Arsenic concentration and speciation in infant formulas and first foods

Arsenic (As) exposure to humans is pervasive, and, increasingly, studies are revealing adverse health effects at ever lower doses. Drinking water is the main route of exposure for many individuals; however, food can be a significant source of As to individuals, especially if their diet is rice-based. Infants are particularly susceptible to dietary exposure, since many first foods contain rice and infants have a low body mass. Here we report on As concentration and speciation in infant formulas and first foods. Speciation is essential for food analysis because of the much greater toxicity of inorganic As species and the possibility that As in food (unlike water) may be present in either inorganic or organic forms. Infant milk formulas were low in total As (2.2–12.6 ng g–1, n = 15). Non-dairy formulas were significantly higher in As than dairy-based formulas. Arsenic in formula was almost exclusively inorganic. Arsenic concentration in purees (n = 41) and stage 2/3 foods (n = 18) ranged from 0.3 to 22 ng g–1. Rice-fortified foods had significantly higher total As concentrations than non-rice-based foods. Again, As speciation was predominantly inorganic with lower concentrations of dimethylarsenic acid (DMA) also present. These data confirm that infants are exposed to As via diet, and suggest that careful attention to diet choices may limit this exposure.