§ The Countess of Marasked Her Majesty's Government:
Whether they will commission further research into the methods of detecting airborne levels of organophosphates in the aerosol generated during sheep dipping and the extent to which these aerosols are absorbed by humans.
Lord LucasAs part of a broader investigation into sheep dipping practices, the relative contribution of contamination of the skin and of the inhaled air to the overall exposure of sheep dippers to organophosphates has been assessed in collaborative studies carried out by the Institute of Occupational Medicine (IOM) Edinburgh, and the Health and Safety Executive. The results were published in 1993.
The assessment methods used are well established and have been validated. In a study of sheep dipping being carried out under normal conditions by farmers, no detectable contamination of inhaled air was found whilst skin contamination was considerable. The detection methods for airborne contamination were sensitive enough to detect contamination well below that which is expected to produce harmful effects. In an additional study involving a contractor using a mobile dip, only trace amounts were found (0.035 mg/m3), which were well below the concentration (0.1 mg/m3) which has been judged to be the safe limit of exposure for 8 hours every day. These studies indicated that inhalation made only a minor contribution to the total exposure to OPs resulting from dipping sheep and that efforts to reduce exposure should be concentrated on measures to prevent the dip from getting on to the skin.
We therefore do not see any need to commission further research.
A scientific summary of the findings and conclusions from these studies has been prepared and I am placing a copy, together with copies of the research reports concerned, in the Library of the House.