At a time when air quality in the national Capital has worsened, Delhi University’s Department of Environment Science has come out with a research suggesting that a few trees/plants can absorb rising values of higher concentration of Suspended Particulate Matter (SPM).

The research taking into account the Knowledge of Air Pollution Tolerance Index (APTI) value of 20 flora species recommended that Azadirachta Indica (neem), Ricinus Communis (castor bean), Prosopis Juliflora (kabuli kikar, vilayati babul), Dalbergia Sisoo (sheesham) and Delonix Regia (gulmohar) are tolerant species and can be used for green belt planning.

“As tolerant species can play a vital role in absorption and detoxification of toxic air, our research work with students has computed APTI at different land use sites, for instance — traffic intersection, riverine, institutional and vegetated,” said Dr Chirashree Ghosh, Senior Assistant Professor, Delhi University.

Delhi has 20.8 per cent area under tree cover. Among the categories of tree C3 and C4, the latter is considered good in the perspective of the cleaning the air.

Considering the tree covered area, Gosh said effective plantation with the study of different land use site will help reduce air pollution in the city.

“like human beings, plants also have a defence immune mechanism which helps to protect the plant and increases the pollution tolerance power and plant life. C4 plants have a higher level of that defence mechanism,” said Gosh.

“The life of plant faces threat because of two type of pollution: Dust pollution and gases (vehicular emission) pollution. C4 plants are most efficient in photo synthesis and henceforth have strong defence mechanism,” Gosh elaborated.

Considering the human health factors, Priyanka, a research scholar, said effective plantation will help to protect human being from harmful effect of Volatile organic Compound (VOC). “VOC is released during the transmission of oil in vehicles. The harmful gases released from the vehicular emission cause lung cancer. The plants having the high tolerance power will help in cleaning air,” added Priyanka.

Reacting on the finding of DU, environmentalist Gopal Krishna said such findings should be considered in policy making on environment issues. “We have scientific evidence now while plantation, one should consider these characteristics.”