Height and blood chemistry in adults with a history of developmental arsenic poisoning from contaminated milk powder

Background Arsenic poisoning interferes with bone metabolism in laboratory animal studies, and human studies suggest lowered bone mass density at elevated exposures. As the long-term consequences of developmental arsenic toxicity are poorly known, we carried out a clinical pilot study of survivors of the mass arsenic poisoning of bottle-fed infants in Japan in 1955. Objectives The purpose was to evaluate the association between developmental arsenic exposure and physical stature and routine blood chemistry reflecting major organ functions more than 50 years later. Methods The study sample consisted of 50 individuals recruited at two hospitals in Okayama Prefecture, Japan: 27 known poisoning victims (14 men and 13 women), and 23 non-exposed local controls of similar age (10 men, 13 women). We collected information from physical examinations that included routine blood counts and blood biochemistry. Results The average height of the exposed group was 6.5 cm below that of the unexposed group (p=0.02), while the latter was in accordance with national data for both sexes. In addition, the exposed participants had a higher mean (SD) serum concentration of alkaline phosphatase (ALP) of 233 (63) U/L than the unexposed participants (191 (44) U/L) (p=0.01). No other statistically significant difference was observed, and liver enzymes were within normal ranges. Conclusions Adults who had suffered arsenic poisoning during infancy showed decreased height and elevated ALP that suggests abnormalities in bone metabolism possibly induced by arsenic incorporated in the bone matrix.