Commuters health risk associated with particulate matter exposures in subway system – Globally

Abstract

The effects of air pollution within subway systems on public health has far been overlooked. A few previous studies have warned that particulate matter (PM)-bound metals in subway air pose a serious threat to public health, but these have been limited by insufficient risk measurement and limited regional data. Present study aimed to determine the levels of human health risk associated with PM10 and PM2.5-bound trace metals in twelve city subways across North America, Asia, and Europe using the human exposure method. Human health risks were estimated via ingestion, inhalation, and dermal exposure methods. The Monte Carlo statistical method using 50,000 iterations was adopted to calculate the probable risk levels for children and adults. Significant levels of non-cancer and cancer risks (CR) were found in subway systems at all regions, regardless of age, although CR were relatively higher in adults. Inhalation and dermal absorption, in which the acceptable range of carcinogenic risk for subway systems was exceeded. Exposure through ingestion made the greatest contributions to overall CR. Among the all subways Tehran and Seoul were estimated as higher CR zone (Total CR > 10