The influence of unsustainable economic activities in developing countries and especially in Colombia, such as illegal mining and the petrochemical industry, among others, use heavy metals in several of their industrial processes and when they do not have an adequate treatment of their residues can be deposited in water sources or released into the environment, compromising the survival and well-being of human beings. The Nechí River, the main tributary in the lower part of the Cauca River in Colombia, receives a wide variety of wastes throughout its route that contain a range of chemical compounds derived mostly from alluvial mining and agricultural products that cause water pollution. The disposal of some heavy metals such as Cadmium and Nickel in quantities above the values allowed in living beings have a great impact on the public health of the inhabitants in the riverside areas of this water tributary. Objective: To determine the exposure to heavy metals (Cadmium and Nickel) in residents of the municipality of Nechí (Antioquia). Methodology: An observational, descriptive study with an analytical component with non-probabilistic convenience sampling was carried out in a group of 104 people who are environmentally exposed to cadmium and nickel in the municipality of Nechí. Measurements of these metals were carried out in biological samples (hair) and in environmental samples (water and fish). Additionally, a socio-demographic characterization was made and the work history of environmental exposure and habits in the study population were investigated. Measures of central tendency and dispersion were calculated and relationships were sought between the variables included in the study. Results: 104 individuals were evaluated whose average age was 48 ± 14 years with an age range between 21 and 83 years, of which 25 (24%) were women and 79 (76%) were men. 41.3% reported working in artisanal gold mining, of which 100% (43) used mercury in their work, the same as 6.9% (3) reported the use of cyanide. The average time they declared having worked with heavy metals was 226.8 ± 173.5 months. Only 9.3% (4) of the mining workers reported the use of a work uniform for the activity, 90.7% (39) reported the use of daily clothes at work, of which 36 (83, 7%) referred to changing clothes when they got home. The determination of the levels of Cadmium and Nickel in hair was carried out in 84 individuals (80.7%), evidencing an average concentration of nickel of 0.410(µg/g) ± 0.403(µg/g) and of cadmium 0.070(µg/ g) ± 0.087(µg/g). It was evidenced that 64 individuals presented levels above the reference values for cadmium and for nickel 45 of them presented values above the allowed. Conclusion: The study population does not have occupational exposure to cadmium and/or nickel, since its main source of economic resources is artisanal gold mining; however, detectable values of both metals were found in biological samples, possibly due to the environmental contamination with said heavy metals, since levels in water and fish were also reported.
