Vehicles core driver of pollution

Hyderabad: The city's air may not yet resemble the choking smog of Delhi, but a quieter crisis is unfolding. Vehicular pollution has emerged as the most persistent contributor to deteriorating air quality, with multiple datasets showing traffic is no longer just a congestion problem but a slow-burning public health emergency. While the city's Air Quality Index (AQI), hovering around 100, may seem less alarming than Delhi (over 300) or Mumbai (around 130), experts warn such comparisons can be misleading. Vehicular emissions remain a major contributor to particulate matter (PM) levels. Pollution Control Board data shows PM2.5 levels ranging from 80 to 140 µg/m³ and PM10 between 70 and 130 µg/m³ across several pockets — far exceeding World Health Organization (WHO) limits of 5 µg/m³ for PM2.5 and 15 µg/m³ for PM10. A large share of this load is linked to vehicle exhaust, tyre and brake wear, and prolonged congestion.Environmentalists point to Hyderabad's exploding vehicle population as the core driver. Official estimates put the city's daily vehicular pollution load at 1,500 tonnes, nearly one-third of total air pollution."With more than 88 lakh vehicles, emissions of PM, nitrogen oxides and sulphur dioxide have become constant rather than episodic," said Babu Rao, a senior environmentalist who has worked on city air quality for three decades.Fresh evidence suggests the burden is worsening. A study by Development Data Lab found Hyderabad ranked third among 10 Indian cities that recorded a rise in PM2.5 concentrations between 2011 and 2022, with levels increasing by 15.4%. Only Surat (24.5%) and Pune (32.2%) fared worse. In contrast, Kozhikode, Kolkata, Chennai and even Delhi recorded declines.More concerning is the post-2022 acceleration. Data compiled by TOI from Pollution Control Board readings shows PM2.5 concentrations rising to 176 µg/m³ this winter, compared to about 140 during the same period last year. PM10 climbed to 185 µg/m³, up from nearly 150 in winter 2024. Measured against WHO benchmarks, PM2.5 levels are now up to 35 times higher than guidelines, while PM10 is as much as 37 times higher.The invisible threatsTraffic congestion not only increases particulates but also intensifies gaseous pollutants.Vehicular emissions are the dominant source of nitrogen dioxide (NO₂), closely linked to respiratory illness and the formation of ground-level ozone. A report titled ‘Beyond North: NO₂ pollution and health risks in seven major Indian cities' found Hyderabad recorded dangerously high NO₂ levels on 307 days in 2023 — more than Mumbai, Bengaluru or Kolkata.Among monitoring stations, Gachibowli recorded the highest average NO₂ concentration at 41 ppb, followed by Old City (23 ppb), Bolarum (22 ppb) and Sanathnagar — all exceeding the WHO's safe limit of 10 ppb."Nearly 80% of NO₂ emissions come from diesel buses, three-wheelers and ageing petrol vehicles," said environmentalist Narsimha Reddy Donthi. He added that chronic traffic idling worsens the situation. "At every signal, thousands of vehicles crawl forward. Idling engines emit carbon monoxide and fine particulates continuously."Ozone pollution, once confined to industrial belts, has also spread to residential areas. A report by the Centre for Science and Environment found 10 of Hyderabad's 14 monitoring stations recorded ozone levels beyond WHO limits between Jan and July 2024. The highest eight-hour average — 150.9 µg/m³ — was recorded in Sanathnagar, followed by ICRISAT Patancheru and ECIL Kapra.Public health crisisFindings published in The Lancet Planetary Health highlight the scale of the crisis. The study ‘Ambient air pollution and daily mortality in ten cities of India' estimated Hyderabad averaged 5,552 deaths annually due to air pollution between 2008 and 2020. The toll continues to rise, with 1,597 pollution-related deaths recorded in 2023 alone.Though updated city-specific health data is limited, doctors report increasing respiratory illness. "We are seeing a rise in asthma and chronic obstructive pulmonary disease (COPD) cases, often requiring ICU admissions, especially among the elderly and vulnerable. Long-term exposure to PM2.5 also increases lung cancer risk even in non-smokers," said pulmonologist Dr Hari Krishna G. "While not every case can be attributed solely to pollution, the growing burden points to air quality as a major contributing factor."Underspent funds, gapsDespite being classified as a non-attainment city under the National Clean Air Programme (NCAP), Hyderabad spent only Rs 11.2 crore of its Rs 20 crore allocation in 2024. The city's action plan identified vehicular emissions, road dust and congestion as priority targets. Yet implementation remains weak.Ecologist BN Sai Reddy argued that even current benchmarks are insufficient. Measures such as excessive paving and mechanical sweeping, he said, may worsen other urban challenges without addressing core emission sources. "Even the CPCB's higher thresholds reduce life expectancy. We are treating symptoms, not causes," he said.Hotspots & solutionsAcknowledging gaps, the GHMC has constituted a city-level monitoring and implementation committee to recalibrate its clean-air strategy."We have identified four chronic vehicular pollution corridors — Punjagutta–Patancheru, Charminar–Nampally, Hi-Tec City and MGBS–Secunderabad — and proposed measures such as electric buses, expansion of electric three-wheelers, stricter pollution-under-control enforcement and better construction waste management," said Raghu Prasad, additional commissioner, GHMC.However, experts caution that without enforcement, plans may remain on paper. Researchers at the Indian Institute of Technology Delhi stress that Hyderabad must urgently reduce dependence on private vehicles."Public transport needs a complete overhaul. Non-motorised mobility — walking and cycling — must be prioritised, and vehicle and fuel standards strictly enforced," said Deepti Jain, an air-quality researcher. "Our responses are largely reactive — advisories and closures — rather than preventive. We need to ask what is adding to pollution today and how vehicular emissions will be controlled over the next decade."