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Clean Air & Sustainable Mobility

10 शहरों पर अध्ययन, दिल्ली-NCR में ओजोन सबसे कमजोर; सीपीसीबी ने एनजीटी को सौंपी रिपोर्ट में किया खुलासा

धरती को सूर्य की हानिकारक पराबैगनी विकिरणों से बचाने वाली ओजोन (ओ3) दिल्ली-एनसीआर में सबसे कमजोर है। राजधानी और मुंबई में देशभर के अन्य शहरों की तुलना में ओजोन सांद्रता में सबसे अधिक वृद्धि देखने को मिली है। इसका खुलासा केंद्रीय प्रदूषण नियंत्रण बोर्ड (सीपीसीबी) ने राष्ट्रीय हरित अधिकरण (एनजीटी) को सौंपी अपनी रिपोर्ट में किया है। राजधानी में ओजोन के बढ़ते स्तर के मामले की कोर्ट जांच कर रहा है। अधिकरण ने दिल्ली स्थित थिंक टैंक सेंटर फॉर साइंस एंड एनवायरनमेंट (सीएसई) की एक रिपोर्ट के आधार पर स्वतः संज्ञान लेते हुए यह मामला उठाया था। उसमें कहा गया था कि 2024 की गर्मियों में देश के 10 प्रमुख महानगरीय क्षेत्रों में हवा में ग्राउंड-लेवल ओजोन का स्तर बढ़ जाएगा। इन क्षेत्रों और शहरों में बंगलूरू महानगर क्षेत्र (कर्नाटक), चेन्नई महानगर क्षेत्र (तमिलनाडु), दिल्ली-एनसीआर, ग्रेटर अहमदाबाद (गुजरात), ग्रेटर हैदराबाद (तेलंगाना), ग्रेटर जयपुर , कोलकाता महानगर क्षेत्र (पश्चिम बंगाल), ग्रेटर लखनऊ (उत्तर प्रदेश), मुंबई महानगर क्षेत्र (महाराष्ट्र) और पुणे महानगर क्षेत्र (महाराष्ट्र) शामिल हैं। सीएसई ने रिपोर्ट में कहा था कि इस वर्ष अब तक दिल्ली-एनसीआर में अध्ययन अवधि के दौरान 176 दिन ऐसे रहे जब जमीनी स्तर पर ओजोन की मात्रा सामान्य से अधिक दर्ज की गई। साथ ही, मुंबई-एमएमआर और पुणे 138 दिन रहे। ऐसे में एनजीटी ने सीपीसीबी और पर्यावरण, वन और जलवायु परिवर्तन मंत्रालय (एमओईएफसीसी) को नोटिस जारी किया था। प्रत्येक स्टेशन पर ओजोन का 1-घंटे की अधिकता 5 फीसदी से अधिक सीपीसीबी ने रिपोर्ट में कहा है कि वर्ष 2023 के दौरान 178 निगरानी स्टेशनों पर ओजोन की निगरानी की गई। इनमें सामने आए आंकड़ों से पता चला कि दिल्ली-एनसीआर और मुंबई महानगर क्षेत्र (एमएमआर) में प्रत्येक एक स्टेशन पर ओजोन का 1-घंटे की अधिकता 5 फीसदी से अधिक मिली। साथ ही, दिल्ली-एनसीआर (15), एमएमआर (10), जयपुर (5) और पुणे (2) में 32 निगरानी स्टेशनों पर ओजोन का 8-घंटे का अतिक्रमण 5 फीसदी से अधिक दर्ज किया गया। रिपोर्ट के अनुसार वर्ष 2024 की गर्मियों के दौरान कुल 178 निगरानी स्टेशनों में से दिल्ली-एनसीआर के 8 स्टेशनों और चेन्नई के 1 स्टेशन में ओजोन की 1 घंटे की अधिकता का 5 फीसदी से अधिक देखने को मिला। यही नहीं वर्ष 2023 के दौरान रात के 10 से सुबह 06 बजे तक ओजोन सांद्रता का अध्ययन किया। इसमें सामने आया कि दिल्ली-एनसीआर और एमएमआर में केवल एक-एक स्थान पर 1 घंटे के मानक से 5 फीसदी से अधिक वृद्धि दर्ज की गई। आठ स्टेशनों में ओजोन का स्तर 5 फीसदी से रहा अधिक राष्ट्रीय परिवेशी वायु गुणवत्ता मानक (एनएएक्यूएस) के अनुसार ओजोन का 1-घंटे की अधिकता 2024 की गर्मियों में दिल्ली-एनसीआर में 57 स्टेशन पर निगरानी हुई। इनमें शून्य से अधिक ओजोन वाले निगरानी स्टेशनों की संख्या आठ रही। यही नहीं इसमें आठ निगरानी स्टेशन ऐसे रहे जहां ओजोन के स्तर में 5 फीसदी से अधिक वृद्धि दर्ज की गई। इन स्टेशन की संख्या 2023 में तीन रही। तब शून्य से अधिक ओजोन वाले निगरानी स्टेशनों की संख्या 19 मिली। इसके अलावा 2023 में 8 घंटे में ओजोन का स्तर मापा गया। इनमें 57 में से शून्य से अधिक ओजोन वाले निगरानी स्टेशन सात रहे। वहीं, 15 स्टेशन में ओजोन के स्तर में 5 फीसदी से अधिक वृद्धि देखने को मिली। ऐसे बनती है ओजोन ओजोन एक द्वितीयक प्रदूषक है जो वायुमंडल में नाइट्रोजन ऑक्साइड (एनओ2) और वाष्पशील कार्बनिक यौगिकों वीओसी के बीच जटिल रासायनिक प्रतिक्रिया से बनता है। यह सूर्य के प्रकाश की उपस्थिति में मानवजनित और जैविक स्रोतों से उत्सर्जित होते हैं। आवासीय और कृषि स्रोतों से उत्सर्जित कार्बन मोनोऑक्साइड (सीओ) और मीथेन (सीएच 4) भी ओजोन निर्माण में भूमिका निभाते हैं। ओजोन परत के प्रमुख स्रोत एनओ2 और वीओसी है।

Clean Air & Sustainable Mobility

10 शहरों पर अध्ययन, दिल्ली-NCR में ओजोन सबसे कमजोर; सीपीसीबी ने एनजीटी को सौंपी रिपोर्ट में किया खुलासा

Water Programme

Getting the basics right

The MDA Government’s proclamation about turning the state into a 10 billion dollar economy by 2028 is an aspiration – nay a bold ambition for Meghalaya. But every vision or aspiration requires a clear roadmap so that the public can buy into that roadmap and be co-creators of the 10 billion dollar economy. After all, people should be prepared for that economic boost and they should know which are the areas for potential growth where they can participate. In the case of Meghalaya will it be agriculture, horticulture or just the extractive industries like mining which the Government is working hard to revive by adhering to the Supreme Court directive of scientific mining which is yet to be tried out and which is an unknown entity. No one is sure if the investment in scientific coal mining will yield the same returns as rat-hole mining which has turned hundreds of mine owners into millionaires. Also, if coal is to be scientifically mined, how about limestone mining and quarrying? Why should they be allowed the reckless model of mining without any environmental plough-back? These are red flags that ought to be considered as critical for a state that is not environmentally sustainable. Considering Meghalaya’s location as a hilly terrain and its loss of forest cover the rain water run-off is phenomenal but other than a few water conservation projects not much is happening to address deforestation. Some NGOs have been employed to regreen Meghalaya and to reclaim its lost soil but these projects will take a long time before they produce results. Meanwhile, scientific studies by the Centre for Science and Environment have shown that Meghalaya is heading towards a drought situation. The reasons are not far to seek. If over 747 water sources are in a critical condition then it requires drastic measures to revive those sources and that will only happen through reforestation. But that will take its own time. Most forested areas in Meghalaya are now under broomstick cultivation. This is seen especially in West Khasi Hills and parts of East Khasi Hills. Broomstick is easy to grow and requires no effort at all but its impact on the soil and its capacity to suck underground water is legendary. It is unfortunate that the farmers of this state are not told to put a stop to broomstick cultivation. So large is the production today that there is a glut in the market. Naturally the price of broomsticks has slumped. That’s the law of the market. Another important aspect that is needed to boost Meghalaya’s economy is to get investors from outside the state to set up state of the art processing units for pineapple, oranges and other local fruit. These industrial units however need a constant power supply, not the present mode of power supply where power cuts are perennial. If industries have to rely on generators, their production costs will go up. Also, can Meghalaya have water guzzling industries when the state is facing a precarious situation as far as water is concerned? These are emergent issues that need to be red-flagged.

Director General Office

Saviours of the environment

Urban Lab

CSE Analysis: Rising Winter Air Pollution Hits All Megacities, Delhi Worst Affected

CSE Analysis: Irrespective of their diverse geographic and climatic contexts, the megacities of India – Delhi, Mumbai, Kolkata, Bengaluru, Hyderabad and Chennai — have seen worsening PM2.5 levels during the winter of 2024-25 (October 1, 2024-January 31, 2025). The overall level and the peaking points of pollution have, however, varied across cities depending on the meteorological conditions of different climatic zones. This has emerged from a new analysis of real time PM2.5 data in these cities during the winter period. The analysis, done by Centre for Science and Environment (CSE), has evaluated pollution trends in peer megacities and provides insights into long-term seasonal variations and annual shifts in particulate pollution during winter. While Delhi, located in the land-locked Indo-Gangetic Plains (IGP) with adverse meteorology, has recorded the highest level of pollution during winter, Kolkata — also at the tip of the IGP – ranks second. The megacities outside the IGP — Mumbai, Chennai, Hyderabad and Bengaluru — despite having more advantageous climatic conditions and natural ventilation, have also experienced increases in average PM2.5 concentrations. Other than Delhi and Chennai, all other megacities have recorded city-wide winter averages that are comparatively lower than the average of the past three winters; but the concentrations across different locations have been high, leading to high exposures. The peaking of pollution during winter in any climatic zone is a sign of the underlying problem of persistent air pollution in these rapidly urbanising and motorising cities. The growing impact of local sources of pollution shows up in the pollution hotspots across these cities, increasing local exposures and risks,” says Anumita Roychowdhury, executive director, research and advocacy, CSE. These cities need stringent action to curb pollution from all sources to meet the clean air standards. But urban centres like Delhi and Kolkata that face an additional challenge of adverse meteorology which enhances the concentrations, need even more stringent action to counter these effects,” Roychowdhury adds. According to Sharanjeet Kaur, programme officer with the Urban Lab at CSE, “While Delhi’s winter air quality often dominates public discourse, rising pollution levels in other megacities remain largely overlooked. Despite some improvement in seasonal pollution trends, winter pollution continues to remain high or has been rising locally.” The Methodology Behind the CSE Analysis This is an assessment of annual and seasonal trends in PM2.5 concentrations for the period October 1 to January 31 in the years 2021-22, 2022-23, 2023-24, and 2024-25. Data points have been cleaned and data gaps addressed based on the USEPA method. The analysis has been done on the basis of real time data available from currently working air quality monitoring stations in Delhi, Kolkata, Mumbai, Chennai, Hyderabad and Bengaluru — 115 continuous ambient air quality monitoring stations (CAAQMS) have been covered. Delhi (40), Kolkata (seven), Mumbai (31), Hyderabad (14), Bengaluru (14) and Chennai (nine) have more than one real time station, therefore city-wide averages have been used for comparative analysis: it is defined as average of all city stations that have been functional for the given study period. The Key Highlights Of The Analysis During this winter, Kolkata and Hyderabad were most polluted after Delhi, while Mumbai, Chennai and Bengaluru saw the fastest worsening of localised pollution levels : Delhi, with a winter average PM2.5 level of 175 microgramme per cubic metre (µg/m³) remains the most polluted megacity by a large margin during winter, even though the winter average has shown improvement over the previous winter. In the other five megacities, the average winter PM2.5 level was 65 µg/m³ in Kolkata; 52 µg/m³ in Hyderabad; 50 µg/m³ in Mumbai; 36 µg/m³ in Chennai; and 37 µg/m³ in Bengaluru. Kaur points out that winter averages cannot be directly compared with a 24-hour average or an annual average. She says: “Indicatively, daily standards for PM2.5 are 60 µg/m³ and annual standards are 40 µg/m³. But city average is not an adequate indicator for high exposures in these cities.” Worst affected locations within megacities have pollution levels 19-60 per cent higher than citywide averages: There is considerable variation in air quality among locations in each megacity, with worst locations being considerably more polluted than the city-wide averages. In Kolkata and Mumbai, for instance, the worst air quality was recorded at Ballygunge and Deonar respectively, where the seasonal average stood at 80 µg/m 3 . Notably, four of the six most polluted locations among the 68 monitoring stations across five megacities were in Mumbai, while the remaining two were in Kolkata. IDA Pashamylaram was the most polluted location in Hyderabad, with the seasonal average at 62 µg/m³. In Bengaluru, the most polluted location was RVCE — its seasonal average was 56 µg/m³. Alandur was the most polluted location in Chennai, with a seasonal average of 47 µg/m³ . When compared to the citywide average, pollution levels in the worst-affected locations within each megacity were significantly higher. Chennai saw a 30 per cent increase, while Bengaluru recorded a 51 per cent rise. Mumbai experienced the highest disparity, with pollution levels 60 per cent higher than the citywide average. In Hyderabad, the worst-affected location had 19 per cent higher pollution, whereas Kolkata and Delhi recorded increases of 23 per cent and 30 per cent, respectively. Longer-term trend in winter averages in mega cities : When compared to the three-year average, Delhi remained the worst performer, with average winter pollution levels continuing to rise, even though by just 1 per cent higher than the average of the last three years. Compared to the winter of 2021-22, Mumbai, Kolkata and Hyderabad show improvement with their winter PM2.5 levels dropping by 16 per cent, 14 per cent and 16 per cent respectively. Delhi has recorded a 7 per cent reduction in pollution levels compared to the pervious winter, but 5 per cent higher than in 2021-22. Meanwhile, Bengaluru and Chennai have recorded an increase in PM2.5 levels compared to 2021-22, reflecting a worsening trend in air quality. Peak winter pollution in Delhi hits worst level in last four years; other cities indicate varying trends: Delhi recorded its highest daily PM2.5 level in four years, with pollution spiking to 602 µg/m³ on November 18, 2024 — the steepest 24-hour average since 2021. This marks a 65 per cent increase from last winter’s peak and is 42 per cent higher than the city’s three-year average, highlighting a worsening pollution trend in the capital. Kolkata and Chennai showed little improvement, with Kolkata’s maximum peak level of PM2.5 stagnating at 135 µg/m³, while Chennai saw a slight reduction from 147 µg/m³ last winter to 119 µg/m³ this year. In contrast, Hyderabad, Mumbai and Bengaluru recorded reductions in peak/maximum winter pollution levels. Hyderabad showed the most improvement in peak levels, with a 51 per cent drop in PM2.5 levels, down to 89 µg/m³ from 183 µg/m³ last year. Bengaluru followed with a 42 per cent decline, reducing peak levels to 67 µg/m³, while Chennai saw a 19 per cent improvement and Mumbai recorded a 12 per cent drop in its peak level, lowering its PM2.5 from 92 µg/m³ to 81 µg/m³. This winter’s peak daily pollution levels in Kolkata, Chennai and Hyderabad were lower than their previous winter peaks, but still fell under the “poor” AQI category. Kolkata’s winter peak stood at 135 µg/m³ registered on November 2, 2024; for Chennai, it stood at 119 µg/m³ registered on October 31, 2024; and for Hyderabad it stood at 89 µg/m³ registered on November 25, 2024. Monthly air quality pattern varies across the megacities: Air pollution trends differ across India’s megacities, with Delhi and Hyderabad experiencing their worst air quality in November, while other cities saw peak pollution in December and January. January emerged as the most polluted month for Kolkata, Bengaluru and Chennai, with air quality deteriorating further compared to previous months. Mumbai, on the other hand, recorded its worst pollution levels in December. Winter is problematic season for all megacities, but the intensity of the problem varies : The days with bad air quality occurred in clusters during the winter season in the megacities. The clustering of bad air days was longer in Delhi, Kolkata and Mumbai, but of shorter duration in Hyderabad, Bengaluru and Chennai. The intensity and duration of these bad air days were long enough in Delhi to get classified as a smog episode. Kolkata registers high number of ‘poor’ AQI days; Delhi remains the worst: Kolkata’s long-term seasonal PM2.5 trend was lower, but it recorded the same number of ‘poor’ air quality days as Delhi. With 15 days of ‘poor’ AQI, Kolkata matched Delhi’s count and also experienced one day of ‘very poor’ AQI. Among the megacities, Chennai had only one day of ‘poor’ AQI, while Mumbai, Bengaluru and Hyderabad recorded zero ‘poor’ AQI days . In terms of cleaner air, Mumbai had only 19 days of ‘good’ AQI, followed by Kolkata with just 11 — the lowest among megacities (excluding Delhi). In contrast, Hyderabad (21 days), Bengaluru (44 days) and Chennai (55 days) recorded higher number of ‘good’ AQI days. Delhi remained the most polluted megacity, registering eight days of ‘severe+’ AQI, 12 days of ‘severe’ AQI, 68 days of ‘very poor’ AQI, and no ‘good’ AQI days this winter.

Urban Lab

Ballygunge most polluted part of Kolkata last winter, Fort William and Bidhannagar follow, finds study

Ballygunge in south Kolkata was the most polluted part of the city last winter followed by Fort William area and Salt Lake; found a pan-India study covering metro cities. The study was carried out by a Delhi-based environment think-tank, based on the data generated by Central Pollution Control Board. Winter months are considered most toxic as the pollution levels surge at this time due to a combination of increased emissions, stagnant atmospheric conditions, and reduced pollutant dispersion. ADVERTISEMENT Ultrafine particulate PM 2.5, considered an extremely toxic pollutant having the ability to penetrate deep into the lungs and trigger range of diseases including fatal ones, has been considered as the benchmark in the study carried out by the Urban Lab at the Centre for Science and Environment (CSE) and released on Tuesday; a copy of which is with the correspondent. The study, led by air pollution expert and CSE executive director (research and advocacy) Anumita Roychowdhury, and covering all metro cities of the country pointed out that Kolkata, overall, recorded improvement in its PM 2.5 level this winter (October 2024 to January 2025), compared to last year. However, pockets of the city showed pollution surges much above the national permissible limit this time. Kolkata was second, right behind Delhi, in winter pollution among the metro cities, as per the study. “Despite seasonal improvements, winter pollution levels in Kolkata surged well above annual averages across monitoring locations. Ballygunge remained the most polluted area, with a winter average PM 2.5 level of 80 micrograms per cubic meter, followed by Fort William (71 micrograms) and Bidhannagar (67 micrograms). Even Rabindra Sarobar, the least polluted location (based on data from seven continuous ambient air quality monitoring stations across Kolkata), saw a 29 per cent increase in winter PM 2.5 levels compared to its annual average” reads the report underlining the high pollution trend in winter. The national limit of PM 2.5 is 60 micrograms. Overall, the city recorded “its lowest winter average PM 2.5 level in four years, with a seasonal average of 65 micrograms per cubic meter — a 19 per cent decline compared to the previous three winters”, but remains above national limit. “The growing challenge of particulate pollution in Kolkata remains a concern despite improvements in winter air quality. While the overall seasonal average has improved, pollution spikes continue to be a challenge,” Roychowdhury told this correspondent on Tuesday morning. The study shows that Ballygunge is clearly the most polluted part of the city with highest day reading during last winter with the highest spike of 195 micrograms — more than three times above normal. Incidentally Ballygunge also recorded the highest annual average of PM 2.5 in city during 2024 with a value of 51 micrograms followed by Fort William (49 micrograms). Rabindra Sarobar recorded the lowest with 39 micrograms. The annual national permissible limit of PM 2.5 is 40 micrograms. The report also has found that, during last winter Ballygunge had 54 very poor and poor air quality days out of 123; much above the city average. The study also pointed out that the city faces a “multi-pollutant challenge” with levels of nitrogen dioxide (NO2) — another major pollutant mainly triggered by the vehicles — rising sharply between November and January. “Victoria witnessed the steepest increase, with NO2 levels surging 6.4 times from October to January,” read the study. “These findings underscore the urgent need for a focused strategy to control pollution from key sources and mitigate the winter air quality crisis in Kolkata,” observed the report. Needs stronger policy; air shade pollution control model State pollution board chairman Kalyan Rudra pointed out that the government has been trying a string of measures to combat city pollution but that it would be difficult to cut significantly more pollution unless the regional air shade pollution control model is pursued. “As the World Bank has been pointing out, we need to pursue the regional air shade pollution control mechanism since much of our pollution comes from outside the city; both across state and international borders,” said Rudra. “The city, being at the tip of the Indo- Gangetic plains, gets affected by the pollution generated in the zone, like Delhi; but inadequate policy implementation also contributes to the problem,” explained Roychoudhury to this correspondent. The expert stressed that Kolkata needs to focus on multisectoral action to counter air pollution. “Like the rest of the country, Kolkata has also been focusing on dust control, which is important, but to substantially reduce pollution levels it needs to act as well to counter pollution from transport, waste burning and likewise,” added the expert. “As observed through in-depth chemical characterisation, solid waste and biomass burning are the dominant sources over Kolkata. Such emissions are enhancing ammonia in the air, which in turn helps form a huge amount of particulate matter. We need to target ammonia emission that is producing ultrafine particulate matter through a secondary process,” explained Abhijit Chatterjee, a scientist associated with the union government research organisation Bose Institute and also an advisor to the union government’s flagship National Clean Air Programme.

Urban Lab

Not just Delhi: Winter pollution spike across megacities

Irrespective of their diverse geographic and climatic contexts, India’s megacities of India – Delhi, Mumbai, Kolkata, Bengaluru, Hyderabad and Chennai – have seen worsening PM2.5 levels this winter. The overall level and the peaking points of pollution have, however, varied across cities depending on the meteorological conditions of different climatic zone, according to a latest analysis by the Centre for Science and Environment (CSE). The analysis of real-time PM2.5 data in these cities during the winter period (October 1, 2024-January 31, 2025) has evaluated pollution trends in peer megacities to provide insights into long-term seasonal variations and annual shifts in particulate pollution during winter. While Delhi, located in the land-locked Indo-Gangetic Plains (IGP) with adverse meteorology, has recorded the highest level of pollution during winter, Kolkata – also at the tip of the IGP – ranks second. The megacities outside the IGP – Mumbai, Chennai, Hyderabad and Bengaluru – despite having advantageous climatic conditions and natural ventilation, have also experienced increases in average PM2.5 concentrations. Other than Delhi and Chennai, all other megacities have recorded city-wide winter averages that are comparatively lower than the average of the past three winters; but the concentrations across different locations have been high, leading to high exposures. “The peaking of pollution during winter in any climatic zone is a sign of the underlying problem of persistent air pollution in these rapidly urbanising and motorising cities. The growing impact of local sources of pollution shows up in the pollution hotspots across these cities, increasing local exposures and risks,” Anumita Roychowdhury, executive director, research and advocacy, CSE, said in a release.

Urban Lab

Delhi's air dirtiest among Indian megacities by wide margin: CSE report

Delhi remained India's most polluted megacity by a wide margin during the 2024-25 winter, with an average PM2.5 concentration of 175 micrograms per cubic metre, according to an analysis released on Tuesday. However, the Centre for Science and Environment analysis found that PM2.5 pollution in the national capital declined in the 2024-25 winter (October 1 to January 31) compared to the 2023-24 winter (189 micrograms per cubic metre). Kolkata was the second-most polluted megacity during the 2024-25 winter, with an average PM2.5 concentration of 65 micrograms per cubic metre. The analysis showed that PM2.5 levels declined in Bengaluru, Mumbai and Kolkata compared to the previous winter but remained the same in Chennai and Hyderabad. The average PM2.5 levels during the 2024-25 winter were 52 micrograms per cubic metre in Hyderabad, 50 in Mumbai, 37 in Bengaluru and 36 in Chennai.

Clean Air & Sustainable Mobility

Delhi Reclaims World's Most Polluted Capital Amid Surge in Winter Pollution

The megacities of India experienced a surge in air pollution during the winter of 2024-25 with Delhi topping the charts recording highest level of pollution during winter, according to a study by Centre for Science and Environment (CSE). The study revealed that other urban centres including Kolkata, Mumbai, Chennai, Hyderabad and Bengaluru also recorded major pollution spikes during the winter period. Delhi recorded an average fine particulate matter (PM) 2.5 concentrations of 175 micrograms per cubic metre (µg/m³) this winter exceeding the safe air quality limits by a large margin. The capital city registered eight days of ‘severe+’ air quality, 12 days of ‘severe’ Air Quality Index (AQI) and 68 days of ‘very poor’ AQI. The capital experienced no ‘good’ air quality days with peak pollution reaching 602 µg/m³ on November 18, 2024, marking the worst daily PM 2.5 level in four years. According to the study, Kolkata ranked second among the mega cities with a winter PM 2.5 average of 65 µg/m³, followed by Hyderabad (52 µg/m³), Mumbai (50 µg/m³), Bengaluru (37 µg/m³) and Chennai (36 µg/m³). Despite these statistics, the study indicated that worst affected locations within megacities recorded pollution levels rising as much as 60% above citywide averages. Mumbai, Chennai and Bengaluru saw the fastest worsening of localised pollution levels, stated the study. “The peaking of pollution during winter in any climatic zone is a sign of the underlying problem of persistent air pollution in these rapidly urbanising and motorising cities. The growing impact of local sources of pollution shows up in the pollution hotspots across these cities, increasing local exposures and risks,” said Anumita Roychowdhury, Executive Director, Research and Advocacy, CSE. Delhi as World’s Most polluted Capital According to another study titled 2024 World Air Quality Report published by IQAir on March 11, Delhi became the most polluted capital city in the world with an average PM 2.5 concentration of micrograms per cubic metre (µg/m³). According to the report, 13 out of the 20 most polluted cities in the world are in India with Byrnihat on the Assam-Meghalaya border being the most polluted metropolitan area of 2024, with an annual average PM2.5 concentration of 128.2 µg/m3. The region of Central & South Asia was home to the top seven most polluted cities in the world. India was home to six of the nine most polluted global cities. India is the fifth most polluted country in the world, with an average Air Quality Index (AQI) of 50.6 μg/m3 – 10 times higher than the World Health Organization’s (WHO) annual PM2.5 guideline value of 5 μg/m3. In 2023, it was the third most polluted country, reported The Indian Express.

Urban Lab

Delhi air dirtiest among Indian megacities by wide margin: CSE report

Delhi remained India’s most polluted megacity during the 2024-25 winter, with an average PM2.5 concentration of 175 micrograms per cubic meter, according to a report released by the Centre for Science and Environment (CSE) on Tuesday. While this marks a decline from the previous winter’s 189 µg/m³, the city continues to grapple with severe air pollution. Kolkata ranked as the second-most polluted megacity, recording an average PM2.5 concentration of 65 µg/m³. Other major cities, including Mumbai, Bengaluru, and Kolkata, saw a decrease in pollution levels compared to last winter, while Chennai and Hyderabad reported no significant changes. The winter PM2.5 averages stood at 52 µg/m³ in Hyderabad, 50 in Mumbai, 37 in Bengaluru, and 36 in Chennai. A separate study by Swiss air quality monitoring company IQAir named Delhi the world’s most polluted national capital for the sixth consecutive year. The World Air Quality Report 2024 revealed that 13 of the 20 most polluted cities globally are in India. The worst-affected city was Byrnihat, on the Assam-Meghalaya border, with an annual average PM2.5 concentration of 128.2 µg/m³. India ranked among the five most polluted countries, alongside Chad, Bangladesh, Pakistan, and Congo. The country’s average PM2.5 concentration stood at 50.6 µg/m³ in 2024, reflecting a 7% improvement from the previous year’s 54.4 µg/m³. However, six Indian cities still made it to the list of the world’s 10 most polluted. The report highlighted severe pollution episodes in northern India, particularly in Delhi, Punjab, Himachal Pradesh, Chandigarh, and Haryana, with extreme levels recorded in November. Crop stubble-burning remained a significant contributor, responsible for up to 60% of PM2.5 pollution during peak periods. Despite marginal improvements, India continues to battle hazardous air quality, with millions exposed to pollution levels far exceeding WHO safety limits.

Urban Lab

Delhi’s air dirtiest among Indian megacities by wide margin: CSE report

Delhi remained India’s most polluted megacity by a wide margin during the 2024-25 winter, with an average PM2.5 concentration of 175 micrograms per cubic metre, according to an analysis released on Tuesday. However, the Centre for Science and Environment analysis found that PM2.5 pollution in the national capital declined in the 2024-25 winter (October 1 to January 31) compared to the 2023-24 winter (189 micrograms per cubic metre). Kolkata was the second-most polluted megacity during the 2024-25 winter, with an average PM2.5 concentration of 65 micrograms per cubic metre. The analysis showed that PM2.5 levels declined in Bengaluru, Mumbai and Kolkata compared to the previous winter but remained the same in Chennai and Hyderabad. The average PM2.5 levels during the 2024-25 winter were 52 micrograms per cubic metre in Hyderabad, 50 in Mumbai, 37 in Bengaluru and 36 in Chennai. PTI GVS GVS SZM SZM

Urban Lab

This Mega City Comes Next To Delhi In Air Pollution, Says Report

Delhi remained India's most polluted megacity in the 2024-25 winter, with an average PM2.5 level of 175 µg/m³, though pollution declined from 189 µg/m³ in the previous winter, according to a CSE analysis. Kolkata ranked second with 65 µg/m³. While PM2.5 levels dropped in Bengaluru, Mumbai, and Kolkata, they remained unchanged in Chennai and Hyderabad.

Urban Lab

दिल्ली देश का सबसे प्रदूषित महानगर, जानें क्या है अन्य महानगरों का हाल; CSE रिपोर्ट में खुलासा

दिल्ली ने एक बार फिर देश के सबसे प्रदूषित महानगर का खिताब अपने नाम किया है। 2024-25 की सर्दियों (1 अक्तूबर से 31 जनवरी) के दौरान दिल्ली में पीएम 2.5 का औसत स्तर 175 माइक्रोग्राम प्रति घन मीटर दर्ज किया गया। यह आंकड़ा अन्य सभी महानगरों की तुलना में काफी अधिक है। हालांकि, एक अच्छी खबर यह है कि पिछले साल की सर्दियों की तुलना में दिल्ली की हवा थोड़ी बेहतर रही। बता दें कि, 2023-24 की सर्दियों में यह स्तर 189 माइक्रोग्राम प्रति घन मीटर था। कोलकाता देश का दूसरा सबसे प्रदूषित महानगर राजधानी दिल्ली के बाद पश्चिम बंगाल की राजधानी कोलकाता देश का दूसरा सबसे प्रदूषित महानगर रहा, जहां 2024-25 की सर्दियों के दौरान पीएम 2.5 का औसत स्तर 65 माइक्रोग्राम प्रति घन मीटर दर्ज किया गया। हालांकि, यह स्तर दिल्ली की तुलना में काफी कम रहा है। इन महानगरों में प्रदूषण की स्थिति में कोई बदलाव नहीं सेंटर फॉर साइंस एंड एनवायरनमेंट (सीएसई) की इस रिपोर्ट में यह भी पाया गया कि मुंबई, बंगलूरू और कोलकाता में पिछले साल की तुलना में प्रदूषण कम हुआ, जबकि चेन्नई और हैदराबाद में प्रदूषण का स्तर पहले जैसा ही बना रहा है। Air Pollution: दिल्ली देश का सबसे प्रदूषित महानगर, जानें क्या है अन्य महानगरों का हाल; CSE रिपोर्ट में खुलासा न्यूज डेस्क, अमर उजाला, नई दिल्ली Published by: पवन पांडेय Updated Tue, 18 Mar 2025 05:18 PM IST सार 86016 Followers देश Air Pollution In Delhi: देश की राजधानी में भले ही प्रदूषण कम करने को लेकर सरकार की तरफ से तमाम प्रयास किए जा रहे हैं। लेकिन ये सभी प्रयास नाकाफी साबित हो रहे हैं। जी हां, सेंटर फॉर साइंस एंड एनवायरनमेंट की रिपोर्ट में देश के महानगरों में प्रदूषण को लेकर बड़ा खुलासा हुआ है। Delhi's air dirtiest among Indian megacities by wide margin: CSE report, News in hindi दिल्ली देश का सबसे प्रदूषित महानगर (सांकेतिक तस्वीर) - फोटो : ANI Reactions विस्तार Follow Us दिल्ली ने एक बार फिर देश के सबसे प्रदूषित महानगर का खिताब अपने नाम किया है। 2024-25 की सर्दियों (1 अक्तूबर से 31 जनवरी) के दौरान दिल्ली में पीएम 2.5 का औसत स्तर 175 माइक्रोग्राम प्रति घन मीटर दर्ज किया गया। यह आंकड़ा अन्य सभी महानगरों की तुलना में काफी अधिक है। हालांकि, एक अच्छी खबर यह है कि पिछले साल की सर्दियों की तुलना में दिल्ली की हवा थोड़ी बेहतर रही। बता दें कि, 2023-24 की सर्दियों में यह स्तर 189 माइक्रोग्राम प्रति घन मीटर था। Trending Videos Advertisement: 0:12 Close Player कोलकाता देश का दूसरा सबसे प्रदूषित महानगर राजधानी दिल्ली के बाद पश्चिम बंगाल की राजधानी कोलकाता देश का दूसरा सबसे प्रदूषित महानगर रहा, जहां 2024-25 की सर्दियों के दौरान पीएम 2.5 का औसत स्तर 65 माइक्रोग्राम प्रति घन मीटर दर्ज किया गया। हालांकि, यह स्तर दिल्ली की तुलना में काफी कम रहा है। विज्ञापन यह भी पढ़ें - Electricity Demand: भीषण गर्मी में भी नहीं होगी बत्ती गुल! आम लोगों को राहत देने सरकार ने तैयार किया ये प्लान इन महानगरों में प्रदूषण की स्थिति में कोई बदलाव नहीं सेंटर फॉर साइंस एंड एनवायरनमेंट (सीएसई) की इस रिपोर्ट में यह भी पाया गया कि मुंबई, बंगलूरू और कोलकाता में पिछले साल की तुलना में प्रदूषण कम हुआ, जबकि चेन्नई और हैदराबाद में प्रदूषण का स्तर पहले जैसा ही बना रहा है। Delhi's air dirtiest among Indian megacities by wide margin: CSE report, News in hindi देश के महानगरों में प्रदूषण का स्तर - फोटो : अमर उजाला 2024-25 की सर्दियों में अन्य महानगरों का प्रदूषण स्तर (पीएम 2.5) हैदराबाद: 52 माइक्रोग्राम प्रति घन मीटर मुंबई: 50 माइक्रोग्राम प्रति घन मीटर बंगलूरू: 37 माइक्रोग्राम प्रति घन मीटर चेन्नई: 36 माइक्रोग्राम प्रति घन मीटर दिल्ली में प्रदूषण घटने के बावजूद स्थिति गंभीर दिल्ली में भले ही पिछले साल के मुकाबले प्रदूषण थोड़ा कम हुआ हो, लेकिन यह अभी भी स्वास्थ्य मानकों से बहुत अधिक है। विश्व स्वास्थ्य संगठन (डब्ल्यूएचओ) के अनुसार,स्वस्थ हवा के लिए PM2.5 का स्तर 15 माइक्रोग्राम प्रति घन मीटर से अधिक नहीं होना चाहिए। इसके मुकाबले दिल्ली का प्रदूषण स्तर ग्यारह गुना ज्यादा रहा है।

Renewable Energy

THE CHINKS IN INDIA’S SOLAR ARMOUR

Urban Lab

Delhi's air dirtiest among Indian megacities by wide margin: CSE report

Delhi remained India's most polluted megacity by a wide margin during the 2024-25 winter, with an average PM2.5 concentration of 175 micrograms per c

Clean Air & Sustainable Mobility

Chock-a-block Kolkata gets 17k more vehicles in first 2 months of year

KOLKATA: The first two months of the year have seen a record number of vehicles getting added to Kolkata's already-choked roads, exacerbating its traffic woes. Jump over 2023 number A total of 16,975 new vehicles were registered in the city's four regional transport offices in Jan-Feb, over a thousand more than the count for the same period in 2024 and 3,000 more than that in Jan-Feb 2023. The 21.5% increase over three years is driven largely by personalised vehicles, underlining the shift away from public transportation. Experts say the the surge, which is even greater than the pre-Covid peak level of 2019, reflects a decaying of the city's once-robust public transport system. "Trams remain largely discontinued, buses are being phased out without replacements, and infra development is prioritising private vehicles over mass transit," said mobility expert Anumita Roychowdhury of Centre for Science and Environment. Transport officials say the shift to private mobility raises concerns about long-term urban congestion and sustainability. "Once a model public transport city, Kolkata now risks the fate of Delhi and Bengaluru, where traffic snarls persist despite greater road space. This signals an urgent need to rethink urban mobility strategies before congestion spirals out of control," said A K Das, a former transport department chief traffic and transportation engineer. Steady rise in registration at Beltala, Behala PVDs At the centrally located PVD Beltala, new vehicle registrations for Jan jumped 48% over the same month 2023. For Behala RTO, the Jan registrations jump over 2023 was even higher at 55%. Behala has, in fact, witnessed a steady increase in vehicle registrations, with Jan figures rising from 765 in 2023 to 962 in 2024 and 1,189 in 2025. Feb also showed consistent growth, moving from 676 in 2023 to 851 in 2024 and 913 in 2025, suggesting a gradual rise in new vehicle ownership in this region. The Kasba RTO, interestingly, bucked the trend with the number of new registrations in both Jan and Feb dipping. January registrations climbed from 1,777 in 2023 to 2,039 in 2024 but dropped to 1,957 in 2025. February figures, too, moved from 1,656 in 2023 to 1,767 in 2024 before declining to 1,627 in 2025 Salt Lake, another key RTO, exhibited strong growth in January with registrations increasing from 1,771 in 2023 to 2,302 in 2024 and 2,343 in 2025. However, February figures dipped from 2,302 in 2023 to 2,024 in 2024 to 1,878 in 2025.