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Centre for Science and Environment data- The New Indian Express

BENGALURU: An analysis of winter air pollution has good news for Bangalore: the city has been able to retain most of the air quality improvements achieved during lockdown in 2020. The analysis, based on Air Quality Index categorization (AQI), indicated that in southern India, Chennai and Kochi have shown a similar trend. The Center for Science and Environment (CSE), New Delhi, published the analysis on Friday. For Bangalore, the number of ‘good’ AQI days in 2021 was 208, only marginally lower than the 214 days recorded in 2020. Interestingly, within the city, Bapuji Nagar, mainly a residential area, was the hardest hit with its December average record 76 ug/m3. Peenya, despite being the industrial center, had the least polluted air with a monthly average of 36 ug/m3 for December 2021. Avikal Somvanshi, Program Manager, Urban Data Analysis Laboratory at CSE, noted that the cause of emissions due to vehicular traffic and burning of garbage nationally in areas such as Bapuji Nagar contributed to air pollution, while a Better regulation and monitoring at Peenya helped control contamination. “In fact, the AQI is worse in BTM Layout and Jayanagar than in the industrial centers,” he said. The analysis covers ten Continuous Ambient Air Quality Monitoring (CAAQMS) stations in Bangalore, of which no data was available for the second half of 2021 (June to December) from two stations: City Railway Station and Sanegurava Halli. In Karnataka, a station was covered in Bagalkot, Bidar, Chamarajanagar, Chikkaballapur, Chikkamagaluru, Davanagere, Gadag, Hassan, Hubballi, Kalaburagi, Kolar, Koppal, Madikeri, Mangaluru, Mysuru, Raichur, Ramanagara, Shivamoggai, Udupi and Udupi. . Gadag and Kalaburagi reported days of poor air quality, in fact the AQI in these cities may fall into the “very poor” category, but due to the large amount of missing data it is unclear how long these episodes of poor air quality actually last. air quality, the report clarified. . During the worst weekly pollution episode in winter, Gadag recorded a weekly average of 192 ug/m3 (nearly five times its annual average) and Kalaburagi recorded 104 in mid-December. Regarding the seasonal increase in NO2 concentration, Kalaburagi recorded a 5.8-fold increase in monthly NO2 levels, Hubballi was 3.3-fold compared to the months of November, October and September. There is a significant increase in the amount of surface ozone (O3) in the air as Kalaburagi (93 µg/m3) and Udupi (81 µg/m3) were listed in the report. “There is a need for urgent action across sectors to control pollution from vehicles, industry, power plants, waste burning, construction, and the use of solid fuels in homes in all states to meet clean air standards throughout the year,” said Anumita Roychowdhury. , Executive Director, Research and Advocacy, CSE.

2020 ರ ಲಾಕ್ ಡೌನ್ ಸಮಯದಲ್ಲಿ ಇದ್ದ ವಾಯು ಗುಣಮಟ್ಟ ಉಳಿಸಿಕೊಂಡ ಬೆಂಗಳೂರು!

ಚಳಿಗಾಲದ ವಾಯು ಮಾಲಿನ್ಯ ವಿಶ್ಲೇಷಣೆ ಬೆಂಗಳೂರಿನವರಿಗೆ ಸಿಹಿ ಸುದ್ದಿ ನೀಡಿದೆ. ನಗರ 2020 ರ ಲಾಕ್ ಡೌನ್ ಅವಧಿಯಲ್ಲಿ ಸುಧಾರಣೆ ಕಂಡಿದ್ದ ವಾಯುಗುಣಮಟ್ಟವನ್ನು ಉಳಿಸಿಕೊಳ್ಳುವಲ್ಲಿ ಯಶಸ್ವಿಯಾಗಿದೆ. ಬೆಂಗಳೂರು: ಚಳಿಗಾಲದ ವಾಯು ಮಾಲಿನ್ಯ ವಿಶ್ಲೇಷಣೆ ಬೆಂಗಳೂರಿನವರಿಗೆ ಸಿಹಿ ಸುದ್ದಿ ನೀಡಿದೆ. ನಗರ 2020 ರ ಲಾಕ್ ಡೌನ್ ಅವಧಿಯಲ್ಲಿ ಸುಧಾರಣೆ ಕಂಡಿದ್ದ ವಾಯುಗುಣಮಟ್ಟವನ್ನು ಉಳಿಸಿಕೊಳ್ಳುವಲ್ಲಿ ಯಶಸ್ವಿಯಾಗಿದೆ. ವಾಯುಗುಣಮಟ್ಟ ಸೂಚ್ಯಂಕ (ಎಕ್ಯುಐ) ವರ್ಗೀಕರಣದ ಪ್ರಕಾರ ದಕ್ಷಿಣ ಭಾರತದಲ್ಲಿ ಚೆನ್ನೈ ಹಾಗೂ ಕೊಚಿ ಇಂಥಹದ್ದೇ ಟ್ರೆಂಡ್ ನ್ನು ಹೊಂದಿದೆ. ಈ ಅಂಕಿ-ಅಂಶಗಳನ್ನು ನವದೆಹಲಿಯ ವಿಜ್ಞಾನ ಮತ್ತು ಪರಿಸರ ಕೇಂದ್ರ ಬಿಡುಗಡೆ ಮಾಡಿದೆ. 2021 ರಲ್ಲಿ ಬೆಂಗಳೂರಿಗೆ ಉತ್ತಮ ಎಕ್ಯುಐ 208 ರಲ್ಲಿದ್ದು ಇದು 2020 ರಲ್ಲಿ 214 ದಿನಗಳ ಕಾಲ ದಾಖಲಾಗಿದ್ದಕ್ಕಿಂತ ಸ್ವಲ್ಪ ಕಡಿಮೆ ಇದೆ. ಅಚ್ಚರಿಯೆಂದರೆ ನಗರದ ಒಳಭಾಗದಲ್ಲಿ ಅತಿ ಹೆಚ್ಚು ಜನಸಂದಣಿ ಹೊಂದಿರುವ ಬಾಪೂಜಿನಗರ ಡಿಸೆಂಬರ್ ನ ಸರಾಸರಿಯಲ್ಲಿ ಅತ್ಯಂತ ಕಳಪೆ ಅಂದರೆ 76 ug/m3 ವಾಯುಗುಣಮಟ್ಟವನ್ನು ದಾಖಲಿಸಿಕೊಂಡಿದೆ. ಪೀಣ್ಯ, ಕೈಗಾರಿಕಾ ಪ್ರದೇಶವಾಗಿದ್ದರೂ ಡಿಸೆಂಬರ್ 2021 ರಲ್ಲಿ ಸರಾಸರಿ 36 ug/m3 ನ್ನು ದಾಖಲ್ಪಿಸಿದ್ದು, ಅತ್ಯಂತ ಕಡಿಮೆ ಪ್ರಮಾಣದಲ್ಲಿ ವಾಯುಮಾಲಿನ್ಯ ಹೊಂದಿದೆ. ಸಿಎಸ್ಇಯ ನಗರ ಡೇಟಾ ಅನಾಲಿಟಿಕ್ಸ್ ಲ್ಯಾಬ್ ನ ಪ್ರೋಗ್ರಾಮ್ ಮ್ಯಾನೇಜರ್ ಆಗಿರುವ ಅವಿಕಲ್ ಸೋಮವಂಶಿ ಈ ಬಗ್ಗೆ ಮಾತನಾಡಿದ್ದು, ವಾಹನಗಳ ದಟ್ಟಣೆಯಿಂದ ಉಂಟಾಗುವ ಎಮಿಷನ್ ನ ಕಾರಣ ಹಾಗೂ ಬಾಪೂಜಿನಗರಗಳಂತಹ ಪ್ರದೇಶಗಳಲ್ಲಿ ತ್ಯಾಜ್ಯ ಸುಡುವುದರಿಂದ ವಾಯುಮಾಲಿನ್ಯ ಹೆಚ್ಚಳವಾಗಿದೆ. ಆದರೆ ಪೀಣ್ಯದಲ್ಲಿ ಉತ್ತಮ ನಿಯಂತ್ರಣಗಳು ಹಾಗೂ ನಿಗಾ ವಹಿಸುವುದರಿಂದ ವಾಯುಮಾಲಿನ್ಯ ನಿಯಂತ್ರಣದಲ್ಲಿದೆ, ವಾಸ್ತವದಲ್ಲಿ ಕೈಗಾರಿಕಾ ಪ್ರದೇಶಗಳಿಗಿಂತಲೂ ಬಿಟಿಎಂ ಲೇಔಟ್ ಹಾಗೂ ಜಯನಗರಗಳಲ್ಲಿ ಎಕ್ಯುಐ ಕೆಟ್ಟದಾಗಿದೆ" ಎಂದು ಹೇಳಿದ್ದಾರೆ.

CSE releases air pollution analysis of states in south India

Andhra Pradesh and Telangana have the worst air in the region Cities in south India are some of the cleanest in the country when it comes to breathable air, but they still suffer from some influence of winter inversion and, resultantly, elevated pollution levels. The levels increase despite the geographical advantages and favorable meteorology due to the region’s proximity to the sea and improved ventilation – finds a new 2019-2021 analysis of winter air quality in India’s south, done by Centre for Science and Environment (CSE). In 2020, the annual average levels of PM2.5 had a downward tilt in this region, but in 2021, they have risen in most cities, finds the CSE analysis. “However, unlike states in other regions of the country, the air quality gains are not completely lost. In most cities, the levels of 2021 are still lower than in 2019. This signals towards early preventive action to prevent further worsening in the coming years. This requires urgent scaling up of across all sectors to arrest the trend in this region,” says Anumita Roychowdhury, executive director, research and advocacy, CSE. “Even though real time air quality monitoring has begun to expand in these states to provide more up-to-date information on air quality, there are serious concerns around missing data and gaps that makes proper risk assessment difficult. In some stations of Karnataka, Hyderabad and Tamil Nadu, data availability is so low that the trend cannot be assessed. Quality control of data is necessary,” says Avikal Somvanshi, programme manager, Urban Data Analytics Lab at CSE. This is evident from the new analysis of real time pollution data as part of the air quality tracker initiative of the Urban Data Analytics Lab of CSE. The objective of this new analysis is to understand the trend and magnitude of pollution in different regions that have real time air quality monitoring systems. This is an assessment of annual and seasonal trends in PM2.5 concentration for the period January 1, 2019 to January 9, 2022. This analysis is based on the real time data available from the current working air quality monitoring stations. A huge volume of data points have been cleaned and data gaps have been addressed based on USEPA (United States Environmental Protection Agency) methods for this analysis. The analysis covers 63 continuous ambient air quality monitoring stations (CAAQMS) spread across 39 cities in five states and one Union territory: Andhra Pradesh: one station each in Amravati, Tirupati, Vijaywada, Rajamahendravaram and Visakhapatnam Kerela: three stations in Kochi, two in Thiruvananthapuram, and one each in Kollam, Kannur, Kozhikode and Thrissur Karnataka: 10 stations in Bengaluru and one station each in Bagalkot, Bidar, Chamarajanagar, Chikkaballapur, Chikkamagaluru, Davanagere, Gadag, Hassan, Hubballi, Kalaburagi, Kolar, Koppal, Madikeri, Mangalore, Mysuru, Raichur, Ramnagara, Shivamogga, Udupi, Vijaypura and Yadgir Tamil Nadu: eight stations in Chennai, and one station each in Coimbatore, Gummidipoondi, and Thoothukudi Telangana: six stations in Hyderabad Puducherry: one station Even though there are multiple real time monitors in a few cities of these states, many could not be considered for long term analysis due to data gaps and lack of quality data. Moreover, in several cases, the real time monitors have been set up recently and therefore, long term data is not available — several cities of the southern region have got their real time monitors in November 2020. Chennai got four out of eight monitors in January 2021. Vijaywada station stopped reporting PM2.5 data after October 2019, and Sanegurava Halli station in Bengaluru stopped reporting PM2.5 data in early 2019. The key findings: Challenge of data gaps and data quality despite automation in Tamil Nadu and Karnataka — situation relatively better in Andhra Pradesh, Telengana and Kerela: Review of data availability from the automated monitoring stations in the region under CAAQMS shows major data gaps. Data availability calculated as number of days with adequate PM2.5 data for computation of a valid 24 hour-average has been low in 19 of the 39 cities in the region. For the second half of the year 2021 (June to December), data availability at Vijaywada station of Andhra Pradesh, City Railway Station and Sanegurava Halli stations of Bengaluru, Thoothukudi station of Tamil Nadu, and Udupi station of Karnataka has been zero per cent. Coimbatore station of Tamil Nadu, and Kalaburagi and Bidar stations of Karnataka have just 27 per cent, 39 per cent, and 7 per cent data availability, respectively. Velachery and Manali Village stations of Chennai also reported data only for 27 per cent and 36 per cent of days, respectively. Among Bengaluru stations, Silk Board has only 61 per cent data while Peenya and Jayanagar are with 64 per cent and 68 per cent, respectively. Gummidipoondi station of Tamil Nadu and Central University of Hyderabad are data poor as well, with 49 per cent and 55 per cent data availability, respectively. Only 12 out of 21 stations of Karnataka outside Bengaluru meet the minimum requirement of 75 per cent. It is not clear why these stations have such poor data availability — this requires additional assessment which is not within the scope of this study. In contrast most stations of Andhra Pradesh and Kerala perform better as they have data availability of more than 75 per cent: the only station below par is at Plammoodu in Thiruvananthapuram, Kerala. Many cities show a rising trend in annual PM2.5 levels after an initial drop during 2020: Among all the regions, cities of south India have shown least of a rebound and a rising trend once again in 2021 after a significant drop due to the pandemic lockdowns of 2020. But there is still a rebound and it should be seen as a warning signal. Twenty-two cities have adequate data for both 2020 and 2021 for annual average computation — 16 of these cities show an increase in their annual PM2.5 averages, while six show further improvement. Kochi has registered doubling of its annual PM2.5 average between 2020 and 2021. Cities that show improvement are Chennai, Kalaburagi, Chikkaballapur, Vijaypura, Chikkmangaluru and Kozhikode. The industrial town of Gummidipoondi near Chennai in Tamil Nadu had the most polluted air in the region with 2021 average at 46 ug/m3. This is followed by Visakhapatnam and Hyderabad with 2021 annual average of PM2.5 at 44 ug/m3 and 41 ug/m3, respectively. In contrast, all other cities in the southern region have met the annual standard. Cities of Andhra Pradesh and Telangana have the worst air among the southern states: Hyderabad with 98 days of bad air (AQI of moderately polluted or worse) is the city with most unhealthy days in the southern states. It is closely followed by Andhra cities — Visakhapatnam with 86 days, Rajamahendravaram with 68 days, and Amravati with 66 days of bad air. Smaller industrial towns of Karnataka namely Gadag and Kalaburagi also report significant bad air days; in fact, the AQI in these cities can cross into very poor category, but due to massive amount of missing data it is unclear how long these bad air episodes actually last. Gummidipoondi has the most bad air days in Tamil Nadu, and Kollam shows the same results in Kerela. Bad air days begin to build up around the end of December in the cities of south Indian states and tend to increase till end of March. Hyderabad and cities in Andhra Pradesh show more pronounced impact of winter pollution compared to other cities of the region. High weekly pollution episode during winter can be more than double the annual concentration in several cities: During the worst weekly pollution episode in winter, the PM2.5 concentration can increase significantly higher than the annual PM2.5 average – about two times higher in several cities. Worst episodes are noted in the industrial towns of Karnataka, where Gadag registered a shocking weekly average of 192 ug/m3 (almost five times its annual average). Similarly, Kalaburgi recorded a weekly average of 104 in mid-December. Among non-industrial cities, during the high pollution episodes, weekly PM2.5 levels can go as high as 100 ug/m3 as recorded in Amravati in December 2021. This winter so far the highest weekly level was recorded as 95 ug/m3 in Hubbali, 89 ug/m3 in Visakhapatnam, 86 ug/m3 in Rajamahendravaram, and 81 ug/m3 in Hyderabad. Changing ratio of PM2.5:PM10 during different seasons of 2021 – PM2.5 share increases during winter making air more toxic: The PM2.5/PM10 ratio is a useful indicator to understand the impact of coarse dust vs tinier dust from combustion sources on air quality. Higher share of smaller particles in total particle concentration makes the air more toxic. The indicative ratio for all cities shows there is a seasonal variation. The share of smaller PM2.5 is higher than the coarser PM10 in monsoon and winter. The long-term variation of the PM2.5/PM10 ratio was analysed from weekly data average for two different seasons: monsoon (June-October) and winter (November-January). The PM2.5/PM10 ratio in all the cities of the southern states has an increasing slope in winters, compared to monsoon — except Thrissur and Kollam in Kerela, which are showing high percentage of PM2.5/PM10 ratio in monsoon compared to winter. Mostly, the concentration of PM2.5/PM10 ratio is higher during the winter months (November to January) hovering between 50 to 70 per cent. This is indicative and there can be variations across years. However, this trend is broadly consistent with what has been noted in other regions of the country. In Andhra Pradesh, Tirupati is showing a high percentage of PM2.5/PM10 ratio — 72 per cent in winters. It is followed by Chikkaballapur in Karnataka with 65 per cent and Kochi in Kerala with 62 per cent. Overall, in the southern India region, the concentration of PM2.5/PM10 ratio is higher during winters (November to January). Multi-pollutant crisis during winters – along with particulate nitrogen oxide (NO2) — increases during winter: There is a significant increase in the amount of nitrogen dioxide (NO2) in air of all cities of southern states during December compared to the previous months of November, October and September in most cities of south India. Coimbatore with 52 µg/m3 monthly NO2 average for December, is the highest in the region. It is followed by Kalaburagi (51 µg/m3), Kollam (40 µg/m3), and Visakhapatnam (38 µg/m3). As for the seasonal increase in NO2 concentrations, smaller cities lead the list. Kalaburagi registered 5.8 times jump in monthly NO2 level; Thoothukudi registered a 4 times increase; Kozhikode had a 3.8 times rise, Hubballi was 3.3 times, and Thiruvananthapuram registered a 2.2 times increase. Surface ozone increases during winter, making air more toxic: There is a significant increase in amount of surface ozone (O3) in the air in all cities during December, compared to the previous months of November, October and September. Rajamahendravaram with a 106 µg/m3 monthly O3 average for December is the highest in the region, which means ozone exceeded the standard in the city on almost every day of December. It is followed by Kalaburagi (93 µg/m3), Udipi (81 µg/m3), and Amravati (70 µg/m3). The problem is especially acute among smaller cities. It is also interesting to note that surface ozone has been relatively lower this winter compared to the previous winter for almost all the cities. Pollution profile of individual cities: Hyderabad: Analysis of days as per AQI categorisation shows that Hyderabad city’s air quality is declining. Number of days recording AQI level worse than satisfactory has increased to 98 in 2021 from 60 days in 2020 and 86 in 2019. Sanathnagar has the worst air in the city, with its December average hitting 83 ug/m3. This is followed by Central University at 57 ug/m3 monthly average for December. Bengaluru: Analysis of days as per AQI categorisation shows that Bengaluru has been able to hold on to most of air quality gains made during 2020. The number of days with the AQI worse than satisfactory (or meeting the standard) was nine in 2021; this is more than the three days in 2020 and much less than 22 days in 2019. Number of ‘good’ AQI days in 2021 stood at 208, which is just marginally lower from 214 good AQI days recorded in 2020. It is an improvement of over 30 per cent from 2019. Within the city, Bapuji Nagar was the worst hit with its December average recording 76 ug/m3. Pennya had the least polluted air with a 36 ug/m3 monthly average for December. Chennai: Analysis of days as per AQI categorisation shows that the Chennai has been able to hold on to most of its air quality gains of 2020. Number of days when the AQI was worse than satisfactory was six in 2021, same as in 2020. But 2019 had witnessed 50 days. Within the city, Manali Village has the worst air with its December average adding up to 56 ug/m3, closely followed by Arumbakam with 54 ug/m3. Velachery has the least polluted air with 19 ug/m3 monthly average for December. Kochi: Analysis of days as per AQI categorisation shows that Kochi city has not been able to sustain the air quality gains of 2020. Number of days when the AQI was worse than satisfactory was eight in 2021 — up by four days compared to 2020. But 2019 had witnessed 50 days above the satisfactory category. Most significant reduction is noted among ‘good’ AQI days which are down by 43. Within the city, Vyttila has the worst air with its December average adding up to 56 ug/m3. Udyogamandal has the least polluted air with a 33 ug/m3 monthly average for December. Visakhapatnam: Analysis of days as per AQI categorisation shows that Visakhapatnam has not been able to sustain the air quality gains of 2020. Number of days when the AQI was worse than satisfactory has risen to 86 in 2021, in contrast to 69 in 2020 and 73 in 2019. Though the number of days with very poor AQI has come down, but this overall increase in bad air days is alarming. The next steps Says the CSE analysis: “States in southern India have a unique locational advantage, with the sea and well-ventilated atmosphere and a more moderate climate that prevents pollution build-up during winter like it happens in north India. But this region is at the risk of losing the air quality gains of pandemic, though it has not yet reached the pre-pandemic levels. The doubling of pollution during winter also indicates high local pollution and exposure that normally is not well captured in the annual average trends. This indicates the need for urgent action across all sectors to control pollution from vehicles, industry, power plants, waste burning, construction, and solid fuel use in households in all the states to meet the clean air standards throughout the year.”

Bangalore retains air quality during lockdown of 2020

The New Indian Express BANGALORE: Winter air pollution analysis has given Bengaluruans some good news. The city has been successful in maintaining improved air quality during the 2020 lockdown. According to the Air Quality Index (AQI) classification, South India and Kochi have similar trends. The figures were released by the Center for Science and Environment in New Delhi. The best AQI for Bengaluru in 2021 is 208, which is slightly less than the 214 days recorded in 2020. Unsurprisingly, Bapujinagar, one of the most crowded areas in the city, recorded a poor average of 76 ug / m3 in December. Although it is an industrial area, it recorded an average of 36 ug / m3 in December 2021, with very little air pollution. Avikal Somawansi, Program Manager of CSE's Urban Data Analytics Lab, spoke about the emission caused by vehicle congestion and the increase in air pollution caused by waste burning in areas such as Bapujinagar. But with better controls and monitoring in the peninsula, air pollution is under control.

Data gaps threaten state’s fight against air pollution

Hubballi: An analysis of winter air pollution in South India, conducted by the Centre for Science and Environment (CSE, New Delhi), has revealed that Karnataka shows major data gaps from the automated air-quality monitoring stations in the region under Continous Ambient Air Quality Monitoring Stations (CAAQMS) program of Central Pollution Control Board (CPCB). The analysis, covering 63 CAAQMS spread across the 39 cities in five southern states, has observed challenge of data gaps and data quality despite automation in Karnataka and Tamil Nadu. The situation relatively better in Andhra Pradesh, Telangana and Kerala. “Among Bengaluru stations, Silk Board has only 61% while Peenya and Jayanagar with 64% and 68%. Only 12 out of 21 stations of Karnataka outside Bengaluru meet the minimum requirement of 75%. It’s not clear why these stations have such poor data availability, this requires additional assessment,” the analysis stressed. Analysis has also stated that data availability calculated as number of days with adequate PM2.5 data for computation of a valid 24hr-average has been low in 19 of 39 cities of 5 states. “For the second half of the year 2021, data availability at city railway station and Sanegurava Halli stations of Bengaluru and Udupi has been zero percent. Kalaburagi and Bidar have registered just 39% and 7% data availability respectively. Gadag and Kalaburagi also report significant bad air days, in fact air quality index (AQI) in these cities can cross into very poor AQI category but due to massive amount of missing data it is unclear how long these bad air episodes actually last.” ‘Officials not concerned’ Commenting on the analysis, former IFS officer and environmentalist Dr A N Yellappa Reddy lamented that air quality monitoring stations are left with no proper maintenance and are installed just for name sake. “Even if the data is available, it is not accurate as many of them are under construction for 2-3 years at tall buildings from where pollution will be circulated in surround areas. This is happening as there is no seriousness among officials of Karnataka State Pollution Control Board (KSPCB). Most of KSPCB officials are engaged only in income generating activities” he said.

Data gaps jeopardise states' efforts to combat air pollution.

Hubballi: Despite automation in Karnataka and Tamil Nadu, an study of winter air pollution in South India by the Centre for Science and Environment (CSE, New Delhi) has revealed that the automated air-quality monitoring stations in the region are undergoing the Continous Ambient Air Quality Monitoring Stations (CAAQMS) scheme of the Central Pollution Control Board (CPCB.The situation is much improved in Andhra Pradesh, Telangana, and Kerala.Silk Board has only 61% of Bengaluru stations, followed by Peenya and Jayanagar, who have 64% and 68%.Only 12 out of 21 stations in Karnataka outside Bengaluru meet the minimum requirement of 75 percent. Data availability has also been low in 19 of 39 cities out of 5 states, where there are sufficient PM2.5 data to produce a valid 24-hr-average.Data at city railway station and Sanegurava Halli stations in Bengaluru and Udupi has been zero percent for the second half of the year 2021.Kalaburagi and Bidar have only reported data availability of 39.9% and 77.7%, respectively.Although Gadag and Kalaburagi also reported significant bad air days, the air quality index (AQI) in those cities can fall into a very poor AQI category, it is unclear how long these bad air days last. Even if the data is available, it is inaccurate, because many of them are expected to be built for about 2-3 years at tall buildings from which waste will be expelled in surrounding areas.Officials of Karnataka State Pollution Control Board (KSPCB) are quiet about this.According to him, the bulk of KSPCB officials are primarily engaged in income-producing activities.

Southern cities get cleaner air, but winters pose a problem: Study

Cities in South India are some of the cleanest in the country when it comes to breathable air, but they still suffer from some influence of winter inversion and, resultantly, elevated pollution levels, a new CSE study has stated. Cities in South India are some of the cleanest in the country when it comes to breathable air, but they still suffer from some influence of winter inversion and, resultantly, elevated pollution levels. The levels increase despite the geographical advantages and favourable meteorology due to the region’s proximity to the sea and improved ventilation, a new 2019-2021 analysis of winter air quality in India’s south, done by the Centre for Science and Environment (CSE), has found. VDO.AI In 2020, the annual average levels of PM2.5 had a downward tilt in this region, but in 2021, they rose in most cities, the CSE analysis found. “However, unlike states in other regions of the country, the air quality gains are not completely lost. In most cities, the levels for 2021 are still lower than in 2019. This signals early preventive action to prevent the worsening of air quality in the coming years. This requires urgent scaling up of all sectors to arrest the trend in this region,” says Anumita Roychowdhury, executive director, research and advocacy, CSE. LACK OF DATA MAKES RISK ASSESSMENT A CHALLENGE “Even though real-time air quality monitoring has begun to expand in these states to provide more up-to-date information on air quality, there are serious concerns around missing data and gaps that make proper risk assessment difficult. At some stations in Karnataka, Hyderabad and Tamil Nadu, data availability is so low that the trend cannot be assessed. Quality control of data is necessary,” says Avikal Somvanshi, programme manager, Urban Data Analytics Lab at CSE. advertisement This is evident from the new analysis of real-time pollution data as part of the air quality tracker initiative of the Urban Data Analytics Lab of CSE. The objective of this new analysis is to understand the trend and magnitude of pollution in different regions that have real-time air quality monitoring systems. This is an assessment of annual and seasonal trends in PM2.5 concentration for the period between January 1, 2019, and January 9, 2022. The analysis is based on the real-time data available from the current air quality monitoring stations. A huge volume of data points has been cleaned and data gaps have been addressed based on USEPA (United States Environmental Protection Agency) method. DATA FROM 63 MONITORING STATIONS IN 39 CITIES ANALYSED The analysis covered 63 continuous ambient air quality monitoring stations (CAAQMS) spread across 39 cities in five states and one Union Territory: Andhra Pradesh: One station each in Amravati, Tirupati, Vijaywada, Rajamahendravaram, and Visakhapatnam Kerala: Three stations in Kochi, two in Thiruvananthapuram, and one each in Kollam, Kannur, Kozhikode, and Thrissur Karnataka: 10 stations in Bengaluru and one station each in Bagalkot, Bidar, Chamarajanagar, Chikkaballapur, Chikkamagaluru, Davanagere, Gadag, Hassan, Hubballi, Kalaburagi, Kolar, Koppal, Madikeri, Mangalore, Mysuru, Raichur, Ramnagara, Shivamogga, Udupi, Vijaypura and Yadgir Tamil Nadu: Eight stations in Chennai, and one station each in Coimbatore, Gummidipoondi, and Thoothukudi Telangana: Six stations in Hyderabad Puducherry: one station Even though there are multiple real-time monitors in a few cities of these states, many could not be considered for long-term analysis due to data gaps and lack of quality data. Moreover, in several cases, the real-time monitors have been set up recently and therefore, long-term data is not available. Several cities of the southern region got their real-time monitors in November 2020. Chennai got four out of eight monitors in January 2021. Vijaywada station stopped reporting PM2.5 data after October 2019, and Sanegurava Halli station in Bengaluru stopped reporting PM2.5 data in early 2019. KEY FINDINGS Challenges pertaining to data gaps and data quality despite automation in Tamil Nadu and Karnataka persist. The situation is relatively better in Andhra Pradesh, Telengana, and Kerala. A review of data available from the automated monitoring stations in the region under CAAQMS shows major gaps in the information. Data availability calculated as the number of days with adequate PM2.5 data for computation of a valid 24-hour average has been low in 19 of the 39 cities in the region. advertisement For the second half of 2021 (June-December), data availability at Vijaywada station of Andhra Pradesh, city railway station and Sanegurava Halli station of Bengaluru, Thoothukudi station of Tamil Nadu, and Udupi station of Karnataka has been zero per cent. Coimbatore station of Tamil Nadu, and Kalaburagi and Bidar stations of Karnataka have just 27%, 39%, and 7% data availability, respectively. Velachery and Manali village stations of Chennai also reported data only for 27% and 36 % of the days, respectively. Among Bengaluru stations, Silk Board had only data for 61% of the days while Peenya and Jayanagar had 64% and 6%, respectively. Gummidipoondi station of Tamil Nadu and Central University of Hyderabad reported poor data as well, with 49% and 55% availability, respectively. Only 12 out of 21 stations of Karnataka outside Bengaluru meet the minimum requirement of 75%. It is not clear why these stations have such poor data availability. This would require additional assessment, which was not within the scope of this study. ANDHRA, KERALA REPORT BETTER DATA AVAILABILITY In contrast, most stations in Andhra Pradesh and Kerala perform better as they have data availability of more than 75 per cent: the only station below par is at Plammoodu in Thiruvananthapuram, Kerala. advertisement Many cities show a rising trend in annual PM2.5 levels after an initial drop during 2020. Among all the regions, cities of South India have shown the least of a rebound and a rising trend once again in 2021 after a significant drop due to the pandemic-induced lockdowns of 2020. But there is still a rebound and it should be seen as a warning signal. Twenty-two cities have adequate data for both 2020 and 2021 for annual average computation — 16 of these cities showed an increase in their annual PM2.5 averages, while six showed further improvement. Kochi registered a doubling of its annual PM2.5 average between 2020 and 2021. Cities that showed improvement are Chennai, Kalaburagi, Chikkaballapur, Vijaypura, Chikkmangaluru and Kozhikode. The industrial town of Gummidipoondi near Chennai in Tamil Nadu had the most polluted air in the region with the 2021 average at 46 ug/m3. This was followed by Visakhapatnam and Hyderabad with the 2021 annual average of PM2.5 at 44 ug/m3 and 41 ug/m3, respectively. In contrast, all other cities in the southern region have met the annual standard. ANDHRA, TELANGANA RECORD WORST AIR AMONG SOUTHERN STATES Cities of Andhra Pradesh and Telangana had the worst air among the southern states: Hyderabad with 98 days of bad air (AQI of moderately polluted or worse) is the city with THE most unhealthy days in the southern states. It is closely followed by Andhra cities -- Visakhapatnam with 86 days, Rajamahendravaram with 68 days, and Amravati with 66 days of bad air. Smaller industrial towns of Karnataka, namely Gadag and Kalaburagi also report significant bad air days. In fact, the AQI in these cities can cross into the very poor category, but due to the massive amount of missing data, it is unclear how long these bad air episodes actually last. Gummidipoondi had the most bad air days in Tamil Nadu, and Kollam showed the same results in Kerela. Bad air days begin to build up around the end of December in the cities of south Indian states and tend to increase till the end of March. Hyderabad and cities in Andhra Pradesh show a more pronounced impact of winter pollution compared to other cities of the region. High weekly pollution episodes during the winter can be more than double the annual concentration in several cities: During the worst weekly pollution episode in winter, the PM2.5 concentration can increase significantly higher than the annual PM2.5 average about two times higher in several cities. Worst episodes are noted in the industrial towns of Karnataka, where Gadag registered a shocking weekly average of 192 ug/m3 (almost five times its annual average). Similarly, Kalaburgi recorded a weekly average of 104 in mid-December. Among non-industrial cities, during the high pollution episodes, weekly PM2.5 levels can go as high as 100 ug/m3 as recorded in Amravati in December 2021. This winter so far the highest weekly level was recorded as 95 ug/m3 in Hubbali, 89 ug/m3 in Visakhapatnam, 86 ug/m3 in Rajamahendravaram, and 81 ug/m3 in Hyderabad. CHANGING RATIO OF PM2.5, PM10 DURING DIFFERENT SEASONS OF 2021 The PM2.5 share increases during winter, making the air more toxic: The PM2.5/PM10 ratio is a useful indicator to understand the impact of coarse dust vs tinier dust from combustion sources on air quality. A higher share of smaller particles in total particle concentration makes the air more toxic. The indicative ratio for all cities shows there is a seasonal variation. The share of smaller PM2.5 is higher than the coarser PM10 in monsoon and winter. The long-term variation of the PM2.5/PM10 ratio was analysed from the weekly data average for two different seasons: monsoon (June-October) and winter (November-January). The PM2.5 and PM10 ratio in all the cities of the southern states has an increasing slope in winters, compared to the monsoon, except Thrissur and Kollam in Kerala, which are showing a high percentage ratio in monsoon compared to winter. Mostly, the concentration of PM2.5/PM10 ratio is higher during the winter months (November to January), hovering between 50% to 70%. This is indicative and there can be variations across years. However, this trend is broadly consistent with what has been noted in other regions of the country. In Andhra Pradesh, Tirupati is showing a high percentage of PM2.5/PM10 ratio -- 72 per cent in winters. It is followed by Chikkaballapur in Karnataka with 65 per cent and Kochi in Kerala with 62 per cent. Overall, in the southern India region, the concentration of PM2.5/PM10 ratio is higher during winters (November to January). MULTI-POLLUTANT CRISIS DURING WINTERS There is a significant increase in the amount of nitrogen dioxide (NO2) in the air of all cities of southern states during December compared to the previous months of November, October and September in most cities of south India. Coimbatore with 52 µg/m3 monthly NO2 average for December, is the highest in the region. It is followed by Kalaburagi (51 µg/m3), Kollam (40 µg/m3), and Visakhapatnam (38 µg/m3). As for the seasonal increase in NO2 concentrations, smaller cities lead the list. Kalaburagi registered 5.8 times jump in monthly NO2 level; Thoothukudi registered a 4 times increase; Kozhikode had a 3.8 times rise, Hubballi was 3.3 times, and Thiruvananthapuram registered a 2.2 times increase. SURFACE OZONE INCREASES DURING WINTER, MAKING AIR MORE TOXIC There is a significant increase in the amount of surface ozone (O3) in the air in all cities during December, compared to the previous months of November, October and September. Rajamahendravaram with a 106 µg/m3 monthly O3 average for December is the highest in the region, which means ozone exceeded the standard in the city on almost every day of December. It is followed by Kalaburagi (93 µg/m3), Udipi (81 µg/m3), and Amravati (70 µg/m3). The problem is especially acute among smaller cities. It is also interesting to note that surface ozone has been relatively lower this winter compared to the previous winter for almost all the cities. POLLUTION PROFILE OF INDIVIDUAL CITIES Hyderabad: Analysis of days as per AQI categorisation shows that Hyderabad city’s air quality is declining. The number of days recording AQI levels worse than satisfactory has increased to 98 in 2021 from 60 days in 2020 and 86 in 2019. Sanathnagar has the worst air in the city, with its December average hitting 83 ug/m3. This is followed by Central University at 57 ug/m3 monthly average for December. Bengaluru: Analysis of days as per AQI categorisation shows that Bengaluru has been able to hold on to most of the air quality gains made during 2020. The number of days with the AQI worse than satisfactory (or meeting the standard) was nine in 2021; this is more than the three days in 2020 and much less than 22 days in 2019. The number of ‘good’ AQI days in 2021 stood at 208, which is just marginally lower than 214 good AQI days recorded in 2020. It is an improvement of over 30 per cent from 2019. Within the city, Bapuji Nagar was the worst hit with its December average recording 76 ug/m3. Peenya had the least polluted air with a 36 ug/m3 monthly average for December. Chennai: Analysis of days as per AQI categorisation shows that Chennai has been able to hold on to most of its air quality gains of 2020. The number of days when the AQI was worse than satisfactory was six in 2021, the same as in 2020. But 2019 had witnessed 50 days. Within the city, Manali Village has the worst air with its December average adding up to 56 ug/m3, closely followed by Arumbakam with 54 ug/m3. Velachery has the least polluted air with a 19 ug/m3 monthly average for December. Kochi: Analysis of days as per AQI categorisation shows that Kochi city has not been able to sustain the air quality gains of 2020. The number of days when the AQI was worse than satisfactory was eight in 2021 -- up by four days compared to 2020. But 2019 had witnessed 50 days above the satisfactory category. The most significant reduction is noted among ‘good’ AQI days which are down by 43. Within the city, Vyttila has the worst air with its December average adding up to 56 ug/m3. Udyogamandal has the least polluted air with a 33 ug/m3 monthly average for December. Visakhapatnam: Analysis of days as per AQI categorisation shows that Visakhapatnam has not been able to sustain the air quality gains of 2020. The number of days when the AQI was worse than satisfactory has risen to 86 in 2021, in contrast to 69 in 2020 and 73 in 2019. Though the number of days with very poor AQI has come down, this overall increase in bad air days is alarming.

Air pollution rapidly becoming matter of concern in Maharashtra, Gujarat: CSE

Air pollution is rapidly becoming a matter of concern in the western states of Maharashtra and Gujarat as well despite their geographical advantages and favourable meteorology, according to a new analysis of regional air pollution levels by the Centre for Science and Environment (CSE). “The number of bad-air days in Mumbai have doubled between 2019 and 2021, while good days are down by 20 per cent. This underscores the urgency of scaling up action across all sectors to prevent further worsening and to arrest the trend in this region,” said Anumita Roychowdhury, executive director, research and advocacy, CSE. The analysis covered 56 continuous ambient air quality monitoring stations (CAAQMS) spread across 15 cities in two states: Maharashtra — one station each in Aurangabad, Kalyan, Nagpur, Nashik and Solapur, two in Chandrapur, four in Navi Mumbai, eight in Pune, and 21 stations in Mumbai; and Gujarat — one station each in Ankleshwar, Nandesari, Vapi and Vatva, four in Gandhinagar, and eight stations in Ahmedabad. Avikal Somvanshi, programme manager, Urban Data Analytics Lab, CSE, pointed out that even though there are multiple real time monitors in a few cities of these states, many of them could not be considered for long-term analysis due to data gaps and lack of quality data. Moreover, in several cases, the real time monitors have been set up recently and therefore, long-term data is not available. VDO.AI The researchers found that nearly all cities in the region show a drop in annual average PM2.5 levels in 2020 — the year with the maximum number of lockdown phases. But there has been a rebound and a rising trend is visible in 2021. Gujarat’s cities are more polluted than those in Maharashtra. Vatva and Ankleshwar have the most polluted air in the region with the 2021 average of PM2.5 at 67 microgram per cubic metre. This is followed by Vapi and Ahmedabad with 2021 annual averages at 54 microgram per cubic metre and 53 microgram per cubic metre, respectively. In Maharashtra, Chandrapur, an industrial city, has recorded levels marginally above the annual standard at 43 microgram per cubic metre. Other stations have met the annual standard though all of them are showing a rising trend in 2021 after the dip in 2020. With 102 days of poor and very poor AQI, Ankleshwar in Gujarat has the unhealthiest days in the region, followed by Kalyan with 84 days, Vatva (75 days), and Navi Mumbai (54 days). Vapi has 48 days of poor and very poor AQI — but its data is missing for 138 days (mainly for the winter months). Mumbai has registered 42 days of poor and very poor AQI despite meeting the annual standard. Bad-air days begin to build up in the cities of the western states during the end of December and persist till the end of January. Cities in the Mumbai Metropolitan Region show a more pronounced impact of winter pollution compared to cities of other regions. Industrial towns have bad-air days across the year, but there is some clustering during winter, the CSE said. PTI GVS ZMN

Delhi air remains in 'very poor' category; second most polluted worldwide

Air pollution is becoming worse in Maharashtra and Gujarat as well despite their geographical advantages, says advocacy group. Delhi's air was 'very poor' Thursday morning, making the national capital the world's second most polluted city as more places in India were warned of similar public health crises. Delhi's Air Quality Index (AQI) was 331 at 8 am, according to the Ministry of Earth Sciences' air quality forecast agency SAFAR. Readings below 50 are considered safe, 51 and 100 is 'satisfactory' and anything above 300 is considered hazardous or 'severe'. According to SAFAR, Delhi's AQI will remain 'very poor' on January 20, 21 and is expected to improve as "high wind speed is likely from Jan 21 resulting in dilution of pollutants and improvement of AQI." Delhi was this morning the world's second most polluted city in the world with an AQI of 255, according to IQAir. This came as a new analysis by advocacy group Centre for Science and Environment (CSE) said air pollution is becoming worse in the western states of Maharashtra and Gujarat as well despite their geographical advantages and favourable meteorology. "The number of bad-air days in Mumbai have doubled between 2019 and 2021, while good days are down by 20 per cent," said Anumita Roychowdhury, executive director, research and advocacy, CSE. India is failing in efforts to improve its toxic air quality, with the number of smog-plagued cities increasing since the launch of a national program to tackle the issue, Bloomberg reported Tuesday. A total of 132 cities now have pollution levels deemed below national standards, from 102 cities when the National Clean Air Programme began in 2019, according to a report by the Centre for Research on Energy and Clean Air.

After PM2.5 dip in 2020, Kolkata air now 29% more polluted than safe level

After PM2.5 dip in 2020, Kolkata air now 29% more polluted than safe level KOLKATA: The city needs nearly 29% cut to meet the annual average standard of 40µg/m3 for PM2.5, the national ambient air quality standard (NAAQS), revealed the latest analysis of air quality status of Bengal cities by the Centre for Science and Environment (CSE). PM2.5 is the tiniest particle in air, considered to be the most harmful for lungs. The analysis of data further stated that Howrah needs 34%, Asansol 32% and Durgapur 50% reduction in PM2.5 level to meet NAAQS. However, the trend in average annual PM2.5 concentration shows a dip in 2020, which had several pandemic-linked lockdown phases. “This analysis of real-time air quality data for the period 2019-2021 shows the downward dip in pollution, which was induced by the lockdown phases, is threatening to bounce back with the levels already rising. But in many cases, the levels are still lower than 2019. This underscores the urgency of scaling up action across all sectors to arrest the trend in this region,” says Anumita Roychowdhury, executive director (research and advocacy) at CSE. “The study corroborates our experiences at hospitals and clinics. There was a drastic drop in patients with breathing distress and related hospitalization in 2020 because of the clean air in 2020. But we are almost back to 2019 level as far as influx of non-Covid patients with breathing distress and related hospitalization is concerned,” said pulmonologist Arup Haldar. Analysis of days as per the categorisation of the national air quality index related to PM2.5 shows that in Kolkata, there were eight days of severe air quality (AQI: 401-500) in 2019. The total number of poor (AQI:201-300), very poor (AQI 301-400) and severe category days have reduced from 93 in 2019 to 83 in 2021. Good air quality (AQI: 0-50) days have increased from 101 in 2019 to 140 in 2021. While satisfactory (AQI:51-100) days have reduced from 111 to 80, poor (AQI: 201-300) days have increased from 45 to 53. However, 2020 was cleaner with higher number of good air quality days at 192.

Deteriorating air quality becoming a matter of concern for Maharashtra: Study

Even though most cities in the state recorded a drop in pollution levels during the early months of 2020 when a strict lockdown was enforced, a rising trend in annual Particulate Matter 2.5 levels has been recorded since then. Despite geographical advantages and favourable meteorology, air pollution is rapidly becoming a matter of concern in Maharashtra, a new analysis of regional air pollution levels by the Centre for Science and Environment (CSE), a New Delhi-based research and advocacy organisation, has found. Even though most cities in the state recorded a drop in pollution levels during the early months of 2020 when a strict lockdown was enforced, a rising trend in annual Particulate Matter 2.5 levels has been recorded since then. Daily Air Quality Index (AQI) analysis based on the 10 oldest stations in Mumbai showed a 20 per cent drop in the number of good AQI days between 2019 and 2021 even as days with poor or very poor AQI have doubled. AQI is a mean of pollutants such as particulate matter (PM2.5 and PM10), ozone (O3), nitrogen dioxide (NO2), sulphur dioxide (SO2) and carbon monoxide (CO) emissions as a single value. The higher the AQI value, the greater the level of air pollution and greater the health concern. The study analysed 40 continuous ambient air quality monitoring stations (CAAQMS) in Maharashtra — one each in Aurangabad, Kalyan, Nagpur, Nashik and Solapur, two in Chandrapur, four in Navi Mumbai, eight in Pune, and 21 in Mumbai. In December 2021, the stations in south Mumbai recorded significantly higher PM2.5 levels compared to the rest of the city. Mazgaon with a monthly average of 134 ug/m3 was the most polluted area, followed by Navy Nagar in Colaba (124 ug/m3), Kurla (101 ug/m3), Vile Parle West (101 ug/m3) and Worli (97 ug/m3). Khindipada at the edge of Sanjay Gandhi National Park in the western suburbs, with a monthly average of 54 ug/m3, was the least polluted area in the city. According to the 2009 National Ambient Air Quality Standards, the annual safety limit of PM2.5 is 40 micrograms/cubic metre. Made up of hundreds of chemicals, PM 2.5 pollutants are emitted into the air by construction sites, unpaved roads, fields, smokestacks, fires, power plants, factories and automobiles. Winter pollution sets during late December and early January when cooler and calmer conditions trap the local pollution, which is high. Starting mid-November last year, Mumbai has been recording poor to very poor AQI, nearing 300. “Even though winter pollution levels in the western region are not as high (as that seen in the Indo-Gangetic Plains) due to its proximity to the sea and improved ventilation, the levels have been seen to be increasing despite the geographical advantages and favourable meteorology,” read the analysis. The study has also highlighted gaps in the data from monitoring stations. For instance, in Mumbai, CSE found that Kurla station had only 55 per cent data while Malad West came up with 68 per cent. Kalyan and Aurangabad were data-deficient as well, with 66 per cent and 43 per cent data availability, respectively. Only one out of eight stations of Pune meet the minimum requirement – the city’s stations have a data availability of less than 75 per cent.

Tale of Mumbai's rising trend of air pollution

Every winter, smog-filled days and nights across entire north India are a common thing and by contrast, the western region looks much cleaner. However, a new analysis of regional air pollution levels by the Centre for Science and Environment (CSE) has shown that proximity to the sea has not helped in containing the increasing air pollution in the financial capital, Mumbai. Even though winter pollution levels in the western region are not as high as that seen in the Indo-Gangetic Plains due to its proximity to the sea and improved ventilation, the levels have been seen to be increasing despite the geographical advantages and favourable meteorology, the CSE analysis said. In other words, increasing air pollution is not restricted to winters but is now an yearlong problem in Mumbai too. "The number of bad-air days in Mumbai have doubled between 2019 and 2021, while good days are down by 20 per cent. This underscores the urgency of scaling up action across all sectors to prevent further worsening and to arrest the trend in this region," executive director, research and advocacy, CSE, Anumita Roychowdhury said. This new analysis, released on Wednesday, of real time pollution data is part of CSE's air quality tracker initiative and also has an assessment of annual and seasonal trends in PM2.5 concentration for the period January 1, 2019, to January 9, 2022. This analysis is based on the real time data available from the current working air quality monitoring stations. Review of data availability from the automated monitoring stations in the region under the continuous ambient air quality monitoring stations (CAAQMS) programme of Central Pollution Control Board (CPCB) shows major data gaps. When it comes to data availability calculated as number of days with adequate PM2.5 data for computation of a valid 24-hour average, among Mumbai stations, Kurla in east-central Mumbai had only 55 per cent data while Malady (West) in north Mumbai came up with 68 per cent. "It is not clear why these stations have such poor data availability despite minimal problems of electricity and internet connectivity in the region," said CSE's programme manager, Urban Data Analytics Lab, Avikal Somvanshi. Like other cities in Maharashtra and Gujarat, studied as part of the same analysis by CSE, Mumbai too has indicated a rising trend in annual PM2.5 levels after an initial drop during 2020 (when there were lockdowns) with a rebound and a rising trend visible in 2021. The CSE analysis to indicate that the number of bad-air quality days are increasing in Mumbai is supported with Air Quality Index (AQI) data. Daily AQI analysis based on 10 oldest stations shows a 20 per cent drop in the number of good AQI days in the city between 2019 and 2021 -- while days with poor or very poor AQI have doubled. South Mumbai has the worst air within the city during winter: In December 2021, the stations in south Mumbai reported significantly higher PM2.5 levels compared to the rest of the city. Mazgaon with a monthly average of 134 micrograms per cubic metres was the most polluted neighborhood of the city, followed by Navy Nagar, Colaba (124 micrograms per metre cube), Kurla (101 micrograms per metre cube), Vile Parle-West (101 micrograms per metre cube) and Worli (97 micrograms per metre cube). Khindipada, in north Mumbai, which is at the edge of Sanjay Gandhi National Park in the suburbs with a monthly average of 54 micrograms per metre cube was the least polluted neighborhood. Bandra and Malad (West) reported low numbers, but the values are not considered valid due to a significantly large amount of missing data from these two stations, the CSE analysis showed.

Majority of Cities in Maharashtra & Gujarat Show Increase in Yearly PM2.5 Levels After Brief Dip in 2020: CSE

Most cities in Maharashtra and Gujarat showcased a rising trend in annual PM2.5 levels with a drop-through in 2020 (during lockdowns) followed by a rebound and an increasing trend visible in 2021, an analysis by the Centre for Science & Environment (CSE) said on Wednesday. Stating that air pollution is rapidly becoming a matter of concern in the two western states, the new analysis of regional air pollution levels said cities in Gujarat are more polluted than those in Maharashtra. The analysis covered 56 continuous ambient air quality monitoring stations (CAAQMS) spread across 15 cities in the two states. Gujarat's Vatva and Ankleshwar have the most polluted air in the region, with the 2021 average of PM2.5 at 67 micrograms per metre cube. This is followed by Vapi and Ahmedabad, with 2021 annual averages at 54 and 53 micrograms per metre cube, respectively. Chandrapur, an industrial city in Maharashtra, has recorded levels marginally above the annual standard at 43 micrograms per metre cube. Other stations have met the yearly standard though they showed a rising trend in 2021 after the dip in 2020. Despite low annual levels, cities in Maharashtra experienced a high number of days with 'poor' and 'very poor' AQI compared to Gujarat. With 102 days of poor and very poor AQI, Ankleshwar in Gujarat had the unhealthiest days in the region, followed by Kalyan (84 days), Vatva (75 days), and Navi Mumbai (54 days). Vapi had 48 days of poor and very poor AQI—but its data is missing for 138 days (mainly for the winter months). Despite meeting the annual standard, Mumbai registered 42 days of poor and very poor AQI compared to Gujarat. During high weekly pollution episodes in winter, levels can be more than double the annual concentration in several cities. During the worst weekly pollution episodes in winter, the PM2.5 concentrations can increase significantly higher than the yearly PM2.5 average—about two times higher in several cities. "This analysis of real-time air quality data for the period 2019-2021 shows that the downward dip in the pollution that was induced by the lockdown phases of the pandemic in 2020 is changing. Pollution levels are threatening to bounce back. In many cases, the levels are even higher than in 2019. This underscores the urgency of scaling up the action across all sectors to prevent further worsening and to arrest the trend in this region," said Anumita Roy Chowdhury, Executive Director, Research and Advocacy, CSE. However, this data challenges data gaps and quality despite automation. A review of data available from the automated monitoring stations in the region under the CAAQMS programme of CPCB shows significant data gaps. Data availability calculated as the number of days with adequate PM2.5 data for computation of a valid 24-hour average has been low in five of the 12 cities in the region, the CSE analysis showed.

Air pollution becoming matter of concern in Maharashtra, Gujarat: CSE

The analysis covered 56 continuous ambient air quality monitoring stations (CAAQMS) spread across 15 cities Air pollution is rapidly becoming a matter of concern in the western states of Maharashtra and Gujarat as well despite their geographical advantages and favourable meteorology, according to a new analysis of regional air pollution levels by the Centre for Science and Environment (CSE). "The number of bad-air days in Mumbai have doubled between 2019 and 2021, while good days are down by 20 per cent. This underscores the urgency of scaling up action across all sectors to prevent further worsening and to arrest the trend in this region," said Anumita Roychowdhury, executive director, research and advocacy, CSE. The analysis covered 56 continuous ambient air quality monitoring stations (CAAQMS) spread across 15 cities in two states: Maharashtra -- one station each in Aurangabad, Kalyan, Nagpur, Nashik and Solapur, two in Chandrapur, four in Navi Mumbai, eight in Pune, and 21 stations in Mumbai; and Gujarat -- one station each in Ankleshwar, Nandesari, Vapi and Vatva, four in Gandhinagar, and eight stations in Ahmedabad. Avikal Somvanshi, programme manager, Urban Data Analytics Lab, CSE, pointed out that even though there are multiple real time monitors in a few cities of these states, many of them could not be considered for long-term analysis due to data gaps and lack of quality data. Moreover, in several cases, the real time monitors have been set up recently and therefore, long-term data is not available. The researchers found that nearly all cities in the region show a drop in annual average PM2.5 levels in 2020 -- the year with the maximum number of lockdown phases. But there has been a rebound and a rising trend is visible in 2021. Gujarat's cities are more polluted than those in Maharashtra. Vatva and Ankleshwar have the most polluted air in the region with the 2021 average of PM2.5 at 67 microgram per cubic metre. This is followed by Vapi and Ahmedabad with 2021 annual averages at 54 microgram per cubic metre and 53 microgram per cubic metre, respectively. In Maharashtra, Chandrapur, an industrial city, has recorded levels marginally above the annual standard at 43 microgram per cubic metre. Other stations have met the annual standard though all of them are showing a rising trend in 2021 after the dip in 2020. With 102 days of poor and very poor AQI, Ankleshwar in Gujarat has the unhealthiest days in the region, followed by Kalyan with 84 days, Vatva (75 days), and Navi Mumbai (54 days). Vapi has 48 days of poor and very poor AQI -- but its data is missing for 138 days (mainly for the winter months). Mumbai has registered 42 days of poor and very poor AQI despite meeting the annual standard. Bad-air days begin to build up in the cities of the western states during the end of December and persist till the end of January. Cities in the Mumbai Metropolitan Region show a more pronounced impact of winter pollution compared to cities of other regions. Industrial towns have bad-air days across the year, but there is some clustering during winter, the CSE said.