An exposome-wide approach of organophosphate flame retardants in the Taiwanese population: Parent-child pairs interaction and potential health risk

BACKGROUND AND AIM: Organophosphate flame retardants (OPFRs) are substitutes for polybrominated diphenyl ethers and are widely used as flame retardants and plasticizers in the commercial products. Human exposure to OPFRs has been raised the great concern due to associations with adverse health effects, especially in susceptible populations. In this study, total body burden and interaction of four exposure pathways of OPFRs were investigated for Parent-child pairs. METHOD: 11 OPFRs of residential environmental matrices (air, dust and skin wipe), selected food samples and the corresponding urinary metabolites were measured for 89 healthy children and their paired parents. The Average daily dose of adults and children through indoor and outdoor inhalation exposure, house dust ingestion and dermal exposure were estimated respectively. The total daily intake of OPFRs was back estimated using urinary OPFRs metabolites. The correlations between the OPFRs in four major pathways as well as the external and internal dose were explored. RESULTS: The average daily exposure dose of Σ11OPFRs for adults and children via inhalation of indoor air (5.08×10-4 to 9.17×10-2 µg/kg bw/day), inhalation of outdoor air (2.12×10-4 to 1.78×10-2 µg/kg bw/day), ingestion of dust (1.11×10-5 to 8.45×10-3 µg/kg bw/day), dermal sorption (7.50×10-4 to 1.05 µg/kg bw/day) and ingestion of foods (2.09×10-2 to 4.79×10-1 µg/kg bw/day) were estimated respectively, which suggested that dermal sorption is an important source of human exposure to OPFRs. Tributoxyethyl phosphate and Tri(1-chloro-2-propyl) phosphate showed the most abundant in all exposure pathways. The positive correlations of external (air inhalation and dermal sorption) and internal intake were found in TDCIPP and TBP. CONCLUSIONS: Dermal absorption is the main exposure pathway of OPFRs but inhalation of indoor/outdoor air and ingestion of house dust cannot be ignored. Exposure to OPFRs in different age and sex groups in Taiwan posed no potential health risk through all exposure pathways.