Evaluation of Individual and Integrated Pollution Indices of Some Heavy Metals in Atmospheric Dust Deposition Around Khak-e-chini, Tile and Ceramic, Sand and Gravel and Glass in Ardakan County Industries in Winter 2018

Striving for employment in developing countries, as industries develop, heavy metals are released to the environment continuously. The purpose of this study was to measure heavy metal concentrations and to evaluate dust pollution levels in a number of industries using ecological indices.

This cross-sectional, descriptive-analytical study was conducted in winter by installing 35 dust traps around the industrial Khak-e-chini, Tile and Ceramic, Sand and Gravel and Glass in Ardakan county. The concentration of heavy metals in dust was measured by ICP-MS. The level of dust pollution was assessed using Contamination Factor, Pollution Index, Threshold Pollution Index, New Pollution Index, Vector Modulus of Pollution Index, Weighted Average of Pollution Index, Enrichment Factor, Multi-Element Contamination, Mean Effects Range-Median Quotient, Exposure Factor and Integrated pollution indices and it was zoned in GIS version 10.5.

Mean heavy metal concentrations in dust were measured in the form of Zinc (3310.54 mg/kg)> Pb (137.28 mg/kg)> Copper (63.65 mg/kg)> Nickel (45.91 mg/kg)> Arsenic (35.12 mg/kg> cobalt (13.73 mg/kg)> molybdenum (4.40 mg/kg). In all sampling stations CF index of lead, arsenic and zinc elements was in very high pollution class and PI index in severe pollution class. Zinc metal showed very high enrichment at 30 stations. For environmental protection user, zinc element PIT index in all sampling stations was very severe in the pollution class. Also, all stations were in severe pollution class based on the IPI index. Based on MERMQ index the heavy metals at 32 stations had 76% toxicity and based on PIN index were in polluted class. Highest values of MEC (3.43) and PIvector (35.93) indices were obtained at S1 and S15 stations, PIwAvg (42.27) at S1 and S12 and ExF (117.11) at S1 stations.

Based on results of zoning a number of pollution indices, dominant downwind in region plays has important role in increase of concentration of heavy metals in downstream stations the industries.