RESUMO
80 clients of a mobile unit for environmental quality testing were contacted after monitoring for potential toxic substances in their homes or places of work. Elevated concentrations of pyrethroids (in all cases at least permethrin) were found in these 80 cases in dust or materials, mainly because of pyrethroid treated carpetings. The clients were questioned whether they removed one or all of the contaminated carpets. Furthermore, they were questioned as to their state of health and the period of time which had passed since the carpets were removed. 75 of the 80 contacted clients had initially called the mobile unit for environmental quality testing because of health impairments, whereas 5 clients had done this only for preventive reasons. 47 (59%) of the contacted clients had removed all carpetings which were contaminated with permethrin. 8 (10%) clients had got rid of a part of the contaminated carpets and 25 (31%) clients did not remove any carpet. 39 (83%) of the clients who had removed all contaminated carpetings, described a complete or at least partial improvement of their complaints. The complaints of 6 (13%) clients did not improve despite removal of their carpets. The lowest concentration of permethrin that was assessed at the homes of clients, who, after removing all contaminated carpet floorings, described complete recovery, were 10-15 mg/kg dust and 15 mg/kg carpet, respectively. The effect of removing all contaminated carpetings on health improvement in comparison with the results of not removing any carpet was statistically significant (test: chi 2, p < 0.0001). The corrected contingency coefficient amounted to 0.71. In 3 cases, where the contaminated carpets had already existed for 5, 7 and 10 years in the homes of clients, there were still permethrin-concentrations of 115, 100 and 150 mg per kg dust. This result indicates that indoor contamination of permethrin is highly persistent.
