Occurrence and Potential Health Risks Due to Trihalomethanes and Microplastics in Bottled Water

In recent years, microplastics (MPs) and trihalomethanes (THMs) in drinking water have attracted widespread concern. In this study, bottled water (BW) samples from India were evaluated for both THMs and MPs, and their health risks were assessed. Forty-four samples of BW of 18 brands were tested and THMs were detected in all 44 BW samples tested. At least 1 THM was quantified in 20 BW samples, and all 4 THMs were found in 7 BW samples. The concentrations of chloroform (CHCl3), bromodichloromethane (CHBrCl2), dibromochloromethane (CHBr2Cl), and bromoform (CHBr3) were in the range of 234.8 ± 711.9, 243.3 ± 734.4, 162.7 ± 540.6, and 446.4 ± 1,042.3 ng/L, respectively. The total measured THM concentration ranged from 0.033 to 12.27 μg/L. MP particles ranged in size from 1 to 30 μm, were found in all tested samples, and were identified as either polypropylene or polyethylene terephthalate. The count and corresponding weight of MPs ranged between 20 ± 5 to 127 ± 35 particles/L and 56 ± 14 to 355.6 ± 98 mg/L, respectively. Monte Carlo simulations (50,000 iterations) were done to estimate the chronic daily intakes (CDI) of THMs and MPs, as well as the THM-associated cancer risk (CR) through ingestion of BW. The average CDI of THMs was 1.64 × 10−4 ± 6.29 × 10−5 mg/(kg·day) and the associated CR ranged from a minimum of 4.89 × 10−7 to a maximum CR of 1.9 × 10−5. The CDI for MPs was 7 ± 2.61 mg/(kg·day), resulting in a yearly intake of 153.3 g. THMs were detected in BW samples even though they had not been chlorinated. Overall, the quantitative information provided through this study has major implications for the consumption of BW with plastic packaging.