At least 160 people have died in Northern Nigeria, and this number is likely to increase as villagers continue to expose themselves to lead poisoning from illegal gold mining.

The discovery of a gold deposit triggered a "gold rush" among impoverished farmers who dug up rocks by hand, unaware the ore contained dangerously high concentrations of lead.

Nigerian authorities have asked for assistance from various international agencies, including the World Health Organisation, to help contain the outbreak.

But the Nigerian government has not stepped in to curb the illegal mining. It is reported that at least 111 of those killed were children, many of them under the age of five.

Just why do these people run this risk? How does it impact the environment? And what can governments do to stop illegal mining?

Inside Story, with presenter Hoda Abdelhamid, discusses with Marcel Langenbach, the head of the emergency desk for Médecins Sans Frontières (MSF), Antony Goldman, the deputy-editor of Africa Confidential, a newsletter on politics and economics in Africa, and Sadeeq Aliyu, a journalist for the newspaper Daily Trust.

This episode of Inside Story aired from Thursday, June 17, 2010.