Residents of a coalmining region in Siberia have been posting videos online showing entire streets and districts covered in toxic black snow that critics say highlight a manmade ecological catastrophe.

In one video, filmed in Kiselyovsk, a town in the Kuzbass region, a woman drives past mounds of coal-coloured snow stretching to the horizon, covering a children’s playground and the courtyards of residential buildings. The scenes in the footage were described as “post-apocalyptic” by Russian media.

The coal dust that turns the snow black in the Kuzbass comes from numerous open pit mines that environmental activists say have had disastrous consequences for the health of the region’s 2.6 million people, with life expectancy three to four years lower than Russia’s national average of 66 for men and 77 for women.

Cancer, child cerebral palsy, and tuberculous rates in the Kuzbass region are all above the national average.

“It’s harder to find white snow than black snow during the winter,” Vladimir Slivyak, a member of the Ecodefense environmental group, said. “There is a lot of coal dust in the air all the time. When snow falls, it just becomes visible. You can’t see it the rest of the year, but it is still there.”

Despite political tensions between Moscow and London, Russia is the leading supplier of British coal imports. Russian mines supplied around half of the 8.5m tons of coal shipped into Britain in 2017, with up to 90% of it coming from the Kuzbass region. Coal is used in Britain for a range of purposes, including the manufacture of cement and steel and in power stations, which the UK government is committed to phasing out by 2025.

Some Russian environmental activists are calling on Britain to boycott Russian coal. “The best way to put pressure on them is to stop buying coal until they improve the situation,” said Slivyak.

The dust contains a variety of dangerous heavy metals, including arsenic and mercury, environmental activists say. Environmental problems are exacerbated by the practice of loading coal on to open train cars for export, with wind and rain depositing dust on towns and rivers along the rail tracks.

Critics say Russian authorities turn a blind eye to routine violations of safety norms and regulations, with open pit mines often located dangerously close to towns and villages. Andrei Panov, the deputy governor of the Kuzbass region, said coal-burning factories, transport-related pollution and unspecified businesses were possible causes of black snow.

The number of environmental protests, which were previously almost unheard of in the Kuzbass, are on the rise, with dozens reported in recent years as locals use the internet to organise.

Officials in Mysky, a town in the region, were mocked recently for painting black snow white in an apparent attempt to improve the appearance of a children’s snow-slide.