Health risks from the exposure of children to As, Se, Pb and other heavy metals near the largest coking plant in China

摘要

Background: Coking influences environmental quality and poses high risks to human health as large amounts of heavy metals and metalloids are emitted into the environment from coal during the coking process, particular for Chinese coals, which have higher contents for most heavy metal(loid)s when compared to those from other countries. Health risks of heavy metal(loid)s depend heavily on multi-pathway and element-specific exposures, which have, unfortunately, been rarely studied in the vicinity of coal-related industrial areas. The objectives of this paper is to 1) quantify the exposure levels of children to heavy metal(loid)s and their contribution from each medium and 2) estimate the children's health risk to heavy metal(loid)s exposures according to the Hazard Index and cancer risk. Methods: Children's health risks and exposure levels to As, Se, and heavy metals (Pb, Cd, Cr, Ni, Co, Zn, Cu, Mn, V and Sb) in the water, soil, dust, air and locally produced food were studied based on field sampling and questionnaire-based surveys around the largest coking area in China. Results: The environmental media were slightly polluted in the vicinity of the coking plant. The non-carcinogenic risks to children mainly resulted from Cr, Mn, Pb, As and Sb, the levels of which were 3 to 10 times higher than the acceptable levels (1.0×10~(-6)). The carcinogenic risks to children were 30 to 200 times higher than the safe level (1.0×10~(-6)-1.0×10~(-4)), which could be attributed to Cr, As and Ni pollution. The estimated risks mainly came from the pathway involving the ingestion of locally produced food, accounting for more than 85% in total for most elements. For As, the food ingestion and air inhalation exposure pathways both contributed approximately 50%, respectively. Conclusion: The high risks in this study highlight the attention paid to the health of children who live in the vicinity of coking activities and the importance of site-specific multi-pathway health risk assessments and food safety to protect potentially exposed children.