The river water samples collected from the 41 sampling locations were grouped into five regions, with three samples collected from each sampling point (Table 1). Drinking water regulatory standards consider water safe for domestic use when it contains the same or a lower concentration of a substance, as stated by regulatory agencies, such as the US EPA, WHO, and NSDWQ. Metal contamination of water is a concern affecting the environment. Even at low concentrations, these metals can be hazardous owing to their non-biodegradable nature (Zaynab et al. 2022). According to the WHO regulatory standard, Cu, Pb, Cr, Ni, and Al have set concentration limits but no limits for Fe, Mn, and Zn concentrations because these metals are rarely found in drinking water samples and thus are not considered threats to human health. The most recent US EPA regulations do not specify concentration limits for Ni because its presence in US drinking water is infrequent. As a result, Ni has become unregulated, and its regulatory limits are being revised. All the chemical elements described in this study have regulatory limits in the NSDWQ. The allowable limits provided in the regulatory standards were compared with the concentration values of the PTMs detected in this study (Table 2). The potential toxicity of the metals, without a basis for comparison across all standards, was evaluated in depth using human health risk assessment. This was crucial for assessing the danger of exposure to prolonged dermal and oral consumption at the measured concentration levels. Metals, which are present in food and the environment in small amounts, are essential for good health; however, larger concentrations can be toxic or detrimental. Their harmful effects on the blood, liver, kidneys, brain, lungs, and other crucial organs can lead to energy depletion. Long-term exposure eventually causes the degeneration of physical, tissue, and neurological processes that mimic diseases such as multiple sclerosis, Parkinson's disease, muscle dystrophy, and Alzheimer's disease (Tenebe et al. 2019a; Zaynab et al. 2022).