| Abstract: | Arsenic was detected in 22 of 525 samples of fruits, vegetables, grain products, fast foods, dairy products, and seafoods analyzed by a multielement X-ray fluorescence method. The arsenic occurrences corresponded almost completely and exclusively with seafoods, and the correspondence was confirmed by additional analyses of separated parts of fast-food fish sandwiches. The geometric mean arsenic concentration for all seafoods was 2.1 μg/g (dry weight), with a geometric standard deviation of 3.2. Relative analytical precisions averaged 5.9% standard deviation, and arsenic inhomogeneity among sample aliquots averaged 4.5%. Accuracies validated by six National Institute of Standards and Technology reference materials averaged within 0.2 μg/g, or 5.1 % of certified values, with a net bias of less than 0.1 μg/g. Total arsenic contents in single servings of the seafoods (geometric MEAN = 109 μg) may account completely for the average U.S. arsenic intake if one serving is consumed every 2 to 10 days. Average total arsenic contents are similar among single servings of fish sandwiches, fish fillets, shrimp, and clam chowder; however, variation among specific samples of these seafoods amounts to a factor of 2 to 3. Arsenic concentrations in fish and shrimp agree with values predicted from bioaccumulation from seawater, suggesting consistency with a broader range of seafoods. |
