Assessment of air pollution tolerance index (APTI) of different plants occurred in Beithanoun industrial area, North Gaza strip, Palestine

Air pollution is a major problem facing by the scientists internationally, particularly in industrial areas of the developing countries. Different studies related to air pollution, have been carried out at several areas of the world, but this is the first investigation, which examined the air pollution tolerance index of some natural plant species in Palestine. Identification of plant species for their tolerance or sensitivity range to air pollutants is significant because the tolerant plant species can used for controlling air pollution in industrial locations. Furthermore, the sensitive plant species can used as biological indicators for air pollution. Therefore, in the present study air pollution tolerance index (APTI) was estimated for different plant species inhabiting six locations namely Hamooda, Abosaphea, Mansoer, Spong, Medicine factory and Al show a station of the industrial area of BeitHanoun, Gaza Strip, Palestine. Samples of leaves of 23 plant species were selected from the six sites of the industrial area. The plant species Solanum elaeagnifolium cav., Malva parviflora L, Polygonum equisetiforme Sm., Marrubium vulgare L., Verbascum sinuatum L. were recorded at all sites of the study area. The four biochemical and physiological factors, relative water content, ascorbic acid content, total leaf chlorophyll, and leaf extract pH were used to evaluate the air pollution tolerance index (APTI) values of plant species. The results revealed a more credible result could be achieved when utilizing the above-mentioned four parameters than those of a single biochemical parameter. Based on APTI, Polygonum equisetiforme was found, at all locations of the study area, to be more tolerant compared to the remaining plant species, followed by Nicotiana glauca, Solanum elaeagnifolium and Silybum marianum successively considered as the most tolerant plant species in the study area. Lower APTI values were found with other plant species suchas Marrubium vulgare followed by Marticaria recutita and then Chenopodium vulvaria, which are considered as the most sensitive plant species. In conclusion, the air pollution tolerance index (APTI) values of the 23 studied plant species are less than 16, therefore all plant species are considered as sensitive to air pollutants and can be used as biological indicator for further monitoring of air quality.