Human lead (Pb) exposure via dust from different land use settings of Pakistan: A case study from two urban mountainous cities

The current study aims to determine the dust-borne lead (Pb) levels into outdoor dust, which were collected from the areas nearby the cities/districts of Islamabad and Swat in Pakistan. In general dust samples from all land use settings (industrial, urban and rural) showed significantly higher (p < 0.05) Pb-levels (median, ppm) from Islamabad (110, 52, 24) than those of Swat district (75, 37, 21), respectively. Index of Geo-accumulation (I-geo values) indicated that industrial and urban areas of both sites were highly polluted due to severe anthropogenic influence, whereas the rural areas were in most parts unpolluted and where moderately polluted, this was mainly due to geological factors and short and/or long distance atmospheric deposition from surrounding polluted areas. According to the calculated chemical daily intake (mg/kg-day) values, dust ingestion is one of the major routes of human exposure for lead. Hazard Index (HI) values, calculated for both adult and children populations, were above unity in industrial and urban areas, indicating serious health risks especially to the children populations. (C) 2016 Elsevier Ltd. All rights reserved.