);
  LOAEL = lowest observable adverse effects level (the lowest dose at which an adverse
effect is observed);
  BMDL = benchmark dose level;
  BMD10 = benchmark dose level associated with a 10% effect.
Experimentally these thresholds can sometimes be hard to tell apart.

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California EPA OEHAA based on a review of human data.  Rationale for and derivation of this
figure  is  provided  in  Salocks  (2009)  [8].    Briefly,  an  estimated  LOAEL  (Lowest  Observable
Adverse  Effects  Level)  of  0.08  mg/kg  body  weight  was  divided  by  a  combined  uncertainty
factor of 300.2

After a toxicological reference dose (RfD) has been established, the guideline development
process  itself  requires  identification  and  quantification  of  possible  exposure  pathways,  or
ways  that  the  contaminant  can  make  its  way  from  the  source  to  become  absorbed  (or
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available  for  absorption)  by  an  individual.    One  of  three  dominant  entry  routes  are
considered  as  the  final  step  in  an  exposure  pathway:  these  are  ingestion,  inhalation,  and
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absorption through the skin. Exposure pathways are context-specific and vary widely. In the
case  of  methamphetamine  on  surfaces  for  example,  one  pathway  is  transfer  of
methamphetamine to a child’s hands which are then transferred to their mouth, leading to
ingestion as the entry route.  Another route is potential absorption through the skin.

Assumptions made in quantifying exposures that could occur through the various pathways
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tend  to  be  realistic  when  good  information  is  available,  and  conservative  (precautionary)
where data is limited.  On the whole, the inclusion of precautionary assumptions around a
number of exposure factors means  that this process probably tends to estimate exposures
as  being  higher  than  they  are  likely  to  be  in  most  cases,  but  this  approach  is  regarded  as
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being appropriate in the face of uncertainty.

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After  exposure  pathways  are  identified  and  numerically  characterised,  then  a  risk-based
guideline  value  can  be  back-calculated  by  working  our  what  level  of  exposure  (from  all
pathways  working  together)  would  be  sufficient  to  meet  the    toxicological  reference  dose
(RfD).
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In recent New Zealand history this sequential process has been illustrated in some detail as
part  of  published  background  work  that  went  into  developing  Soil  Contaminant  Standards
(SCS  values)  for  use  in  the  Resource  Management  (National  Environmental  Standard  for
Assessing  and  Managing  Contaminants  in  Soil  to  Protect  Human  Health)  Regulations  2011
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2  The factor of 300 itself includes:

  Division of the LOAEL of 0.08 mg/kg by 10 for extrapolation from a LOAEL to a NOEL (No Observed
Effect Level);
  A further division by 10 for inter-individual variation in population response; and
  A further division by 3 to allow for incompleteness in the database.

No additional factor was found to be necessary to allow for differences between short and long-term
exposure, due to the nature of the toxicological response (end-point).

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(also known as the NESCS) [2].   Reference doses for priority contaminants in soils were first
developed  as  documented  in  ‘Toxicological  Intake  Values  for  Priority Contaminants  in  Soil’
[4];  and  an  exposure-pathway  methodology  was  then  refined  and  applied  through  which
concentration limits in soil were developed by being indexed against the reference doses, as
documented  in  ‘Methodology  for  Deriving  Standards  for  Contaminants  in  Soil  to  Protect
Human  Health’  *3]  (with  both  documents  being  published  by  the  Ministry  for  the
Environment in 2011).   The ‘Methodology’ document [3] is now incorporated by reference
into  the  national  environmental  standard  (NESCS)  [2].    Through  incorporation  into
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regulations by reference, the risk-based guidelines developed through this process made a
transition  to  becoming  standards,  and  are  referred  to  as  Soil  Contaminant  Standards  (SCS
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values).

A  key  point  about  risk-based  guideline  values  (or  standards)  is  that  the  name  ‘risk-based’
refers to the process that was followed in their development.  Specifically the phrase ‘risk-
based’  means  that  through  consideration  of  exposure  pathways,  the  guideline  is  one  that
was  quantitatively  indexed  to  an  agreed  toxicological  reference  value  (RfD  or  equivalent).
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The  toxicological  reference  value  itself  is  set  at  a  very  conservative  level  to  effectively
guarantee lack of an effect, and variability in some of the exposure assumptions can often
produce  guidelines  that  may  vary  by  factors  of  2,  3,  4  or  5  times  (see  section  below).
Generally the various estimates will produce guidelines of a similar magnitudes, and defining
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a safe order-of-magnitude is really how most guidelines of this type should be viewed, from
a risk perspective.
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For  these  reasons,  exceeding  a  ‘risk-based’  guideline  value  by  a  marginal  amount  can  not
(and  should  not)  be  taken  to  imply  the  onset  of  any  genuine  or  measureable  health  risk.
Such guidelines do not have that level of precision, and are also buffered by an aggregate of
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uncertainty factors that in combination tend to make them highly precautionary.
Guidelines or standards developed through less rigorous methods are usually referred to by
another  name,  as  ‘threshold’  values.    The  distinction  between  ‘risk-based’  guidelines  and
‘threshold’ values is emphasized in Ministry for the Environment (2003, revised 2011) [2]:
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“Environmental  guideline  values  can  be  risk-based  or  threshold  values.    Risk-based  values  are
derived  from  a  given  exposure  scenario  (protection  of  human  health)  or  the  protection  of  a
nominal  proportion  of  species  in  an  ecosystem.  Threshold  values  may  be  derived  from
toxicological  data  where  insufficient  data  is  available  to  calculate  risk-based  values.  Guideline
values  may  also  be  classified  as  threshold  values  where  insufficient  information  on  their
derivation is provided.”

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2.2.3  Origin of New Zealand’s recommended  guideline

Ministry  for  the  Environment  (2003,  revised  2011)  [2]  sets  out  principles  and  a  preferred
hierarchy  for  selection  of  numeric  guidelines/standards  in  New  Zealand,  as  recognized  by
the authors of the NZ Methamphetamine Guidelines [1].   The hierarchy, in order from most
to least preferred, is:

1.  New Zealand derived risk-based guideline values;
2.  Rest  of  the  world  derived  risk-based  guideline  values,  with  preference  given  to  those  that
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employ risk assessment methodologies and exposure parameters consistent with that already
used in New Zealand;
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3.  New Zealand derived threshold values;
4.  Rest of the world derived threshold values.
The  first  preference  in  this  guideline  hierarchy is  not  available  now,  and  was  not  available
when the NZ Methamphetamine Guidelines [1] were written.  This is because New Zealand
has  not  yet  developed  its  own  risk-based  guideline  for  methamphetamine  residues  on
surfaces.
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At the time that the NZ Methamphetamine Guidelines [1] were being written however, two
other  ‘risk-based’  guidelines  had  been  developed  or  drafted  in  overseas  jurisdictions.    In
keeping with requirements of the second category of the guideline hierarchy, both of these
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employed  risk  assessment  methodologies  and  exposure  parameters  consistent  with  those
already  used  in  New  Zealand.    Either  of  these  overseas  guidelines  could  potentially  be
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adopted under step 2 of the guideline hierarchy:
1.  In California, a clean-up standard of 1.5 μg/100 cm2 had been formally adopted through
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amended  legislation.    The  NZ  Methamphetamine  Guidelines  [1]  discuss  this  and  other
numbers, and explain its background and rationale as follows:
“In  California,  the  Office  of  Environmental  Health  Hazard  Assessment  (OEHHA)  and
Department  of  Toxic  Substances  Control  (DTSC)  have  developed  a  risk-based  target
remediation  standard/guideline  (clean-up  standard)  for  methamphetamine  in  residences
used  to  illegally  manufacture  methamphetamine.  On  1  January  2010  the  statute  was
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amended to less than or equal to 1.5 μg/100 cm2 when legislation was passed by AB 14898
(Health  and  Safety  Code  section  25400.16)  replacing  the  standard  0.1  μg/100  cm2  on  the
grounds  that  extensive  research  found  the  standard  (0.1  μg/100  cm2)  to  be  overly
conservative and that a standard of 1.5 μg/100 cm2 would be sufficiently protective to make
properties safe for human occupancy.”
2.  Meanwhile  in  Australia,  an  ‘Investigation  Level’  (IL)  of  0.5  µg/100  cm2  for
methamphetamine on surfaces had been prepared by the consulting firm Environmental
Risk Sciences Pty Ltd under contract to the Australian Crime Commission.  This report [9]
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had (and has3) only been released in draft form; however the technical author followed
an appropriate risk-based methodology of a type that could qualify under category 2 of
the New Zealand guideline hierarchy.   It is unclear whether this value was ever formally
peer-reviewed, but it was subsequently adopted as part of Australia’s ‘Clandestine Drug
Laboratory Remediation Guidelines’ (published in 2011) [5].
Both of these figures could be seen as risk-based, but for reasons that may remain unclear,
the Australian ‘Investigation Level’ (0.5 μg/100 cm2) was chosen for recommendation in the
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New  Zealand  methamphetamine  guidelines  (see  [1],  Table  3:  Summary  of  remediation
guidelines  for  New  Zealand  residential  properties).4    Given  that  the  California  EPA
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OEHAA/DTSC  guideline  was  based  on  the  same  toxicological  reference  dose  and  most
sensitive  receptor  [8]  and  made  use  of  a  more  sophisticated  exposure  model  [9],  and  had
been adopted by statute by an overseas jurisdiction at time that the NZ Methamphetamine
Guidelines [1]  were written, it could be argued that the Californian figure of 1.5 µg/100 cm2
may  have  been  a  more  justifiable  first  choice  as  a  New  Zealand  remediation  guideline.
(Having  noted  this, there  is  one  ‘external’  reason  for  recommendation of  the  lower  of  the
two  numbers  in  the  context  of  a  methamphetamine  laboratory  cleanup,  which  relates  to
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potential  risks  from  chemical  residues  other  than  methamphetamine.    This  reason  is
outlined below in Section 2.2.4.)
Variations  in  assumptions  made  in  risk  modelling  can  change  the  outcome  significantly.
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Environmental  Risk  Sciences  (2009)  [9]  acknowledge  and  discuss  reasons  for  the  factor  of
three difference between their derived figure of 0.5 µg/100 cm2 now used in Australia and
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California’s  OEHHA/DTSC  guideline  of  1.5  µg/100  cm2.    Both  derivations  started  with  the
same  toxicological  reference  dose  (RfD),  and  derivation  of  both  was  based  on  potential
effects on the most sensitive residential receptor: young children aged 6 months to 2 years
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3   Environmental  Risk  Sciences  (2009).  Derivation  of  Risk-Based  Investigation  Levels,  Clandestine  Drug
Laboratory, Site Investigation Guidelines. Prepared for the Australian Crime Commission, Ref: ACC/09/R001,
6  October  2009.  Available  from:    http://www.enrisks.com.au/wp-content/uploads/2012/12/Derivation-of-
Risk-Based-Guidelines-for-Website.pdf
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4  Note  that  a  cursory  reading  of  the  summary  provided  in  Section  5.5  of  the  NZ  Methamphetamine
Guidelines [1] may potentially mislead by giving the opposite impression, that the adopted guideline
came  from  a  US  jurisdiction.    This  summary  reads:  “In  an  effort  to  determine  a  level  of
methamphetamine at or below which the site remediation process could be considered adequate for
the  protection  of  people  who  would  subsequently  reoccupy  a  dwelling,  the  Ministry  of  Health  has
evaluated  the  current  remediation  guidelines  used  overseas,  in  particular  in  the  United  States.  The
Ministry  of  Health  currently  recommends  that  surface  wipes  for  methamphetamine  not  exceed  a
concentration of 0.5 μg/100 cm2 as the acceptable post-remediation re-occupancy level for a dwelling
that has been used as a clan meth lab.”

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[8,  9].    In  discussing  reasons  for  differences  in  the  resulting  guideline,  Environmental  Risk
Sciences (2009) (Appendix C) [9] describe their own approach in the following terms:
“...a  point  value,  simplistic  application  of  a  more  complex  exposure  model  (which  considers
exposure distributions and microactivity patterns based on diary entries), SHEDS (USEPA, 2007).
The  conservative  nature  of  the  approach  adopted  can  be  illustrated  by  comparison  of  the  IL
derived for methamphetamine with that derived by OEHAA (2009) using the more complex SHEDS
model…”
With  these  factors  in  mind  it  may  be  worth  noting  the  disclaimer  in  the  NZ
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Methamphetamine  Guidelines  [1],  to  accommodate  the  possibility  of  an  alternative  view
being  taken  on  the  most  appropriate  source  of  a  remediation  target  that  meets  the
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conditions outlined in category 2 of the guideline hierarchy:

“These  guidelines  have  no  statutory  effect  and  are of  an  advisory  nature only.  The  information
should not be relied upon as a substitute for the wording of the relevant legislation or for detailed
advice  in  specific  cases,  or,  where  relevant,  as  formal  legal  advice.  If  advice  concerning  specific
situations or other expert assistance is required, the services of a competent professional advisor
should be sought.”
Information

Some comments about the possibility of New Zealand developing its own guideline are
provided in Section 2.3 of this report.
2.2.4  A secondary rationale for use of a low number
Official

As indicated above, the majority of potential health risks associated with buildings used as
the
clandestine  laboratories  are  linked  to  inhalation  risks  of  the  higher-volume  and  toxic
chemicals  that  are  used  in  the  manufacturing  process,  in  particular,  various  solvents;  but
also other potential by-products of the methamphetamine manufacturing process that may
under
exist  on  walls  and  other  surfaces.      For  this  reason  the  methamphetamine  remediation
target  in  the  NZ  Methamphetamine  Guidelines  [1]  is  only  one  of  several  numeric
remediation guidelines.

In  the  context  of  a  lab  clean-up,  methamphetamine  residues  can  be  used  as  a  marker  for
potential presence of o
Released  ther unknown chemical by-products of manufacturing. In this context
a very low clean-up target for methamphetamine can be very useful, because cleaning down
to  a  very  low  remediation  target  for  a  known  residue  will  ensure  that  other  unmeasured,
unidentified or unquantifiable chemical residues on interior surfaces would also be reduced
to extremely low concentrations.

13

Reasoning here is that if the readily measurable target substance methamphetamine can be
reduced to vanishingly small quantities, then any other potentially problematic precursors or
by-products from the manufacturing process that might be present on surfaces would also
be reduced to very low concentrations, whether or not they were identified and measured.
In this way, methamphetamine  residues can be used as a convenient  marker for the likely
removal  of  all  other  possible  chemical  residues  produced  in  a  clandestine  lab  during
manufacturing,  some  of  which  may  be  more  toxic.    (This  reasoning  does  not  apply  to  the
1982
home smoking scenario.)

Act
The  authors  of  the  NZ  Methamphetamine  Guidelines  [1]  understood  this  and  explain  that
these  considerations  as  being  part  of  their  reasoning  in  recommending  conservative
remediation guidelines for known contaminants.   They note:
“The  Ministry  of  Health’s  rationale  for  the  remediation  guidelines  assumes  that  if
decontamination  activities  are  sufficient  to  remove  methamphetamine  and  VOCs  (also  iodine,
lead and mercury if the amalgam/P2P method is used) to acceptable levels, other chemicals for
Information
which  a  remediation  guideline  value  has  not  been  given  will  have  been  sufficiently  removed  as
well.” *1; page 23].

2.2.5 How the New Zealand guideline might be viewed in other contexts

Official
In  California,  where  a  risk-based figure  of  1.5  µg/100  cm2  is  in  use,  the  Australian  IL being
used in New Zealand and all lower values might be regarded as ‘technology based’ clean-up
the
targets  [7].    This  phrase  reflects  that  fact  that  a  driver  of  remediation  can  be  our  modern
ability to detect ultra-trace levels of various organic compounds down to vanishingly small
(ultra-trace or ‘forensic level’) concentrations.
under

The authors of the NZ Methamphetamine Guidelines [1] noted that although over 20 states
in the US have/had established their own clean-up targets for methamphetamine residues
from surfaces, these other values were/are not ‘risk-based.’   Rather they are based on levels
that (a) can be that could be measured down to using modern analytical instruments, and
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(b) are so low that they are “believed to be set at sufficiently conservative levels to still be
health-protective.”

Modern  instrumental  methods  for  chemical  analysis  used  in  commercial  laboratories  can
commonly reach over ten times lower than the Australian IL (to ~0.05 µg/100 cm2) but every
method will eventually reach an instrumental detection limit.  When that detection limit is
reached, the result is simply reported as being ‘less than’ (<) the detection limit, or a ‘non-
14

detect.’      In  relation  to  these  considerations  and  for  some  purposes  it  can  be  useful  to
appreciate the following points:

  ‘Non-detected’  results  do  not  mean  that  the  residues  are  no  longer  present.    Non-
detected  results  simply  mean  that  if  residues  are  still  present  they  are  below  the
detection limit of the available methodology and technology; we have reached the point
where an analytical instrument or method can no longer detect them.

1982
  Though risk-based, a constraint on the numeric value of any clean-up standard is that it
must be set at a level that a range of capable instrumental methods used in commercial
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laboratories  can  comfortably  reach.    If  the  New  Zealand  standard  had  been  set  20-30
years earlier, the limit would have necessarily been  set at a much higher value.  This is
because we would have been relying on an earlier generation of analytical instruments
possessing higher detection limits.5
2.3 Possibility of a New Zealand risk-based guideline
Information
2.3.1 Existence of the option

New Zealand could at any point take the approach of developing its own risk-based guideline
value for methamphetamine residues on surfaces.  Such a value would sit at the top tier of
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the  guideline  hierarchy  [2]  and  supersede  the  need  to  resort  to  guidelines  developed  in
other  jurisdictions  operating  under  similar  but  slightly  different  contexts.    In  keeping  with
the
contaminated land guideline development, the Ministries of Health and Environment would
be appropriate sponsoring agencies.
2.3.2 Potential relevance of external constraints
under
Potential significance of background prevalence

Constraints  imposed  by  external  realities  occasionally  insert  themselves  into  the  guideline
setting  process,  resulting  in  guidelines  that  are  higher  than  they  would  be  in  a  world
determined by idealized
Released   assumptions expressed in toxicological equations.

The  Maximum  Acceptable  Value  (MAV)  for  arsenic  in  drinking  water  (10  µg/L)  is  a  good
example  of  this.    Long-term  excess  cancer  risk  from  at  this  concentration  is  likely  to  be

5   For  modern  testing  of  organic  compounds  to  trace  level  the  industry  standard  is  now  based  on
chromatographic  separation  with  detection  by  mass  spectrometry  (with  abbreviations  including  GC-MS,
HPLC-MS, and HPLC-MS-MS).  Before mass spectrometric interfaces were developed detection relied on the
previous generation of chromatographic techniques (e.g. GC-FID and HPLC).
15

substantially higher [10, 11] than the excess cancer risk of 1 in 100,000 normally tolerated in
New  Zealand,  and  used  in  setting  other  guidelines  for  non-threshold  contaminants  of  this
type  [3].    In  this  case  the  external  reality  is  that  arsenic  occurs  naturally  at  reasonably
elevated  concentrations  in  some  source-waters,  and  this  would  make  it  difficult  for  some
drinking water supplies to realistically meet the MAV after treatment if the MAV were set at
a  substantially  lower  concentration.    For  example,  the  natural  long-term  average
concentration  of  arsenic  in  water  leaving  Lake  Taupo  at  the  start  of  the  Waikato  River  is
already  10  µg/L,  before  any  anthropogenic  influence  of  the  Wairakei  geothermal  power
1982
station is felt [12].

Act
The tolerable intake for cadmium in food is a second example, where there is essentially no
safety  factor  between  modern  dietary  intakes,  and  the  lowest  concentrations  that  might
correspond to adverse health effects in some people; or in the words of Järup and Åkesson
[13]: “...no margin of safety between the point of departure and the exposure levels in the
general  population.”    This  reality  is  imposed  by  the  combined  effect  of  natural  and
anthropogenic cadmium in modern foods and diets [14], a significant proportion of which is
Information
attributable to the long-term use of phosphate fertilizers on farmland [15, 16].

Similarly,  soil  standards  for  arsenic  and  cadmium  were  set  with  reference  to  survey  data
defining  the  background  ranges  of  these  two  elements  in  New  Zealand  soils  [3].    Further
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examples can be found in the National Environmental Standards for Air Quality (where the
threshold value for urban PM10 is higher than ideal), and several of the environmental and
the
human  health  ‘bottom  lines’  set  in  the  National  Policy  Statement  for  Freshwater
Management 2014.

The  relevance  of  this  to  methamphe
under  tamine is the extent to which in any future guideline
development or revision process, allowance should be made for background prevalence and
expected  concentration  ranges  of  trace  methamphetamine  on  the  interior  surfaces  of
residential properties where it has not been manufactured.   A related question is whether
specific  surveying  (or  analysis  of  available  data)  should  at  least  be  undertaken  to  reliably
determine background prevalence and concentration statistics.
Released

A  further  consideration  may  be  how  this  type  of  trace-level  exposure  may  compare  with
background  exposures  that  could  theoretically  exist  through  contact  with  other  common
items that are transferred between people in a community and carried into homes.

Banknotes are a commonly-encountered item in this category.

16

A range of studies have shown that traces of various illicit drugs can be found on a significant
proportion  of  banknotes  that  are  in  circulation,  often  with  geographical  differences
reflecting drug use within a given population.  A brief review of this area may provide some
wider context from which to view traces of methamphetamine residues on interior walls of
non-laboratory sites.   This review is provided in Appendix 2 (Section 5.2).

Internationally,  detection  of  drug  residues  including  methamphetamine  on  banknotes  has
not been interpreted as a direct cause for public health alarm, and there is no prospect of
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any jurisdiction requiring that banknotes be decontaminated between users.

Act
In  a  hierarchy  of  relative  health  hazards  and  risks,  contaminated  banknotes  and  houses
where methamphetamine has been smoked would be at the low end of any scale.  Former
methamphetamine  laboratories  would  be  at  the  high  end,  as  would  households  within
which methamphetamine is still being smoked.6
2.4 Section summary

Information
The  current  remediation  guideline  for  methamphetamine  residues  from  surfaces  of  “a
dwelling that has been used as a clan meth lab,” as recommended by the Ministry of Health
in the NZ Methamphetamine Guidelines [1], is 0.5 µg/100 cm2.    This is:

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  A preliminary (‘current’) recommended figure rather than a mandatory standard;


the
  A  ‘risk-based’  guideline  adopted  from  Australian  work  which  was  (at  the  time)  still  in
draft form;

  One of two risk-based guidelines which could have been selected from overseas at the
under
time, the other being 1.5 µg/100 cm2 which had been adopted in a US jurisdiction.

Part of the rationale for selection of a conservative guidelines for known chemical residues
associated  with  methamphetamine  manufacture  is  that they  can be used  as  a markers  for
other  chemical residues that  may  have  been produced  and  deposited  on  surfaces  as  a  by-
Released
product of the operation. This reasoning does not apply to a smoking scenario.


6   In  any  reformulation  of  wider  health  priorities,  it  might  be  usefully  appreciated  that  the  greatest
involuntary  exposure  risks  are  to  children  who  are  living  in  households  with  current
methamphetamine  smokers,  in  contrast  to  children  living  in  houses  where  methamphetamine  was
previously  smoked.  The  former  group  are  the  more  likely  to  experience  habitual  and  potentially
health-significant exposures to methamphetamine through all three main intake routes.
17

The  meaning  of  the  phrase  ‘risk-based’  in  the  context  of  guidelines  is  commonly
misunderstood,  and  refers  to  the  nature  of  the  methodology  that  was  followed  when  a
guideline is developed, rather than consequences of one being exceeded.

Risk-based guidelines are set at levels that are so low that long-term exposure could carry no
appreciable,  nor  quantifiable,  health  risk.    For  this  reason  exceeding  a  surface
methamphetamine loading of either 0.5 µg/100 cm2, or 1.5 µg/100 cm2, would not denote
the sudden onset of any discernible health risk.   Guidelines like these are not set at values
1982
just below where a health-risk begins.  They are set at values which are  many times lower
than the point where a health risk could become quantifiable.
Act

In application, the currently recommended remediation guideline for methamphetamine has
seen considerable ‘scope-creep.’  The NZ Methamphetamine Guidelines [1] were developed
to provide advice to support the remediation of clandestine laboratories that had been used
for  the  manufacture  of  methamphetamine.    In  this  wider  context,  the  recommended
methamphetamine  guideline  does  not  exist  in  isolation,  but  is  one  of  many  precautionary
Information
guidelines set for a range of chemical residues that can exist at drug manufacturing sites at
relatively  high  concentrations.    At  the time the NZ  Methamphetamine Guidelines  [1]  were
written  it  was  not  anticipated  that  the  0.5  µg/100  cm2  methamphetamine  guideline  might
be widely applied – almost in isolation – to cases where methamphetamine may have been
Official
smoked within the walls of a dwelling.

the
‘Forensic-levels’  of  trace  contamination  on  interior  surfaces  that  can  result  from  smoking
methamphetamine are not dissimilar in concept to the common existence of drug residues
on banknotes, which reflect local use patterns within a community.

under
In  a  hierarchy  of  relative  health  hazards  and  risks,  contaminated  banknotes  and  houses
where methamphetamine has been smoked would be at the low end of any scale.  Former
methamphetamine  laboratories  would  be  at  the  high  end,  as  would  households  within
which methamphetamine is still being smoked.

Released
The  recommended  remediation  guideline  for  methamphetamine  does  not  fall  into  the
category of being a ‘New Zealand risk-based guideline,’ and one of these has not yet been
developed. However, New Zealand could at any time develop its own risk-based guideline of
this  type,  which  would  supersede  the  currently  adopted  value.    In  any  future  guideline
development  process  it  would  be  advisable  to  have  regard  to  any  constraints  set  by  the
background prevalence and (where detected) distribution of methamphetamine loadings on
the interior surfaces of various types of dwellings.
18

3 Assessment of the lowest ‘health-relevant’ surface loading
3.1 Context and question

As  discussed  in  Section  2  of  this  report,  the  current  remediation  guideline  for
methamphetamine residues from surfaces, as recommended by the Ministry of Health in the
NZ Methamphetamine Guidelines [1] is 0.5 µg/100 cm2, as developed in Australia.  Based on
the same toxicological reference dose but with perhaps more realistic exposure modelling,
1982
the California EPA OEHAA/DTSC adopted a standard of 1.5 μg/100 cm2 as being sufficiently
protective to make properties safe for human occupancy.  Both figures represent the same
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general order-of-magnitude and compliance with either number is designed to ensure safety
based on absence of any appreciable health risk, rather than indicate presence or absence of
a potential for actual harm.

Due to the nature of toxicological reference doses and the emphasis on ensuring absence of
potential for harm in guideline development, and marginal exceedance of either figure can
Information
not be taken to indicate the onset of a quantifiable health hazard.

This  raises  the  question  of  what  surface  concentration  may  correspond  to  onset  of  harm
becoming  plausible  to  the  most  sensitive  receptor,  assuming  that  all  of  the  exposure
Official
assumptions are aligned and operative.  The question can be put as:

the
Is  it  possible  to  estimate  the  lowest  surface  concentration  at  which  adverse  health  effects
could become plausible?
3.2 General approach
under

A  technical  paper  is  available  in  the  peer-reviewed  scientific  literature  [7]  which  can  be
adapted  to  provide  an  estimate  of  this  quantity.      This  paper,  a  copy  of  which  will  be
provided with this report, is identified as reference [7]:

  Hammon,  T.  L.,  &  Griffin,  S.  (2007).  Support  for  selection  of  a  methamphetamine  cleanup
Released
standard in Colorado. Regulatory Toxicology and Pharmacology, 48 (1), 102-114.

Briefly,  the  approach  will  be  to  compare  modelled  estimates  of  potential  exposures  that
could  be  experienced  by  the  most  sensitive  receptor  with  a  health-based  reference  value
that  was  derived  by  Hammon  and  Griffin  [7],  rather  than  a  toxicological  reference  dose
(RfD).  Whereas an RfD provides a level at which long-term exposure is without appreciable
risk, a health-based reference value provides the lowest level at which the first onset of the
19

most  sensitive  possible  health  effect  may  begin  to  occur,  still  taking  uncertainties  into
account.    This  approach  is  possible  here  because  the  specific  purpose  of  the  research
described  by  Hammon  and  Griffin  [7]  was  to  establish  whether  several  technology-based
guidelines for methamphetamine residues on surfaces (including a figure of 0.5 µg/100 cm2)
would  in  fact  be  health-protective.  The  paper’s  authors  were  employed  by  the  Colorado
Department of Public Health and Environment (Hammon), and US Environmental Protection
Agency  (Griffin),  and  were  conversant  with  established  USEPA  protocols.  To  establish  a
credible  and  documented  answer  to  this  question  Hammon  and  Griffin  [7]  presented  a
1982
complete analysis which includes both a detailed exposure assessment, and derivation of a
health-based reference value for methamphetamine.  The authors make a clear distinction
Act
between the purpose and design of their approach and the procedure used for developing a
(more protective) reference dose (RfD) [7]:

“The intent of this effort is to compare the intakes expected from the range of proposed cleanup
standards to a health-based reference value to determine if the proposed cleanup standards are
adequately protective for children and adults. *…+  For this reason, we are using a process similar
to  the  U.S.  Environmental  Protection  Agency’s  (USEPA)  Reference  Dose  process  to  develop  a
Information
health-based  reference  value  for  methamphetamine.    It  should  be  noted  that  this  is  not  a
Reference Dose for methamphetamine and should not be construed as such.”
3.3 Derivation of the health-based reference value
Official

The  health-based  reference  value  derived  by  Hammon  and  Griffin  [7]  was  based  on  the
the
(lower) 95% confidence limit of benchmark dose levels (called the BMDL) associated with a
10% effect (the BMD10), as calculated according to the EPA’s Reference Dose Methodology.
This  gave  a  BMDL  range  of  1.5  to  20  mg/kg  body  weight/day,  with  the  most  sensitive
toxicological  endpoint  (1.5  mg/kg  body-weight/day)  being  decreased  fetal  weight.
under
Consistent with other work, these authors also then applied an uncertainty factor of 3007  to
the  BMDL.    This  step  is  probably  conservative  for  the  context  of  attempting  to  estimate
actual  likelihood  of  a  measureable  effect  to  any  given  individual,  but  appropriate  because
the  uncertainties  that  are  accommodated  in  this  way  (see  footnote  7)  are  still  genuine

Released
7  The factor of 300 itself includes:

  Division of the BMDL of 1.5 mg/kg-bw by 10 for interspecies variability, because the critical studies in this
case were in experimental animals.
  A further division by 10 for inter-individual variation in population response, and
  A further division by 3 to allow for incompleteness in the database.

Although the first factor applied for both the RfD and health-based reference value was 10, reasons for use of this
first factor differed.  In the RfD this factor was for extrapolation from a human LOAEL to a NOEL; here it was to
account for differences between animals and humans. Reasons for second and third factors of 10 and 3 were as for
derivation of the RfD.  As with the RfD derivation, no additional factor was found to be necessary to allow for
differences between short and long-term exposure, due to the nature of the toxicological responses (here,
reproductive and developmental studies).

20

uncertainties.  The safety factor of 300 provides an assurance that appropriate caution has
been exercised in allowing for the possibility of the onset of a health effect.  As with other
derivations, the authors also focused on infants as the most sensitive receptor class.

With the uncertainty factor applied, the lowest health-based reference value linked to onset
of  a  possible  effect  was  then  estimated  [7]  as  0.005  mg/kg-body  weight/day  (which  is  1.5
mg/kg body-weight/day, divided by the factor of 300).  Estimated exposures are compared
with this health-based reference value by Hammon and Griffin [7] in their Table 5.   1982

3.4 Relationship between surface loading and exposure dose
Act

I have reviewed the methodology applied by Hammon and Griffin [7] and established to my
own  satisfaction  that  estimated  intakes  produced  by  their  exposure  model  are  directly
proportional  to  the  surface  methamphetamine  residue  loading,  as  can  also  be  seen  in  the
results  provided  in  their  Table  5.      In  other  words,  although  the  exposure  modelling  is
reasonably complex in its internal detail, there is a linear relationship between the surface
Information
methamphetamine loading and the dose estimates produced by the exposure model.

For  example,  for  a  surface  methamphetamine  loading  of  0.05  µg/100  cm2  the  estimated
potential  intake  for  an  infant  is  0.00002  mg/kg-bw/day.  When  the  surface  loading  of
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methamphetamine  is  increased  by  a  factor  of  10  (to  0.5  µg/100  cm2)  the  corresponding
estimated  intake  value  also  increases  by  a  factor  of  10  (to  0.0002  mg/kg-bw/day).    At  a
the
further  tenfold  increase  in  surface  methamphetamine  loading  to  5  µg/100  cm2,  the
estimated intake value would be 0.002 mg/kg-bw/day.  At surface loadings in the microgram
(e.g.  0.05-50  µg)  per  100  cm2  range,  there  would  be  no  specific  reason  to  expect  any
under
significant deviation from this linear relationship between loading and estimated dose.

Three  estimates  of  each  quantitiy  provided  by Hammon  and  Griffin  [7], and  three  pairs  of
extrapolated values, are provided in Table 1.

Released

21

Table 1.  Relationship between surface loading of methamphetamine and the estimated daily intake
of an infant (the most sensitive receptor).

Surface loading
Infant intake dose
(µg/100 cm2)
(mg/kg body weight / day)
0.05
0.00002
0.1
0.00004
0.5
0.0002
5.0
0.002
1982
10.0
0.004
12.5
0.005
Act

Note:  rows  1-3  from  [7];  rows  4-6  (italicised)  extrapolated
from  data  in  [7]  based  on  the  linear  relationship  between
surface loading and estimated intake dose.

3.4 Lowest plausible health-effects concentration
Information
3.4.1 Estimated value

As can be seen from the data in Table 1, the derived health reference value of 0.005 mg/kg
body-weight/day  would  be  reached  at  a  surface  methamphetamine  concentration  of  12.5
Official
µg/100 cm2. For what follows I will round this surface loading figure down to 12 µg/100 cm2.

the
In  my  opinion,  12  µg/100  cm2  represents  a  lowest  surface  methamphetamine  loading  at
which adverse health effects could become remotely plausible in the most sensitive receptor
(infants).      My  estimates  based  on  the  exposure  modelling  carried  out  by  Hammon  and
Griffin [7] indicate that this is the surface concentration at which the health-based reference
under
dose could first be reached assuming that all identified exposure pathways were operative.

As new toxicological information becomes available various improvements can be made to
models like these which can change this type of estimate in either direction.  It is possible
that  new  lower  effects  levels  (BMD10,  NOEL,  etc.)  may  be  found  and  incorporated  in
Released
databases  which  result  in  a  revision  and  reduction  of  the  reference  dose.    In  my  opinion
based  on  the  range  of  toxicological  endpoints  already  considered  and  consistency  of
responses to methamphetamine, I think that this is unlikely.   On the other hand it is possible
(perhaps probable) that gradual improvements in the toxicological database over time will
eventually reduce the need to apply some uncertainty factors, resulting in the flexibility to
revise reference or health dose estimates in an upward direction.

22

For these and other reasons outlined above, I would be most comfortable presenting both
the  recommended  clean-up  guidelines  (Section  2  of  this  report)  and  the  health-based
estimate that I have presented here based on extrapolation from Hammon And Griffin [7] as
indicating relative orders-of-magnitude.

Surface  methamphetamine  loadings  in  the  range  0.5-1.5  µg/100  cm2  (including  the
Australian IL recommended in the NZ Methamphetamine Guidelines [1]) represent levels at
which  risk  is  neither  appreciable  nor  quantifiable.    The  lowest  point  of  potential  for  a
1982
plausible health effect in infants from on-going exposure appears to be about 10 times (one
order-of-magnitude)  higher  than  this  range  (or  20  times  higher  than  the  0.5  µg/100  cm2
Act
guideline).  These ideas are illustrated in Figure1.

Information
Official
the
under
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Figure 1.   Graphical representation showing  relative ranges of methamphetamine clean-up
targets compared with the ‘lowest plausible’ health threshold as estimated here.

23

3.4.2  A hidden precautionary factor

A  hidden  precautionary  factor  in  these  estimates  is  that  in  the  exposure  modelling,  it  is
assumed  that  a  given  surface  methamphetamine  loading  will  remain  at  a  constant  level
indefinitely, so that a child will be exposed to the same amount day-after-day for weeks and
months.    In  reality  this  is  very  unlikely  to  happen  in  any  specific  case  once  the  external
source  of  methamphetamine  has  been  removed.    The  expected  pattern  would  be  one  of
decline, for three reasons.   These are as follows.
1982

1.  Each  assumed  exposure  event  necessary  removes  a  proportion  of  methamphetamine
Act
from  the  surfaces  that  were  contacted  (e.g.  carpets,  walls),  making  less
methamphetamine  available  for  subsequent  release.    Based  on  standard  guidance,
transfer efficiencies assumed in Hammon and Griffin [7] were 5% for carpets and 10% for
hard surfaces.

2.  Surface methamphetamine will undergo some natural rate of loss through degradation
Information
and/or  fixation  processes,  as  well  as  transfer  and  loss  routes  that  do  not  lead  to
absorption by a child (for example transfer of methamphetamine to clothes rather than
skin, where clothes are subsequently put through a washing machine).

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3.  In cases where significant methamphetamine has previously been absorbed by a porous
surface  and  may  migrate  out  again  in  response  to  surface  loss  (creating  a  diffusion
the
gradient), the expected pattern is not one that would result in a higher concentration on
the surface than was present on the surface to begin with.
3.4.3  Comparison to doses used for treatment of ADHD in children
under

In the US, methamphetamine is legally produced as a prescription medicine (Desoxyn®),8 for
use in treatment of ADHD in children (age 6 or older), narcolepsy, and short-term weight loss
[7,  1].    This  is  classified  as  a  controlled  substance,  being  subject  to  control  under  DEA
schedule  II  (substances  with  a  high  potential  for  abuse  which  may  lead  to  severe
psychological  or  physical  dependence).  Dextroamphetamine  (Dexedrine®),  and
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methylphenidate  (trade  name  Ritalin®),  both  of  which  are  available  in  New  Zealand  under
restriction,9  are  classified  in  the  same  way.10      The  first  of  these,  also  known  as
dexamphetamine, is an amphetamine (i.e. this is its chemical class).

8   Drugs.com, 2016. Desoxyn (methamphetamine hydrochloride). See: http://www.drugs.com/pro/desoxyn.html
9   New Zealand Medicines and Medical Devices Safety Authority (MedSafe), 2016. Medicines: Restrictions on the Supply,
Prescribing or Administration of Medicines under the Medicines Act 1981 and Misuse of Drugs Regulations 1977. See:
http://www.medsafe.govt.nz/profs/riss/restrict.asp
10   US Department of Justice, Office of Diversion Control, 2016. Controlled Substances Schedules. See:
http://www.deadiversion.usdoj.gov/schedules/#define
24

In cases where methamphetamine is prescribed for children an initial dose is set at one or
two 5 mg tablets per day.  This dose has documented side-effects which can include anxiety,
difficulty falling asleep and reduced appetite; but the therapeutic use of methamphetamine
provides an external point of reference regarding orders-of-magnitude.  Methamphetamine
is not prescribed for infants, but for a 6 year old child (assumed weight 21.7 kg), one 5 mg
tablet  of  Desoxyn®  per day  would translate to a  dose  of  0.23  mg/kg  body weight per day.
The health reference value of 0.005 mg/kg body-weight/day derived by Hammon and Griffin
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(2007) is 46 times lower than this figure.11

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Therefore to a first approximation the potential dose that could be transferred from surface
methamphetamine  loadings  of  10-12  µg/100  cm2  (corresponding  to  the  health  reference
value)  is  about  1/50th  of  the  dose  used  in  cases  where  methamphetamine  is  intentionally
prescribed for the treatment of ADHD.
3.4.4  Use of the words ‘contamination’ and ‘contaminated’

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Exceedance  of  a  methamphetamine  surface  loading  of  0.5  µg/100  cm2  by  up  to  20  times
does not denote the onset of any health risk.   All that can be said is that a very conservative
guideline  value  has  been  exceeded.    For  this  reason,  properties  where  methamphetamine
residues are less than 12 µg/100 cm2 should really not be referred to as ‘contaminated’ by
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methamphetamine.

the
They  could  only  be  considered  to  be  contaminated  following  a  particular  scientific  usage
which  does  not  apply  here,12  and  is  not  the  sense  that  is  commonly  being  expressed  in
public. In public discourse including media statements, phrases such as ‘methamphetamine
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contamination  of  properties’  and  ‘houses  contaminated  by  methamphetamine’  are
commonly  being  used,  and  the  clear  connotation  is  that  methamphetamine  residues  are
present at levels that are hazardous to human health.   This connotation is misleading.
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11   If for a hypothetical calculation, the therapeutic dose is scaled down to allow for infant weight (11.2 kg) ,
the factor of 46 remains the same.  (This is because the scaled-down dose becomes 2.6 mg/day; and the
health reference value for a 11.2 kg infant translates to 0.056 mg per day.)
12   In environmental chemistry (and as a non-universal but widely-applied practice) the term ‘contamination’
refers to the presence of a substance that either (a) does not occur naturally, or (b) (if natural) occurs
noticeably higher levels than its natural concentration range.  By this scientific meaning, almost every
aspect of our modern environment, indoors and outdoors, would be regarded as contaminated; so the
definition is not very useful.   When levels of contamination have become high enough to cause actual
adverse effects, the environment is referred to as being ‘polluted.’   Under the Resource Management Act,
the term ‘contaminated land’ maps to the scientific concept of ‘polluted land.’
25

However this issue extends beyond communications to the regulatory environment. Under
Section 2 of the Resource Management Act (RMA, 1991):

contaminated land means land that has a hazardous substance in or on it that—
(a)
has significant adverse effects on the environment; or
(b)   is reasonably likely to have significant adverse effects on the environment

...where ‘the environment’ is always taken to include people,13 and land has a wider meaning
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than  only  soil.14    The  RMA  definition  of  contaminated  land  carries  the  same  sense  of
‘significant harm’ as the popular use of a ‘meth contaminated property’, but sets this effects-
based  threshold  in  a  regulatory  context.    Relative  to  guideline  values,  there
Act  is a high
threshold before  a  property can  be deemed  to meet  the  RMA definition  of  ‘contaminated
land.’

To  reach  or  exceed  that  threshold,  we  would  need  to  be  reasonably  confident  that  the
hazardous substance is present at levels that would actually, or would be reasonably likely
to, cause significant adverse effects on people or the wider environment.  Not negligible or
Information
less-than-minor,  and  not  minor,  but  significant.    ‘Significant’  is  the  strongest  term  of  this
type used in the RMA.15

In  my  opinion  no  property  at  which  methamphetamine  has  only  been  smoked  is  likely  to
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meet the RMA definition of contaminated land, which carries the same sense of significant
harm as the popular usage.
the

For  these  reasons  I  would  recommend  that  public  agencies  stop  referring  to  properties  as
‘meth contaminated’ (or similar phrasing) if the only basis for this  classification is that the
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0.5 µg/100 cm2 remediation guideline for methamphetamine residues on surfaces has been
exceeded.


13   environment  includes—(a)  ecosystems  and  their  constituent  parts,  including  people  and  communities;
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and (b) all natural and physical resources; and (c) amenity values; and (d) the social, economic, aesthetic,
and cultural conditions which affect the matters stated in paragraphs (a) to (c) or which are affected by
those matters
14   land—(a) includes land covered by water and the airspace above land…
15   In regulatory practice, the contaminated land aarea is about managing potentially contaminated sites in
relation  to  conservative  Soil  Contaminant  Standards  (SCS  values)  and  other  guideline  values,  in  the
context of controls set out in a National Environmental Standard.  To date there has not been a need to
establish  that  the  RMA  definition  of  contaminated  land  has  ever  been  reached.    Most  potentially
contaminated sites which are tested and subsequently remediated would not meet the threshold.

26

3.5 Section summary

Surface  methamphetamine  loadings  in  the  range  0.5-1.5  µg/100  cm2  represent  levels  at
which risk is neither appreciable nor quantifiable.  In my opinion, the lowest surface loading
with the potential for a plausible health effect in infants from daily exposure appears to be
about 10-20 times higher than this range (10-12 µg/100 cm2).

Exceedance  of  a  methamphetamine  surface  loading  of  0.5  µg/100  cm2  by  up  to  20  times
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does not denote the onset of any health risk.   All that can be said is that a very conservative
guideline value has been exceeded.
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When  applied  to  cases  where  methamphetamine  has  not  been  manufactured,  use  of
phrases such as ‘methamphetamine contamination of properties’ and ‘houses contaminated
by methamphetamine’ are misleading because they imply that methamphetamine residues
are present at levels that are hazardous to human health.

Information
At  a  regulatory  level,  Section  2  of  the  Resource  Management  Act  (1991)  defines
‘contaminated land’ in a very specific way relating to likelihood of significant adverse effects
occurring.    If  applied  here  this  definition  would  (rightly)  preclude  most  houses  where
methamphetamine has been smoked but not manufactured.
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4. References cited

1.  Ministry of Health (2010). Guidelines for the Remediation of Clandestine Methamphetamine
Laboratory Sites. Wellington: Ministry of Health. Available from:
http://www.health.govt.nz/publication/guidelines-remediation-clandestine-methamphetamine-
laboratory-sites.

2.  Resource Management (National Environmental Standard for Assessing and Managing
Contaminants in Soil to Protect Human Health) Regulations 2011.  Available from:
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http://www.legislation.govt.nz/regulation/public/2011/0361/latest/DLM4052228.html

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3.  Ministry for the Environment (2011). Methodology for Deriving Standards for Contaminants in
Soil to Protect Human Health.  Wellington: Ministry for the Environment. Available from:
http://www.mfe.govt.nz/publications/hazards/methodology-deriving-standards-contaminants-
soil-protect-human-health

4.  Ministry for the Environment (2011). Toxicological Intake Values for Priority Contaminants in
Soil.  Wellington: Ministry for the Environment.  Available from:
http://www.mfe.govt.nz/publications/hazards/toxicological-intake-values-priority-contaminants-
Information
soil

5.  Australian Government Attorney-General’s Department (2011). Clandestine Drug Laboratory
Remediation Guidelines.  Commonweath of Australia, 2011.  Available from:
https://www.ag.gov.au/CrimeAndCorruption/Drugs/Documents/Clandestinedruglaboratoryreme
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diationguidelines.pdf
6.  Ministry for the Environment (2003, revised 2011). Contaminated Land Management Guidelines
the
No. 2: Hierarchy and Application in New Zealand of Environmental Guideline Values (revised
2011). Wellington: Ministry for the Environment. Available from:
http://www.mfe.govt.nz/publications/land-hazards/contaminated-land-management-guidelines-
under
no-2-hierarchy-and-application-new

7.  Hammon, T. L., & Griffin, S. (2007). Support for selection of a methamphetamine cleanup
standard in Colorado. Regulatory Toxicology and Pharmacology,  48 (1), 102-114.

8.  Salocks, C. (2009). Development of a Reference Dose (RfD) for Methamphetamine. California
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Environmental Protection Agency. Office of Environmental Health Hazard Assessment. Integrated
Risk Assessment Branch.

9.  Environmental Risk Sciences (2009). Derivation of Risk-Based Investigation Levels, Clandestine
Drug Laboratory, Site Investigation Guidelines. Prepared for the Australian Crime Commission,
Ref: ACC/09/R001, 6 October 2009. Available from:  http://www.enrisks.com.au/wp-
content/uploads/2012/12/Derivation-of-Risk-Based-Guidelines-for-Website.pdf

28

10. Saint-Jacques, N., Parker, L., Brown, P., & Dummer, T. J. (2014). Arsenic in drinking water and
urinary tract cancers: a systematic review of 30 years of epidemiological evidence.
Environmental Health, 13: 44 (32 pages).

11. Piper, J., and Kim, N.D. (2006).  Arsenic in Groundwater of the Waikato Region. Waikato Regional
Council technical report 2006/14. ISSN: 1172-4005. Available from:
http://www.waikatoregion.govt.nz/TR200614/

12. Kim, N. D. (2010). Box 5.2 Arsenic in Bed Sediments. In K. J. Collier, D. P. Hamilton, W. N. Vant, &
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C. Howard-Williams (Eds.), The Waters of the Waikato (pp. 80). Environment Waikato and the
Centre for Biodiversity and Ecology Research (The University of Waikato).
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13. Järup, L., & Åkesson, A. (2009). Current status of cadmium as an environmental health
problem. Toxicology and Applied Pharmacology, 238(3), 201-208.

14. Alexander, J., D. Benford, A. Cockburn, J. P. Cravedi, E. Dogliotti, and A. D. Domenico.
(2009). Cadmium in food-scientific opinion of the panel on contaminants in the food
Information
chain. EFSA Journal 980 (2009): 1-139.

15. Satarug, S., Baker, J. R., Urbenjapol, S., Haswell-Elkins, M., Reilly, P. E., Williams, D. J., &
Moore, M. R. (2003). A global perspective on cadmium pollution and toxicity in non-
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occupationally exposed population. Toxicology Letters, 137(1), 65-83.

the
16. McDowell, R. W., Taylor, M. D., & Stevenson, B. A. (2013). Natural background and
anthropogenic contributions of cadmium to New Zealand soils. Agriculture, Ecosystems
& Environment, 165, 80-87.

under
17. Jourdan, T. H., Veitenheimer, A. M., Murray, C. K., & Wagner, J. R. (2013). The
quantitation of cocaine on US currency: survey and significance of the levels of
contamination. Journal of Forensic Sciences, 58(3), 616-624.

18. Seneviratne, S. (2016). Drugs on your money?  Journal of Interdisciplinary Science Topics,
Released
5.  The Centre for Interdisciplinary Science, University of Leicester.

19. Wimmer, K., & Schneider, S. (2011). Screening for illicit drugs on Euro banknotes by LC–
MS/MS. Forensic science international, 206(1), 172-177.

20. Lavins, E. S., Lavins, B. D., & Jenkins, A. J. (2004). Cannabis (marijuana) contamination of
United States and foreign paper currency. Journal of Analytical Toxicology, 28(6), 439-
442.
29

21. Jenkins, A. J. (2001). Drug contamination of US paper currency. Forensic Science
International, 121(3), 189-193.

22. Fultz, B. A., Mann, J. A., & Gardner, E. A. (2012) Methamphetamine Contaminated
Currency in the Birmingham, Alabama Metropolitan Area. Microgram Journal, 9(2), 57-
60.

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23. Lahoda, K. G., Collin, O. L., Mathis, J. A., LeClair, H. E., Wise, S. H., & McCord, B. R. (2008).
A survey of background levels of explosives and related compounds in the environment.
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Journal of Forensic Sciences, 53(4), 802-806.

24. Lowe, A. M., Crowson, C. A., Cullum, H. E., & Hiley, R. W. (1996). A survey of high
explosives traces in public places. Journal of Forensic Science, 41(6), 980-989.

25. Clausen, J., Robb, J., Curry, D., & Korte, N. (2004). A case study of contaminants on
military ranges: Camp Edwards, Massachusetts, USA. Environmental Pollution, 129(1),
Information
13-21.

Official

the
Signed
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(Dr Nick D Kim)
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13 June 2016

30

5. Appendices
5.1  Appendix 1.  Overview of my expertise in ‘Brief of Evidence’ format

1.  My full name is Nicholas Duncan Kim.

2.  I live in Wellington.

3.  I  am  a  senior  lecturer  in  the  School  of  Public  Health,  Massey  University  Wellington,  a
1982
position I have held since 2012.

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4.  I  hold  the  degrees  of  BSc(Hons)  (First  Class)  in  Chemistry  from  the  University  of
Canterbury (1987), and PhD in Environmental Analytical Chemistry from the University
of Canterbury (1990).

5.  Previous positions I have held have included employment as a Lecturer (1991-1997) and
Senior Lecturer (1998-2001) in Chemistry at the University of Waikato, and employment
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as an environmental chemist (2002-2011) by the Waikato Regional Council.

6.  At  the  University  of  Waikato  (1991-2001)  I  undertook  teaching  and  research  in
Environmental, Analytical and Forensic Chemistry.  My activities included supervision of
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postgraduate  (MSc,  MPhil  and  PhD)  research  projects,  and  coordination  and
development of courses in Advanced Analytical Chemistry and Environmental, Forensic,
the
and  Toxicological  Chemistry  (both  at  undergraduate  level)  and  Applied  and
Environmental Analytical Chemistry (at masters level).

7.  At  the  Waikato  Regional  Council  (2002-2011)  my  main  roles  were  the  provision  of
under
technical  advice  in  relation  to  a  range  of  chemical  contamination  issues,  identification
and management of contaminated sites, and coordination of research projects relating
to trace chemical contamination of soil, sediment, air and water.

8.  At  Massey  University  (2012  to  present)  I  am  major  leader  for  the  undergraduate
Released
teaching programme in Environmental Health, and teach into a number of areas related
to chemistry, human health and risk assessment including the  papers Chemistry in the
Environment, Toxic Substances, Human Health and the Environment, and Environmental
Monitoring and Investigative Techniques.  I continue to carry out research and supervise
postgraduate research students.

9.  I have co-authored or authored over 40 scientific papers in peer-reviewed journals or as
book  chapters,  along  with  8  peer-reviewed  technical  reports,  and  about  50  other
31

scientific  publications  or  conference  presentations,  and  provided  significant  written
content to 5 national guidelines.

10.  I  have  supervised  or  co-supervised  about  45  postgraduate  (MSc,  MPhil  and  PhD)
research  projects,  and  routinely  act  as  an  external  examiner  for  masters  and  doctoral
research theses from other New Zealand Universities. Some of these have been in the
area of methamphetamine contamination and decontamination.

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11.  Overall  I  have  29  years  experience  in  environmental  chemistry,  analytical  chemistry,
forensic  chemistry,  toxicology  and  risk  assessment,  resource  management,  and
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regulatory policy development.

12.  Of  these,  my  core  area  of  professional  expertise  is  the  technical  appraisal,  risk
assessment and management of chemical contamination issues.

13.  Over time I have contributed to a number of national projects relating to management
of contaminated land, trace contaminants, hazardous substances, and air quality.  These
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involvements include, but are not limited to:

  Member  of  Ministry  for  the  Environment’s  technical  advisory  groups  on
development  of  contaminated  sites  classification  guidelines  (2002-3),  a
Official
contaminated  land  risk  screening  system  (2004),  and  sampling  and  analysis
guidelines (2004, 2008);  the

  Member  of  Ministry  for  the  Environment’s  Technical  Advisory  Group  and
Toxicological Advisory Groups relating to development of a National Environmental
under
Standard (NES) for contaminants in soil (2005, 2007-10);

  Member  of  the  Ministry  for  the  Environment’s  Policy  Advisory  Group  on
agricultural/horticultural land contamination (2002-6);
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  Member  of  the  national  Cadmium  Working  Group  (convened  by  the  Ministry  of
Agriculture and Forestry) (2005-10);

  Member of the steering committee for the Sustainable Management Fund project
to develop management guidelines for old sheep dip sites (2002-5);

  Technical  policy  advisor  for  amendments  required  to  improve  workability  of  the
Hazardous Substances and New Organisms (HSNO) Act (2003-4).
32

14.  I  have  made  written  or  other  contributions  to  the  development  of  eight  New  Zealand
best  practice  guidelines  and  national  assessments  in  areas  that  include  contaminated
sites management and environmental sampling and monitoring, and I was a member of
Ministry for the Environment’s technical advisory groups that oversaw development of
technical documents that support the Resource Management (National Environmental
Standard for Assessing and Managing Contaminants in Soil to Protect Human Health)
Regulations 2011.
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15.  In relation to this evidence it is mainly relevant that I provided some technical input by
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way of peer review to the content of the Guidelines for the Remediation of Clandestine
Methamphetamine  Laboratory  Sites  (Ministry  of  Health,  2010),  Methodology  for
Deriving Standards for Contaminants in Soil to Protect Human Health (Ministry for the
Environment,  2011)  and  Toxicological  Intake  Values  for  Priority  Contaminants  in  Soil
(Ministry for the Environment, 2011).

16.  I  have  previously  provided  expert  evidence  at  resource  consent  hearings,  in  the
Information
Environment Court, and District Court.

17.  I am certified to serve as an independent hearings commissioner meeting accreditation
as referenced in  Resource Management Act (1991) sections 39A to 39C, and have acted
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in this capacity on one occasion in December 2015, on behalf of Tasman District Council.

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5.2 Appendix 2. Trace-level contamination of banknotes

One  aspect  of  the  history of  forensic  science  is  that  once  testing  is  carried  out  for  various
chemical compounds at trace and ultra-trace levels, many unusual substances can be found
in a range of unexpected locations.

The  majority  of  banknotes  in  the  US,  the  UK  and  Europe  contain  traces  of  cocaine  and
opiates  [17,  18,  19].    The  concentrations  are  not  high,  but the  trace  contamination  is  very
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widespread.  Seneviratne [18] calculated that to be technically prosecutable for possession
of  100  milligrams  of  cocaine,  a  UK  citizen  would  need  to  carry  £17,575  in  £5  notes.    To
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accumulate the same amount of cocaine on US $1 bills the total came to $3,782 (USD).16

In a US study which included several foreign currency denominations, Lavins et al. [20] found
that 9 out of 10 samples of New Zealand currency contained Δ9-tetrahydrocannabinol (THC)
and CBN, which are both markers of cannabis (marijuana) contamination.  The authors note:

“For  the  foreign  currency  notes    in  the  study  the  highest  amounts  of  THC  and  CBN  detected
Information
were  0.065  and  0.197  µg/bill,  respectively.  These  constituents  were  found  exclusively  in  the
New Zealand currency.”

This finding is unlikely to represent all New Zealand banknotes, but will rather reflect habits
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of a local community.  In this case it may well be relevant that all ten of the New Zealand
banknotes  tested  in  the  international  study  cited  above  were  sourced  from  Whangaroa  in
the
Northland.

More  significantly  in  the  context  of  this  report,  a  range  of  other  drugs  including
methamphetamine are occasionally detected on banknotes when they are tested for these,
under
with geographical variation in results thought to relate to patterns of drug use in the local
community that become reflected in a local currency pool [20].

Jenkins  [21]  analysed  50  randomly  collected  US$1  notes  (10  from  each  of  five  cities)  for
cocaine,  heroin,  6-acetylmorphine  (6-AM),  morphine,  codeine,  methamphetamine,
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amphetamine and phencyclidine (PCP).  Codeine was not detected in any of the bills, but all
of the other drugs listed were detected.  Results showed that paper currency was most often
contaminated  with  cocaine  (92%  of  the  bills  tested,  average  loading  28.75  µg  per  note).
However, in addition [21]:


16   Average loadings per bill were assumed to be 28.75 µg of cocaine per note, with calculations taking
into account that 99% of UK banknotes and 92% of US dollar bills have cocaine traces on them.
34

“Heroin was  detected in seven bills in amounts  ranging from 0.03  to 168.50 μg per bill:  6-AM
and morphine were detected in three bills; methamphetamine and amphetamine in three and
one  bills,  respectively,  and  PCP  was  detected  in  two  bills  in  amounts  of  0.78  and  1.87  μg  per
bill.” (Jenkins, 2001).

One  research  paper  specifically  reports  the  sudden  appearance  of  methampetamine
contamination  in  a  community,  in  US  banknotes  sourced  from  the  Birmingham  Alabama
Metropolitan Area.  Fultz et al. [22] found that 42% percent of bills collected from within this
community  in  2012  were  contaminated  with  methamphetamine,  more  than  has  been
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previously  reported  for  any  drug  other  than  cocaine  in  the  United  States.    These  authors
commented [22] that:
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“The  high  percentage  of  contamination  detected  in  this  study,  and  its  sudden  appearance,
indicates  a  significant  change  in  the  pattern  of  drug  contamination  of  currency  around
Birmingham,  probably  reflecting  higher  methamphetamine  abuse  in  the  local  populace.  This
conclusion  is  in  agreement  with  and  complements  the  findings  reported  in  the  National
Substance  Abuse  Index,  which  states  that  methamphetamine  abuse  currently  exceeds  that  of
cocaine throughout the state of Alabama *…+ The results of this study suggest that it is possible
Information
to track significant changes in methamphetamine abuse in a specific region over time.”
Traces of methamphetamine have also been detected on Euro banknotes [19].

Parallels  exist  for  other  categories  of  chemical  compounds,  where  local  activities  and  use
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patterns  result  in  characteristic  ‘forensic  levels’  of  environmental  contamination.    For
example,  like  methampetamine  and  most  drugs,  high  explosives  are  also  organic
the
compounds.  Traces of high explosive residues are rare in public places in the US and UK [23,
24]; as might be expected because most members of the public are not in routine contact
with  high  explosives  such  as  nitroglycerine,  trinitrotoluene  (TNT),  pentaerythritol
under
tetranitrate  (PETN),  or  cyclotrimethylene  trinitramine  (RDX).    By  contrast,  nitroglycerine,
which is associated with firearm use, was more commonly detected at UK police sites [24],
and  going  a  step  beyond  this,  traces  of  a  range  of  high  explosives  can  be  found  at  any
operational military range [25].

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Based  on  this  ability  of  banknotes  to  carry  a  trace  history  of  drug  use  within  a  local
population, it would be expected that if testing were to be carried out, low concentrations of
methamphetamine  would  be  detectable  in  a  proportion  of  New  Zealand  banknotes,
reflecting current use of this drug in the New Zealand community.

An  interesting  implication  of  this  likelihood  is  that  traces  of  methampetamine  may  exist
within the walls of most households in New Zealand at least some of the time, on banknotes
carried in by the occupants.
35