Air pollution is a major problem confronting Pakistan, with cities like Lahore and Karachi ranking among the most polluted worldwide.
According to data released by IQAir, a global environmental think tank,Lahore is the most polluted place in the world, with the city's air quality index (AQI) standing at 372 on Monday morning, way ahead of the world's second most polluted city, Zagreb in Croatia, which has an AQI of 174.
The list is updated every few minutes.
The higher the AQI value, the greater the level of air pollution and danger to human health.
Air quality is considered safe if the AQI is under 50.
An AQI of between 100 and 150 poses a potential risk to children and people with heart and lung disease. An AQI of above 150 is unhealthy for everyone, while levels over 300 are classified as hazardous.
According to the World Health Organization (WHO), air pollution is responsible for millions of deaths worldwide every year. The health body says its data shows that people in low and middle-income countries suffer the most because of their relatively high exposure to pollutants.
In South Asia, the health of around 12 million children is at risk, as they're exposed to air pollution that is six times the safe limit, said a UNICEF report. In Pakistan, one in 10 deaths in children under the age of five is caused by air pollution.
And according to the Global Alliance on Health and Pollution, an estimated 128,000 Pakistanis die annually from air pollution-related illnesses.
High concentration of particulate matter
Muhammad Irfan Khan, a professor of environmental sciences at Islamabad's International Islamic University, says the problem is mainly due to the concentration of particulate matter smaller than 2.5 micrometers, called PM2.5, or less than one-thirtieth the width of a human hair in the nation's cities.
That is small enough to penetrate the lung barrier and enter the bloodstream, raising the risk of developing heart and lung disease as well as affecting brain development and growth.
"PM2.5 concentration is currently 5.9 times above the WHO annual air quality guideline value," he told DW, adding: "The PM2.5 is generated by vehicles and factories, and also other seasonal factors such as stubble burning in winter months."
Mome Saleem, an Islamabad-based environmentalist, said transportation and the widespread use of low-quality fuel are the biggest factors contributing to air pollution.
Many vehicles in Pakistan still use a type of highly polluting sulphur-laden gas, compounding the problem of air pollution, according to a 2019 report by the UN's Food and Agriculture Organization.
Transportation alone is responsible for 25% of carbon emissions in Pakistan, Saleem told DW, adding that land degradation, poor urban planning and building construction are additional factors contributing to the problem.
"Our green belts are also shrinking because we are trying to make way for cars and vehicles," she said.
Switch over to Euro 5 standard
To control air pollution and improve the quality of life, the Pakistani government ordered a switch to the Euro 5 emissions standard for all new vehicle approvals from January 2021.
But the share of Euro 5 vehicles in the country is still very low, said Ali Tauqeer Shaikh, an expert in environmental affairs and policies, noting that less than 5% of cars in Pakistan comply with the standard.
"Moreover, heavy taxes on the use of Euro 5 vehicles are discouraging people from buying and using them.
Industrial policies and practices in Pakistan also compound the problem, Shaikh bemoaned, pointing to the burning of tires to power factory units and brick kilns, while farmers burn their fields to prepare for more planting.
Despite the government urging factories to install new technologies to lower air pollution, progress has been slow, the expert said.
What is government doing to tackle the problem?
Prime Minister Imran Khan's government says it is paying special attention to curbing air pollution, pointing to a raft of policies unveiled during its tenure, ranging from banning the import of low-quality fuel to mandates for factories and refineries to install emissions-reducing technology.
"We have come up with this idea of urban forests, which are being developed in different cities, besides cracking down on industries that are using old technologies," Muhammad Bashir Khan, an MP from the ruling party, told DW, adding that the billion-tree scheme, Euro 5 introduction, hybrid vehicles and abolishing coal-fired power are some of the steps the government has taken to combat the problem.
Muhammad Irfan Khan shares a similar view.
"The government is making efforts at different levels to reduce air pollution by promoting cleaner technologies, supporting research and development through the Higher Education Commission and enforcing regulatory compliance."
Still, some bemoan that the authorities have not taken the issue seriously.
"The government has never had a clear and consistent policy for improving air quality," Tariq Banuri, a leading environmentalist, told DW.
"Instead, reliance has been placed on slogans ad hoc/ isolated projects, and random crackdowns, like the one on brick kilns. Given the weakness of this particular regime, one should not expect any change during their tenure," he stressed.