Assessment of physico and chemical properties and quality indices of trace metals of surface waters in the shallows of the city of Bafoussam (Central -Africa): Implications for health risks and suitability for irrigation.

Abstract

Water pollution is a major problem worldwide, as water is a natural resource essential to life. Water quality is deteriorating as a result of increasing demographic and human activities. This study aimed to assess the level of trace metal element contamination in the shallow waters of Bafoussam, focusing on the impact of human activities on their physicochemical and ionic composition and their suitability for irrigation (West Cameroon). Thirty surface water samples were collected from urban water bodies in Bafoussam to analyze major ions (Na⁺, Ca²⁺, K⁺, Mg²⁺, NO₃⁻, Cl⁻, SO₄²⁻, F⁻) and trace metals (Fe, Al, Sr, Ba, Mn, Co, V, Zn). The average physicochemical properties are as follows: CE (291 μS/cm), pH (7.37), Eh (409.70 mV), TDS (185 mg/L), and DO (0.52 mg/L). The decreasing distribution of mean values for major ions (in mg/L) is as follows: Na²⁺ (17.17) > Ca²⁺ (12.15) > K⁺ (6.31) > Mg²⁺ (3.90) and NO₃^- (18.42) > Cl^- (15.94) > SO₄^2- (3.78) > F^- (0.11). The distribution of metals in descending order is as follows: Sr (86.32) > Fe (61.69) > Al (58.43) > Ba (31.25) > Mn (18.55) > Zn (3.54) > V (1.01) > Co (0.19). These elements have values relatively higher than the norms prescribed by WHO, which can lead to health problems. Pollution index values show that water at all sites is pure (0.3 < IEML < 1), except P9 and P29, which show high toxicity (IMP > 100). A high non-carcinogenic risk (HI > 1) is observed in samples P29 and P30. The results indicate that irrigation with water from sampling points P29 and P30 can reduce crop production rates.