The occurrence of pesticides intended for non-agricultural use was investigated in 206 dust samples drawn from vacuum-cleaner bags from residential flats in Italy. The multi-residue analysis targeted on 95 different active principles was performed with UPLC-MS/MS, with a Limit of Quantification (LOQ) of 0.008 μg/g dry weight. The results indicated the presence of imidacloprid (IMI) and carbendazim (CARB) in 30% and 26% of the samples, with a mean and P95 concentration between 1.6 and 39 and between 0.08 and 4.9 μg/g, respectively. Combined presence of two biocides was noted in 19.4% samples, of three biocides in 9.2% samples, of four biocides in 3.4% samples, and of five and six biocides in 0.5% and 1% samples, respectively. According to the estimated dust intake in infants/toddlers aged 6-24 months (16-100 mg d-1) and cats (200 mg d-1), it was possible to obtain risk characterization with respect to the Acceptable Daily Intake (ADI) for IMI of 0.060 mg/kg body weight (bw) proposed by the European Food Safety Authority (EFSA) and the chronic Population Adjusted Dose (cPAD) of 0.019 mg/kg bw d-1 by US-EPA. Under the worst-case scenario, the presence of IMI in dust indicates potential exceedance of the cPAD in kittens, to be considered as sentinel also accounting for combined exposure. This study highlights the relevance of consumer empowerment about the responsible use of pesticides as biocidal products in indoor environment.

The presence of the insecticide Fipronil and its main products of toxicological relevance, namely Sulfone and Desulfinyl, was assessed in 161 residential house dust samples in the absence (N = 101) and presence (N = 60) of cats and dogs in Italy. High-resolution mass spectrometry analysis revealed a significant difference (p < 0.001) in the dust contamination in the presence of pets (median: 467 vs. 24 ng/g dry weight), even if the highest value was found in the absence of pets (82,069 vs. 67,799 ng/g dry weight). Fipronil intake estimates from dust in toddlers, computed according to US-EPA and EU-ECHA guidelines, ranged from 333 to 556 and from 20 to 34 ng/kg per day for acute and chronic scenario, respectively. Dust seemed not able itself to lead to Fipronil overexposure with respect to acute and chronic toxicity health-based guidance values. Kittens were potentially overexposed to Fipronil under both acute (26,076 ng/kg per day) and chronic (1,633 ng/kg per day) scenarios. The mild symptomatology associated with acute intoxication could possibly determine case underreporting within pharmacosurveillance schemes. Its administration was estimated in 7.3–9.7 tons per year. Such a range suggests its prudent use under strict veterinary control to prevent pest resistance and ecotoxicological outcomes.