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Environmental health research is classically concerned with health risks from involuntary physical environmental exposures such as chemical pollutants in air, water or food. However, it is increasingly recognised that few health risks are truly “involuntary”. Social and cultural factors condition our behaviour and health-related choices and therefore need to be considered along with physical exposures.

The role of indirect “upstream” mechanisms affecting global health are increasingly recognised. For example, social inequality is a major driver of ecologically unsustainable practices and global health disparities.

Our people

Our projects

Health and air pollution in New Zealand (HAPiNZ) 3.0

Empirical modelling of effects of long term exposure to air pollutants on morbidity and mortality in New Zealand. (Simon Hales, funded by NZ government Ministries via Emission Impossible)

Health impacts of nitrates in drinking water

There is increasing evidence linking exposure to nitrate in drinking water to multiple negative health outcomes, including colorectal cancer, preterm births and neural tube defects. In many studies, the risk of the adverse health outcome was found to occur at drinking water nitrate levels significantly lower than New Zealand's 'Maximum Acceptable Value' of 11.3 mg/L nitrate-nitrogen (Drinking water Standards for New Zealand 2005 (revised 2018)). (Tim Chambers)

Aim: Investigate the potential public health burden of nitrate contamination in New Zealand drinking water.

Nitrate contamination in drinking water and adverse birth outcomes emerging evidence is concerning for New Zealand

Public health response to report on potential risk of nitrate from drinking water

Climate change, extreme rainfall events and enteric disease outbreaks

Analysis of relationships between extreme rainfall events and water-borne enteric infections, including the impact of local factors, e.g. land use, source water and type of water supply. (Simon Hales, funded by HRC)

The impact of nitrate in drinking water on preterm birth

Aim: Investigate the association between nitrate in drinking water and preterm births.
Lay summary: HRC website
Funding: Health Research Council from 1 July 2022 – June 2025
Lead: Tim Chambers

Research impact

Papers, reports and Presentations


Climate Change

  • Cyclone Gabrielle by the numbers: A review at six months. Wilson, N., Broadbent, A., & Kerr, J. The Briefing, 14 August 2023.
  • Emphasis on indigenous forests in ETS would benefit public health. Prickett, M., Broadbent, A., Wilson, N., Baker, M., & Hales, S. The Briefing, 1 August 2023.
  • Huang, W., Li, S., Vogt, T., Xu, R., Tong, S., Molina, T., … Hales, S., … Guo, Y. (2023). Global short-term mortality risk and burden associated with tropical cyclones from 1980 to 2019: A multi-country time-series study. Lancet Planetary Health, 7(8). doi: 10.1016/s2542-5196(23)00143-2 
  • Water infrastructure failures from Cyclone Gabrielle show low resilience to climate change. Wilson N, Chambers T, Prickett M, Broadbent A, Kerr J. The Briefing, (25 May).
  • Cyclone Gabrielle joins list of Aotearoa NZ's 'sudden mass fatality events'. John Kerr, George Thomson, Nick Wilson.  The Briefing, 28 March 2023
  • Grout L, Thornley L, Wilson N.  Seven decades of severe weather events in Aotearoa New Zealand: What are the human health impacts?Public Health Expert Blog. 22 June 2022.
  • Wilson N, Boyd M. Climate change – how might it rank in importance as a global catastrophic risk and an existential risk? [Presentation, Panel 37]. 16th World Congress of Bioethics (WCB) Basel Switzerland 20-22 July 2022.
  • Grout L, Hales S, Thornley L, Wilson N.
    An Exploration of the Human Health Impacts Associated with Seven Decades of Severe Weather Events in Aotearoa New Zealand: The Need for Better Data [Report] (PDF)
    Wellington: University of Otago Wellington, 2022.
  • Chambers, T., Hales, S., Shaw, C., Baker, M., Ball, J., Cleghorn, C., & Wilson, N. (2021). New Zealand's Climate Change Commission report: The critical need to address the missing health co-benefits of reducing emissions. New Zealand Medical Journal, 134(1542), 109-118.
  • Analitis, A., Becker, P., Biggeri, A., Bouchama, A., De'Donato, F., D'Ippoliti, D., … Hales, S., … Wolf, T. (2009). Improving public health responses to extreme weather/heat-waves: EuroHEAT. Copenhagen, Denmark: World Health Organization, 60p.
  • Matthies, F., Bickler, G., Cardeñosa Marín, N., & Hales, S. (Eds.). (2008). Heat-Health action plans. Copenhagen, Denmark: World Health Organisation, 45p.
  • Butler, C. D., Hales, S., Beggs, P. J., & Ebi, K. L. (2016). From Paris towards 1.5 degrees C. In C. D. Butler (Ed.), Climate change and global health. (Revised reprint ed.) (pp. 293-305). Wallingford, UK: CABI International.
  • Bambrick, H., & Hales, S. (2014). Dengue: Distribution and transmission dynamics with climate change. In C. D. Butler (Ed.), Climate change and global health. (pp. 77-84). Abingdon, UK: CAB International.
  • Lal A, Lill AWT, Mcintyre M, Hales S, Baker MG, French NP. Climate variability, Agricultural Land Use and Human Enteric Zoonotic Diseases in New Zealand. ANZJPH, 2014, Accepted.
  • Lal A, Hales S, French N, Baker MG. Seasonality in human zoonotic enteric diseases: a systematic review. PLoS One. 2012;7(4):e31883. Epub 2012 Apr 2.
  • Lal A, Baker MG, French N, Hales S. Potential effects of global environmental changes on cryptosporidiosis and giardiasis transmission. Trends Parasitol 2013 29:83-90. Epub 2012 Dec 5.
  • Christensen AL, Rasmussen LH, Baker MG, Lip GYH, Dethlefsen C, Larsen TB. Seasonal variation and trend in hospital admissions for stroke in patients with atrial fibrillation in Denmark and New Zealand: analysis of hospital discharge data from 1977 to 2008 . BMJ Open. 2012 Aug 24;2(4). doi:pii: e001210. 10.1136/bmjopen-2012-001210.
  • Wilson N, Slaney D, Baker MG, Hales S, Britton E. Climate change and infectious diseases in New Zealand: a brief review and tentative research agenda. Rev Environ Health 2011;26(2):93-99.
  • Wilson N, Slaney D, Baker MG, Hales S. Infectious Diseases and Climate Change in New Zealand: A Brief Review. [Poster presentation 59]. 2010 International Conference on Emerging Infectious Diseases. Atlanta, USA; 11-14 July, 2010.
  • Wilson N, Lush D, Baker MG. Meteorological and climate change themes at the 2010 International Conference on Emerging Infectious Diseases. Euro Surveill 2010;15(30). pii:19627.
  • Hales S, Blakely T, Foster RH, Baker MG, Howden-Chapman P. Seasonal patterns of mortality in relation to social factors. J Epidemiol Community Health 2010 Oct 19. [Epub ahead of print]
  • Britton R, Hales D, Venugopal K, Baker MG. The impact of climate variability and change on cryptosporidiosis and giardiasis rates in New Zealand. J Water Health. 2010; 8: 561-71.
  • Wilson N, Lush D, Baker MG. Meteorological and climate change themes at the 2010 International Conference on Emerging Infectious Diseases. Euro Surveill. 2010; 15: pii=19627.
  • Metcalfe S, Woodward A, Macmillan A, Baker M, Howden-Chapman P, et al. Why New Zealand must rapidly halve its greenhouse gas emissions. NZMJ 2009; 122:1-24.
  • Telfar Barnard L, Baker MG, Hales S, Howden-Chapman P. Excess winter morbidity and mortality: still a lack of evidence that housing or socio-economic status makes much difference. Rev Environ Health 2008; 23: 203-221.
  • Davie GS, Baker MG, Hales S, Carlin J. Trends and determinants of excess winter mortality in New Zealand: 1980 to 2000. BMC Public Health. 2007; 7: 263.
  • Hales S, Baker M, Howden-Chapman P, Menne B, Woodruff R, Woodward A. Implications of global climate change for housing, human settlements and public health. Rev Environ Health 2007; 22: 295-302.
  • Mann S, Baker M, Hales S, Kamalesh V, Telfar Barnard L, Zhang J, et al. Excess winter cardiovascular mortality and morbidity in New Zealand is seen in all disease subcategories. Heart, Lung and Circulation 2009;18(Supplement 2):S21-S22

Environmental health

  • Pourzand, F. (2022). Regional differences in the effects of drought events on farm profitability in New Zealand. Environmental Hazards. Advance online publication. doi: 10.1080/17477891.2022.2141180.
  • Graham, F. F., Kim, A. H. M., Baker, M. G., Fyfe, C., & Hales, S. (2023). Associations between meteorological factors, air pollution and Legionnaires' disease in New Zealand: Time series analysis. Atmospheric Environment, 296, 119572. doi: 10.1016/j.atmosenv.2022.119572.
  • McKerchar, C., Smith, M., Stanley, J., Barr, M., Chambers, T., Abel, G., Lacey, C., Gage, R., … Signal, L. (2020). Food store environment examination: FoodSee: A new method to study the food store environment using wearable cameras. Global Health Promotion, 27(3), 73-81.
    doi: 10.1177/1757975919859575
  • Gage, R., Leung, W., Stanley, J., Reeder, A., Mackay, C., Chambers, T., Smith, M., Barr, M., & Signal, L. (2019). Studying third-parties and environments: New Zealand sun-safety research. Health Promotion International, 34(3), 440-446.
    doi: 10.1093/heapro/dax094
  • Gage, R., Barr, M., Stanley, J., Reeder, A., Mackay, C., Smith, M., Chambers, T., Leung, W., & Signal, L. (2018). Sun protection and shade availability in New Zealand's outdoor recreation spaces. New Zealand Medical Journal, 131(1484), 30-37.
  • Telfar Barnard L, Baker MG, Hales S, Howden-Chapman P. Novel use of three administrative datasets to establish a cohort for environmental health research. BMC Pub Health, 2015;15: 246.
  • Keall, MD, Pierse N, Howden-Chapman P, Cunningham CW, Cunningham M, Guria J, Baker MG. Reduction in fall injury rates achieved by home modification: a cluster randomised controlled trial. The Lancet 2015;385:231-8.
  • Keall MD, Crane J, Baker MG, Wickens K, Howden-Chapman P, Cunningham M. A measure for quantifying the impact of housing quality on respiratory health: a cross-sectional study. Environ Health. 2012 May 14;11:33
  • Howden-Chapman P, Baker MG, Bierre S. The houses children live in: Policies to improve housing quality. Policy Quarterly 2013; 9: 35-9.
  • Keall MD, Ormandy D, Baker MG. Injuries associated with housing conditions in Europe: a burden of disease study based on 2004 injury data. Environmental Health 2011, 10: 98.
  • Wilson N, Parry R, Jalali J, Jalali R, McLean L, McKay O. High air pollution levels in some takeaway food outlets and barbecue restaurants: pilot study in Wellington City, New Zealand. N Z Med J 2011;124(1330):81-86.
  • Keall M, Baker MG, Howden-Chapman P, Cunningham M, Ormandy D. Assessing housing quality and its impact on health, safety and sustainability. J Epidemiol Comm Health 2010; 64: 765-71.
  • Gillespie-Bennett J, Pierse N, Wickens K, Crane J, Nicholls S, Shields D, Boulic M, Viggers H, Baker M, Woodward A, Howden-Chapman P; Housing, Heating, and Health Team. Sources of nitrogen dioxide (NO2) in New Zealand homes. Finding from a community randomized controlled trial of heater substitutions. Indoor Air 2008; 18: 521-8.
  • Wilson N, Horrocks J. Lessons from the removal of lead from gasoline for controlling other environmental pollutants: A case study from New Zealand. Environ Health 2008;7:1.
  • Horrocks J, Wilson N. NGO power versus leaded petrol in New Zealand. International Journal of Environmental, Cultural, Economic and Social Sustainability 2008;4(5):19-28.


  • Queenstown outbreak highlights future challenges for clean drinking water. Baker, M., Prickett, M., Pourzand, F., Kerr, J., & Hales, S. The Briefing, 29 September 2023.
  • Royal, H. (2023, July). Assessing nitrate contamination in drinking water on Indigenous Māori reserves in the Ngai Tahu takiwā, South Island, New Zealand. Verbal presentation at the Royal New Zealand College of General Practitioners (RNZCGP) Conference for General Practice, Tāmaki Makaurau - Auckland, New Zealand.
  • Where do the parties stand? Protecting water sources and drinking water quality. Prickett, M., Chambers, T., Wilson, N., Baker, M., Broadbent, A., Kerr, J., & Hales, S. The Briefing, 28 August 2023.
  • Puente-Sierra, M., Chambers, T., Marek, L., Broadbent, J. M., O'Brien, B., & Hobbs, M. (2023). The development and validation of a nationwide dataset of water distribution zones in Aotearoa New Zealand: A cross-sectional geospatial study [Data article]. Data in Brief, 49, 109349. doi: 10.1016/j.dib.2023.109349
  • Pourzand, F., & Hales, S. (2023). Impacts of extreme weather events on enteric infectious disease outbreaks: Evidence from New Zealand. Population Medicine, 5(Suppl.), (pp. 91). doi: 10.18332/popmed/165758[Abstract]
  • When the first barrier fails: Strengthening protection for drinking water sources. Marnie Prickett, Tim Chambers, John Kerr, Michael Baker, Simon Hales. The Briefing, 14 March 2023
  • Chambers, T. (2022). Understanding the human health impacts of nitrate contamination in drinking water. Proceedings of the National Freshwater Conference.
  • Chambers, T., Hobbs, M., Broadbent, J. M. (2022). An assessment of compliance with optimal fluoride levels for oral health benefit by New Zealand drinking water suppliers. Journal of Public Health Dentistry. Advance online publication. doi: 10.1111/jphd.12548.
  • Hashimi, F. N., Bennett, J., Baker, M. G., Moreland, N. J., Merry, T. L., Loh, J. M. S. (2022). The effects of sugar in drinking water on Streptococcus pyogenes colonisation in a murine nasopharyngeal infection model. Scientific Reports, 12, 17716. doi: 10.1038/s41598-022-22648-5.
  • Chambers, T., Wilson, N., Hales, S., Prickett, M., Ellison, E., Baker, M. G. (2022). Beyond muddy waters: Three Waters reforms required to future-proof water service delivery and protect public health in Aotearoa New Zealand. New Zealand Medical Journal, 135(1566), 87-95. Retrieved from [Commentary].
  • Grout, L., Chambers, T., Hales, S., Prickett, M., Baker, M. G., Wilson, N. (2023). The potential human health hazard of nitrates in drinking water: A media discourse analysis in a high-income country. Environmental Health, 22, 9. doi: 10.1186/s12940-023-00960-5.
  • Chambers T, Wilson N, Hales S, Prickett M, Baker M. Three Waters reforms are needed to protect public health and ensure changes are economically sustainable and efficient. Public Health Expert Blog. 22 July 2022.
  • Chambers, T., J. Douwes, A. t. Mannetje, A. Woodward, M. Baker, N. Wilson and S. Hales (2022). "Nitrate in drinking water and cancer risk: the biological mechanism, epidemiological evidence and future research." Australian and New Zealand Journal of Public Health.
  • Richards, J., T. Chambers, S. Hales, M. Joy, T. Radu, A. Woodward, A. Humphrey, E. Randal and M. G. Baker (2022). "Nitrate contamination in drinking water and colorectal cancer: Exposure assessment and estimated health burden in New Zealand." Environmental Research 204: 112322.
  • Bennett, J. and M. Baker (2022). Skin infections confirmed as a cause of rheumatic fever
  • Whitcombe, A. L., R. McGregor, J. Bennett, J. K. Gurney, D. A. Williamson, M. G. Baker and N. J. Moreland (2022). "Increased breadth of Group A Streptococcus antibody responses in children with Acute Rheumatic Fever compared to precursor pharyngitis and skin infections." J Infect Dis.
  • Chambers, T., Joy, M., Wilson, N., Hales, S., & Baker, M. (2021). Quantifying the nitrate levels in bottled water in New Zealand. Australian & New Zealand Journal of Public Health. Advance online publication.
    doi: 10.1111/1753-6405.13196
  • Richards, J., Chambers, T., Hales, S., Joy, M., Radu, T., Woodward, A., Humphrey, A., Randal, E., & Baker, M. G. (2021). Nitrate contamination in drinking water and colorectal cancer: Exposure assessment and estimated health burden in New Zealand. Environmental Research. Advance online publication.
    doi: 10.1016/j.envres.2021.112322
  • Chambers, T., Hales, S., & Anglemyer, A. (2021). Correction: Nitrate-nitrite exposure through drinking water and diet and risk of colorectal cancer: A systematic review and meta-analysis of observational studies. Clinical Nutrition. Advance online publication.
    doi: 10.1016/j.clnu.2021.09.027

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