[Statistical description of health complaints after pyrethroid exposure]

In 96 pyrethroid-exposed persons data on subjective health impairment were collected by means of a questionnaire. The present explorative statistical analysis is restricted to a subgroup of 51 out of the 96 persons for which pyrethroid concentrations in dust samples from residential dwellings or from work places could be determined. Since measurements were taken from dwellings or work places, there is in some cases only one common measured value for families or teams. In total, we have 34 independent measurements. Based on the type of measured exposures, the 51 participants can be divided into 3 groups: 26 cases exposed to permethrin and tetramethrin (type-I pyrethroids), 13 cases exposed to deltamethrin, cyfluthrin or cypermethrin (type-II pyrethroids), and 12 cases with mixed exposure to the mentioned type-I and type-II pyrethroids. For the 3 groups we computed weighted mean values of pyrethroid concentrations, each independent measurement being weighted with the number of corresponding persons. The mean values are 425.7, 56.1, and 958.9 mg pyrethroid/kg dust for the groups in the above order. After combining the two highly exposed groups into one new group with now 38 members and a mean pyrethroid concentration of 594.1 mg/kg, an increased frequency of health complaints was found as compared to the group exposed only to type-II pyrethroids.