Air pollution tolerance, metal accumulation and dust capturing capacity of common tropical trees in commercial and industrial sites

Bioaccumulation potential of indigenous plants for heavy metal phytoremediation in rural areas of Shaheed Bhagat Singh Nagar, Punjab (India)

The present study was planned to explore the bioaccumulation potential of 23 plant species via bioaccumulation factor (BAf), metal accumulation index (MAI), translocation potential (Tf), and comprehensive bioconcentration index (CBCI) for seven heavy metals (cadmium, chromium, cobalt, copper, iron, manganese, and zinc). The studied plants, in the vicinity of ponds at Sahlon: site 1, Chahal Khurd: site 2, and Karnana: site 3 in Shaheed Bhagat Singh Nagar, Punjab (India), were Ageratum conyzoides (L.) L., Amaranthus spinosus L., Amaranthus viridis L., Brassica napus L., Cannabis sativa L., Dalbergia sissoo DC., Duranta repens L., Dysphania ambrosioides (L.) Mosyakin & Clemants, Ficus infectoria Roxb., Ficus palmata Forssk., Ficus religiosa L., Ipomoea carnea Jacq., Medicago polymorpha L., Melia azedarach L., Morus indica L., Malva rotundifolia L., Panicum virgatum L., Parthenium hysterophorus L., Dolichos lablab L., Ricinus communis L., Rumex dentatus L., Senna occidentalis (L.) Link, and Solanum nigrum L. BAf and Tf values showed high inter-site deviations for studied metals. MAI values were found to be more substantial in shoots as compared with that of roots of plants. Maximum CBCI values were observed for M. azedarach (0.626), M. indica (0.572), D. sissoo (0.497), and R. communis (0.474) for site 1; F. infectoria (0.629), R. communis (0.541), D. sissoo (0.483), F. palmata (0.457), and D. repens (0.448) for site 2; D. sissoo (0.681), F. religiosa (0.447), and R. communis (0.429) for site 3. Although, high bioaccumulation of individual metals was observed in herbs like C. sativa, M. polymorpha, and Amaranthus spp., cumulatively, trees were found to be the better bioaccumulators of heavy metals.

Use of Leaves as Bioindicator to Assess Air Pollution Based on Composite Proxy Measure (APTI), Dust Amount and Elemental Concentration of Metals

Monitoring air pollution and environmental health are crucial to ensure viable cities. We assessed the usefulness of the Air Pollution Tolerance Index (APTI) as a composite index of environmental health. Fine and coarse dust amount and elemental concentrations of Celtis occidentalis and Tilia × europaea leaves were measured in June and September at three sampling sites (urban, industrial, and rural) in Debrecen city (Hungary) to assess the usefulness of APTI. The correlation between APTI values and dust amount and elemental concentrations was also studied. Fine dust, total chlorophyll, and elemental concentrations were the most sensitive indicators of pollution. Based on the high chlorophyll and low elemental concentration of tree leaves, the rural site was the least disturbed by anthropogenic activities, as expected. We demonstrated that fine and coarse dust amount and elemental concentrations of urban tree leaves are especially useful for urban air quality monitoring. Correlations between APTI and other measured parameters were also found. Both C. occidentalis and T. europaea were sensitive to air pollution based on their APTI values. Thus, the APTI of tree leaves is an especially useful proxy measure of air pollution, as well as environmental health.

Assessment of Air Pollution Tolerance Index (APTI) and Anticipated Performance Index (API) of Roadside Plants for the Development of Greenbelt in Urban Area of Bathinda City, Punjab, India

The aim of the present study is to biomonitor the tolerance level of roadside plant species towards mitigation of air pollution for the development of greenbelt. The leaves of four plant species (Azadirachta indica, Ficus benghalensis, Melia azedarach and Polyalthia longifolia) were collected from 41 sampling sites of Bathinda city during summer and winter seasons. Seasonal variation in APTI and API was determined in selected plants. Highest APTI (13.54) was reported in F. benghalensis during summer and lowest APTI (11.69) in A. indica during winter season. The APTI and API value revealed that F. benghalensis was the best performer, A. indica and M. azedarach were excellent performers and P. longifolia a good performer in greenbelt development to mitigate the air pollution. Pearson's correlation analysis illustrated significant correlation between APTI, ascorbic acid, total chlorophyll, relative water and pH, respectively.

Assessment of anticipated performance index of some deciduous plant species under dust air pollution

Green vegetation improvement is an economical strategy to mitigate dust air pollution. The anticipated performance index (API) is considered a main criterion to select the suitable plants of urban forests. API is calculated by taking air pollution tolerance index (APTI) and socio-economic and biological aspects into account. In the present work, API of four current deciduous tree species in urban areas of Iran was evaluated. The seedlings were soil-dusted by a dust simulator in plastic chambers at levels of 0, 300, 750, and 1500 μg/m³ at intervals of 1 week for 70 days. At 750 and 1500 μg/m³ dust concentrations (DCs), greatest dust collection capacity was observed with Morus alba and the lowest one with Melia azedarach. Increasing DC declined APTI of all species. At 750 μg/m³ DC, only Morus was tolerant, but at 1500 μg/m³ DC, this species and Melia were categorized as intermediate, and Celtis caucasica and Fraxinus rotundifolia as sensitive. Morus was assessed as a good performer under two higher DC. Celtis was recognized as a moderate under 750 μg/m³ DC and poor performer under 1500 μg/m³ DC. Thus, Celtis can be considered as a biomonitor for air quality or as sink for dust in high dusty areas because of its high capacity of dust deposition. At two higher DCs, Fraxinus and Melia showed very poor and poor performance; planting these species in high dust areas is not recommended. In contrast, Morus is the most suitable tree species for urban green spaces in dusty regions, due to its high dust collection capacity and high APTI and API values.