Temporospatial variation and health risk assessment of trihalomethanes (THMs) in drinking water (northwest Iran)

Abstract

Trihalomethanes (THMs) are one of the most common classes of disinfection by-products. In this study. the temporo-spatial trends and health risks due to exposure to THMs in the Tabriz water distribution network were investigated. THMs series were analysed using gas chromatography equipped with electron capture detector. The non-carcinogenic and carcinogenic risks due to exposure to THMs were calculated using Monte Carlo simulations.Mean concentrations of THMs in January (winter) and June (summer) were 10.2 ± 9.3 µg/l and 252 ± 185.9 µg/l, respectively. More than 80% of THMs identified were bromodichloromethan.The mean values of lifetime cancer risks (LTCR) from THMs were calculated as 4.23E-06 and 2.38E-04 for winter and summer, respectively. This study showed that there were noticeable levels of THMs in Tabriz's distribution network water, especially in the centre of the city. Although non-carcinogenic risks from THMs were below permissible recommended levels, carcinogenic risks likely remain due to high levels of THMs in some locations.

Exposure and carcinogenic risk assessment of trihalomethanes (THMs) for water supply consumers in Addis Ababa, Ethiopia

“…In addition, inhalation was the second most common route of exposure in this work. A similar finding was also reported in other studies in which inhalation were the major route of exposure to THMs [52] , [54] , [55] . A recent related study also signified that the utilization of hot water for showering was a risk factor for colorectal cancer that might be due to exposure to THMs, as the volatility of the THMs is higher in hot water [6] , [56] .…”

Probabilistic Approach For Health Hazard Assessment of Trihalomethanes Through Successive Showering Events

“…They observed similar patterns in the incremental increases of CDIs as well as HIs and cancer risk for up to 9 showering events, exponential increase in the beginning, and slower rate towards the 9th event. Generally, in the studies, the HI of inhalation is left unattended either because the inhalation-CDI is less than ingestion and dermal CDIs or because of the lack of RfD values for inhalation risk (Kujlu et al, 2020;Kumari and Gupta, 2018;Mosaferi et al, 2021). However, assessing the inhalation-HI along with the other two gives a clear idea about how much it differs from them and can be used in future studies for inclusion in the database.…”

“…Computational human exposure models for THM risk assessment which are generally practiced are modi cations to the USEPA method based on the water as well as study population parameters. A deterministic approach to such models fails to address the variability in the parameters and hence a probabilistic method by considering the variabilities of input parameters is recommended (USEPA, 2019) and is lately being used in THM risk assessment (Chowdhury, 2013;Mosaferi et al, 2021).…”

Probabilistic approach for health hazard assessment of trihalomethanes through successive showering events

“…Where i represents 4 THM species (TCM-TBM) and j represents 3 exposure routes (oral, dermal, and inhalation). Hazard quotient (HQ) and hazard index (HI) were assessed using the following equations (Mosaferi et al, 2021).…”