In Yunnan province, in southwestern China, more than 80 children are currently suffering from lead poisoning due to illegal gold smelting in the region.

Last year, amid a public outcry, China pledged to tackle heavy metal poisoning.

The children are among many people who have reported suffering drastic health consequences due to heavy metal pollution in China.

At least 84 of the children had dangerously high blood levels of lead, according to the local government of Heqing county, where the children live.

The authorities only realised that the children were suffering from lead poisoning after they administered routine health checks, revealing larger-than-expected numbers of victims.

Since the health authorities of Heqing county are now testing all of the villagers in the area, they expect the number of cases to increase, although they would not share any further details about the situation.

People are uncertain as to how the children were poisoned.

Some people think that the children may have inhaled lead fumes from the gold smelters nearby.

But other tests have shown that the soil near such villages is heavily polluted by solid waste, and probably lead as well.

And some of the locals blame the larger smelters in town for the seemingly ubiquitous lead poisoning there.

Heqing already has a long history of lead mining, and the county produces gold and silver from refining the lead.

Several decades ago, the government shut down some of the smaller factories in the town.

The same factories have since reopened, and are producing a lot of metals for sale.

Lead poisoning can damage the nervous system, as well as the reproductive system and kidneys.

It can also give people high blood pressure and anaemia.

For children, being exposed to lead is one of the most harmful things that can happen.

Children who are exposed to lead often end up with behaviour problems and irreversible learning difficulties.

One year ago, Chinese protesters smashed trucks and tore down fences at a smelting factory they claimed had poisoned over 600 children.