Heavy Metals in Indoor Dust in China: Occurrence, Source, and Health Risk

Abstract

Exposure to heavy metals in indoor dust may affect human health and has gained increasing attention in recent years. However, the occurrence, sources, and health risks of heavy metals in indoor dust in China are still poorly understood, thus leading to certain knowledge gaps. This review systematically discussed the pollution characteristics and the associated health risks of heavy metals in indoor dust in China. Results show that the heavy metals in indoor dust in China are more serious than that in other countries with concentration distribution patterns of Zn > Mn > Pb > Cu > As > Cr > Ni > V > Co ≈ Cd > Hg. Mining and smelting activities, electronic waste recovery, and industrial production can increase heavy metal concentrations in indoor dust in sampling cities. Due to the variation of sources, significant spatial differences are observed among different regions and between rural and urban homes. Results from source apportionment show that mining activity and traffic are the dominant sources of indoor heavy metals. In comparison with adults, children have higher non-carcinogenic and carcinogenic risks due to more frequent ingestion of indoor heavy metals. Residents in South China are suffering from high carcinogenic risks due to high As occurrence levels. Children in South, East, and Southwest China are suffering from non-carcinogenic risks due to Pb exposure. To our theme, more studies, especially in rural homes, involved with more kinds of microenvironments are welcomed in the future. Meanwhile, in the premise of setting a standard guideline for a consistent target heavy metal, activity patterns should be considered when estimating the health risk. Results from this study are expected to provide crucial information for policymakers and researchers to alleviate indoor heavy metal pollution.

Graphical Abstract