Moth reports: safe, responsible attitude to health

Moth reports show safe and responsible attitude to public health.

DATE 30 June 2005

Reports on exotic moth eradication campaigns in Auckland and Hamilton released today demonstrate a safe and responsible attitude to public health concerns, and have the backing of international best practice and accepted scientific methods, Biosecurity New Zealand eradication programmes manager Ian Gear says.

MAF conducted an aerial eradication for Painted Apple Moth in Auckland from 2002 to 2004 and for Asian Gypsy Moth in Hamilton in 2003. In both cases Foray 48B, a biological water-based spray product containing bacterial spores which only affect moth caterpillars, was used.

MAF today released Health Monitoring Reports of health services set up for both campaigns. They support research that there would be no significant adverse health effects, but some symptoms, such as mild respiratory, skin, and eye irritations might occur in a small proportion of people. People who believed they would be significantly affected were assisted in moving out of the treatment zones.

Also released was a peer reviewer note on those reports, a literature review of health impact studies of Foray 48B spray use in the United States, Canada and New Zealand, and a peer review of reports to health services set up for concerned residents during the spraying programmes.

“The reports are consistent. They show that what the experts told us would happen has – that no significant adverse health effects have been apparent during spraying in either Auckland or Hamilton. Mild mainly respiratory and skin irritations were expected – and reported. Predominant symptoms were non-specific. If there were major health issues, we would have expected them to have been reported to the Director of Public Health,” Ian Gear says.

“MAF expects to be held accountable, and these reports are part of that process. We’ve used the best tools we’ve got, which are accepted scientific principles and taking advice from qualified experts. We have done everything we can to demonstrate that the risks are as low as they get. For us, this is a big step forward in putting to bed what has been a controversial issue for some,” Ian Gear says.

There has been a high level of support for MAF’s eradication programmes, including a survey of 200 Aucklanders about Fall webworm moth in 2004, when aerial eradication efforts were ongoing.

The survey showed strong awareness, at 68 percent, that aerial treatment was an option for fall web worm, and an increase from 76 to 91 percent in support to eradicate it. Support for aerial treatment was similar to the previous year – down 1 to 76 percent. Approval of MAF’s biosecurity actions in general were up from 66 to 79 percent, and those that disagreed decreased from 20 to 8 percent. The margin for error was 6.9 percent.

“That suggests to us that the general public thinks we’re not only on the right track, but that when necessary, they’re also prepared to back us on the right horse – if we need to use it,” Ian Gear says.

The reports are online at www.biosecurity.govt.nz/pests-diseases/forests/painted-apple-moth/index.htm and www.biosecurity.govt.nz/pests-diseases/forests/gypsy-moth/residents/index.htm

ENDS

Conclusions from the Ministry of Health-commissioned peer review of health monitoring services reports for Painted Apple Moth (PAM) and Asian Gypsy Moth (AGM).

Use of the PAM and AGM Health Service does not indicate wide-spread effects. About 3.6% of residentially exposed householders used the health service during treatments for the Asian Gypsy Moth, compared to 1.6% during Painted Apple Moth treatments in Auckland

In Auckland, 697 people were placed on practical support plans. In Hamilton, 316 people were on practical support plans.

The most common reported problems were respiratory, general and skin complaints

The most common symptoms reported for Hamilton residents were asthma, allergic reactions, such as skin problems and allergic runny noses

The most common symptoms reported for Auckland residents were asthma, allergic reactions, such as throat symptoms and headache

The health service GPs grouped common symptoms into five clinical syndromes. For AGM, the highest presentation rate was for upper respiratory, followed by eye, lower respiratory, skin and headache. For PAM, presentations were most commonly for upper respiratory, then eye, skin, lower respiratory and headache

It couldn’t be determined if the rate of these was greater than the general population.

In general, the reported symptoms were the same across age, gender, whether a person was residentially exposed or not, and whether the person had a medical diagnosis or not

Based on census data, females and under-fives were over-represented in those who presented

Although the spraying programmes were of markedly different durations (two months for Hamilton and two years for Auckland) the symptoms reported were similar.

HEALTH SERVICE STATISTICS

Programme PAM AGM

Total health service encounters by householders 27646 7739

Number of householders added to health register 3636 1536

Number of householders reviewing any first assessment 1128 510

Number of householders completed health service doctor assessments 1524 554

Number of householders who have completed specialist assessments 136 3

Number of new practical support plans activated 697 316

Number of days on which aerial operations

- occurred 69 8

- were postponed 140 9

related health service activities occurred 200 15

Exposed population 193188 23598

Health survey usage (% exposed population) 1.60% 3.60%

Health cost 11.5m 1.13m

Ministry of Health Media release

29 June 2005

Ministry provided with final reports on Painted Apple Moth and Asian Gypsy Moth health services.

The Ministry of Health has been provided with copies of the final health monitoring reports from the providers of the Painted Apple Moth and Asian Gypsy Moth health support services.

Aer’Aqua Medical Services, funded by the Ministry of Agriculture and Forestry, provided health support services during aerial application programmes to eradicate the Painted Apple Moth (PAM) in West Auckland and the Asian Gypsy Moth (AGM) in Hamilton. MAF has provided copies of these reports to the Ministry of Health.

These reports showed that during the PAM programme, from 2002 to 2004, approximately 1.6% of the population in the residential area included in the eradication programme reported heath concerns to the health service. The most commonly reported symptoms were respiratory or skin ailments and headaches. There were 689 people who received a support plan, such as spray avoidance through relocation for the day or night, from the service.

In the AGM programme in 2003, approximately 3.6% of people who resided in the area sprayed reported health effects to the health service. The most commonly reported symptoms were respiratory and skin concerns. There were 316 people provided with practical support plans.

“We are pleased that these reports do not find anything that wasn’t expected for this spraying programme,“ said Director of Public Health, Dr Mark Jacobs.

Health Risk Assessments (HRA) for the biological spray Foray48B, conducted by the Auckland District Health Board prior to the spraying, concluded that some people may complain of minor skin, eye and upper respiratory tract irritation, or aggravation of existing asthma or allergies if directly exposed to the spray.

“We must acknowledge however that though we may call them minor health effects to some people they were distressing and uncomfortable.”

An independent review of these reports, commissioned by the Ministry of Health, concluded that

The draft reports are based on those people who lived in the spray area who either telephoned on their own or another household member’s behalf or attended the Health Service. In the absence of a random survey (e.g. telephone) of residents carried out during the spray programme it is not known how representative of the health status of the total population they were, although it is reasonable to assume that those with more severe and more frequent symptoms would have reported them.

The predominant symptoms were nonspecific. In the absence of background prevalence data for these symptoms it is not possible to determine to what extent, if any, they were associated with the spray and to what extent they were the result of increased health awareness as a result of publicity about the spray programme.

Whilst the commonest reported symptoms (respiratory, skin) were those that may be associated with an environmental irritant, and expected from the HRA of Foray 48B, there was no evidence of a dose-response relationship suggesting that increased health awareness may be the more likely explanation.

There is no evidence of widespread adverse health effects associated with the spray.

The findings are consistent with current knowledge about the human health impact of aerial spraying of Btk, including Foray 48B

The Ministry of Health is expecting a number of further reports from MAF and a report by the Institute of Environmental Science and Research (ESR) into hospitalisation rates in West Auckland before and during the PAM programme.

Once these reports are available, the Ministry will review all the information it has received in relation to health issues associated with the eradication programmes, and recommend to MAF what, if any, further investigation or action is required.

The Ministry of Health is one of several agencies, who have provided advice to MAF on this programme.

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