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

Article excerpt

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 woman 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 [lesser than or equal to] 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.

KEY WORDS: indoor air, insecticides, pregnancy, residential. Environ Health Perspect 116:1681-1688 (2008). doi: 10.1289/ehp.11367 available via http://dx.doi.org/[Online 15 August 2008]

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Understanding the pattern of residential pesticide use and exposure is critical to identifying risks and devising prevention strategies. Widespread residential pesticide use among urban communities in the United States has resulted in ubiquitous, low-level exposure to pesticides. Research documenting the potential for development and reproductive toxicity resulting from low levels of pesticides led to stringent and uniform pesticide regulations focusing on the safety and protection of infants and children (National Research Council 1993). This legislation, the Food Quality Protection Act (FQPA; 1996), profoundly affected the pattern of residential pesticide use in the United States. For example, in 2000-2001, the U.S. Environmental Protection Agency (EPA) withdraw the residential registrations for two commonly applied pesticides, chlopyrifos and diazinon (U.S. EPA 2000, 2001). Before these regulations, chlorpyrifos and diazinon were the most widely used insecticides for residential pest control in the United States, including among inner-city communities in New York City (Their et al. 1998). Subsequent studies have demonstrated the 2000-2001 EPA regulations nearly eliminated the sale of both chlorpyrifos and diazinon in these communities (Carlton et al. 2004). Data from the Columbia Center for Children's Environmental Health (CCCEH) also show a highly significant decrease in levels of chlorpyrifos and diazinon in environmental and biologic samples collected between 1999 and 2001 from New York City African Americans and Dominicans during pregnancy, although the mothers reported no change in their use of pesticides. These initial findings indicated that the degree of pesticide use had not changed, but the mix of active ingredients contained in pesticide formulations had changed. …