Application of a Monte Carlo Simulation to the Estimation of the Risk for Health Due to Children Exposure to Lead in Polluted Soils in the Matanza Riachuelo Basin (Argentina)

Abstract

The purpose of this work was to assess the health risk for the population of children of both sexes from 3 to 6 years of age in a neighborhood of the Matanza Riachuelo Basin, Argentina, based on the calculation of weekly intake of lead (Pb) present in the surface soil of a polluted recreational space using a method of probabilistic analysis of the data: a Monte Carlo simulation. From the results of 144 determinations of the concentration of Pb in the soil and dust using a portable X-ray fluorescence spectrometry unit, 10,000 cases of exposure and calculation of the weekly intake of Pb were simulated for 3-year-old boys and girls, and another 10,000 cases for 6-year-old children. As a reference value, the provisional tolerable weekly intake (FAO/WHO) of 25 μg Pb/kg·week was used. This reference value means that for every 1 μg Pb/kg·week that is ingested, the IQ of child drops 0.11 points. The results indicate that children in the neighborhood under the age of 6 face a 30% risk of losing IQ points, whereas in 5% of the cases it would reach up to 20 IQ points, if chronic exposure to Pb were to remain at the level they are currently experiencing in the neighborhood where they live. These findings where essential to making the decision to remediate the site, while the hygiene and dietary measures and the toxicological and medical monitoring of the children continued.