In England, they used to send small children up chimneys to clean them. These kids would be covered head to toe in soot and the British have a reputation for bathing once in 6 months or so. This resulted in these kids getting cancer on the scrotum.
In Kashmir, it gets very cold in the winter. People would put some coal in a clay container (a kangri) and hug the kangri to keep warm. This led to cancers on the abdomen due to irritation of the skin by the hot kangri.