Seasonal concentrations of lead in outdoor and indoor dust and blood of children in Riyadh, Saudi Arabia.

Because detrimental effects of exposure to lead (Pb) on human health have been observed, we previously investigated concentrations of Pb in water supplies and blood of adult residents of Riyadh, Saudi Arabia. The objectives of the present study were to: (1) examine seasonal rates of deposition of Pb in dust in several areas of Riyadh city, (2) measure concentrations of Pb in both outdoor and indoor dust, (3) compare concentrations of Pb in dust in Riyadh with those reported for other cities, and (4) quantify Pb in blood of children living in Riyadh. Mean, monthly deposition of PB in outdoor dust was 4.7 × 10(1) ± 3.6 tons km(-2), with a mean Pb concentration of 2.4 × 10(2) ± 4.4 × 10(1) μg/g. Mean, monthly deposition of Pb in indoor dust was 2.7 ± 0.70 tons km(-2), with a mean concentration of 2.9 × 10(1) ± 1.5 × 10(1) μg Pb/g. There was a significant (P < 0.01) correlation between concentrations of Pb in outdoor and indoor dust. There was no correlation between concentrations of Pb in indoor dust and that in blood of children of Riyadh, whereas there was a weakly significant (P < 0.05) correlation between concentrations of Pb in outdoor dust and that in blood of children. The mean (±SD) concentration of Pb in blood of children in Riyadh was 5.2 ± 1.7, with a range of 1.7-1.6 × 10(1) μg/dl. Concentrations of Pb in blood of 17.8 % of children in Riyadh were greater than 10 μg/dl, which is the CDC's level of concern.