Pakistan's Punjab has declared a health emergency due to toxic smog and warned a three-day lockdown may be enforced if air quality conditions do not improve.
Punjab has banned construction, shut schools for another week, advised residents to stay indoors, and moved universities courses online, the province's Senior Minister Marriyum Aurangzeb said.
"A complete lockdown will be enforced on Friday, Saturday, and Sunday [next week] if the situation does not improve by Wednesday," Mr Aurangzeb said.
More than 70,000 patients with respiratory issues have been treated daily in Pakistan due to the high levels of air pollution. (AP Photo: K.M. Chaudary)
Punjab battles toxic smog every winter as cold air traps dust, emissions, and smoke from illegal stubble burning on fields. Air quality has deteriorated drastically in recent weeks and the province's capital Lahore currently ranks as the world's most polluted city, according to IQAir.
Air Quality Index (AQI) readings in Lahore reached 637 at on Friday, significantly higher than levels recommended by the World Health Organization.
By way of comparison, AQI readings of Sydney and Melbourne on Friday were 13 and 18 respectively, according to IQAir.
The eastern province has already banned entry to parks, zoos, playgrounds and other public spaces.
Earlier this month, the UN's children agency UNICEF warned that the toxic smog puts the lives of 11 million children under the age of five in "peril".
Children are among the worst affected by air pollution, as they have lower immunity, smaller lungs, and breathe faster than adults. (AP Photo/Channi Anand)
Other cities choked by smog
High levels of air pollution have been recorded in other regions in South and Southeast Asia this month.
India's capital of New Delhi, the world's most polluted capital city, banned all non-essential construction, moved younger children to virtual classrooms and asked residents to avoid using coal and wood from Friday to combat increasing air pollution.
India's Taj Mahal was obscured by toxic smog this week. (Reuters)
In many areas of the city, air pollution levels were more than 50 times higher than the World Health Organization’s recommended safe limit. Forecasters warned air quality will worsen before the arrival of cold winds next week that could blow away the smog.
What is causing high air pollution in South Asia?
Punjab has blamed this year's particularly high pollution levels partly on toxic air flowing from neighbouring India.
Air pollution in the region worsens particularly in winter months when the burning of crop residue in agricultural areas coincides with cooler temperatures that trap the smoke.
The smoke is blown into cities, where there are more people and where auto emissions further add to the pollution. Emissions from industries without pollution controls and the use of coal to produce electricity are also linked to poor air quality in urban areas.
Several studies have estimated more than a million people in India die each year from air pollution-related diseases.
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