Repeated surveillance of exposure to cadmium, manganese, and arsenic in school-age children living in rural, urban, and nonferrous smelter areas in Belgium

Abstract

Once a year from 1974 to 1978, the intensity of exposure to Cd, As, Mn in groups of school-age children living around a lead smelter was assessed. By comparison, groups of children living in an urban and a rural area were also examined. The metal content of blood, urine, hand-rinsing, air, dust, and dirt collected in the school-playground was compared. The urinary excretion of cadmium in children living around the lead smelter is greater than in those living in the urban and in the rural area. In the latter there seems to exist a time-dependent trend in the renal accumulation of cadmium. This suggests that the overall pollution of the environment by cadmium in Belgium is progressively increasing. In the smelter area, both the oral and pulmonary routes play a role in the children's exposure to cadmium. Their relative contribution to the amount of cadmium absorbed appears similar. The concentration of arsenic in urine of children living around the smelter is significantly higher than that of rural children. Speciation of the chemical forms of arsenic in urine indicates that the difference is not due to different dietary habits of the children examined but to different intensity of exposure to inorganic arsenic. The amount of arsenic on the hand of children living at less than 1 km from the smelter ( X = 17.6 μg As/hand) was more than 10 times that found in children living at 2.5 km from the plant ( X = 1.5 μg As/hand) whereas that found in children living in urban and rural areas was below 0.2 μg As/hand. The arsenic concentration of dust and dirt collected in the school-playground in the different areas follows the same trend. As expected, there are strong interrelationships between the degree of hand contamination by lead, cadmium, and arsenic ( r ⩾ 0.8). No statistically significant influence of the dwelling place of the children on the manganese level in blood, urine, and hand rinsing was found. Our results demonstrate that by comparison with the rural and urban children, those living in the vicinity of a nonferrous smelter may be more exposed not only to lead, but also to cadmium and arsenic. The possible long-term effects of such exposure deserve further evaluation.