Human Exposure to Heavy Metals in Aeolian Sediments from an Urban Area
摘要
Exposure to heavy metals through erosive winds is a serious concern in arid regions can be harmful to human health. Soil fine particles play an important role in air pollution due to carrying xenobiotics including heavy metals. Tabas is located in an arid region where erosive winds contain dust and may bring heavy metals to residents. This study evaluates the exposure to several heavy metals including Fe, Zn, Cu, Mn, Pb, Cd, and Ni through ingestion, respiration, and dermal contact in adults and children in Tabas during different months of the year. In order to sample aeolian sediments entering Tabas, sediment traps were installed in central part of the city. Suspended sediments were taken monthly since January to December 2021. The concentrations of the studied heavy metals were measured using atomic absorption spectrometer following the extraction by aqua regia and the exposure routes were determined. Results showed that the exposure to the studied heavy metals in children was higher than adults via ingestion and dermal contact and in adults higher than children via respiration. The most predominant route of human exposure to heavy metals by both children and adults is Ingestion, while respiration has a less impact on human health. In addition, Fe, Zn, and Mn posed the greatest health risk to both children and adults respectively, across all exposure routes. Furthermore, the highest rates of daily intake were found for Fe (0.00736 mg kg− 1 d− 1 for adults and 0.0696 mg kg− 1 d− 1 for children) via ingestion, for Zn (3.38 × 10− 12 mg kg− 1 d− 1 for adults and 3.66 × 10− 13 mg kg− 1 d− 1 for children) via respiration, and for Fe (2.97 × 10− 5 mg kg− 1 d− 1 for adults and 1.97 × 10− 4 mg kg− 1 d− 1 for children) via dermal contact. Spring and summer were known as the most high-risk seasons for human exposure to heavy metals in Tabas. Predominance of exposure routes was as follows: ingestion> dermal contact> respiration.