A recent report released by the World Health Organisation (WHO) has stated that air pollution is killing nearly 8,00,000 people a year in the southeast Asia region, with India alone accounting for at least 75 per cent of pollution-related casualties due to cardiovascular diseases and lung cancer. The report also stated that nine out of 10 people globally suffer from poor quality air, while nearly 90 per cent of air-pollution-related deaths occur in low and middle-income countries. With such proportions of loss, the WHO has rightly ascribed the conditions as ‘public health emergency’.

This state of emergency pertinently applies to Delhi, which has witnessed deteriorating levels of air quality, at times challenging and almost displacing Beijing as the most polluted city. Nearly 97.5 per cent of Delhi’s 16.8 million people live in urban areas, giving the city a density of 11,297 persons per sq km and making it one of the most populous regions in the country. The national capital’s air quality has particularly deteriorated with fine particulate matter (PM) levels at almost four times above the daily safe standard. The PM 2.5 particles of soot and other contaminants suspended in the air are 2.5 micrometers in diameter and about 30 times finer than a human hair. Fine dimensions of the PM allow it to be trapped in the lungs, thereby making it one of the greatest concern to public health, as it has been shown to cause lung cancer, cardiovascular and respiratory diseases, asthma, and other health problems.

The monsoon season is the only time when Delhi’s air is relatively clean, because rain and winds diminish the impact of pollutants. But with winter approaching, Delhi and other parts of north India show a noticeable spike in air pollution. Delhi experiences air quality that is more than twice as polluted than during the spring and summer. On an average, winter day, concentrations of PM 2.5 exceed 200 milligrams per square meter (mg/m2), which is considered as a very poor rating on the Air Quality Index.

The spike in air pollution levels in India during the winter season is a regular annual feature and is caused due to the culmination of several major polluting activities taking place between October and December. The air quality during the winter season plummets as biomass is burnt to heat homes in the urban and peri-urban areas. Also, this part of the year is the end of the harvest season, which causes the farmers to burn the stubble off their fields. In fact, satellite imagery released by Nasa each year shows immense smoke emanating from crop stubble burning in north Indian States such as Punjab and Haryana.

These polluting conditions during winters are further exacerbated due to the functioning of many brick kilns that operate on the periphery of Delhi. Though the Supreme Court banned brick-manufacturing in Delhi in 1996, the industry responded by simply shifting production to just outside the city’s municipal limits. As on date, more than 1,000 brick kilns operate inside the National Capital Region and their main production period coincides with Delhi’s winter season. Estimates suggests that nearly 15 per cent of the PM 2.5 affecting Delhi can be attributed to brick kilns, putting kilns on par with truck traffic and power generation as sources of PM 2.5.

These polluting activities are joined by meteorological forces in the form cool air that stagnates over the city, keeping pollution close to the ground where people breathe. Additionally, Delhi’s persistent winter fog and the festival of Diwali only worsen the problem. Given this critical situation, the Government must recognise the public health damage being caused by air pollution every year, especially during winter, and formulate adequate strategies to counter the menace.

Though the authorities have recognised crop-burning as a major contributor and have imposed stiff penalties on the offenders, besides prosecuting them, there is an actual gap between the regulation and its forceful implementation. The enforcement officers at the district level are facing increasing difficulties due to acute staff shortage, resulting in a single vigilance officer being responsible for more than one district. This makes it virtually impossible to detect and monitor cases of crop-burning.

Another hindrance is the fact that the local authorities do not have any power to impose penalty on the farmers and can only recommend cases for prosecution — this in itself is a long-drawn process. For instance, during the last paddy season, a total of 46 cases were recommended for prosecution, while during the wheat season, 48 cases were recommended. The Government must combine regulations with incentives in order to get the desired result.

The winter season and its relationship with pollution levels are critical factors that have so far escaped the observation of the policymakers. The intensity of pollution reaching intolerable levels, especially during the winters, is a recurrent annual phenomenon that needs to be curbed by the Government on a priority basis. There needs to be a roadmap for the purpose.