Potential cancer risks of metals/metalloids and radionuclides through the intake of food crops grown around the mining area

Background

Food crop consumption is one of the primary routes through which the environment is polluted with radionuclides, metals, and metalloids. In recent years, the negative impacts of metals, metalloids, and radionuclides on crop quality via the food-human system have jeopardized both human health and food security. Because some metals, metalloids, and radionuclides are persistent and non-biodegradable, they build up in the human body's essential organs, causing a variety of serious health issues, including cancer. It is therefore absolutely essential to evaluate the potential cancer risks of radionuclides as well as metals and metalloids in the food crops consumed in the study area to avoid negative health consequences.

Objective

The aim of this study was to assess the potential cancer risks of metals and metalloids (As, Cd, Cr, and Pb) and Radionuclides (U-238, Th-232, and K-40) via consumption of food crops cultivated around the Riruwai mining area, northeastern Nigeria.

Methodology

Thirty-three (33) food crops (15 vegetables and 18 cereal crops) were collected directly from the farmlands in the study area. The concentrations of radionuclides, metals, and metalloid in each food crop were assessed using a microwave-plasma atomic emission spectrometry (MP-AES) and a high-purity germanium (HPGe) gamma-ray spectrometer, respectively. The measured concentrations of radionuclides, metals, and metalloid were used to calculate their lifetime cancer risks (LTCRs).

Results

The findings of the study revealed that the concentrations of As, Cd, Cr, and Pb in all the investigated food crops were above the threshold limits, while lower activity concentrations in all the investigated food crops below the world average standard were observed in U-238, Th-232, and K-40. LTCRs of all the individual metal and metalloid as well as radionuclide in each food crop were determined to be below the global threshold limits, indicating no likelihood of cancer risk from consuming the food crops. However, it was discovered that the total cumulative LTCRs of all the metals and metalloid in all food crops combined were 2.51E-04, which was over twofold the acceptable limit of 1.00E-04

Conclusion

The individual metal, metalloid, and radionuclide LTCRs in each food crop were found to be below global threshold limits, indicating no cancer risk from consumption. However, the cumulative LTCRs of all the metals and metalloid in all food crops were found to exceed the acceptable level, which requires proper monitoring and government intervention. Cancer risk is influenced by factors beyond food consumption, such as alcohol consumption, heredity, and air pollution, so multidimensional studies are needed before making a final decision on cancer risks in the study area.