A comparative study of cadmium levels in blood from exposed populations in an industrial area of the Amazon, Brazil

Chemical pollution from industrial sources is one of the main problems affecting the environment. In urban areas, the emission of toxic gases and particulates to the atmosphere can damage human health. Cadmium (Cd) is one of the most ecotoxic metals among these pollutants, even at low concentrations. In this study, environmental exposure to Cd was evaluated from the Cd blood levels (CdB) of the human populations living in two Amazonian districts. The first was Bairro Industrial (BIN), which is located next to the industrial complex in Barcarena City, while the second was Vila do Beja (VBJ), a control group located in the farthest area from industrial activities in Abaetetuba City. Sectional and comparative studies were applied for both districts. Sampling (N = 469) occurred in 2012 and 2013. Gender, age, residence time, drinking water source, alcohol consumption, and smoking were used as independent variables. CdB levels were analyzed by induced coupled plasma mass spectrometry (ICP-MS). In BIN, geometric mean and median CdB levels were 0.27 and 0.43 μg∙L^-1, respectively (range: ≤0.03-17.49 μg∙L^-1), while in VBJ these were 0.19 and 0.23 μg∙L^-1 (range: ≤0.03-2.38 μg∙L^-1). The higher CdB concentration in the blood of people from BIN was similar to levels previously found in people living near other industrial areas, and showed that the BIN residents were more exposed to Cd pollution. The studies showed the need for surveillance actions to evaluate possible routes of exposure, avoiding the future worsening of the health of the population living next to industrial areas in the Amazon.