Spatial patterns and correlations' of lead concentrations in soil, leaf vegetables and human hair in the Pearl River Delta region, South China

A total of 924 soil samples, 170 leaf vegetable samples and 53 human hair samples were collected to evaluate the regional lead (Pb) concentration levels in soil, leaf vegetables and human hair across the Pearl River Delta (PRD) area. Soil Pb concentrations were greater than the risk screening value of Pb (80 mg kg(-1)) in 3.5% of the vegetable planting area; about 8% vegetable Pb concentrations were exceeded the national standard of the maximuin level of contaminants of 0.3 mg kg(-1). Pearson correlations indicated that there was no correlation between soil Pb and vegetable Pb in the study area. Pb concentrations of 12 hair samples were higher than the upper limit of the normal value of 10.0 mg kg(-1), and lower than the high-exposure risk value of 25 mg kg(-1). Therefore, the young residents in the PRD area had not suffered a high exposure to Pb, but still had a potential health risk. This health risk did not directly come from local leaf vegetable consumption.