Organic UV filters in indoor dust and human urine: A study of characteristics, sources, associations and human exposure

Organic ultraviolet (UV) filters are emerging contaminants that may pose health risks to humans. We measured the concentrations of four commonly used organic UV filters (2-hydroxy-4-methoxybenzophenone (BP-3), 4-methylbenzylidene camphor (4-MBC), homosalate (HMS), and octocrylene (OC)) in 203 indoor dust samples and 98 human urine samples from households in eastern China. The total concentrations of the four organic UV filters ranged from 66.6–56,123.0 ng g −1 in indoor dust and 1.17–52.15 μg g −1 (creatinine-adjusted concentration (Cr)) in urine. BP-3 was the most abundant organic UV filter in the urine samples (median concentration: 1.89 μg g −1 Cr), while OC was the most abundant in the indoor dust samples (median concentration: 325.7 ng g −1 ). No significant correlations were found between organic UV filter concentrations in paired urine and dust samples, but the concentrations of UV filters in the indoor dust samples were positively correlated with family income and sunscreen use. The sources of the organic UV filters in the indoor dust samples differed based on the geographical location of the tested household. The fraction of human exposure to organic UV filters that resulted from ingestion or dermal absorption of indoor dust was close to 8%.