Widespread occurrence of pesticides in low-income housing

BACKGROUND: Low socioeconomic status (SES) residents living in social housing may have higher exposures to pesticides used indoors due to structural deficiencies, poor maintenance, and related factors. OBJECTIVE: To estimate exposure of residents in low-SES social housing built in the 1970s to legacy and current-use pesticides and to investigate factors related to exposures. METHODS: Twenty-eight particle-phase pesticides were measured in the indoor air of 46 units in seven social housing multi-unit residential buildings (MURBs) in Toronto, Canada. Portable air cleaners with high-efficiency media were deployed for 1 week in 2017; target analytes included organochlorines, organophosphates, pyrethroids/pyrethrins, and strobilurins. RESULTS: At least one pesticide was detected in 89% of units. Current-use pyrethroids had the highest detection frequencies and concentrations; pyrethrin I had the highest measured particle-phase concentration (32,000 pg/m³). Heptachlor (restricted in Canada in 1985) had the highest estimated maximum total (particle + gas) air concentration (443,000 pg/m³). Several pesticides (heptachlor, lindane, endosulfan I, chlorothalonil, allethrin, permethrin) were higher than reported in comparable low-income residences elsewhere. Tobacco smoking was significantly correlated with higher concentrations of five pesticides used on tobacco crops. Building-level distributions suggested contributions from pest eradication programs and/or resident use. IMPACT: Low-income social housing residents experienced widespread exposure to numerous pesticides, including long-banned organochlorines, current-use pyrethroids, strobilurins likely from treated building materials, and pesticides associated with tobacco. These results provide the first Canadian indoor air data for most of these pesticides and indicate prevalent multi-pesticide exposure in this vulnerable population.

Sara Vaezafshar, Jeffrey A. Siegel, Liisa Jantunen, Miriam L. Diamond