Latest news with #AnumitaRoychowdhury
The Hindu
16-07-2025
- Health
- The Hindu
Hyderabad's Bolarum saw highest ozone pollution this summer, says study
Ozone pollution spiked in several parts of Hyderabad this summer, but it was the industrial belt of Bolarum that saw the worst of it. Between March 1 and May 31, Bolarum recorded 17 days when ground-level ozone levels breached the safe limit — the highest in the city — according to a research paper published by the Centre for Science and Environment titled 'An invisible threat: Ground-level ozone – Metro cities' based on a study by Anumita Roychowdhury and Sharanjeet Kaur. The study tracked air quality in five major cities — Hyderabad, Mumbai, Kolkata-Howrah, Bengaluru and Chennai — using data from 80 stations under the Continuous Ambient Air Quality Monitoring System (CAAQMS). As per the study, Bolarum is most chronically affected by ground-level ozone pollution, and exceeded the standard for 17 days in the study period. While the standard is 100 μg/m³ (micrograms per cubic metre of air), the levels of ozone nearly touched 140 μg/m³ on the days mentioned. There were no exceedances at other stations in the city barring ICRISAT which exceeded the standard for two days and Ramachandrapuram which exceeded for one day, totalling to 20 days of ozone exceedance in the city. The days of exceedance in Hyderabad were more concentrated between May 2 and 20. Good news is that the figure is 55% lower than what was recorded last summer. A comparison of May 2025 with May 2024 reveals that ground-level ozone is now lingering in the atmosphere even after sunset, and the average hourly ozone peak is 3% higher than last year, the study noted. At 45, Bengaluru recorded the highest number of days with ozone exceedance. Mumbai recorded 32 days, Kolkata 22 days, and Chennai recorded the lowest at 15 days. Unlike primary pollutants which are emitted directly from sources such as vehicles and industries, ground level ozone is formed through intricate chemical reactions involving nitrogen oxides, volatile organic compounds (VOCs) and carbon monoxide, which are the pollutants released by vehicles, power plants, factories and other combustion sources, the study said. In the presence of sunlight, these substances undergo a series of cyclic reactions that result in the ozone formation near the ground. VOCs also have natural sources such as vegetation adding to the complexity, which explains the higher levels at ICRISAT. What's more threatening is that the ground level ozone can travel long distances, turning into a regional pollutant. It impacts agricultural productivity, threatening food security. Ozone is a highly reactive gas which can be harmful even with short duration exposure, and result in serious public health crisis, the study warned. Ground level ozone can inflame and damage the airways, increase susceptibility to infections and worsen respiratory conditions such as asthma, chronic bronchitis and emphysema. Children with underdeveloped lungs, order adults and people with existing respiratory conditions are particularly vulnerable. Hyderabad is prone to experience ozone exceedances during winter too, driven by cold, stagnant conditions and poor vertical mixing. But this winter, there was substantial improvement, with the city recording just nine days of exceedance which is a sharp decline from 43 days recorded during the winter of 2024, the study observed.
Indian Express
16-07-2025
- Health
- Indian Express
High summer-time ozone levels in megacities a cause for concern: CSE study
Ozone levels in all megacities of the country have been high during the summer of 2025, with Bengaluru and Mumbai recording levels above prescribed standards for over a third of summer days, said a new Centre for Science and Environment (CSE) analysis. The new assessment used data from 80 continuous ambient air quality monitoring stations across Mumbai, Kolkata, Bengaluru, Chennai, and Hyderabad. When the CSE analysed Delhi's ozone (O3) levels last month, they were found to have exceeded the prescribed standard on each summer day between March 1 and May 31. Ozone levels in Bengaluru exceeded prescribed limits 45 out of the 92-day summer days monitored by the CSE, which was a 29 per cent increase compared to last summer, the new analysis said. In Chennai, ozone levels exceeded prescribed levels for 15 out of 92 days, in comparison to no exceedance days for the corresponding period last year. Mumbai recorded ozone exceedance on 32 out of 92 days, marking a 42 per cent decline compared to the corresponding period last year. In Kolkata, about 22 out of 92 days this summer registered an exceedance of ozone standards, which was an improvement over last year by 45 percent. Due to its reactive nature, O3 levels are monitored in an eight-hour average period, instead of 24-hour averages, unlike other pollutants. The prescribed ozone standard for an eight-hour period is 100 micrograms/cubic metre as per the National Ambient Air Quality Standards (NAAQ). Anumita Roychowdhury, executive director, CSE, said, 'If unchecked, this can become a serious public health crisis as ozone is a highly reactive gas and can be harmful even with short-duration exposures. In contrast to cities in north India, where high summer temperatures and intense solar radiation can lead to ozone levels exceeding the standards, other cities in warm climates are experiencing consistent ozone exceedance during other seasons as well.' 'Ground-level ozone is beginning to emerge as a pollutant of concern with cities experiencing days exceeding the 8-hour standards. While the level of exceedance is expected to be higher during the summer months with strong sun-shine days and heat, this is emerging as a round-the-year problem in the warmer climate. Clean air action plans for cities and the states need to address this multi-pollutant challenge urgently,' CSE recommended in its analysis. Ozone is not a primary, but a secondary pollutant formed through chemical reactions between other pollutants under sunlight. Hence, summer months see a spike in ozone concentrations. These chemicals include nitrogen oxides (Nox), volatile organic compounds, and carbon monoxide (CO), pollutants emitted from vehicle tailpipes, power plants, factories, the CSE analysis stated. Ground-level ozone can affect the airways and lungs adversely, increase susceptibility to infections, worsen respiratory ailments, and decrease lung function. An award-winning journalist with 14 years of experience, Nikhil Ghanekar is an Assistant Editor with the National Bureau [Government] of The Indian Express in New Delhi. He primarily covers environmental policy matters which involve tracking key decisions and inner workings of the Ministry of Environment, Forest and Climate Change. He also covers the functioning of the National Green Tribunal and writes on the impact of environmental policies on wildlife conservation, forestry issues and climate change. Nikhil joined The Indian Express in 2024. Originally from Mumbai, he has worked in publications such as Tehelka, Hindustan Times, DNA Newspaper, News18 and Indiaspend. In the past 14 years, he has written on a range of subjects such as sports, current affairs, civic issues, city centric environment news, central government policies and politics. ... Read More
Time of India
16-07-2025
- Health
- Time of India
Mega cities in India see high concentration of ozone pollution this summer
A recent analysis by the Centre for Science and Environment (CSE) reveals high ground-level ozone pollution in major Indian cities like Kolkata, Bengaluru, Mumbai, Hyderabad, and Chennai this summer. Ozone, formed by reactions involving pollutants from vehicles and industries, poses a public health risk. The analysis emphasizes the need for improved monitoring and mitigation strategies to address this growing concern. Tired of too many ads? Remove Ads Tired of too many ads? Remove Ads Tired of too many ads? Remove Ads All mega cities in India, including Kolkata, Bengaluru, Mumbai, Hyderabad and Chennai, saw high concentration of ground-level ozone pollution this summer season, according to a new analysis by think tank Centre for Science and Environment (CSE).A previous analysis had shown that ozone, instead of particulate matter, was the main pollutant in Delhi's daily Air Quality Index (AQI) on several days this new analysis by the CSE's Urban Lab highlighted that ozone, unlike primary pollutants, is not released directly from any forms through complex chemical reactions involving nitrogen oxides (NOx), volatile organic compounds (VOCs) and carbon monoxide (CO), pollutants emitted by vehicles, power plants, industries and other sources of substances react in the presence of sunlight, leading to the formation of ozone at the ground level. Anumita Roychowdhury , executive director at the CSE, said: "If unchecked, this can become a serious public health crisis as ozone is a highly-reactive gas and can be harmful even with short-duration exposures."She added that while cities in north India experience high ozone levels in summer due to intense heat and strong sunlight, cities in warmer climates are also seeing consistent ozone exceedance in other current policy focus must be expanded to include improved monitoring, the mitigation of this toxic gas and a reduction in high local mitigation needs drastic control over a range of gases from vehicles, industry and all combustion sources, Roychowdhury Kaur, deputy programme manager at the CSE's Urban Lab, said: "Inadequate monitoring, limited data and inadequate methods of trend analysis have weakened the understanding of this growing public health hazard across cities of India. Instead of merely averaging out the levels for the city, which is the standard practice to estimate the AQI, it is also important to adequately capture the high levels of local build-up and exposures in the hotspots and design mitigation strategies accordingly."Between March 1 and May 31 this year, Mumbai recorded ozone exceedance on 32 out of 92 days across its monitoring stations, a 42-per cent drop compared to the same period last year. The worst day in terms of spread was March 29, when eight out of 31 stations reported exceedance. The highest ground-level ozone concentration recorded was 90 micrograms per cubic Kolkata, ozone levels crossed the safe limit on 22 out of 92 days, a 45-per cent decline compared to last summer. The city also saw an overall improvement, with the average hourly ozone peak dropping by 22 per saw ozone exceedance on 45 of the 92 days, a 29-per cent increase from last year. The worst day was March 31, when four of 14 stations recorded levels above the recorded 20 ozone exceedance days, a 55-per cent drop compared to last summer. The highest ozone level recorded in the city was 51 micrograms per cubic saw ozone exceedance on 15 days this summer. No such exceedance was reported during the same period last year. In comparison, the city had three exceedance days in 2023 and 19 in 2022. The highest level this year was 64 micrograms per cubic metre.
Scroll.in
09-07-2025
- Automotive
- Scroll.in
Why Delhi's crackdown on old vehicles may not be effective in tackling air pollution
On July 1, the Delhi government undertook a significant measure to tackle air pollution: it banned fuel stations from selling fuel to diesel vehicles that were more than ten years old and petrol vehicles that were more than 15 years old. Vehicular emissions are one of the leading causes of air pollution in Delhi through the year. They can contribute between one-third and two-thirds of the capital's toxic air, a 2018 analysis showed. The government's move was based on a 'directive order' issued by the Commission for Air Quality Management in April. The commission is a statutory body established by the Union environment ministry to manage the air quality of the National Capital Region and its adjoining areas. To identify such 'end-of-life' vehicles, automated camera systems were installed in 498 petrol stations in Delhi to scan the number plates of vehicles that entered – if any was found to be above the age limit, or to not possess a pollution under control certificate, the station was to deny it fuel. Authorities also cracked down on overage vehicles: across the city, 87 such vehicles were impounded and 176 notices were issued to owners of others. But these apparently decisive moves belied considerable confusion over strategy and policy within the government. This became apparent just three days later on July 3, when the Delhi government asked the commission to reconsider its guidelines because it was facing challenges in implementing the ban: perhaps most significantly, faulty camera systems were often erroneously flagging newer cars. Delhi's chief minister, Rekha Gupta, posted on X that the move was 'adversely affecting the daily lives and livelihoods of millions of families'. After deliberations between Delhi government and the Commission for Air Quality Management, the commission on July 8 decided to 'partially amend' its earlier instructions, and instead direct that the fuel ban be activated from November 1 onwards in five 'high vehicle density districts' – Gurugram, Faridabad, Ghaziabad, Gautam Budh Nagar and Sonipat. From April 2026, the ban will extend to the rest of the National Capital Region. Even as the ban is set to return, experts argue that rather than imposing blanket bans, a more targeted approach to removing polluting vehicles from the streets would be more effective, and easier to implement on a large scale. 'Older vehicles do require action, but a standalone ban dependent on just age alone is concerning,' said Anumita Roychowdhury, executive director of research and advocacy at the Delhi-based Centre for Science and Environment. The organisation has for long argued that drastic measures are needed to reduce the number of vehicles on city roads. But Roychowdhury argued that the ban should not merely be based on age, but on 'the actual emission performance of the vehicles'. While generally older vehicles do pollute more, she explained, newer vehicles can also be significantly polluting because of technical malfunctions or poor maintenance. 'Identifying the worst polluters should be the criteria to declare an end-of-life vehicle,' she said. The rationale The current ban on refuelling has its roots in a 2015 order by the National Green Tribunal, which directed that end-of-life vehicles not be permitted to ply in the National Capital Region. Three years later, in October 2018, after examining a report on the matter by the Environment Pollution (Prevention and Control) Authority, the Supreme Court issued an order that reiterated the tribunal's ban. But the government did not implement the ban in the years that followed. In January 2024, a union government committee of secretaries – a term for an inter-ministerial committee formed to discuss specific kinds of matters and proposals – remarked in a meeting that there was 'very slow progress in this context.' Experts had also begun pointing out that these older vehicles needed to be replaced with new ones that followed Bharat Stage-VI, or BS-6 emission standards. The ministry of road transport and highways introduced these standards in April 2020 – the engines of vehicles that adhered to these standards would emit significantly lower levels of pollutants. According to the ministry's notification, all vehicles manufactured after April 2020 would have to meet these standards. But vehicles manufactured prior to 2020 are still on the country's streets – currently, the vehicular fleet is dominated by those that follow older BS III and BS IV standards. 'The challenge is to accelerate fleet renewal based on the current BS VI standard in the coming decade,' a report by the Centre for Science and Environment said. In its April letter, the commission estimated that Delhi had more than 62 lakh overage vehicles – the highest number among National Capital Region territories and adjoining regions. In comparison, it estimated that Haryana had 27 lakh such vehicles, Uttar Pradesh had around 12 lakh, and Rajasthan around 6 lakh. In the same letter, the commission stated that the ban on overage vehicles should be implemented starting from July 1. The commission also recommended that the administration run checks on vehicles parked in public spaces and impound those that were found to be overage. Owners could reclaim them by paying a penalty of Rs 10,000 for a four-wheeler and Rs 5,000 for a two-wheeler, and providing an undertaking that the vehicle would be removed from the national capital region. But some experts have arrived at much lower estimates of the number of old vehicles in Delhi, and explained that communicating this information to the public would significantly increase support for the implementation. Delhi-based think-tank Council for Energy, Environment and Water, for instance, ran calculations based on existing research that estimate how long vehicles are typically used for, and concluded that of the 1.5 crore vehicles registered in the city in the last few decades, only between 83,000 and 4 lakh overage vehicles remained. 'Most older vehicles have either found new homes in other states or have been informally scrapped,' said Karthik Ganesan, director of strategic partnerships at the council. He added, 'The directive must be supported by studies that help attribute impact and establish drawbacks and effectiveness, which can make a case for such interventions nationwide.' Defining an 'end-of-life' vehicle Delhi surpasses all other Indian cities with 1.18 crore vehicles on the road, over 90% of which are two-wheelers and cars. But a comparison of emissions of diesel trucks and personal cars shows why targeting vehicles based on actual emissions was crucial to managing the problem. A 2024 study by the Real Urban Emissions Initiative analysed emissions by a range of vehicles and found that as cars aged, they emitted increasing amounts of most pollutants, such as nitrogen oxide and carbon monoxide. The increase in emissions of these substances between new cars and those that were more than ten years old ranged from around 2.6 times to more than 5.3 times. In contrast, the study found that with buses, emissions typically peaked in vehicles that were either between three and six years old or between six and ten years old. The increase in emissions of these substances ranged from more than eight times to more than 33 times. Broadly, the Real Urban Emission Initiative study found that commercial vehicles like light goods vehicles, taxis, three-wheelers and buses 'generally exhibited higher emission levels' than personal vehicles and two-wheelers. But this did not mean that personal vehicle ownership should be promoted, Ganesan cautioned. Ultimately, he said, 'The effort needs to also go beyond and eventually deter private transport and make it convenient for people to rely on public transport.' Roychowdhury argued that there was an onus on the government to 'improve the surveillance system' to more precisely identify the most polluting vehicles. Currently, a mandatory pollution under control certificate is the only such check on vehicular emission levels. Roychowdhury argued that this method is insufficient, since it does not capture how the emissions on vehicles vary with driving patterns and different speeds. Moreover, media reports from around the National Capital Region revealed that testing centres often issue pollution under control certificates even to unfit vehicles in exchange for bribes as small as Rs 50. 'There is a need to have more rigorous centres and accountability' for pollution certificate, Roychowdhury said. Towards a step in that direction, the Delhi government has begun work on pilot testing a programme to conduct remote-sensing monitoring of vehicular emissions using machines installed by the sides of roads. If a vehicle emission is detected as being above the prescribed limit, authorities can penalise it immediately. Incentivising scrapping In October last year, the Delhi government's transport department also introduced financial incentives to encourage vehicle owners to scrap older vehicles. For those who scrapped old 'non-transport vehicles' and purchased new ones that ran on petrol, CNG or LPG, the government offered a 20% concession on motor vehicle tax, which vehicle owners have to pay while registering a new vehicle – similarly, those who bought new diesel vehicles were offered a 15% concession on this tax. A similar concession on the tax was available for 'transport vehicles' – 15% for non-diesel new vehicles and 10% for diesel ones. Roychowdhury described this as a 'good step forward' and added that it would become clearer with time how effective the incentive was and what fine tuning it might need. But Ganesan argued that voluntary scrapping would only be effective if states were better coordinated with each other. In a recent analysis, he noted that vehicles that become overage in Delhi 'can re-register in other parts of the country, possibly even without proving their 'fitness''. Only when states coordinate, he argued in the analysis, can they ensure that 'leakages' of such overage vehicles do not happen from 'one jurisdiction to another'. Other cities and states have also implemented strategies to tackle vehicular pollution. Some, including Uttar Pradesh, Maharashtra and Karnataka have introduced a ' green tax ' on old vehicles as a way to discourage their use. These taxes, levied on vehicles more than 15 years old at the time their fitness certificate is renewed, largely range between Rs 200 and Rs 1,000 for different categories. Only Maharashtra levies significantly higher taxes – for instance, the owner of a petrol car that is more than 15 years old has to pay a green tax of Rs 3,000. Experts believe that though this strategy can help, the amounts levied in most cases may be too small. Such taxes 'would have to be much higher for a person to rethink continuing using his vehicle or would have to be charged based on usage', said Ganesan. Some regions have also tried bans on vehicles. In 2003, Lucknow began phasing out older vehicles, while in 2008, the Kolkata High Court capped the age of commercial vehicles at 15 years. Kolkata's experience is revealing of one problem with the strategy. This year, more than 15 years after the ban was implemented, the policy had to be modified in the face of numerous complaints from bus associations that they would face economic losses because their vehicles were at risk of being arbitrarily deregistered because of their age. Now, vehicles over 15 years old have to undergo a mandatory biannual fitness and emission test – only if they are found to be in poor mechanical or environmental health are they declared unfit and taken off the road.
Time of India
07-07-2025
- Climate
- Time of India
Monsoon gift that Delhi is thankful for: Clean air
New Delhi: The city recorded its 12th consecutive day of satisfactory air quality on Monday with an AQI of 85. Monsoon months are generally the cleanest in Delhi as favourable meteorological conditions, including rain and strong winds, help in settling pollutants down. During the monsoon last year, Delhi saw 27 consecutive days of satisfactory air quality, from July 28 to Aug 23. You Can Also Check: Delhi AQI | Weather in Delhi | Bank Holidays in Delhi | Public Holidays in Delhi The city experienced 13 such days in a row in the monsoon of 2023, 11 days in 2022, and 20 days in 2021. However, the monsoon of 2020, which was the Covid year, was the best with Delhi recording 51 straight days of satisfactory air quality, including four 'good' air days. A spell of 20 consecutive satisfactory days, including two good days, was seen each in 2019 and 2017. Anumita Roychowdhury, executive director of research and advocacy at the Centre for Science and Environment (CSE), said: "The air quality during the monsoon months is substantially cleaner primarily because of the washout and cleansing effect of the rains and strong winds. The level of particulate matter reduces substantially and as a result, the toxic gaseous pollutants like ozone become the lead pollutant in the city. by Taboola by Taboola Sponsored Links Sponsored Links Promoted Links Promoted Links You May Like Formigamento nos pés? Idosos estão usando esse item e sentindo alivio. A arte do herbalismo Undo " She added that the cleaner air quality that is achieved due to the climatic and atmospheric conditions needs to be achieved year-round with the help of clean air action. Sunil Dahiya, founder and lead analyst at EnviroCatalysts, said: "Air quality is a function of emissions and meteorology. A higher number of rainy days and rainy hours wash down the pollution, reducing the concentrations, which ensures relatively cleaner days during the monsoon every year. We have seen good rainfall this season, which has definitely contributed to relatively cleaner June-July months so far compared to past years. " Delhi environment minister Manjinder Singh Sirsa said the best-performing hotspots were Rohini and Bawana on Monday with an AQI of 70. He said 6,471km of roads were swept, 594 KL of water was sprinkled across 1,071.45km of roads, 11,252 MT of garbage was removed, and 2,278.9 MT of construction and demolition waste was lifted on Monday. According to the Air Quality Early Warning System for Delhi, which is the forecasting body under the Union ministry of earth sciences, the air quality of Delhi is likely to remain satisfactory till July 10.
