Pyrethroids are important insecticides used in agriculture, forestry, horticulture, and in the home. In humans, they are rapidly metabolized and renally eliminated. In numerous studies, pyrethroid metabolites have been detected in urine after occupational exposure to insecticides. In this study, we used a new, reliable, easy, and sensitive analytical method to assess the internal pyrethroid exposure of an urban population without exposure to pyrethoids at home or at work (children and adults). A total of 1,177 persons took part in this investigation, including 331 children under 6 years of age and 247 children between 6 and 12 years of age. None of them reported exposure to pyrethroids at home or at work. Accordingly, the levels of permethrin found in household dust from their homes were lower than expected (median < limit of detection; 95th percentile, 4.8 mg/kg; maximum value, 19 mg/kg). Urine specimens were analyzed for cis-3-(2,2-dibromo-vinyl)-2,2-dimethylcyclo-propanecarboxylic acid (Br(2)CA), cis- and trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-carboxylic acid (cis-Cl(2)CA and trans-Cl(2)CA), and 4-fluoro-3-phenoxybenzoic acid (F-PBA) using a gas chromatographic method with mass-selective detection. The limit of detection for pyrethroid metabolites was between 0.1 and 0.2 microg/L. trans-Cl(2)CA was detected in 65% of the urine specimens tested, cis-Cl(2)CA was detected in 30%, and Br(2)CA and F-PBA were found in 19% and 16%, respectively, of the urine specimens. The urinary metabolite levels in children did not differ from those in adults, and there was no correlation between the levels of metabolites and indoor exposure to permethrin in household dust. Moreover, no seasonal correlations could be found. The 95th percentile levels in urine specimens were as follows: Br(2)CA, 0.30 microg/L; cis-Cl(2)CA, 0.51 microg/L; trans-Cl(2)CA, 1.43 microg/L; F-PBA, 0.27 microg/L. Background exposure to pyrethroids was found in the general population; it seems to be caused by the uptake of pyrethroids with the diet. This hypothesis needs to be tested in duplicate diet studies combined with biomonitoring. As long as representative data are lacking, however, the rounded 95th percentile values obtained in our study may be used as reference values for pyrethroid metabolites in urine samples from the population in Germany; 95th percentile values for children and adults are as follows: Br(2)CA, 0.3 microg/L; cis-Cl(2)CA, 0.5 microg/L; trans-Cl(2)CA, 1.5 microg/L; and F-PBA, 0.3 microg/L.

Concentration of urinary metabolites is frequently used for biomonitoring of exposure to synthetic pyrethroids, the class of non-persistent insecticides. These chemicals are currently widely used in agriculture, households and public health all over the world. Most of them are easily metabolized in mammals and in the form of metabolites excreted in urine. The concentration in urine is thus susceptible to significant variations, even within a short period of time. In this study, temporal changes in urinary metabolites concentrations in seven subjects (four females and three males aged: 24-71) were monitored over seven consecutive days. All urine voids (281 in total) were collected and analyzed for cis- and trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-carboxylic acid (cis-Cl2CA and trans-Cl2CA), cis-3-(2,2-dibromo-vinyl)-2,2-dimethylcyclo-propanecarboxylic acid (Br2CA) and 3-phenoxybenzoic acid (3PBA) using a validated gas chromatography ion-trap mass spectrometry method. Only 3PBA was detectable in more than 60% of the collected samples enabling a reliable statistical analysis. Statistical analysis was performed to evaluate temporal variability in urinary excretion of 3PBA over the studied period. Both volume and creatinine (Cre) adjusted concentrations were evaluated with the latter one being the most reliable. Among all samples, first morning voids (FMV) were the least reproducible (interclass correlation coefficient - ICC, 0.551 and 0.350 for volume and creatinine adjusted concentrations, respectively). Spot and reconstructed 24-h samples were more reproducible in this study. ICC values for ng/mL concentrations were 0.599 and 0.681 (in spot and 24-h samples) and 0.846 and 0.796 for μg/g creatinine concentrations. Results of this study suggest fairly constant short-term exposure to pyrethroids metabolized to 3PBA among the urban population in Poland. Creatinine adjustment should be performed in epidemiological studies and spot or multiple spot samples should be preferentially collected for the highest reliability of the measurement.

Few studies have detailed the prenatal pesticide exposure levels of women employed in or residing near large-scale agricultural industries. This study reports pesticide metabolite levels during and shortly after pregnancy in a pilot study of workers in Ecuador. Urine samples were collected for 16 rose workers and 10 nonagricultural workers enrolled into the study in early pregnancy. We measured six nonspecific organophosphatedialkylphosphate (DAP) pesticide metabolites, two alkylenebis-dithiocarbamate pesticide metabolites [ethylene thiourea (ETU) and propylene thiourea (PTU)], 3,5,6-trichloro-2-pyridinol (TCPy), malathion dicarboxylic acid, and two pyrethroid metabolites (2,2-dimethylcyclo propanecarboxylic acid and 3-phenooxybenzoic acid). We collected 141 urine samples (mean: 5.4 per woman). We observed high detection frequencies for five DAP metabolites and ETU, PTU, and TCPy. We report elevated levels of ETU in the entire sample (median 4.24 ng/mL, IQR 2.23, 7.18), suggesting other possible non-occupational pathways of exposure. We found no statistical differences in pesticide levels by current employment status, although the highest pesticide levels were among rose workers. We observed within-woman correlation in TCPy and PTU levels, but not in ETU or DAP levels. The present study is the first to characterize prenatal pesticide exposure levels among working women in Ecuador. Limitations include a small sample size and use of a convenience sample. Strengths include a longitudinal design and multiple urine samples per woman. Results provide an initial characterization of prenatal pesticide exposure levels and how these levels vary over pregnancy in a community impacted by agricultural industry and will inform further studies in the region.