Blurred vision: Cold wave and smog conditions across the capital hit road, rail and air traffic movement. Photo: Ninara, flickr.

Marginal improvement in air quality 4 years after NCAP launch

Under the National Clean Air Programme (NCAP), marginal improvements in air quality were seen last year in certain cities but most of them continue to breach the safe limits under the national ambient air quality standards. Delhi remained at the top of the most polluted cities in the country in 2022 with an annual average of PM 2.5 concentration 99.7 micrograms per cubic metre (ug/m3) of air, much above the Central Pollution Control Board (CPCB) standard of 40 ug/m3 of air, according to analysis by NCAP Tracker which showed that PM 2.5 levels in Delhi showed a 7% improvement from 108 ug/m3 in 2019.

The programme, meant for 131 non-attainment cities, has so far spent over ₹6,897 crore since its launch in Jan 2019. most cities in the top 10 most polluted list of 2022 are from the Indo-Gangetic Plain, demonstrating the need for an airshed approach for better air pollution management in the region beyond Delhi, the report states. Among the least polluted non-attainment cities last year, nine of the 10 cities have,however, breached the annual permissible limit of 60 micrograms per cubic meter (ug/m3) for PM 10, indicating the air isn’t safe even in the cleanest cities.

Data also reiterates the need to check pollution at source to obtain maximum benefit from pollution mitigation efforts. All three of Bihar’s non-attainment cities – Patna, Muzaffarpur and Gaya, now feature in the top 10 most polluted cities on the basis of PM 2.5 levels. In comparison to the 2019 rankings, five cities still rank among the top 10 most polluted cities in the PM2.5 list – Delhi, Noida, Ghaziabad, Jodhpur and Mandi Gobindgarh.

‘Severe’ to ‘very poor’ air quality: low visibility, accidents, train and flight delays

All of last week Delhi saw cold wave conditions (min temperatures around 3 degrees), with very dense fog with visibility to just 25 metres, hitting road, rail and air traffic movement, the weather channel reported. Around 29 trains were delayed by two to five hours, and around 15 flights were affected by the fog. Visibility recorded (in m) at 0530 hours IST of 09.01.2023. Punjab: Bhatinda-0, Amritsar-25; Haryana, Chandigarh & Delhi: Chandigarh-0, Ambala-25, Hissar-50, Delhi (Safdarjung)-25, Delhi (Palam)-50; Uttar Pradesh: Agra-0, Lucknow (Amausi)-0, Varanasi (Babatpur)-25, Bareilly-50,” said India Meteorological Department in a tweet. Satellite imagery revealed the fog layer extended from Punjab and adjoining northwest Rajasthan to Bihar across Haryana, Chandigarh & Delhi and Uttar Pradesh, IMD reported. 

Delhi recorded an overall ‘very poor category’ air quality index at 395 on Monday morning, according to System of Air Quality and Weather Forecasting And Research (SAFAR). The AQI at Pusa and Delhi University reached 404 and 415 in the severe category, while Lodhi Road recorded 377, Dhirpur 391 and Ayanagar 379, all in the ‘very poor category’ on Monday morning. An AQI between zero and 50 is considered ‘good’; 51 and 100 ‘satisfactory’; 101 and 200 ‘moderate’; 201 and 300 ‘poor’; 301 and 400 ‘very poor’; and 401 and 500 ‘severe’. WHO recommended level for PM2.5 is 5-10, and PM 10 is 15-20.

Delhi-NCR coal ban: Industries battle soaring gas prices, tough emissions standards

Industries in the National Capital Region (NCR) around Delhi are finding it tough to operate after the government’s Commission for Air Quality Management (CAQM) banned use of coal and other ‘dirty fuels’ on June 23, 2022. The panel released a list of approved fuels for various applications across NCR which allowed low-sulphur coal in thermal power plants. Rising PNG prices and difficulty in using biomass including the problem of storing it is forcing industrial units to shut down or make plans to relocate out of the NCR. Many units are burning wood as an alternative, which is not in the approved list of fuels, and authorities have not been able to provide a solution for such problems. 

Meanwhile, The commission has ordered pollution control boards to shut the industrial units that are defaulting on fuel norms without warning from January 1, 2023. The commission has allowed firewood and biomass briquettes for religious purposes, cremation, for grill and tandoors, dhabas and restaurants. 

‘Polluted Paradise’: Kashmir’s air quality worsens during winter, and summer

There’s a steep rise in cases of respiratory tract infections because of rising air pollution in Kashmir in winters and in summers as well. reported Mongabay. Srinagar city has the highest incidence of lung cancer in the country, and J&K has a high prevalence of lung diseases, and air pollution is a major risk factor for the ailments, according to a lung specialist quoted by Mongabay. Earlier study of lung cancer had found that Age Standardized Rate  for males and females in Kashmir valley is 11.21/100,000 population, being 17.21/100 000 in males. Srinagar district has the highest ASR of 19.34/100 000 in males in India. According to a study, 4,750 people per 100,000 population suffer from chronic obstructive pulmonary diseases, with air pollution being the leading risk factor.  A 2018 study indicates  that the emissions due to domestic coal usage account for 84% (1246.5 tons/year) of the total annual emission, followed by the emissions from vehicular combustion that is 220.5 tons/year. The least are the emissions from fuel wood burning that is around 8.06 tons/year.

Srinagar has been declared as a Non-attainment city (NAC) in the J&K action plan under the National Clean Air Program (NCAP). Non-attainment cities are those that have fallen short of the National Ambient Air Quality Standards (NAAQS) for over five years.

PM 2.5 Study: Chloride dominates inorganic aerosol formation from ammonia in the Indo-Gangetic Plain during winter

A new study from the Indian Institute of Tropical Meteorology has found that Chloride (HCl / Cl−) dominates inorganic aerosol formation from ammonia in the Indo-Gangetic Plain during winter:  The study shows Chloride was missing from the assessments in the standard model. The study, for the first time in South Asia, evaluates the performance of a chemical transport model (WRF-Chem) in modeling NH3, NH, and total NHx, by comparing them against the The Winter Fog Experiment (WiFEX) measurements (MARGA). 

The study said, under the winter conditions of high relative humidity (RH) in Delhi, hydrogen chloride (HCl) was found to promote the increase in the particle fraction of NH (which accounted for 49.5 % of the resolved aerosol in equivalent units), with chloride (Cl−) (29.7 %) as the primary anion. By contrast, the absence of chloride (HCl  Cl−) chemistry in the standard WRF-Chem model results in the prediction of sulfate (SO) as the dominant inorganic aerosol anion. Scientists concluded that modelling the fate of NH3 in Delhi requires a correct chemistry mechanism accounting for chloride dynamics with accurate inventories of both NH3 and HCl emissions.

The study suggests that anthropogenic HCl may be promoting this increase in particle fraction of NH and Cl− via partitioning into the aerosol, deprotonating in the aerosol water, followed by NH3 partitioning and being protonated by the ionization of the strong electrolyte HCl. 

Typical Delhi winter conditions of excess NH3, high RH, and low T favor gas-to-particle partitioning of NH3. It is likely that high Cl− in Delhi resulted from gas–to-particle partitioning of HCl into aerosol water in the presence of excess NH3 . The site was impacted by a cluster in northwest Delhi of industrial processes, such as steel pickling industries, and others include metal finishing and electroplating, which are known to be vital HCl emitters, the study said. 

Indoor air pollution: US govt agency plans to ban gas stoves

A US government agency is planning to ban gas stoves amid rising concern about harmful indoor air pollutants emitted by the appliances. The US Consumer Product Safety Commission is considering a ban  to address the pollution which can cause respiratory problems. “This is a hidden hazard,” Richard Trumka Jr., an agency commissioner, said in an interview. “Any option is on the table. Products that can’t be made safe can be banned.”, reported Bloomberg citing new peer-reviewed research published last month in the International Journal of Environmental Research and Public Health found that more than 12% of current childhood asthma cases in the US can be attributed to gas stove use.

Natural gas (campaigners say the term “natural” was coined by fossil fuel industry itself) stoves which are used in about 40% of homes in the US, emit NO2, CO (carbon monoxide) and fine particulate matter at levels the EPA and WHO have declared unsafe and linked to respiratory illness, cardiovascular problems and  cancer, according to reports

Few lawmakers in a letter asked the commission to consider warning labels, range hoods and performance standards and called gas-stove emissions a “cumulative burden” on Black, Latino and low-income households that disproportionately experience air pollution.