Children's personal exposure to PM10 and associated metals in urban, rural and mining activity areas

There has been limited study of children's personal exposure to PM10 and associated metals in rural and iron ore mining activity areas where PM10 concentrations can be very high. We undertook a small study of 70 children where 13 children were recruited in an area of iron ore mining processing and shipping, 15 children from an area in the same region with no mining activities, and 42 children in an urban area. Each child provided a 24 h personal exposure PM10 sample, a first morning void urine sample, a hair sample, time activity diary, and self administered questionnaire. Children's 24 h personal PM10 concentrations were low (median of 28 μg m−3 in the mining area; 48 μg m−3 in the rural area and 45 μg m−3 in the urban area) with corresponding outdoor PM10 concentrations also low. Some very high personal PM10 concentrations were recorded for individuals (>300 μg m−3) with the highest concentrations recorded in the mining and rural areas in the dry season. PM10 concentrations were highly variable. Hair aluminium, cadmium and manganese concentrations were higher in the iron ore activity area, while hair mercury, copper and nickel concentrations were higher in the urban area. Factors such as season and ventilation appear to be important but this study lacked power to confirm this. These results need to be confirmed by a larger study and the potential for absorption of the metals needs to be established along with the factors that increase exposures and the potential for health risks arising from exposure.