If you live in a metro, or big cities like Delhi, Mumbai, Bengaluru, and Ahmedabad, you will often find giant screens staring down at you at prominent crossroads. These screens indicate pollution levels and temperature. The numbers are supposed to alarm us, but most of us drive past. We have been cutting trees for decades now to accommodate development.

We keep reading about variations in weather due to climate change. The changes have been so rapid and on such large scale that, at times, predictions made by experts fall flat. Rapid industrialisation and increased use of vehicles and electronic goods have added to our miseries. Cities in our country often find mention among the most polluted ones in the world. There have been big talks about saving the environment, but when it comes to the implementation, we have failed miserably.

Today is World Environment Day. Like every year, this year, too, the government and non-government bodies will organise plantation drives, conferences, and awareness drives, and yet the situation will continue to worsen with each passing year.

The theme for this year’s World Environment Day is biodiversity. Incidentally, plants and trees are accurate indicators of the quality of air, water and sand. The presence of pollutants instantly affects the growth of leaves and plants. For instance, the presence of Sulphur Dioxide and Nitrogen Dioxide in the atmosphere leads to Necrosis (premature death of living tissues) and Chlorosis (discoloration of green leaves) in pine trees. The tender, needle-like leaves give this indication.

We should study plants to know about the presence of pollutants in the atmosphere and use it as an effective tool in pollution monitoring. Many studies have been carried out in this regard that have successfully established a connection between pollution and its ill-effects on leaves and plants. These plants include small tress, big trees, shrubs, trees grown in farms and those grown along roads.

Pollution has also led to a change in the chemical composition of plants. In 1986, a study conducted by a few scientists revealed that the presence of pollutants and Suspended Particulate Matter (SPM) affected Cordia myxa plants. While these changes were observed in many plants and trees like peepul, Maharukh, Akona, Ashok and Parijaat, the Banyan tree was the least affected.

The presence of SPM and dust affect Mango trees the most. It affects their productivity. The dust particles tend to get stuck onto mango leaves. Similarly, Neem and Gular plants “attract” industrial ash. This affects the process of photosynthesis and leaves, and after a while the whole plant, die a natural death. Scientists Baig and Farooq, in a study conducted in 1988, found that the presence of Sulphur Dioxide in the atmosphere has an adverse impact on imli, jungle jalebi, peepul, neem and gular. The leaves fall off before they ripen.

Scientist Kulshrestha and his colleagues published a report in 1994 which mentioned that diesel vehicles cause immense damage to narangi and jamun leaves. Likewise, scientist Ghosh, in his report, mentioned that petrol and diesel vehicles affected wood-producing quality of sagwan trees by 26%.

Thus, many studies have proven that each and every plant reacts in a different way to pollution. One must read an article published in 2005 by Pramod Kumar Singh from the Institute of Rural Management, Anand. Trees and plants are accurate indicators of environmental pollution. It is imperative to keep these factors in mind while carrying out plantation drives.

Plants that are susceptible to petrol, diesel and industrial ash should not be planted in such areas. This way we will save both, time, and money. If we see any changes in plants and leaves, experts must study those changes periodically. We must, in fact, plant trees in parks, along the roadside or simply for beautification purpose so that it’s easier for us to study rising pollution and its aftereffects. If we want out next generation to breath, we must act now and do something.