New technologies and higher prices of raw materials have promoted the expansion of mining activity throughout the world; if not properly regulated, this activity can lead to contamination of the local and regional environment. The city of Cerro de Pasco is located close to a large open-pit mine and, in recent years, several reports have provided evidence of environmental contamination and related health problems. The aim of this paper is to evaluate the contamination in fluvial water, sediments and biological fluids from this area. The collective results show elevated metal and metalloid concentrations in rivers and sediments, especially in the areas downstream of the mine. For instance, Pb concentration in rivers downstream of the mine was 4.451 mg/L while it was 0.037 mg/L upstream of the mine. Sediments also show higher concentration of metals and metalloids in the areas under the influence of the mine. Concentrations of elements in human blood were measured in the population of Paragsha, a village close to the mine. Analysis of the blood samples revealed elevated levels of metals and metalloids, particularly Pb, Cr, Al, Ni and Mn. All of the studied population showed blood concentrations of Al, Cr and Ni higher than that recommended by the WHO. The high concentration of elements found in the blood of the population could be related to the high concentration in the surrounding water sources, but further study is required to determine the exact sources of exposure to these metals and metalloids.