Dichlorvos residues in food arising from the domestic use of dichlorvos PVC strips

Abstract

Trials have been carried out with “VAPONA” Pest Strips under practical conditions in houses in the U.K. and France. The purpose of these trials was to determine the residues of dichlorvos that occur in food prepared in kitchens in which strips were placed. Samples, each of which consisted of the combined food and drink for an adult for a day, were taken at intervals during the trials. The food items were exposed and the meals prepared, including any cooking, in the way normal to the household. The analyses for dichlorvos were carried out by a g.l.c. method using flame photometric detection. The results show that the residue concentrations from all the individual samples were less than 0.1 part/million. In the U.K. trial, the mean dichlorvos levels in samples taken 7, 42 and 70 days after the strips were hung were 0.03, 0.03 and 0.02 part/million respectively. In the French trial, the mean concentrations were a little lower, being 0.02, 0.02 and less than 0.01 part/million at the same times. The items of food and the way in which they were processed varied widely from sample to sample and also between the two countries. However, the residue concentration in a sample did not appear to be correlated with the food items or with the manner of processing. No relationship was observed between the volume of the kitchens used, which varied from 14 to 45 m3, and the level of residues found in the samples.

Measurement of residues of dichlorvos absorbed by food exposed during disinsection of aircraft

“…Elgar et al (1970) reported on a method which was developed for analysis of dichlorvos in crops and tissues with a sensitivity to 0.01 ppm. This method was used by Elgar et al (1972) for determination of dichlorvos residues in meals exposed to vapors from dichlorvos resin strips in houses in England and France. The method was found to be unsatisfactory for use with the meals exposed in this experiment because of their high fat content, which would have required a lengthy steam distillation cleanup procedure.…”