The toxic smog season in India's capital has just begun, but those unable to escape cancer-causing poisonous fumes say the hazardous impact on health is already taking its toll. New Delhi regularly ranks among the world's most polluted capitals, with a melange of factory and vehicle emissions exacerbated by agricultural fires blanketing the city each winter, stretching from mid-October until at least January. Cooler temperatures and slow-moving winds trap deadly pollutants, suffocating the megacity of 30 million people in putrid fumes.

Factory worker Balram Kumar returns home exhausted from work, but then is up all night coughing. ALSO READ: Delhi AQI worsens: Check long-term dangers of exposure to toxic air on brain health "I am barely able to sleep all night," Kumar, 24, told AFP as he waited outside a special pollution clinic, set up at the government-run Ram Manohar Lohia hospital. "My chest hurts every time I cough.

I have been taking medicines but there is no relief," said Kumar. He pointed dejectedly to an X-ray of his chest. "My cough is just not going," he said.

Thousands of deaths On Tuesday, the level of PM2.5 particles -- the smallest and most harmful, which can enter the bloodstream -- topped 278 micrograms per cubic metre, according to monitoring firm IQAir. That is 18 times the daily maximum recommended by the World Health Organization.

ALSO READ: Delhi's air quality worsens after Diwali: Detox your body from toxic air with these foods to combat poor AQI effect.