Environmental groups and New Delhi residents staged a protest at India Gate on Tuesday to press for action on air pollution.

The air quality in the Indian capital improved slightly on Tuesday as the wind picked up to blow away some of the pollution shrouding the city but the air remained at the “hazardous” level.

The air is more than five times the recommended safe limit of 60 PM 2.5 particles in the teeming capital of more than 20 million people.

Such a pollution reading indicates a serious aggravation of heart and lung disease and premature mortality in people with existing diseases and the elderly.

It also means a serious risk of effects on the respiratory systems of the general population.

The city government has declared a public health emergency and imposed an “odd-even” system restricting private vehicles to driving on alternate days, at least until November 15.