Tolerance of Plants to Air Pollution in the Industrial Complex of Glass, Khak-e-Chini, Tile and Ceramics in Ardakan, Iran

Air Pollution Tolerance Index (APTI), as a criterion for assessing plants' resistance to air pollution, is one of the important tools for managing air quality around industrial complex buildings. The aim of this study was to determine air quality and the APTI of native plants grown around the Industrial Complex of Glass, Khak-e-chini, Tile and Ceramics and Glass in Ardakan, Iran.

This was a cross-sectional, descriptive-analytical study. First, the concentration of air pollutants in the industrial area was assessed. Then, APTI was determined as follows: measuring the pH of leaf extracts, relative water content, total chlorophyll and ascorbic acid contents of leaves in samples of native plant leaves. In addition, the concentrations of lead, chromium and cadmium were measured in plants by atomic absorption using the dry digestion method. For statistical analysis of the data the SPSS software version 22 was used.

The mean plant concentrations of Co, O3, NO2, SO2 and PM10 in the industrial are were 2.06 ppm, 7.75 ppm, 3.28 ppm, 33.94 ppb and 70.55 µg/m3, respectively; these concentrations were all below the respective standards, as were those of lead, cadmium and chromium. The tolerance index of plants around the Industrial Complex was measured in the floor/parts sensitive to air pollution, proportional to low air quality pollutant and heavy metal concentrations in plants. Among the rangeland, tree and shrubs species, the following had the highest air pollution tolerance index, respectively:  Boiss.fortuynia (8.49), Punica granatum (16.80) and Albizia lebbeck (9.37).

Based on the Air Pollution Tolerance Index it is suggested that the nonproductive species Punica granatum be used as a more tolerant species and Artemisia species as a biomarker for the expansion of green space.