Children as young as 4 years old are mining cobalt (used in lithium batteries) by hand in the DRC.[1][2]
"More than half the world’s supply of cobalt comes from the DRC, with 20% of cobalt exported coming from artisanal mines in the southern part of the country. In 2012, Unicef estimated that there were 40,000 children working in all the mines across the south, many involved in mining cobalt."
"Adult miners dig up to 600ft below the surface using basic tools, without protective clothing or modern machinery. Sometimes the children are sent down into the narrow makeshift chambers where there is constant danger of collapse.
"Cobalt is such a health hazard that it has a respiratory disease named after it – cobalt lung, a form of pneumonia which causes coughing and leads to permanent incapacity and even death.
"Even simply eating vegetables grown in local soil can cause vomiting and diarrhoea, thyroid damage and fatal lung diseases, while birds and fish cannot survive in the area.
"No one knows quite how many children have died mining cobalt in the Katanga region in the south-east of the country. The UN estimates 80 a year, but many more deaths go unregistered, with the bodies buried in the rubble of collapsed tunnels. Others survive but with chronic diseases which destroy their young lives. Girls as young as ten in the mines are subjected to sexual attacks and many become pregnant.
The cobalt "ends up in smartphones, cars and computers sold to millions across the world, by household brands including Apple, Microsoft and Vodafone"
"Car maker Tesla – the market leader in electric vehicles – plans to produce 500,000 cars per year starting in 2018, and will need 7,800 tons of cobalt to achieve this. Sales are expected to hit 4.4 million by 2021. It means the price of cobalt will soar as the world gears itself up for the electric car revolution, and there is evidence some corporations are cancelling their contracts with regulated mines using industrial technology, and turning increasingly to the cheaper mines using human labour."
[1] - http://www.dailymail.co.uk/news/article-4764208/Child-miners...
[2] - https://www.theguardian.com/global-development/2016/jan/19/c...