Assessment of cancerous and non-cancerous health risks due to the presence of trihalomethane compounds in drinking water of Tehran's Pardis Water Treatment Plant

Document Type : Original Research

Authors
soodeh Homayoun 1
Amir arsellon Pardakhti 2
1 Faculty of EnvironmentUniversity of Tehran
2 دانشگاه تهران
Abstract
Chlorination, owing to its low cost and ease of application, remains one of the most prevalent disinfection strategies for treated drinking water, particularly in developing regions. Nevertheless, trihalomethanes (THMs), the principal class of chlorination by-products, have been implicated in both carcinogenic and non-carcinogenic adverse health outcomes. This study employs the RAIS framework to conduct a comprehensive health risk assessment of THMs in the effluent of the Pardis drinking-water treatment plant between 1396 and 1401, Separately for children and adults .

Carcinogenic risk was quantified by calculating the chronic daily intake (CDI) for ingestion, inhalation, and dermal exposure pathways,, then multiplied by the appropriate oral slope factors and inhalation unit risk coefficients. Non-carcinogenic risk was evaluated by computing the hazard index (HI), based on reference dose (RFD) and reference concentration (RFC) parameters, for both ingestion and inhalation scenarios

.Findings reveal that inhalation contributes approximately 90 % of the total lifetime carcinogenic. Dibromochloromethane and chloroform contributing the largest and the smallest share respectively.. In the non-carcinogenic assessment, the ingestion‐based HI values for both children and adults were below 1, confirming that the treated water meets acceptable safety criteria for consumption. Conversely, in four sampling events, the inhalation‐based HI for chloroform exceeded 1, signaling a potential non-cancer health concern associated with inhalation of chloroform during treated water use.

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