No abstract

Numerous studies have described environmental exposure of humans to heavy metals in African populations. Little is known about the exposure to heavy metal toxins from processed or unprocessed foods consumed in Africa, and no data exists on the food concentrations of arsenic and chromium, which are potential carcinogens and systemic toxicants. This study determined the concentrations of arsenic and chromium in beverages and fruit drinks commonly sold in Nigeria. Fifty samples of commonly consumed canned and non-canned beverages (imported and locally manufactured) purchased in Nigeria were digested in nitric acid and analyzed by atomic absorption spectrophotometry (AAS). 33.3% of the canned beverages had arsenic levels that exceeded the maximum contaminant level (MCL) of 0.01 mg/L set by U.S. EPA while 55.2% of non-canned beverages had their arsenic levels exceeding the MCL. The arsenic concentrations ranged from 0.003 to 0.161 mg/L for the canned and 0.002 to 0.261 mg/l for the non-canned beverages. Whereas 68.9% of the non-canned beverages showed chromium levels that exceeded the US EPA’s MCL of 0.10 mg/L, 76.2% of the canned beverages had chromium levels that were greater than the MCL. The concentration range of total chromium in the canned beverages was 0.04 to 0.59 mg/L and 0.01 to 0.55 mg/L for the non-canned beverages. The sources of arsenic and chromium in the commercially available beverages are unclear and merit further investigation. This preliminary study highlights the need to study the toxicological implications of chronic low-level exposure to heavy metals from African markets.

Iron, manganese and nickel were analyzed using Atomic Absorption Spectrophotometry (AAS) in 50 beverages sold in Nigeria. Iron levels ranged from 0.020-2.460 mg/l for canned and 0.020-2.090 mg/l for non-canned beverages. In 95.24% of the canned beverages, iron levels exceeded the maximum contaminant level (MCL) of 0.30 mg/l, while 75.86% of the non-canned beverages had iron levels exceeding the MCL. Manganese levels ranged from 0.001-0.730 mg/l for canned and 0.001-0.209 mg/l for noncanned beverages. 42.86% of the canned beverages had manganese levels that exceeded MCL of 0.05 mg/l, while 51.72% of the non-canned beverages had manganese levels exceeding the MCL. Nickel levels ranged from 0.013-0.993 mg/l for the canned and 0.009-0.938 mg/l for non-canned beverages. 80.95% of the canned beverages had nickel levels that exceeded MCL of 0.10 mg/l while 72.41% of the noncanned beverages had nickel levels exceeding the MCL. The sources of these contaminants are unclear and merit further investigation.