Used electronics like old mobile phones or computers are one of the fastest growing sources of waste globally.

In Kenya, it is estimated that about 15,000 tonnes of electronic waste are shipped in every year.

Almost all such devices contain toxic chemicals. But a supply chain of slum residents, garbage collectors, recyclers and exporters are turning the country’s e-waste burden into a lucrative business venture.

Al Jazeera's Catherine Soi reports from Machakos, Kenya.