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Background.Elevated arsenic and trace metal contamination of the terrestrial food chain represents one of the most significant environmental risk exposures for human populations in developing countries. Metalloid and metal contamination in horticultural crop produce such as fruit is a public health concern in Nigeria. Local fruits are cheap sources of vitamins and minerals for the resident population and pose an important dietary threat of metal(loid) toxicity through consumption.Objectives.Market basket investigation of five locally grown (guava, pineapple, orange, and pawpaw) and imported (apple) fruits was conducted to measure the total concentrations of arsenic (As), mercury (Hg), copper (Cu), and lead (Pb) present in these fruits from southeastern Nigeria (Awka, Anambra).Methods.Fruits were analyzed for As and the three metals using atomic absorption spectrophotometry. Moisture content of fruits was determined and used to transform metal concentrations in dry weight to wet weight and compared to Codex food grade standards and assorted (sub)tropical fruits, edible and inedible peels.Results.The mean ± standard deviation of elemental concentrations in dry weight ranged from 20.0±0.71–96.84±0.00 μg g−1 for As, 0.02±0.02 – 0.89±0.33 μg g−1 for Hg, 0.11±0.01 - 0.18±0.40 μg g−1 for Cu, and <0.001 – 0.03±0.05 μg g−1 for Pb. The As concentrations (wet weight) in fruits were ~32–166 orders of magnitude higher than Codex Alimentarius Commission (Codex) maximum As food grade levels. Guava and apple methyl Hg concentrations were ~6–~1 orders of magnitude higher than Codex maximum levels, while the content of Cu and Pb in fruits were within acceptable standard limits.Conclusions.The significant concentrations of As and Hg in the examined fruits indicate a potential public health threat. Efforts are needed to initiate and sustain continued monitoring of trace elements in fruits and food sold to consumers due to variation in contaminating sources to ensure food safety. Although a great deal of information exists on Hg toxicity, research on metalloids such as As remains limited in Nigeria and no reliable guidelines exist. Further research is recommended to determine the ecotoxicity of As in Nigeria.

Aim: Contamination of the Anambra River with heavy metals (arsenic, As; cadmium, Cd; chromium, Cr; copper, Cu; lead, Pb; nickel, Ni; and zinc, Zn) was examined in two preponderant fish species (Synodontis clarias and Tilapia nilotica) following earlier detection of the elements in water column. Methods: Levels of heavy metals were measured in both seasonal regimes (rainy and dry) at five selected locations with atomic absorption spectrophotometer. Factorial effects and interactions were explored on completely randomized block design. Quantitative risk of metal exposure through contaminated fish consumptions among the resident community population at the river was assessed to extrapolate the probable public health threat. Results: The result showed variations among heavy metal concentrations in fish and Zn and Cu recorded significant amounts with S. clarias recording higher concentrations than T. nilotica. Season, species of fish and location and their interactions had significant effects on the amounts of Cu and Zn accumulated in the fish tissues except season by species effect. Zinc recorded the highest concentrations at all locations measured, with Onono (location 5) producing the fish species with the highest amount of metals compared with other locations. The heavy metal concentrations were below the comparable international safe standards. Margin of exposure and exposure dose calculated for the heavy metals were all below reference standards and tentatively considered not to be of risk to public health. Conclusion: However, there is considerable concern of contamination of the fish species with heavy metals and recommended regular monitoring or examination of edible fish species.