Within- and Between-Home Variability in Indoor-Air Insecticide Levels during Pregnancy among an Inner-City Cohort from New York City

BACKGROUND Residential insecticide use is widespread in the United States, but few data are available on the persistence and variability in levels in the indoor environment. OBJECTIVE The study aim was to assess within- and between-home variability in indoor-air insecticides over the final 2 months of pregnancy among a cohort of African-American and Dominican women from New York City. METHODS Women not employed outside the home were enrolled between February 2001 and May 2004 (n = 102); 9 insecticides and an adjuvant were measured in 48-hr personal air samples and 2-week integrated indoor air samples collected sequentially for 7.0 +/- 2.3 weeks (n = 337 air samples). RESULTS Sixty-one percent of the women reported using pest control during the air samplings. Chlorpyrifos, diazinon, and propoxur were detected in 99-100% of personal and indoor samples (range, 0.4-641 ng/m(3)). Piperonyl butoxide (a pyrethroid adjuvant) was detected in 45.5-68.5% (0.2-608 ng/m(3)). There was little within-home variability and no significant difference in air concentrations within homes over time (p > or = 0.2); between-home variability accounted for 88% of the variance in the indoor air levels of propoxur, 92% in chlorpyrifos, 94% in diazinon, and 62% in piperonyl butoxide (p < 0.001). Indoor and maternal personal air insecticide levels were highly correlated (r = 0.7-0.9, p < 0.001). Diazinon and chlorpyrifos levels declined 5-fold between 2001 and 2004 but were detected in all homes 1.5 and 2.5 years, respectively, after the U.S. Environmental Protection Agency ban on their residential use. CONCLUSION Results showed that the insecticides were persistent in the home with little variability in air concentrations over the 2 months and contributed to chronic maternal inhalation exposures during pregnancy.