Kabwe, around 150 kilometres (95 miles) north of the capital Lusaka, is one of the world's most polluted places from decades of lead and zinc mining.

More than 30 years after the mine's closure in 1994, residents are still exposed to extreme levels of toxic lead, found in the soil and dust around homes, schools and roads.

Yet the government is still "facilitating hazardous mining and processing" in the area, HRW said in a report, citing licenses issued to South African, Chinese and Zambian businesses.

It urged the government to revoke permits and clean up the notorious hazard.

Zambia's government did not respond to AFP's request for comment.

HRW said it interviewed residents and miners, conducted open-source research and analysed geo-spatial data.

"Companies are profiting in Kabwe from mining, removing, and processing lead waste at the expense of children's health," HRW's children's rights director Juliane Kippenberg said in the statement.

Needed by industry, lead is a particularly toxic metal that can cause severe health problems including brain damage and death, particularly in children, according to the World Health Organization.

More than 95 percent of children living near the Kabwe mine had elevated blood lead levels with about half requiring urgent treatment, HRW said.

- 'Sacrifice zone' -

Highly toxic waste had also been transported to various locations across the city, forming unfenced "piles of dark, sandy material, several metres high", the report said.

This had exposed up to 200,000 people to pollution, HRW said.

"I have tried all medicines to cure my grandson" but it was found that "he has high lead poisoning", Kabwe resident Rose Asabi, 58, testified at the report launch in Lusaka.

"He cannot do well at school because of lead poisoning," she said.

The concentration of lead in the soil has reached 60,000 milligrams per kilogramme, according to the report, 300 times the threshold considered a hazard by the US Environmental Protection Agency.

In 2022, a UN expert listed Kabwe as being among so-called "sacrifice zones" where pollution and resultant health issues were the norm for nearby communities.

"The Zambian government should be protecting people from highly hazardous activities, not enabling them," said Kippenberg.

The Kabwe mine was part of mining company Anglo American from 1925 to 1974, during which experts say two-thirds of the lead in the local environment was likely to have been deposited.

Anglo American has denied responsibility, saying they only "provided certain technical services to the mine, but at no stage owned or operated the mine".

It was then run by the Zambian government when the mining industry was nationalised, until its closure in 1994.

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Anglo American