Gurgaon: Even as policymakers and residents focus on tackling winter pollution, a silent killer has emerged in the warmer months. Ground-level ozone — invisible, unlike smog or dust — is breaching national safety standards across Haryana, and doctors are warning that prolonged exposure raises the risk of serious respiratory and cardiovascular complications.Data from Central Pollution Control Board, recently analysed by Centre for Research on Energy and Clean Air, found that 12 of Haryana’s 30 air-quality monitoring stations exceeded national ozone standards during May.The exceedances were recorded at stations in Sirsa, Panchgaon, Palwal, Hisar, Gurugram, Yamunanagar, Fatehabad, Jind, Manesar, Karnal, Kurukshetra and Ballabgarh. Nathu Colony in Ballabgarh recorded the seventh-highest ground-level ozone concentration in the country, with a maximum eight-hour average of 278 micrograms per cubic metre — nearly three times the national standard of 100 µg/m3. The NISE monitoring station at Gwal Pahari in Gurugram recorded four days when ozone levels exceeded the prescribed limit.Ground-level ozone is not directly emitted but forms when pollutants from vehicles and industries react with sunlight and heat, making hot summer afternoons particularly conducive to its build-up. Its invisibility means the effects often go unnoticed until a health emergency strikes.High concentrations inflame the airways, producing symptoms such as sore throat, chest pain, coughing and wheezing. In people with existing respiratory conditions, exposure can trigger severe flare-ups.“Ozone pollution in its highest concentration can be detrimental to health,” said Dr Kuldeep Kumar Grover, associate director of pulmonology and critical care at CK Birla Hospital. The pollutant also drives inflammation and oxidative stress, worsening cardiovascular disease — and emerging evidence suggests it may be of particular concern for older adults and those with hypertension or diabetes.Hospitals are already seeing the pattern. “There is a consistent increase in the use of emergency services for breathing difficulties, chest discomfort, worsening asthma, dizziness and acute exacerbations of underlying heart or lung disease during episodes of high ground-level ozone,” said Dr Mohan Kumar Singh, senior consultant and director of general medicine at Narayana Hospital.Those at greatest risk include children, the elderly, pregnant women, outdoor workers, athletes and anyone with asthma, COPD or heart disease.Doctors advised checking air-quality indices regularly, staying well hydrated and keeping windows closed when outdoor air quality deteriorates. “Simple preventive measures can go a long way in reducing the health risks associated with summer ozone exposure,” said Dr Arunesh Kumar, director and head of pulmonology at Paras Health.
