Entitled "Hard work, long hours and little pay," the report said workers absorb up to 54 milligrams a day of dissolved nicotine through their skin. The report initially said that is equivalent to 32 cigarettes but Plan International revised it to 50.

"Sometimes it feels like you don't have enough breath, you don't have enough oxygen," an unnamed child tobacco worker in Kasungu, in central Malawi, told Plan International's investigators. "You reach a point where you cannot breathe because of the pain in your chest. Then the blood comes when you vomit. At the end ... you remain with a headache."

The symptoms resemble "green tobacco sickness," said MacDonald Mumba, a Plan International official in Malawi. The malady comes from absorbing nicotine from the skin, particularly from wet tobacco.