Moth spray link to asthma not proved

A report into the health effects of aerial insecticide spraying in West Auckland has found child asthma rates rose during the programme but says other factors could have accounted for the rise.

The Institute of Environmental Science and Research report based the findings on hospital discharge rates during the Ministry of Agriculture and Forestry's campaign.

It said that while several findings pointed to a "plausible" link to the spray programme, chance, bias and other factors were also possible explanations. The underlying trend for respiratory disease in the spray zone was evident before spraying began.

The report by Dr Simon Hales found that for boys aged up to 4 years, hospital discharge rates doubled over the period 2002 to mid-2004 in the exposed population (from 6.5 per 10,000 to 13.4).

For girls aged 5 to 14, the rate increased from 1.8 per 10,000 to 3.2.

Overall, the monthly hospital discharge rate for asthma conditions increased by 40 per cent (from 1.6 per 10,000 to 2.3) for the exposed population between the two time periods (before and during spray-time) and decreased 11 per cent for the national population.

Ministry public health chief adviser Ashley Bloomfield said that while the rise of serious asthma attacks in children was "significant", he believed the report's findings would reassure West Aucklanders.

"Given the increases occurred prior to the spraying, and the increases were very small numbers, there is nothing to suggest a significant adverse impact on the incidence of respiratory diseases for the West Auckland population," he said.

Maf sprayed with Foray 48B from January 2002 to May 2004 against the moth pest.

Aer'Aqua Medical Services, funded by the Ministry of Agriculture and Forestry, found approximately 1.6 per cent of the population in the spray zone reported health concerns. Most common were respiratory problems or skin ailments and headaches.

Dr Bloomfield said the Ministry of Health was expecting reports related to Btk spraying, one on birth defect rates (and including data from Hamilton in the aerial campaign against Asian gypsy moth) and the other on thyroid disorders in newborns.

The ministry would review all information on health issues associated with the eradication programme once those reports were completed.

A father whose daughter was hospitalised 28 times in a year with serious asthma says the report confirmed his fears over the impact of the spraying.

West Aucklander Andrew Harvey's daughter Emily was 5 when aerial spray campaign against the painted apple moth finished after more than 2 1/2 years. She became seriously ill, even though the family was evacuated from their Kelston home each spray day.

Mr Harvey said his own asthma also got worse during spraying.