Evaluation of the effects of dust pollution on specific plant species near and around the marble mining site in Rajasthan, India

Airborne particles (dust pollution) pose a significant threat to both human and plant populations. Plant leaves act as crucial biofilters, capturing significant amounts of air pollution; this characteristic offers a valuable tool to measure local pollution levels and assess individual plant species' ability to intercept and mitigate harmful dust particles. The present study was carried out to asses the effect of responses of various plant species to dust pollution near and around the marble mining site comprising residential site, highway area, and Central University of Rajasthan as control. The anticipated pollution index, air pollution tolerance index (APTI), dust absorption capacity, metal accumulation index (MAI), and biochemical factors were used to evaluate plant responses. Azadirachta indica A. Juss. demonstrated the highest (29.0) and Vachellia nilotica L. showed lowest (5.6) APTI, respectively. A. indica showed maximum MAI values in comparison to other plant species situated at residential site. Additionally, monitoring of particulate matter (PM10) observed to highest at highway, followed by mining, residential, and control sites. Overall A. indica representing highest APTI and effective dust capturing capacity at all sites could serve as potential pollution sinks. V. nilotica, with its very low APTI, can be marked as biomonitoring tool for detecting dust pollution.

Selection of tropical trees and shrubs for urban greening in coal mine complex: a case study of Singrauli, Madhya Pradesh

An experimental investigation was conducted to determine the effectiveness of roadside trees for removing dust and the effects of dust load on the physiology and micromorphology of the foliage. The present study was conducted near an open coal mining complex situated in Singrauli, Madhya Pradesh, India, to assess the air pollution tolerance index (APTI), anticipated performance index (API), dust capturing capacity (DCC), and leaf morphology of trees and shrubs growing around the coal fields. Results showed that Azadirachta indica, Mangifera indica, Ficus religiosa, Ailanthus excelsa, and Ficus benghalensis were the most tolerant species towards air pollution (high APTI scores), while plants like Calotropis gigantea, Lantana camara, and Tectona grandis were proven to be bio-indicator species. Butea monosperma, Ficus benghalensis, Alstonia scholaris, and Terminalia arjuna were plant species with the highest DCC. Two-way ANOVA showed significant differences site-wise and season-wise in the biochemical parameters of APTI and a considerable difference site-wise with respect to dust capturing capacity. Correlation and regression analyses revealed a very high positive correlation between APTI and ascorbic acid value. The study recommends suitable plant species to manage rising air pollution in the coal mine and nearby areas apart from suggesting the development of a green belt.

Assessment of air pollution tolerance potential of selected dicot tree species for urban forestry

Air pollution is one of the killers of our age especially for the urban areas. Urban forestry which involves planting more trees has been considered as one of the prominent strategies to mitigate air pollution. Identification of trees tolerant to air pollution is important for plantation drives being organized across the country. The present study aimed to compare the air pollution tolerance potential of 46 tree species growing in Guru Nanak Dev University (GNDU) campus, Amritsar, using two indices, viz., Air Pollution Tolerance Index (APTI) and Anticipated Performance Index (API). APTI is based on four biochemical parameters, viz., relative water content, leaf extract pH, total chlorophyll, and ascorbic acid contents of leaf samples, whereas API takes into consideration morphological and socioeconomic values of plant species along with their APTI. Based on APTI values calculated for 46 tree species, only 2 tree species, viz., Psidium guajava (46.26) and Cassia fistula (41.83), were found to be tolerant to air pollution, while 25 species showed intermediate tolerance. API scores revealed one tree species, namely, P. guajava, as an excellent performer, 8 species as very good performers, and 28 species as moderate to good performers against air pollution. In conclusion, tree species like Alstonia scholaris, C. fistula, Ficus tsjakela, Grevillea robusta, Kigelia africana, Mangifera indica, Melia azedarach, P. guajava, Pongamia pinnata, Pterospermum acerifolium, Putranjiva roxburghii, Syzygium cumini, Terminalia arjuna, and Toona ciliata can be considered as most desirable for plantations in areas around GNDU campus.

Evaluating the ability of green roof plants in capturing air pollutants using biogas-digestate: Exploring physiological, biochemical, and anatomical characteristics

The undeniable impact of plants in reducing air pollution and the crucial role of nutrition in improving stress tolerance in plants has brought attention to the use of eco-friendly fertilizers. The objective of the study was to investigate how Biogas-digestate (BD) can enhance the tolerance of green roof plants in capturing air pollutants. Four plant species, namely reflexed stonecrop (Sedum reflexum), blue fescue (Festuca glauca), garden mum (Chrysanthemum morifolium), and Peppermint (Mentha piperita) were planted in three urban sites in Mashhad, Iran, with different levels of air pollution. The physiological, biochemical, and morphological characteristics of the treated plants were compared to assess their ability to trap air pollutants. The results showed that the treated M. piperita at Razavi with BD, exhibited the highest level of APTI. Although it was influenced by the site conditions, the determination of the optimum API yielded same results. The F. glauca treated in Khayyam had the highest proline content, while S. reflexum at the Honarestan site had the lowest H2O2 level, without significantly affecting BD. F. glauca, S. reflexum, and M. piperita exhibited the highest levels of SOD, PPO, and GPX activity, respectively, which were significantly increased by the BD treatment. Most of the heavy elements showed increased levels with BD treatment, and M. piperita had the highest concentrations of heavy elements. The leaf surfaces of S. reflexum and M. piperita, had the highest and lowest deposition of particulate matter (PMs), respectively. Carbon and oxygen constituted the majority of PMs on the surface of leaves at all three study locations. The following ranks included the elements Si, Ca, Mg, and Al. BD, particularly in the case of S. reflexum and M. piperita, enhanced the plants' tolerance to air pollution. It is recommended to cultivate S. reflexum using BD on the green roof in polluted areas due to its superior capacity to absorb PMs and the fact that it is not edible.

Air mapping during COVID-19 and association between air pollutants and physiochemical parameters of the plants using structural equal modeling: a case study

In urban areas around the world, air pollution introduced by vehicular movement is a key concern. However, restricting vehicular traffic during the COVID-19 shutdown improved air quality to some extent. This study was conducted out in the smart city of Bhubaneswar, which is also the state capital of Odisha, India. The study has tried to map Bhubaneswar by collecting the air quality data before, during, and after the COVID lockdown of six air quality monitoring stations present in Bhubaneswar established under "National Ambient Air Monitoring Program" (NAMP). Furthermore, plants, which are the most vulnerable to air pollution, can show a variety of visible changes depending on their level of sensitivity. Moreover, leaves of Mangifera indica, Monoon longifolium, Azadirachta indica, Millettia pinnata, Aegle marmelos were collected from nearby of six air monitoring stations to assess the "Air Pollution Tolerance Index." M. indica was found to be intermediately tolerant, and all of the other species were found to be sensitive. The structural equation modeling results also revealed a significant relationship between total chlorophyll content, relative water content, ascorbic acid content, leaf extract pH, APTI with species, air quality index, and PM10.

Environmental impacts of air pollution and its abatement by plant species: A comprehensive review

Air pollution is one of the major global environmental issues urgently needed attention for its control through sustainable approaches. The release of air pollutants from various anthropogenic and natural processes imposes serious threats to the environment and human health. The green belt development using air pollution-tolerant plant species has become popular approach for air pollution remediation. Plants' biochemical and physiological attributes, especially relative water content, pH, ascorbic acid, and total chlorophyll content, are taken into account for assessing air pollution tolerance index (APTI). In contrast, anticipated performance index (API) is assessed based on socio-economic characteristics including "canopy structure, type, habit, laminar structure, economic value and APTI score" of plant species. Based on previous work, plants with high dust-capturing capacity are identified in Ficus benghalensis L. (0.95 to 7.58 mg/cm2), and highest overall PM accumulation capacity was observed in Ulmus pumila L. (PM10 = 72 µg/cm2 and PM2.5 = 70 µg/cm2) in the study from different regions. According to APTI, the plant species such as M. indica (11 to 29), Alstonia scholaris (L.) R. Br. (6 to 24), and F. benghalensis (17 to 26) have been widely reported as high air pollution-tolerant species and good to best performer in terms of API at different study sites. Statistically, previous studies show that ascorbic acid (R2 = 0.90) has good correlation with APTI among all the parameters. The plant species with high pollution tolerance capacity can be recommended for future plantation and green belt development.

Investigating the Biochemical Responses in Wheat Cultivars Exposed to Thermal Power Plant Emission

The current study aimed to assess how high concentrations of ozone (O₃) and suspended particulate matter (SPM) alter biochemical properties of high yielding wheat cultivars (i.e., HD3086 and HD2967) grown under 10 km radius in 8 villages, located around Thermal Power Plant (TPP), Auraiya, Uttar Pradesh, India. Significant foliar damage was brought on by O₃ and SPM exposure in both wheat cultivars and noted for consecutive 2 years as per emission patterns, air movement and biochemical defense capabilities. The detected air pollutants at the chosen experimental site ranged from 34 to 46 ppb O₃ and 139-189 µg/m³ SPM. Range of biochemical parameter for both cultivars are as pH 6.6-7.1, relative water content (RWC) 44-62%, chlorophyll 0.23-0.35 mg/g, ascorbic acid (AA) 54-68 mg/g and air pollution tolerance index (APTI) 47-72. It has been observed that SPM deposition had a meaningful impact (P-value = 0.05) on the chlorophyll, pH, RWC and APTI.

Estimation of air pollution tolerance and anticipated performance index of roadside plants along the national highway in a tropical urban city

One of the most serious environmental issues is air pollution. Unlike other environmental concerns, this form of pollution is extremely challenging to regulate. The greenery of roadside trees plays a significant role in air purification and pollutant absorption, therefore helping to mitigate environmental pollution. Several plants can absorb and store toxins in their leaves from the atmosphere. Green plants have the potential to work as sinks and filters for air pollutants. Green belt development along national highways is a cost-effective and environmentally sustainable method of reducing air pollution. Sensitive and tolerant plants against air pollution can be identified by evaluating their air pollution tolerance index (APTI) and anticipated performance index (API) values. In this study, the susceptibility level of plant species to air pollution was assessed using APTI and API. The four parameters on which APTI depends are ascorbic acid content, total chlorophyll content, relative water content, and leaf extract pH. For the estimation of API, the plant's biological and socioeconomic factors like tree habit, canopy structure, type, size, texture, and hardness of the plant are also assessed. These parameters were determined and incorporated into a formula that represents the APTI and API of plants. Moreover, multilinear regression modeling was performed using a Statistical Package for the Social Sciences (SPSS, V25) and found that pH and ascorbic acid content in plant leaves have a significant role in the calculation of APTI and tolerance potential of plants. Therefore, APTI was assessed with seventeen plant species that are abundant in the area along the national highway in Kanpur, Uttar Pradesh, from Jan to Mar 2020. The APTI showed that Saraca asoca was the most resistant to air pollution, whereas Vachellia nilotica was the most sensitive. In addition, plants with higher APTI can also be used to reduce air pollution, while plants with lower APTI can be utilized to monitor air pollution. Based on the calculated API score, it is found that Ficus elastica (% score > 90) is the best option for green belt development. Urban local body (ULB) can also adopt Ficus religiosa, Saraca asoca, and Aucuba japonica (having % a grade score of 80-90) for mitigation of air pollution. The study indicates that plantations of tolerant species are useful for biomonitoring and developing green belts on and along national highways.

Impact of vehicular emissions on anatomical and morphological characteristics of vascular plants: A comparative study

Abbottabad is a famous tourist destination due to its greenery and location. However, rapid increase in population and unplanned urbanization cause various environmental problems. Among different environmental stress, vehicular emission is the major issue for the survival and sustainability of plant species. This study aimed to investigate the effects of atmospheric pollution (caused by vehicular emission) on the anatomical, biochemical and morphological aspects of plant species present alongside the roads of Abbottabad, Pakistan. The plants were also collected from control sites (away from road-sites) for comparison. The results showed that various morphological characteristics of plant species including petiole length, vein-to-vein difference between leaves and length to breadth ratio of leaves were adversely affected by air pollution. The stomatal index varies in plant species because of variations in the numbers of epidermal cells. The air pollution tolerance index (APTI) of plant leaves from contaminated areas was reported to be higher as compared to control (non-contaminated) areas. Consequently, the findings from this study confirmed that plant species growing alongside of Abbottabad roads has greater tolerance than plant species growing in solitude areas away from road sites (control sites). Among different studied plants, Juglans regia, Morus nigra, Xanthium strumarium, Prunus armenica, Diospterus lotus and Populus ciliata have highest APTI and found to be more suitable for plantation in Abbottabad.

Study of biochemical factors in assessing air pollution tolerance index of selected plant species in and around Durgapur industrial belt, India

Increasing levels of pollution put plants under stress, leading to changes in their biochemical factors, which can be measured using the pollution tolerance index (APTI). APTI is a measure of environmental stress on flora, and it is calculated using four parameters (chlorophyll, ascorbic acid, relative water content, and pH). Earlier work in the same belt showed a positive correlation between stress and APTI but concentrated on woody trees only. This study was conducted in the Durgapur industrial belt, West Bengal, from August 2019 to February 2020. Eighteen plant species (herbs) were collected, assessed, and categorized as sensitive, intermediate, and tolerant based on their seasonal APTI values. Results showed that Solanum sisymbriifolium fell in the intermediate range in all three seasons. Persicaria sp. was identified as a tolerant species throughout and could be used to form a green belt. Persicaria orientalis was a sensitive species and can be used as an indicator of pollution.

Air pollution tolerance index of plants around brick kilns in Rawalpindi, Pakistan

In any contaminated environment, the sensitive plant species can serve as bio-indicator of air pollution while tolerant plant species can act as a sink for air pollutants. Air pollution tolerance index (APTI) is an important tool to screen out plants based on their tolerance or sensitivity level to different air pollutants. The present study was aimed to identify the sensitive and tolerant plant species in the vicinity of brick kilns in the Rawalpindi city. To determine the susceptibility level of the selected plant species, four biochemical parameters, ascorbic acid, total chlorophyll content, relative water content and pH of leaf extract, were assessed and APTI was calculated. Plant sampling was carried out with increasing distance of 100, 300 and 500 m around three brick kiln sites and APTI values were calculated by following the standard methods. The results of the study revealed that among nine studied plant species, Calotropis procera (APTI = 20.05) and Althernanthera pungens (APTI = 17.13) were found to be the most tolerant species, whereas Malva neglecta (APTI = 8.83) was found to be the most sensitive species. Inconsistent trend of variations was seen in the APTI values at each site. The present study suggested that the most tolerant species, C. procera and A. pungens, could be grown in the vicinity of such pollution sources as a remedial measure of brick kiln pollution.