If you go up on a high building in Kolkata and look down on the glittering lights of the street below, you can see an engulfing gray haze, especially in the winter months. Although Kolkata has become much cleaner in last few years, particularly with an efficient waste management system in place, it is high time to consider better measures to control air pollution in Kolkata.
In the past two-and-a-half years, Kolkata’s air qualified as ‘good’ only once for a fortnight in August 2015. In the 31 months between January 2014 and July 2016, and all through this period the average monthly SPM (Suspended Particulate Matter) count was always above the permissible limit without any exception.
According to data recorded by equipment installed to measure SPM count, the fine suspended particulate matter of 2.5-micron dimension varies from high to very high to terrible between October and March every year. The fine particles in the air enter the respiratory tract unhindered and have aÂ severe health impact. Generally the worst month is January when the air is heavy with PM 2.5 that hangs low over the surface because of low atmospheric temperature. The best month is August when rains make the deadly particles settle down and consequently the air is much cleaner.
A large number of people walk to work or take public transport compared to other megacities of India. These are the people who are the most vulnerable to poor air quality in Kolkata for respiratory diseases, asthma and heart disease.
The Concentration of Coarse Dust Particles are Particularly High in Kolkata
A recent report published by the World Health Organization (WHO) states that the coarse dust particles â€“ chiefly a byproduct of construction activities – have made Kolkata the fourth most polluted â€˜megacityâ€™ in the world,Â The report is based on the presence of such particles in the air of the city between 2011 and 2015.
This report ranked the large cities in terms of the bigger coarse particles as opposed to the fine ones. These particles are denoted as PM10 level â€“ particulate matter. In other words, these are between 2.5 and 10 micrometers in diameter and float in the air.
While the cityâ€™s PM10 level soared to around 140 micrograms per cubic metre, the WHOâ€™s safety limit for this coarse pollutants is not more than 20 micrograms per cubic metre. The Indian safety limit is 60 micrograms per cubic metre.
The report has placed Delhi at the top of the list, while Cairo and Dhaka occupy the second and third positions respectively. Kolkata comes fourth just ahead of Mumbai.
These particles, when inhales with air, lodge deep in the lungs and invade the respiratory systemâ€™s natural defenses. They increase the number and severity of asthma attacks, cause or aggravate bronchitis and other lung diseases, and reduce the bodyâ€™s ability to fight infections. Children and the elderly are most vulnerable. Such cases have shot up manifold in Kolkata over the years.
High Number of Diesel Cars Aggravates Kolkataâ€™s Vehicular Pollution
Kolkata has very limited road space compared to other cities and vehicular congestion is particularly high in Kolkata. The presence of Nitrogen Dioxide (NO2) is almost twice the permissible limit in Kolkata. Other vehicular pollutants like the oxides of Carbon and Sulphur are also high in Kolkata as 65% of new vehicles in Kolkata are diesel cars. Moreover, 45 per cent of the total oil consumption by the cityâ€™s vehicle users is constituted by diesel. Thatâ€™s nearly half the fleet of vehicles adding to pollution in Kolkata.
Recent data on Kolkata air pollution released by the Centre for Science and Environment clearly points towards an alarming situation in the â€˜City of Joyâ€™.
Measures to Control Air Pollution in Kolkata
The biggest challenge to air quality in Kolkata is the exponential growth of private vehicles and in particular, diesel vehicles. Automobile emissions are reportedly responsible for more than half of the air pollution load in Kolkata. The city has an additional problem of theÂ very old fleet of vehicles â€” nearly 54 per cent of these is old and highly polluting, and 55 per cent is diesel-driven.
The government must fight the problem on few fronts. On the one hand, it must ensure better mobility for cars while making its public transport system modern and efficient. We need a system that focuses on efficiently moving the bulk of the city passengers and not only flyovers and more roads for cars. This is particularly important in Kolkata, which is also constrained by the road space â€“ it has less than 10 per cent of its land area under roads, against Delhiâ€™s 25 per cent. Therefore, even though the city has fewer cars than Delhi â€“ 0.4 million against Delhiâ€™s 1.1 million, the result is the same â€“ growing congestion and pollution. It is important to expand the infrastructure for buses and not cars.
Kolkata is one of the few cities which have got multi-modal transport systems. Ensuring all components of this system to work in an efficient and integrated manner is vital. It is also important to ensure compliance of pollution checks by all vehicle owners with stricter penal provisions for non-compliance.
While the government must continue with environmental awareness development campaigns through mass media, the citizens must do their bit to have a clearer air to breathe in. Kolkatans must use more of public transport and pool cars while going to the workplace. Regular efforts at tree plantation also help in spreading the message. The citizens must focus on green livingÂ as a way of life to minimize the effects of air pollution in Kolkata.
Kolkata can also consider installing mega air purifiers at chronic traffic-prone junctions in the city.
Kolkata gets a lot of dust particles carried by north-westerly winds coming from the Northern India. Dust absorbing cleaning vehicles can be used to clean the roads as well as regularly washing them with water.
The authorities should also take specific steps to control the spreading of coarse particles by engaging with the construction industry and finding out remedial measures.
It is commendable that the authorities have started on a plan to control air pollution in Kolkata. As a part of the process, a team of experts from the National Environment Engineering Research Institute, Nagpur, are in Kolkata to conduct an 18-month-long study to understand the different sources of pollution affecting the city.
West Bengal Pollution Control Board is also considering various measures to fight the air pollution menace in Kolkata.