In northern Chennai's Ennore region, a large thermal power plant cluster towers over a few neighbourhoods with largely working-class residents.
A health study released last month estimated that more then 60 per cent of children below the age of five have been living with respiratory illnesses caused by the hazardous pollutants spewed from the heavily industrialised zone.
The survey by a non-governmental initiative and a public health school in Tamil Nadu, India, found that among the 207 children surveyed, 63 per cent had experienced at least one sign of respiratory infection.
The symptoms included runny nose, cough and wheezing.
Mr Logeshwaran G., a 22-year-old who lives in the north Chennai neighbourhood of Thiruvottiyur, said he has been dealing with sinus problems since he was 14.
Environmental and social activist Nityanand Jayaraman said: "Tamil Nadu's best athletes come from North Chennai."
But the 53-year-old noted that in recent years, the kabaddi (an ancient South Asian form of group tag) players' stamina has gone down, mainly due to respiratory issues caused by the thick, noxious air in the region.
India has the world's second largest coal fleet, after China.
On a global scale, a study released last week by a German think-tank calculated that an early phasing-out of coal plants around the world could avoid more than 14.5 million premature deaths over the next 30 years.
On top of releasing planet-warming carbon dioxide into the atmosphere, coal-fired power plants expel ultra-fine PM2.5 particles - which can reach deep into the lungs - and other toxic gases such as sulphur dioxide and nitrogen oxide.
The think-tank NewClimate Institute said in its report: "These micro-particles can cross the lung barrier and enter the blood system, negatively impacting the cardiovascular system and also directly causing respiratory illnesses."
It added that the leading causes of death from the air pollutants are heart disease, stroke, lung cancer and chronic inflammatory lung disease that causes obstructed airflow from the lungs.
Mr Nityanand said: "Unfortunately, air pollution became an issue only when climate change became an issue."
The NewClimate Institute is known for co-creating the closely followed Climate Action Tracker, which monitors government climate action.
The institute's researchers also developed a Web tool that shows the air pollution health impacts from all existing and planned coal generation units in 24 countries. These 24 nations account for over 90 per cent of global coal capacity.
The online tool, called Airpolim, shows China dominating the mortality driven by pollutive coal, with close to 21 million premature deaths in 30 years - if there are no measures to curtail the use and construction of coal plants.
"Despite signing the Glasgow Climate Pact last year, China continues to channel significant investment into boosting its domestic coal industry... (There are) ongoing concerns that Russia's invasion of Ukraine may drive it to further boost domestic reliance on coal," added the institute.
The pact was an outcome of last year's United Nations climate change conference. It called on nations to phase out unabated coal power and inefficient subsidies for fossil fuels.
