Metals and trace element associated health risk in size-segregated household dust of an industrial town in India

Household dust can be a major source of exposure to heavy metals to children and adults alike. However, only a few studies have examined the metal risk due to size-segregated dust exposures. This study aims to examine the levels of toxic heavy metals in size-segregated dust (< 45 to 250 μm) from the roadside and households of an industrial town in Maharashtra, India. Further, the sources of these toxic metals and associated health hazards are evaluated. Fe dominated the roadside (RS, 41.8 ± 9.4 mg g^-1) as well as household dust (HH, 40 ± 5.3 mg g^-1), having particles < 45 μm size suggesting its crustal origin in the study area. Most of the heavy metals decreased with increasing dust particle sizes. The RS/HH (roadside-to-household) ratio was greater than one for all metals in all size ranges except for Tl, Mn, Cd, Ni, and As, suggesting some influence of road traffic on household dust. However, based on the enrichment factor, the geo-accumulation index, and the pollution index, the study shows a minimal contribution of the anthropogenic source. Four major source groups affecting dust in the study area were identified, accounting for 75% (RS) and 66% (HH) of the dust metal variability from three common sources: mixed sources (biomass burning, coal mining activity and fly ash), vehicular exhaust and vehicular non-exhaust. Exposure indices for dust-bound metals were within IARC limits (≤ 10‾⁶) indicating that the dust did not pose any discernible carcinogenic risk. Therefore, the major industries (mining and cement production) do not pose a significant risk of exposure to metals, while the resuspension of road dust could be a potential source.