Kia ora Alisha,

  

Thank you for your request under the Official Information Act 1982 (the
Act), received by the Ministry of Health - Manatû Hauora on 29 March 2026.
You requested:

 

“I am requesting the following information and internal documentation:

(Scope Limitation to prevent substantial collation:

To ensure this request is highly targeted and does not require substantial
collation or research under Section 18(f) of the OIA, I am happy to limit
the scope of any searches for "emails," "meeting minutes," or
"correspondence" to the 12-month period between January 1, 2024, and
December 31, 2024. Furthermore, for any requested "memos," "models," or
"evaluations," providing the final approved versions rather than draft
iterations is perfectly fine.)

Part 1: The 2024 Cochrane Review

I was reading the 2024 Cochrane Review, and it noted a 40% fluorosis
prevalence, a marginal benefit of only 0 to 1/4 of a tooth for primary
dentition, and didn't find eligible studies for adult benefit. I'm trying
to figure out how to weight a fraction of a tooth against a 40% prevalence
rate mathematically in a public health cost-benefit model.

1. Could I please request any internal memos, meeting notes, or emails
from the OCSA discussing this Cochrane review?

2. I would also need to see any mathematical models, statistical analyses,
or documents the OCSA produced that show how they factored these specific
Cochrane findings—specifically the 1/4 tooth benefit versus the 40%
fluorosis rate—into their conclusion that the safety and proportionality
of the mandate remained unchanged.

Part 2: US National Toxicology Program (NTP) Monograph

For the August 2024 US NTP Monograph, I'm trying to learn how standard
toxicological safety margins are applied to population-wide policies.

3. Could I please request any literature reviews or toxicological
evaluations the OCSA did specifically assessing the neurodevelopmental
hazards identified in the NTP report?

4. Could I also request any specific calculations the OCSA performed to
establish the safety margins (such as standard 10x or 100x uncertainty
factors) for vulnerable demographics like infants and pregnant women in
light of the NTP's findings?

Part 3: Genetic Vulnerability, Metabolic Disability, and Demographic
Dosing

I have also been looking into population subgroups with genetic
vulnerabilities and metabolic disabilities, but I can't seem to find the
standard public health models outlining the physiological dose burdens for
these specific groups.

5. Could I please request any OCSA risk assessments, literature reviews,
or internal communications that look at how systemic fluoride interacts
with the MAOA-L genetic phenotype, as well as specific polymorphisms
clinically recognized as resulting in metabolic disability (such as the
VDR Bsm, MTHFR, and CBS C699T variants)?

6. Additionally, could I request the modelling or documentation the OCSA
used to calculate the cumulative dose burden (mg/kg of body weight) for
exclusively formula-fed infants? I'm particularly interested in how the
OCSA calculations accounted for the statistically higher rates of formula
feeding within Mâori and Pacific populations.

Part 4: 2009 Oral Health Survey

Finally, I noticed the 2009 New Zealand Oral Health Survey didn't track
fluorosis or structural enamel defects for children under 8 or adults over
30. Since this survey is used as a baseline for safety, I'm a bit confused
about how to account for those missing age brackets.

7. Could I please request any scientific evaluations or memos produced by
the OCSA that discuss how they addressed these missing diagnostic data
points when confirming the safety of the policy?

Part 5: Biological Mechanism and Classification of Dental Fluorosis

I was also reading the Ministry's recent publication, Community Water
Fluoridation: An evidence review (published December 2024 by the Ministry
of Health). On page 3, it summarises the OPMCSA's conclusion that dental
fluorosis is a "tooth enamel defect" and states that at NZ levels it is
"generally mild (i.e., of no health concern and little-to-no cosmetic
concern)".

However, in my pathology and histology readings, dental fluorosis is
described as an "inside-out" systemic condition resulting from the
disruption of ameloblasts during tooth formation, leading to subsurface
hypomineralisation and increased dentin porosity, rather than just a
surface-level enamel stain. I am trying to figure out how to classify this
in a physiological harm model.

8. Could I please request any histological reviews, biological models, or
internal evaluations the Ministry of Health (including the OCSA and Public
Health Agency) relied upon to medically classify fluorosis strictly as a
surface-level "enamel defect" rather than a systemic structural impairment
involving subsurface and dentin porosity?

9. Could I also request any specific risk assessment frameworks, clinical
rubrics, or memos the Ministry of Health uses to mathematically draw the
line between a "cosmetic concern" and a "health/structural concern" when
calculating the overall harm vs. benefit for public health directives?

10. As the Ministry's 2024 review adopted the OPMCSA's specific
conclusions, could I please request any correspondence, emails, or meeting
minutes between the Ministry of Health and the OPMCSA discussing this
biological classification of fluorosis and how to weight it in a safety
assessment?

Part 6: Exclusion of Benchmark Dose (BMD) Modeling

I was also reviewing the methodology in "Appendix 3: Exclusion table for
neurodevelopmental outcomes" of the December 2024 Evidence Review. I
noticed that several landmark toxicological studies (such as Grandjean et
al. 2022 and Hirzy et al. 2016) were entirely excluded from the safety
analysis, with the stated reason being: "Wrong outcome (benchmark dose
analysis)".

In my environmental toxicology coursework, Benchmark Dose (BMD) modeling
is taught as the international gold standard for establishing safe
exposure thresholds and Point of Departure (POD) metrics for public health
regulations. I am confused as to why BMD is classified as the "wrong
outcome" for a chemical safety review in New Zealand.

11. Could I please request any internal OCSA or Ministry of Health
methodological guidelines, memos, or correspondence that dictate why
Benchmark Dose Analysis is classified as an invalid or "wrong" outcome
when assessing the safety of community water fluoridation?

12. Since BMD modeling was excluded, could I please request the specific
alternative mathematical models and toxicological frameworks the OCSA or
Ministry of Health relied upon to accurately establish the Point of
Departure (POD) and safe reference dose for neurodevelopmental toxicity in
the December 2024 review?”
 

The reference number for your request is H2026080738. We will endeavour to
respond to your request as soon as possible and in any event no later than
29 April 2026 being 20 working days after the day your request was
received. If we are unable to respond to your request by then, we will
notify you of an extension of that timeframe.

 

If you have any queries regarding your request, please feel free to
contact the OIA Services Team on [1][email address]. If any
additional factors come to light which are relevant to your request,
please do not hesitate to contact us so that these can be taken into
account. 

 

Under section 28(3) of the Act you have the right to ask the Ombudsman to
review any decisions made under this request. The Ombudsman may be
contacted by email at: [2][email address] or by calling 0800
802 602.

 

 

Ngâ mihi, 
 
OIA Services Team

Ministry of Health | Manatû Hauora

 

M[3]inistry of Health information releases

 

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Kia ora Alisha
Please find attached the response to your request for official
information.
Ngā mihi,

OIA Services Team

Ministry of Health | Manatū Hauora

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Statement of confidentiality: This e-mail message and any accompanying
attachments may contain information that is IN-CONFIDENCE and subject to
legal privilege.
If you are not the intended recipient, do not read, use, disseminate,
distribute or copy this message or attachments.
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immediately and delete this message.
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