For 3 days from June 13 to 15, 2018 air quality at ‘severe’ levels in the city of Delhi. The spike in pollution levels led to the Lieutenant Governor of Delhi banning all construction activities in Delhi until June 17, 2018. The air quality started improving on June 15, 2018 when an AQI (Air Quality Index) of 447 for the day was recorded (HT, 2018). During the 3 days, Delhi was covered with a thick blanket of smog and haze whose chief cause was attributed to dust storms occurring in western India due to anti-cyclonic winds (Gandhiok, 2018).
According to the Central Pollution Control Board (CPCB), the levels of PM10 particles had shot up to about 8 times that of safe limits on June 13. According to the System of Air Quality and Weather Forecasting and Research (SAFAR) PM10 concentrations on Wednesday reached up to an extremely high 981 µg/m3 and the average concentration remained mostly between 900 and 932 µg/m3 (Singh, 2018). By 6 pm on Friday, June 15, these levels had dropped to 638 µg/m3 while PM2.5 concentrations came down to below levels deemed severe to 162 µg/m3. The thick blanket of smog and haze was removed with visibility at the Indira Gandhi International (IGI) airport in Delhi improving from 1,500 m on June 13 to 2,500 m on June 15 due to the weakening of the strong westerly winds that was bringing dust from arid regions in western India. The chief mode of operations adopted by the Delhi government for mitigation was sprinkling water on roadsides, sweeping of major roads and issuing challans for those indulging in construction activities during the period (HT, 2018).
Air Pollution in Delhi
While in China, air pollution exposures have begun to exhibit a slight decline, India has witnessed among the steepest increases in air pollution levels in the world since 2010.In India concentrations of PM2.5 and PM10 particles and ground level Ozone have been significantly increasing in the present decade. Air pollution can lead to strokes and ischemic heart disease, chronic obstructive pulmonary disease, acute lower respiratory infections and lung cancer. About 25 per cent of deaths globally (out of a total of 4.1 million deaths) due to long term exposure to ambient PM2.5 in 2016 occurred in India (HEI, 2018). A study by IIT Bombay, the Institute for Health Metrics and Evaluation (IHME) and the Health Effects Institute (HEI) found that the largest sources for health impacts due to air pollution in India are coal combustion and household burning of fuel (IIT, IHME & HEI, 2018). Other significant sources of air pollution in India can include burning of crops, proliferation of dust, emissions from brick kilns, industrial emissions, vehicular emissions and emissions due to construction activities. Sometimes an arbitrary event like the dust storm in western India as in the recent event can also contribute to a spike in air pollution.
The Central Pollution Control Board (CPCB) is responsible for measuring the air quality for the Government of India and also helps in framing policies on combating air pollution. Real-time air quality data for multiple locations in the country is provided by the CPCB with the provision of manual and also automatic ambient air quality monitoring in some places. The CPCB functions as the apex body, which works along with state functionaries to formulate programmes for preventing and controlling pollution in the respective states. CPCB works in cooperation with State Pollution Control Boards (SPCBs) for monitoring air pollution levels and presenting the results to the Ministry of Environment, Forests and Climate Change (MoEF&CC) which is the governing body. The MoEF&CC drafts and formulates policies on the basis of the data that is provided.
The Ministry of Earth Sciences (MoEF) in collaboration with the Indian Institute of Tropical Meteorology (IITM) set up the System of Air Quality and Weather Forecasting and Research (SAFAR) to monitor air quality under its SAFAR monitoring network. SAFAR uses multiple micro-environments instead of depending on a single source to calculate the air quality index of the target city. Delhi is among the four cities serviced by the system which also checks levels of pollutants for Mumbai, Pune and Ahmedabad. Pollutants such as PM1, PM2.5, PM10, carbon monoxide, ozone, sulphur dioxide, benzene, non-methane hydrocarbons and mercury are monitored by the system. Certain meteorological parameters such as solar radiation, ultraviolet radiation, temperature and rainfall are also analyzed by the system. Apart from air quality monitoring stations on the ground, satellite images can also provide information on the extent of the situation, especially during periods with peak-pollution levels. However, monitoring is not enough and it at best represents a first step along with regulations governing emissions which can be considered a necessity in mitigating air pollution and structured strategies are required to provide comprehensive solutions.
Very few cases have been registered under the Air (Prevention and Control of Pollution) Act, 1981, and the policy approach has largely been focused on monitoring of air pollution without comprehensive directives on limiting the extent of emissions. Most action on limiting emissions in Delhi mostly occurs in periods when air quality deteriorates to significant levels. In Delhi although the Graded Response Action Plan (GRAP) was introduced in 2017 for tackling air pollution in the capital on a daily basis, actions mostly include prohibiting certain activities that contribute to air pollution depending on whether the air quality is at the good to severe to emergency levels. Even in emergency levels for AQI, certain activities are suspended temporarily, instead of placing a focus on permanently limiting emission from sources. Mitigating air pollution requires a focus on achieving a level of limiting emissions that is more constant and consistent. Air pollution being temporary and transient in nature requires a system of constant monitoring and mitigation in which temporary prohibitions on emission sources will not help in achieving the ideal solution.
Air pollution in Delhi, however, can remain consistently high, as can be illustrated if we take the account of 10 most polluted days of 2018 based on the AQI measured by the CPCB till May 2018. Pollution can be high in Delhi in the winter months, when the air can remain relatively stagnant. All of the 10 most polluted days in Delhi in 2018 till May occurred in the Month of January. The most polluted day in 2018 was January 2, with an AQI of 408. This was followed by January 6, with an AQI of 404, January 19 (403), January 1 (400), January 3 (398), January 18 (395), January 5 (388), January 4 (362), January 9 (357) and January 13 (357). The most polluted day in Delhi in 2018 till May apart from the top 10 days in January was April 21 with a AQI of 356 (CPCB, 2018). The other months apart from January had comparatively lower pollution levels which nonetheless were still consistently unhealthy. However, on June 15 an AQI of 447 was recorded in Delhi making the day more polluted than January. Policy must not look only at days when air pollution reaches severe to emergency levels as these represent days when pollution reaches hazardous levels and air pollution levels in Delhi for 2018 have remained consistently unhealthy which is the most important aspect to note.