Pesticide residues in bedroom dust: occurrence, determinants, and health risk assessment

Settled dust in bedrooms-spaces where individuals spend substantial time-can act as a reservoir for pesticide residues. This study analyzed floor dust from 112 bedrooms in Belgium and the Netherlands to assess pesticide levels in relation to two factors: proximity to agricultural fields and the presence of pets, alongside a cumulative health risk assessment. Homes were located either within 250 m of agricultural fields (55 with pets, 49 without) or in urban/peri-urban areas more than 500 m from fields (10 homes; 5 with pets, 5 without), serving as controls. Using liquid and gas chromatography-mass spectrometry, 494 pesticides were targeted, and determinants of occurrence were studied via logistic regression. We detected 122 residues (61 approved, 59 non-approved). Pesticides were ubiquitous: over 98 % of homes had at least one, and 95 % contained five or more. The most common mixture-dichloran, permethrin, 2-phenylphenol, DEET, and propiconazole-was found in 33 % of samples. Households near agricultural land tended to show higher modeled detection probabilities for multiple pesticides, while homes with pets showed elevated levels of fipronil and permethrin. Both compounds are banned for agricultural use in the EU but remain authorized as biocides. A worst-case cumulative risk assessment indicated that most organ systems had hazard index (HI) values below 1, suggesting low overall health risk. The neurotoxicity threshold (HI = 1.45) was exceeded in one household with exceptionally high fipronil concentrations, illustrating a potential worst-case scenario rather than a population-wide effect. The frequent detection of legacy pesticides underscores their persistence indoors and highlights the challenge of mitigating long-term exposure. Findings suggest the need for more comprehensive exposure assessments and targeted strategies to mitigate pesticide contamination in residential environments.