Reports and Studies

Three major aerial spraying programmes to eradicate moth pests have been carried out over heavily populated urban areas in New Zealand using the Bacillus thuringiensis var Kurstaki ( Btk) pesticide in the commercial formula Foray 48B.

The aerial spraying took place in

  • East  Auckland  between 1996 and 1997 for the White Spotted Tussock Moth;
  • Hamilton City in late 2003 against a presumed infestation of the Asian Gypsy Moth, and
  • West Auckland ( Waitakere City) between 2002 and 2004 against the Painted Apple Moth.

A huge volume of reports, studies, surveys and investigations have arisen from these three eradication campaigns.  The wealth of information, conclusions and recommendations in these comprehensive reports and studies is vital evidence that should be taken into account when assessing any proposed aerial spray programmes in which there is inevitable and unavoidable public exposure.

All the reports and studies posted below have been undertaken in New Zealand and relate to the New Zealand experience.  Additionally, in conjunction with, and arising from these programmes, there has been a number of Government assessments, reports and surveillance studies.  These are listed on the link page below, together with other relevant studies, papers and reports from both New Zealand and overseas.

Link to other assessments, reports and surveillance studies


Report of the March 2006 People’s Inquiry into the Impacts and Effects of Aerial Spraying Pesticide over Urban areas of Auckland  Dr Joanna Goven, Dr Tom Kerns, Prof Romeo Quijano, Dell Wihongi.  October 2007.   This Report is the outcome of eighteen month’s research, review and evaluation by the four independent commissioners.  They considered evidence from over 160 people, of whom 70 gave public testimony at the Inquiry held in March 2006 where they were able to be questioned and examined by the commissioners. The testimony included submissions from the community, local representatives, scientists and doctors on the effects of the spraying campaign. Arising from the wide-ranging conclusions of adverse health and human rights impacts, mismanaged programmes and inappropriate treatment of affected people, there are twenty seven detailed recommendations for restitution and management of any future incursions.

Link to testimony and written submissions to the People’s Inquiry


Report of the Opinion of Ombudsman Mel Smith on complaints arising from Aerial Spraying of the Biological Insecticide Foray 48B on the population of parts of Auckland and Hamilton to destroy incursions of Painted Apple Moths, and Asian Gypsy Moths, respectively during 2002-2004.  Office of the Ombudsmen, Wellington, New Zealand.  December 2007.  This Report is the result of a four year investigation by the NZ Parliamentary Ombudsman into complaints raised by members of the community in Auckland and Hamilton cities. The Ombudsman’s responsibilities and powers of investigation are fairly wide and are not confined to the strict details of the complaint laid with him.  His statutory access to Government Ministers and public servants together with his ability to obtain even confidential government documents and reports not available to the public have ensured that his conclusions and recommendations are highly reliable and authoritative.

The most important finding was that the pesticide used was not benign or harmless and thousands of people experienced adverse health effects.  It is his opinion that insufficient consideration was given to ensuring that the health concerns of the sprayed population were given equal consideration with biosecurity.  Strong recommendations for urgent research into long-term health effects and amendments to Government Acts and processes to ensure the protection of people exposed to these sorts of programmes are detailed.

Descriptive study of hospital discharges for respiratory diseases in spray zone for Painted Apple Moth (Auckland) relative to local and national statistics 1999-2004  Gallagher et al.  September 2005.  Report for the New Zealand Ministry of Health by the Institute of Environmental Science and Research (ESR), comparing the hospitalisation rates for respiratory diseases before and during the Painted Apple Moth aerial spraying programme.   The authors found statistically significant differences in hospitalisation rates both locally and compared to the national population.  They concluded there were several findings indicating a real increase in asthma discharges that could plausibly be associated with the spray programme.

Clustering of childhood asthma hospital admissions in New Zealand, 1999-2004.  Hales et al.  Study presented to the 17th Annual Colloquium of the Spatial Information Research Centre, University of Otago, Dunedin, New Zealand.  November 2005.   The context for this study was public concern about aerial spraying of biological insecticides over Auckland, New Zealand.  Covering the period of the Painted Apple Moth eradication campaign – July 1999 to December 2004 – childhood asthma hospital admissions for the whole of New Zealand were analysed using a spatial scan statistic. The study confirmed that among several clusters identified there had been a significant space-time cluster of acute childhood asthma admissions in West Auckland during the period of the aerial operations that could plausibly be associated with the spraying.  The authors conclude that “the hypothesis that chronic exposure to biological insecticides may lead to asthma exacerbations deserves further study”.

Assessment of the potential health impacts of the “Painted Apple Moth” aerial spraying programme, Auckland. Hales et al.  February 2004.  Wellington School of Medicine Report to the New Zealand Ministry of Health on the community health concerns, symptoms and effects associated with the Foray 48B aerial spraying programme.  The report raised several important health concerns relating to the use of biologically-based insecticides in New Zealand and considers the most serious potential impact of the spray may well be a long-term effect on chronic diseases, especially respiratory diseases.  They conclude there is a lack of adequate assurance of safety from existing scientific knowledge and recommend scientifically robust methods of study that could answer the question of safety.

Painted Apple Moth Focus Group Study. Virginia Baker.  Institute of Environmental Science and Research (ESR), April 2004.   This report is a component of the Wellington School of Medicine Report Assessment of the potential health impacts of the “Painted Apple Moth” aerial spraying programme, Auckland.  The focus group study complements the wider investigation of the WSM Report by selecting people whose voices and view-point may not have been heard.  Four formal group interviews were conducted with Maori, Pacific Island peoples and migrant groups.  The author concludes that the aerial spray programme had multiple impacts on the health, well-being and everyday life of many residents, with the most serious health impacts for those with existing respiratory and allergenic conditions.

Hamilton’s Fraser High School – Final Report – Occupational Safety & Health Service (OSH).  James R Napier, Health and Safety Inspector.  November 2003.  Report of the investigation of a complaint from the high school’s Principal that significant numbers of his staff were severely affected by the aerial spraying with the pesticide Foray 48B.  The report documents the severe health reactions experienced by his staff and his difficulty in getting the problems recognised and taken seriously by the government’s health providers. A causal link between adverse health effects and occupational exposure to the Btk pesticide was confirmed, and the author notes that the investigation served as a timely reminder for all practicable steps to be implemented to ensure safety and health within workplaces affected by environmental programmes.

Precautionary Health Risk Assessment:  Case Study of Biological Insecticides.  Simon Hales.  EcoHealth – Published online October 2004.  Proposes an alternative approach to conventional risk assessment of a precautionary health risk assessment, in which the scientific questions to be addressed are defined by community consultation. He illustrates the approach with a case study of exposure to biological insecticides, concluding that it would be prudent to avoid aerial spraying of biological insecticides over populated areas until the results of detailed follow-up of exposed populations is available.

Painted Apple Moth Eradication Programme – Health Risk and Effects.  Meriel Watts, PhD. January 2003.   Paper addressing the adverse health effects apparently experienced by the two communities exposed to the aerially applied Btk insecticide Foray 48B – the 1996 to 97 Tussock Moth campaign and the current 2002 Painted Apple Moth one. The paper compares the difference between health effects apparently experienced and the government’s assessment of the health risk.  The author concludes that the HRA was flawed for a number of reasons including inadequate characterization of exposure, the discounting of reported effects, and the influence of the underlying value system inherent in risk assessment. This resulted in an inadequate depiction of the real risks to which West Aucklanders are exposed from the aerial application of this pesticide.

Review of: Watts M. Painted apple moth eradication programme: health risk and effect s (2003).  Dr Deborah Read. April 2003.  Government commissioned review of Dr Watts’s paper.  Although the Health Risk Assessment (HRA) was not available to the author and she was therefore unable to confirm the validity of the criticisms raised by Watts, she does conclude that the concerns are reasonable, in particular recognition of the legitimacy of community experience in the face of conflicting previous conclusions.

Interim Report of the Community-based health & incident monitoring of the aerial spray programme. January – December 2002.  Hana Blackmore.  Feb 2003.   Report detailing the impacts and effects of the first year of the Painted Apple Moth aerial spraying programme.  Includes nearly 1,400 reported spray related incidents and symptoms from 315 people.  Details for the first time the social and economic impacts, and questions the adequacy of the health risk assessment to accurately predict the level, extent and seriousness of the adverse effects experienced.

Commentary on the Blackmore Interim Report of February 2003. Dr. David Phillips. (ESR)  Ministry of Health commissioned review of the Blackmore Report. Includes comment on the problems of exposure assessment, the apparent absence of predictive modeling, and contingency planning for adverse effects.  The author details the implications for public health, and seven recommendations to address what he considers is the urgent need to ameliorate the level of disquiet and distrust in the community.

Symptom complaints following aerial spraying with biological insecticide Foray 48B.  Petrie. K et al. the New Zealand Medical Journal 14 March 2003, Vol 116 No 1170.  The study investigated self-reported symptoms of 292 residents recruited in a door to door survey in the initial 500 hectare PAM spray zone.  It compares the changes in their symptom complaints from ten weeks prior to the spraying commencing and ten weeks later – after three spray rounds had been completed.   The study found symptom complaints increased significantly following the aerial spraying and concluded that “aerial spraying with Foray 48B is associated with some adverse health consequences in terms of significant increases in upper airway, gastrointestinal and neuropsychiatric symptoms, as well as a reduction in overall perception of health in the exposed population.”

Legal Opinion on the Painted Apple Moth Spraying.  Sir Geoffrey Palmer. December 2002.  Preliminary legal advice for community groups on the issues around the possibility of securing an injunction to stop the aerial spraying of West Auckland.  Examines adverse health effects, human rights and the non-disclosure of spray ingredients.  Legal remedies with a reasonable chance of success are confirmed and outlined.

Painted Apple Moth Eradication Campaign (legality of aerial spraying) – Report to the Prime Minister.  Hana Blackmore.  October 2004.   Report detailing serious concerns regarding the legality of continued aerial spraying, lack of public consultation and governmental review, and the failure of the compensation system.  Calls for urgent action and the setting up a full public inquiry.

Is PAM Easy?  John Clearwater.  Published in The Spiders Web (16) June 2003 8-9.  Analysis and comparison of two moth eradication projects – the White spotted Tussock Moth and the Painted Apple Moth – detailing critical decisions that resulted in two totally different outcomes.

New Zealand Education Institute (NZEI) West Auckland aerial spraying survey.  Meredydd Barrar – NZEI West Auckland Committee of management.  May 2003.   Survey of staff and principals in West Auckland schools carried out during February 2003 on the effects of the Painted Apple Moth aerial spraying on teachers and pupils.  The report concludes that the survey raises some very serious concerns about the aerial spraying, both with the disruption to the children’s’ learning, and the health problems experienced.  Over 57% of the 353 staff who responded had recorded adverse effects from the spray, or had observed similar effects in the children.

A Review of the Painted Apple Moth Eradication Programme.  Kubi Witten-Hannah.  January 2003.   A paper reviewing the PAM eradication programme after one year of aerial spraying.  Examines a programme that is neither safe nor effective.  Details the need to work with the community to develop an approach that can succeed, and proposes effective solutions and strategies.

Exposure Risks for Schools during the Painted Apple Moth Aerial Spray Programme.  Updated Report.  Hana Blackmore, Meriel Watts, Meredith Youngson, Glenys Bean.   October 2002.   Open letter and updated 2001 Report to parents, schools and childcare establishments in the exposed West Auckland spray zone.   Details what is, and what is not being revealed about the exposure risks and unique hazards faced by children.  Outlines prudent actions that should be taken to protect them.

Report and Recommendations of Special Science Meeting – Painted Apple Moth Eradication – Community Option.  Dr Meriel Watts, Hana Blackmore.  May 2002.  Report of a specially convened science meeting of six scientists with experience in successful eradication of NZ insect pests, to critique, develop and strengthen the community’s option for eradicating the Painted Apple Moth.  Formed part of the community submission to the Ministry of Agriculture and Forestry’s (MAF) eradication options to the Government.  Includes the PAM Community Advisory Group’s 10 point plan for eradication.

MAF bungle the Biosecurity in West Auckland.  Meriel Watts, PhD.  January 2002.   A paper outlining fundamental reasons why the PAM eradication programme has gone so badly wrong.   Examines the failure of the Ministry to learn the lessons of a previous successful eradication programme, and details concerns about their use of toxic chemical sprays.

Aerial spraying against the Painted Apple Moth – Btk pesticide exposure, spray drift and environmental persistence.  Hana Blackmore.  November 2001.  Report detailing issues of concern about the proposed PAM aerial spraying programme in West Auckland.  Covers questions of the level of pesticide exposure and drift, penetration into buildings and homes, and environmental persistence.  Recommends urgent studies and advice on prudent avoidance for vulnerable people.

Timeline comparison of Two Moth Eradication Programmes. Hana Blackmore. Feb 2001.  Detailed timetable comparing the responses and actions taken by the government to eradicate the White Spotted Tussock Moth (April 1996 – April 1999) and the attempted eradication of the Painted Apple Moth (April 1999 – January 2001).  Taken from the joint paper, Tackling tussock moths: strategies, timelines and outcomes of two programs for eradicating tussock moths from Auckland Suburbs. Clearwater, Gries & Blackmore.  Presented to the Eradication of Island Invasives international conference, University of Auckland February 2001.

Biosecurity & Pest Management.  Implications of the Painted Apple Moth eradication programme.  Report to the Minister of Biosecurity.  Hana Blackmore.  August 2000.  Report raising concerns about the failure to eradicate the fifteen month-old Painted Apple Moth infestation in West Auckland and the implications for pest-management strategies in New Zealand.  Details the need for an urgent review of current Biosecurity, pest management programmes and policies.

Participation and Communication Approaches that influence Public and Media Responses to Scientific Risk:  A Comparative Study of Two Biosecurity Events in New Zealand.  Marie J McEntee. Paper published in the International Journal of Interdisciplinary Social Sciences, 2007.   Paper comparing the factors that increased community resistance, and influenced media coverage between the Tussock Moth and Painted Apple Moth eradication campaigns.  The paper argues that scientific bureaucracies must step beyond a narrow operational focus of their statutory responsibilities, and meaningfully engage with stakeholders to build consensus based on participation, trust and understanding.  (See also Marie’s commentary article published in the New Zealand Herald, December 17 2007 – Lessons in mishandled anti-moth campaign.) 

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