Report on the effects of the moth spray programme
27 April 2004
Report on the effects of the painted apple moth spray programme
The Director of Public Health’s office has released the independent report into the health effects of the painted apple moth spraying programme in West Auckland.
The Ministry of Agriculture and Forestry programme to eradicate the moth, a significant threat to this country’s biosecurity, in particular to forests and some native species, began in May 1999. Aerial operations are due to be completed next month. As part of the control programme an insecticide, Foray 48B, was sprayed over a maximum area of 10,500 hectares of West Auckland.
The Ministry of Health commissioned the report after concerns were expressed by the West Auckland community in regard to possible effects on their health from this spray.
Many of the symptoms reported by those who participated in the study were consistent with those identified as being associated with this spray in the Health Risk Assessment, a health report done prior to the aerial spraying beginning.
A Health Risk Assessment looks at the potential effects on the health of the population and the distribution of those effects in the population. The effects that were identified in this Health Risk Assessment as being associated with Foray 48B include short term irritant effects, and worsening of pre-existing conditions such as allergies and asthma. The Health Risk Assessment also identified the possibility of transient symptoms such as headaches and sore throats. A health service was established to provide support to people who might experience these effects.
It was expected that a small percentage of the population would experience some effect from the spray programme. Data from the MAF operated painted apple moth health service suggests that the actual reported proportion is about two percent of the population reporting an effect. The proportion of people who were with a practical support plan due to a need to avoid the spray is less than 0.5 percent.
“Even so, the impacts on some people are very disruptive and uncomfortable, and their tolerance has been appreciated in order for all New Zealanders to benefit from the eradication of this pest,” said Acting Director of Public Health, Ashley Bloomfield.
The report poses a theoretical question about whether biological insecticides could contribute to chronic respiratory conditions such as asthma. Bacillus thurigensis (Bt), the active ingredient in Foray 48B, is widely used for organic pest control.
“The Ministry will be seeking further information on this issue from experts, some of whom are overseas, who do know about this area. If the spray does act in this way, peoples’ exposure would depend on many factors such as droplet size, how many of the droplets of the appropriate size actually got into peoples homes and workplaces and were then breathed in, and the length of time people were exposed, “ said Dr Bloomfield.
However, it is important to note that this theoretical risk did not lead the authors to recommend stopping or modifying the existing spray programme.
The report has a number of recommendations.
“We are seeking expert advice from outside the Ministry about how to effectively implement some of the recommendations and work is already underway to progress others,” Dr Bloomfield said.
Dr Bloomfield said the report also confirmed the importance of involving the community in making decisions regarding eradication programmes.
“We need to think about how we can work together to make sure that the public is adequately consulted and involved in decisions that have such an impact on their lives,” said Dr Bloomfield.
“We know that these impacts range from having to redo loads of sprayed washing to having to move affected family members out of the area on spray days. This creates a lot of stress for people who already have busy lives.”
Dr Bloomfield said that future biosecurity threats to New Zealand’s environment and economy were likely and it is vitally important to learn lessons from this experience.
“While it is not a recommendation of this report, we feel that from the comments made, there needs to be further discussion on how communities can better participate in decision making and how we can reduce some of the impacts of programmes on the day to day lives of people in the affected areas.”
The Director of Public Health will put this information together to feed it into the review that will be conducted following the completion of the spraying programme.
We will actively participate in a review on completion of the programme. This will assess how programmes that may be required in the future can be more effectively run.”
The report and expert commentary are available on the Ministry of Health website at www.moh.govt.nz.