Through the thick air

This Diwali, PM 10 and PM 2.5 reached eight times the safe limit. Its not the first time and it won't be the last. Burning of crop stubble, road dust and vehicular emissions are main culprits

By Polash Mukerjee, Shambhavi Shukla, Anisha Raman
Published: Tuesday 01 November 2016
People with heart or lung disease, older adults, and children have been advised to remain indoors. Credit: BD Photo 1/ Flicker

Delhi faces its worst smog; CSE calls for emergency action

As visibility remains poor and the city chokes its way through a haze, the Centre for Science and Environment (CSE) has pressed the alarm buttons on one of the worst smog cases in many years in Delhi. The CSE experts say that the India Meteorological Department (IMD) suggests that the smog on November 2, 2016 was the worst in 17 years.

Says Anumita Roychowdhury, executive director (research and advocacy), CSE and head of CSE’s air pollution and sustainable mobility teams: “This demands emergency response to protect the vulnerable— those who are suffering from respiratory and heart diseases and children. The government should aggressively inform all and advise them to stay indoors and avoid outdoor exercises. At the same time, it should roll out stringent winter pollution control for all sources along with emergency action.”

The CSE analysis of available official data brings out the following:

Post-Diwali peak of pollution is higher than the Diwali peak.

  • The analysis of data from the Delhi Pollution Control Committee shows that the levels of PM2.5 have increased by 62.7 per cent on November 2 as compared to that on Diwali. On November 2, the levels were 9.4 times the standard.
  • On the night of November 1, (12 am to 6 in the morning of November 2), the PM2.5 concentration had hit 548 microgramme per cubic metre (µg/m³)—nine times the safety standard. The following day (November 2), PM2.5 concentration (6 am to 12 noon) increased to 696.25 µg/m³—11.6 times the standard. The morning concentration was 27.1 per cent higher compared to the night time concentration. The hourly averages were as high as 800-900 µg/m³.
  • According to SAFAR, the PM2.5 levels are in severe category and are expected to remain in this category for more than three days.

Worst ever smog in 17 years—November 2, 2016

According to the Indian Meteorological Department, this is the worst smog with very poor visibility in 17 years. The Indira Gandhi International Airport in Delhi recorded the worst levels of smog in 17 years on November 2, with visibility as low as 300-400 metres. The period between 11AM and 2:30 PM was the worst in the day with respect to airport visibility. The post-Diwali smog reduced the visibility there to 800-1,200 metres since October 30. Pollution during Diwali and other sources of pollution along with weather-related factors lead to such abnormal levels of smog.

Meteorological scientists explain that lower level anticyclone—a weather phenomenon which prevented the dispersion of smog— developed around Delhi on November 2, 2016. There was virtually no wind in the vertical column. This situation is expected to persist for few more days.

The Central Pollution Control Board has already warned that the average wind speed this year on Diwali day was much less—1.3 m/s compared to 3.4 m/s in 2015. Also, the mixing height this year was 492 metres, whereas in 2015 it was 590 metres. The lower wind speed and mixing height do not allow wind to disperse quickly leading to higher concentration of pollutants on the surface.

Unending paddy burning in Punjab, Haryana and Uttar Pradesh

The satellite images of NASA’s fire mapper showed that incidences of paddy burning in Punjab, Haryana and Uttar Pradesh have increased after Diwali. The images clearly revealed that after October 30, 2016, crop burning in the Punjab, Haryana and Uttar Pradesh became more aggressive, leading to severe smog in the national capital.

Crop burning in neighbouring states leading to severe smog in the national capital. Source: NASA Fire Mapper

Act Now

“Delhi needs strong action to protect people from such deadly exposure. It is imperative to put out hard health evidences and heath alerts in the public domain to sensitise people about the harmful effects of smog and push action. Delhi needs an effective winter pollution mitigation plan that can make a difference.  Without a strong action, smog is only expected to get worse this winter. It comes with serious public health costs,” says Roy Chowdhury.

  • Issue daily health advisory to people: India has already adopted a system of issuing health advisories along with its air quality index. But this is not being utilised to issue alerts to people. It clearly states that not only those who are ailing are extremely vulnerable at the current level of pollution, but also the general public who can develop a host of symptoms.
  • Issue official advice to children and ailing to stay indoors: Health advisory needs to inform people to keep children and those suffering from heart and respiratory ailments and chronic obstructive pulmonary disease (COPD) indoors and avoid outdoor exercises. Schools should be shut if necessary. Children are more vulnerable as they have a poor defence mechanism. Their ability to metabolise and detoxify environmental agents is different. Given their hyper level of physical activities, they inhale more volume of air than adults and therefore, breathe in more pollution. Joint studies of Central Pollution Control Board and the Chittaranjan National Cancer Research Institute from Kolkata have shown that every third child in Delhi has impaired lungs. At their growing age, due to greater level of physical activity, they inhale more volume of air and therefore more pollution.
  • Need pollution emergency plan to cut peak pollution levels: The government must announce a slew of emergency actions. It needs to implement measures to reduce vehicle numbers, shut down the Badarpur power plant and take very stringent action on waste burning, construction activities and ban on fireworks in all social events during winter.
  • Roll out short- to mid-term action for enduring change: This year has been a lost opportunity when it comes to adopting both short- mid-term measures. Other than truck entry, no other tangible action has been taken, especially on improving public transport, encouraging walking and cycling and putting restraints on parking. A time-bound action will have to be rolled out immediately.
  • Need inter-state cooperation and intervention of the Central government to control farm fires in Punjab and Haryana: The action directed by the Supreme Court as well as the National Green Tribunal related to subsidy for farmers to buy appropriate technology that will prevent burning of straw as well as the infrastructure for reusing straw should be put in place very quickly. This needs financial support from the central as well as state governments.

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