133 Molesworth Street
PO Box 5013
Wellington 6140
New Zealand
T+64 4 496 2000
3 May 2022
Craig Stevenson
[email address]
Tēnā koe Craig
Community water fluoridation next steps
Thank you for responding to my letter of 15 December 2021 and providing information
on your local authority’s ‘readiness’ to fluoridate, and estimated costs and timeframes to
install the necessary related infrastructure.
I have now made a preliminary assessment of the New Plymouth drinking water supply
against the decision-making requirements set out under Part 5A Section 116E (3) of the
Health Act 1956 (the Act). Appendix One outlines the factors and information that I have
considered in my preliminary assessment.
In view of this assessment, I am proceeding with the next steps. Before I can consider
issuing a direction to fluoridate, I am required under the Act to invite written comment
from you, in relation to the New Plymouth supply, on:
a) the estimated financial cost of adding fluoride to the drinking water, including any
additional costs of ongoing management and monitoring
b) the date by which your local authority would be able to comply with a direction.
The Act requires that I give you at least 40 working days to respond to my request for
written comment. As such, I require that you provide written comment to me by 29 June
2022. Please send your response to
[email address]. I will consider any written
comment received when considering issuing a direction.
I note that your local authority has already provided some of the information (eg,
estimated costs) that I am seeking written comment on now. Please confirm or update
any information already provided, and where applicable provide additional comment.
As previously advised, there is some funding available to local authorities that
commence fluoridation in 2022. Further details on funding will be provided in due
course.
Nāku noa, nā
Dr Ashley Bloomfield
Te Tumu Whakarae mō te Hauora
Director-General of Health
Document Set ID: 8760832
Version: 1, Version Date: 03/05/2022
Appendix One – New Plymouth District Council
Analysis
Criterion
1. Scientific evidence on the effectiveness of adding fluoride to drinking water in reducing the prevalence and severity of dental decay
Evidence
We have considered the following information:
•
Fluoridation: an evidence update | Office of the Prime Minister's Chief Science Advisor (June 2021)
•
Health effects of water fluoridation: A review of the scientific evidence (August 2014) Office of the Prime Ministers Chief Science
Advisor and Royal Society of New Zealand Te Aparangi
•
Water fluoridation to prevent tooth decay | Cochrane Collaboration (June 2015)
Analysis
The sources of evidence referred to above are reviews that examine significant bodies of research over a long time period on the safety and
effectiveness of community water fluoridation at reducing dental decay. The evidence indicates the provision of community water
fluoridation at a level of 0.7-1 mg/L significantly reduces the prevalence and severity of dental decay. While the review’s outcome is not
dependent on any specific study, findings from individual studies cited in the reviews include:
-
data from the 2009 New Zealand Oral Health Survey showed that children and adolescents from un-fluoridated areas had 1.7 times
as many decayed, missing or filled teeth (when adjusted for sex, ethnic group and socio-economic status) than those from
fluoridated areas
-
an Australian review undertaken in 2017 found that fluoridation reduces tooth decay in children and adolescents by 26 to 44
percent, and in adults by 27 percent
-
the UK NHS/York review calculated that in the United Kingdom the “number needed to treat” was six (ie, a median of six people
needed to receive community water fluoridation for one additional person to be caries- free).
On this basis, the provision of community water fluoridation at a level of 0.7-1 mg/L in New Plymouth would significantly reduce the
prevalence and severity of dental decay within these areas. Fluoridation at these levels is considered to be safe and effective at reducing
decay.
Criterion
2. whether the benefits of adding fluoride to drinking water outweigh the financial costs, taking into account:
Criterion
2a. the state or likely state of the oral health of a population group or community where the local authority supply is situated
Analysis
We have considered the following information:
• data o
n Age 5 and Year 8 oral health outcomes from the Community Oral Health Service (Ministry of Health)
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• data from the New Zealand Health Survey: Oral Health
(New Zealand Health Survey | Ministry of Health NZ)
• Oral Health Survey Report
(Our Oral Health: Key findings of the 2009 New Zealand Oral Health Survey | Ministry of Health NZ)
• New Zealand Index of Deprivation (NZDep)
(Socioeconomic deprivation profile | ehinz).
Analysis
The New Plymouth water supply is situated within Taranaki District Health Board.
2020 District health board data for children aged 0-12 in Taranaki District Health Board shows:
-
overall, 36 percent of children had experienced tooth decay at age five (compared to national average of 43 percent)
-
on average, children at age five have 1.09 decayed, missing or filled primary teeth, and at school year 8 have on average 0.60
decayed, missing or filled adult teeth (compared to the national average of 1.98 and 0.73 respectively)
-
Māori and Pacific children have significantly worse outcomes than other children within Taranaki District Health Board. For example,
59 percent of Māori children had experienced decay at age five compared to 29 percent for all other (non-Māori and non-Pacific)
children.
The 2017-2020 New Zealand Health Survey results for New Plymouth District Council show:
-
52.1 percent of adults (15+) had one or more teeth removed in their lifetime due to decay, an abscess, infection or gum disease
(compared to the national average of 46.2 percent)
-
9 percent of adults (15+) had one or more teeth removed in the last 12 months due to decay, an abscess, infection or gum disease
(compared to the national average of seven percent).
Within New Plymouth District Council there are variations in deprivation levels. However, there are some high deprivation areas that are
decile 7-10. There is a significant body of evidence that higher deprivation areas are likely to have poorer oral health outcomes.
Overall, a person living in the New Plymouth District Council area is likely to have slightly worse oral health outcomes than the average
person in New Zealand. The data shows that there are still significant opportunities for overall improvement. There are inequitable oral
health outcomes between Māori and non-Māori in New Plymouth. Approximately 16 percent of the population in New Plymouth District
council are Māori. It is likely the deprived communities within New Plymouth District Council have poorer oral health outcomes. These could
be better addressed via community water fluoridation.
Criterion
2b. the number of people who are reasonably likely to receive drinking water from the local authority supply
Evidence
We have considered the following information:
•
the Public Register of Drinking Water Suppliers
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Analysis
Water supply
Population size
New Plymouth
59,072
Criterion
2c. the likely financial cost and savings of adding fluoride to the drinking water, including any additional financial costs of ongoing
management and monitoring
Evidence
We have considered the following information:
•
Review of the Benefits and Costs of Water Fluoridation in New Zealand. Sapere Research Group. May 2015.
•
Water Fluoridation Engineering Costs. August 2015.
Analysis
Community water fluoridation is recognised as one of the most cost-effective, equitable, and safe measures communities can take to
prevent decay and improve oral health. There is evidence estimating that adding fluoride to New Zealand’s water treatment plants classified
as medium (ie, those supplying populations over 5,000), is cost-saving.
Population size
Estimated cost from New
Cost saving
Water Supply
Plymouth District Council
New Plymouth
59,072
$250,000
Considered to be cost-saving
Total
59,072
$250,000
It should be noted that New Plymouth water supply was previously fluoridated until 2010. They have inspected the equipment which
remains on site and found that it is no longer fit for purpose. They therefore consider that a “new build” solution would be required.
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