Spectroscopy Letters, 2026 (SCI-Expanded, Scopus)
Tigris River is one of the longest rivers in West Asia with a length of ∼1800 km and the surface waters of Şırnak are one of the most important tributaries contributing to this river system. This study aimed to determine the water quality characteristics and human health risks for adults and children through ingestion and dermal contact of the surface waters in Şırnak for the first time. Physico-chemical parameters and the concentrations of nine heavy metals (Al, Ba, Co, Cr, Fe, Mn, Mo, Ni, and Zn) were determined using the UV-VIS spectrometry and inductively coupled plasma mass spectrometry (ICP-MS), respectively. The weighted arithmetic water quality index (WAWQI), heavy metal pollution index (HPI), and metal index (MI) were preferred for general water quality and metal pollution levels. The potential human health risks or non-carcinogenic risks (NCR) which include hazard quotient (HQ) and hazard index (HI), and carcinogenic risk (CR) indices were used to assess the human health risks associated with heavy metals. Ba, Co, Mn, Mo, and Ni levels were above the acceptable values specified in the relevant regulations. WAWQI results showed that six stations (S1, S2, S3, S5, S6, and S8) were classified as “unsuitable for drinking,” two stations (S7, S9) as “very poor” and two stations (S4, S10) as “poor.” The overall HPI (mean 355.7) were classified as “totally unsuitable.” Human health risk assessment has shown an increased risk of NCR for adults and children exposed to surface waters through ingestion (HQ, HI > 1), while there is no threat through dermal contact (HQ, HI ˂ 1) for populations. Total CR values above 1.0 × 10−4 caused by Cr and Ni through ingestion indicate a high probability of increased cancer risk associated with human health for both groups. Consequently, the surface waters are not suitable for direct consumption as drinking water.