Cloud seeding was used to counter the hazardous smog in the megacity of Lahore, one of the world’s most polluted cities.
Planes equipped with cloud-seeding equipment flew on Saturday over the eastern city, often ranked one of the worst places globally for air pollution.
“It drizzled in at least 10 areas of Lahore,” caretaker chief minister of Punjab, Mohsin Naqvi, told reporters, adding that the authorities were monitoring the impact of artificial rain in a radius of 15km (nine miles).
Air quality in Lahore has been particularly bad in the last few weeks and the Punjab government employed several tactics including the early closure of businesses and keeping schools off for two extra days to help improve the air quality – but nothing worked.
The “gift” was provided by the United Arab Emirates, Naqvi said.
“Teams from the UAE, along with two planes, arrived here about 10 to 12 days ago. They used 48 flares to create the rain,” he said.
Naqvi said the team would be able to assess the effects of the experiment by Saturday night.
The UAE has increasingly used cloud seeding, sometimes referred to as artificial rain or blueskying, to create rain in the arid expanse of the country.
In the cloud-seeding process, silver iodide, a yellowish salt, is burned in clouds in a compound with acetone to encourage condensation to form as rain.
Naqvi reassured the public of the safety of the artificial rain, citing more than 1,000 annual missions by the UAE and similar technologies used in dozens of countries, including the United States, China and India.
Lahore’s toxic smog
Even very modest rain is effective in bringing down pollution, experts have said.
Levels of PM2.5 pollutants – cancer-causing microparticles that enter the bloodstream through the lungs – were measured as hazardous in Lahore on Saturday at more than 66 times the World Health Organization’s danger limits.
Air pollution has worsened in Pakistan in recent years, as a mixture of low-grade diesel fumes, smoke from seasonal crop burn off and colder winter temperatures coalesce into stagnant clouds of smog.
Lahore has suffered the most from the toxic smog, choking the lungs of more than 11 million residents in Lahore during the winter season.
Breathing the poisonous air has catastrophic health consequences.
Prolonged exposure can trigger strokes, heart disease, lung cancer and respiratory diseases, according to the WHO.
The Pakistani authorities blame industrial emissions, smoke from brick kilns and vehicles, and the burning of crop residue and general waste for causing air pollution and smog in the central Punjab province.
Naqvi said that there would be more instances of artificial rain in the city, in which smog towers – large-scale air purifiers designed to capture pollution – would also be installed in the coming weeks.
Growing industrialisation in South Asia in recent decades has driven an increase in pollutants emanating from factories, construction activity and vehicles in densely populated areas.
The problem becomes more severe in cooler autumn and winter months, as temperature inversion prevents a layer of warm air from rising and traps pollutants closer to the ground.
Rising air pollution can cut life expectancy by more than five years per person in South Asia, one of the world’s most polluted regions, according to a report published in August which flagged the growing burden of hazardous air on health.
Pakistan is responsible for less than 1 percent of global carbon emissions but is among the top 10 most climate-vulnerable nations.