2. Material andmethods
2.1. Sample size
Single dust samples were collected from 105 homes of families
participating in the MICASA study. Of the 105 available samples, 70
had sufficient quantities of dust after sieving for instrumental analysis
of pyrethroids. Of those, therewere 55 samples selected,with relatively
higher selection probabilities assigned to those households with
elevated levels of the common pyrethroid urinary metabolite 3-
phenoxybenzoic acid (3PBA) in urine samples collected from the
children in order to increase the probability of having detectable levels
of pyrethroids in the dust. Data on the 55 dust samples that were analyzed
are presented here. Data on urine concentrationswill be reported
in a future publication