Assessment of Dietary Exposure and Health Risk to Multiple Heavy Metals amongst Some Workers in Yaoundé, Cameroon

This study reports on the dietary exposure of people in Yaoundé, Cameroon to heavy metals: lead (Pb), cadmium (Cd), mercury (Hg), copper (Cu) and zinc (Zn). One hundred and fifty table-ready food, water and soft drink samples were collected from households and street restaurants in Yaoundé and analyzed for heavy metals contents using atomic absorption spectrophotometer. Lead (93%, range 0.019-1.77 ppm), Cd (70%, range 0.01-4.68 ppm), Hg (81%, range 0.03-10.56 ppm), Cu (90%, range 0.004-40.32 ppm) and Zn (87%, range 0.014-2,447.04 ppm) were detected in studied samples. Maximum level of each metal exceeded its corresponding European Commissions legislative limits. Samples from street restaurants were most tainted with heavy metals. The highest average daily intakes (ADIs) of Pb (0.96 mg/day) and Hg (1.84 mg/day) were through tap water, while Cd (1.15 mg/day), Cu (5.42 mg/day) and Zn (601.6 mg/day) were through rice/peanut sauce mixed food. The ADI for Cd and Hg was each higher than its respective PTDI (provisional tolerable daily intake) as defined by JECFA (Joint FAO/WHO Expert Committee on Food Additives) and EVM (Expert Group on Vitamins and Minerals). The estimated average daily exposure dose of each detected metal significantly (p = 0.001) exceeded its corresponding PTDI. However, the health risk index was < 1 for all studied samples and it was found to be safe, indicating there is a relative absence of health risks associated with the ingestion of contaminated foods, water and soft drinks. Notwithstanding, the detected levels and ADI being higher than legislative limits and PTDI respectively speculates need for awareness raising towards reducing exposure levels to heavy metals in Cameroon.