Changes in pest infestation levels, self-reported pesticide use, and permethrin exposure during pregnancy after the 2000-2001 U.S. Environmental Protection Agency restriction of organophosphates

Abstract

Background: Widespread residential pesticide use throughout the United States has resulted in ubiquitous, low-level pesticide exposure. The mix of active pesticide ingredients is changing in response to 2000-2001 regulations restricting use of the organophosphorus insecticides chlorpyrifos and diazinon.

Objectives: We aimed to determine the impact of U.S. Environmental Protection Agency regulations on pest infestation levels, pesticide use, and pesticides measured in indoor air samples.

Methodology: 511 pregnant women from inner-city New York were enrolled between 2000 and 2006. Permethrin, a pyrethroid insecticide; piperonyl butoxide (PBO), a pyrethroid synergist; chlorpyrifos; and diazinon were measured in 48-hr prenatal personal air samples. Data on pest infestation and pesticide use were collected via questionnaire.

Results: Eighty-eight percent of women reported using pesticides during pregnancy; 55% reported using higher-exposure pesticide applications (spray cans, pest bombs and/or professional pesticide applicators). Self-reported pest sightings and use of higher-exposure applications increased significantly after the regulations were implemented (p < 0.001). PBO, cis-, and trans-permethrin were detected in 75, 19, and 18% of personal air samples, respectively. Detection frequencies of PBO and cis- and trans-permethrin increased significantly over time (p < 0.05 controlling for potential confounders). Levels and/or detection frequencies of these compounds were significantly higher among mothers reporting use of high exposure pesticide applications (p < or = 0.05). Chlorpyrifos and diazinon levels decreased significantly over time (p < 0.001).

Conclusion: In this cohort, pest infestations, use of pesticides, and use of permethrin appear to increase after the residential restriction of organophosphorus insecticides. This is one of the first studies to document widespread residential exposure to PBO.

Keywords: indoor air; insecticides; pregnancy; residential.

Figure 1

Reported cockroaches and residential pesticide use among pregnant African-American and Dominican women enrolled from prenatal clinics located in Northern Manhattan and the South Bronx between 2000 and 2006. Y/N, yes, no. Data were gathered from questionnaires administered during the 32nd week of pregnancy. (A) Subjects (%) reporting cockroaches in the home during pregnancy. (B) Subjects (%) reporting pesticide use in the home during pregnancy over time.

Figure 2

cis-and trans-Permethrin in 48-hr personal air samples collected from pregnant African-American and Dominican subjects enrolled from prenatal clinics located in Northern Manhattan and the South Bronx between 2000 and 2006.

Figure 3

Insecticides measured in personal air samples and reported pesticide use. Personal air samples (48-hr) collected during the third trimester of pregnancy among women reporting that no pest control methods were used as well as the three following groups: use of lower-exposure pesticide applications only (non-spray); use of spray cans and pest bombs (with or without the use of the lower-exposure pesticide applications); and use of spray by a professional pesticide applicator (with or without the use of the other methods). Analysis included 309 women with air monitoring results for whom questionnaire data on use of pest control methods in the home was also collected. (A) Concentration of PBO (ng/m³). Prevalence of detection (%) of cis-permethrin (B) and trans-permethrin (C) in 48-hr personal air among different pesticide use categories. *Kruskal–Wallis, p < 0.001. **Chi-square test, p < 0.05.