NEW DELHI: After pollution levels improved to 'very poor' from 'severe' on Monday, India's capital New Delhi will reopen its primary schools this week and curb certain construction activities.

Residents in the capital have been waking up in recent weeks to hazy mornings with the sky a shade of grey.

Its 20 million residents suffer from respiratory illnesses caused by a thick layer of smog that accumulates in winter due to cold, heavy air trapping construction dust, vehicle emissions, and smoke from burning crops in neighbouring states.

The air quality index at almost all monitoring stations in the city is between 300 and 400, or in the "very poor" category, which experts say can cause respiratory ailments on prolonged exposure.

However, this is an improvement on last week's reading of 400-500 with the index being described as "tough".
"Work-from-home instructions will be amended and offices will function at full capacity from today," Delhi state environment minister Gopal Rai told reporters.

Primary schools will reopen on Wednesday.

The central and state governments ordered the closure of primary schools, banned the entry of diesel vehicles carrying non-essential goods and suspended most construction and demolition activities in the national capital region last week.

Rai said private demolition and construction will still remain banned, but public works relating to highways and power transmission will be permitted.

Air quality could worsen later this week, however, the System of Air Quality and Weather Forecasting and Research said on its website.