Using physiologically based pharmacokinetic models to estimate the health risk of mixtures of trihalomethanes from reclaimed water

• Published in: Journal of hazardous materials Vol. 285; pp. 190 - 198
• Main Authors: Niu, Zhiguang, Zang, Xue, Zhang, Ying
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 21.03.2015
• Subjects: Acceptability; Air Pollutants - pharmacokinetics; Air Pollutants - toxicity; Carcinogens; Computer Simulation; Estimates; Flushing; Health; Human risk assessment; Humans; Inhalation Exposure - adverse effects; Inhalation Exposure - analysis; Mixture exposure; Models, Biological; Monte Carlo Method; Neoplasms; PBPK model; Reclaimed water; Recycling; Risk; Risk Assessment; Risk levels; Sensitivity analysis; Toilet Facilities; Trihalomethanes; Trihalomethanes - pharmacokinetics; Trihalomethanes - toxicity; Water Pollutants, Chemical - pharmacokinetics; Water Pollutants, Chemical - toxicity; China, People's Rep; China, People's Rep., Tianjin; Mixture exposure; Human risk assessment; Reclaimed water; Trihalomethanes; PBPK model
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2014.11.051

[Display omitted] •We conducted a mixture health risk of THMs in reclaimed water for toilet flushing.•The probability of HIinteraction-based exceeding the acceptable level (1) is 22.97%.•The carcinogenic risk of mixture exceeds the acceptable level (1×10−6).•Exposure to the mixture of THMs in reclaimed water should be paid more attention.•BDCM concentration was the most influential variable for the outcome of risk. To estimate the health risk of mixture of trihalomethanes (THMs) from reclaimed water during toilet flushing, the interaction-based Hazard Index (HIinteraction-based) and the mixture carcinogenic risk (CRM) according to tissue dose were conducted through the integrated use of both the exposure concentrations model and the physiologically based pharmacokinetic (PBPK) model of THMs. Monte Carlo simulations were employed to implement the probabilistic risk analysis and sensitivity analysis. Nine samples were analyzed, which were collected from J Water Reclamation Plant (JWRP) in Tianjin of China. The results indicated that the mean HIinteraction-based (=0.85) was lower than the acceptable risk level (=1). The probability that the HIinteraction-based exceeded the acceptable risk level is 22.97%. For carcinogenic risk, the CRM ranges from 9.41×10−7 to 3.54×10−5, with a mean of 5.49×10−6. Moreover, the probability of exceeding the acceptable risk level (1×10−6) is near 100%. And the values of HIinteraction-based from sample no. 1, 5, and 7 exceeded 1, while the values of CRM for all samples exceeded 1×10−6. Consequently, the reclaimed water used for flushing toilets should be paid more attention, though non-carcinogenic effect is relatively small. Furthermore, the concentrations of DBCM had greater impact on both the carcinogenic and non-carcinogenic risk based on sensitivity analysis.