An analysis of results from 3 case control studies in the United States and Canada, which involved more than 3200 participants, showed that exposure to the pesticides carbaryl, captan, and DDT is associated with increased risk for the development of myeloma in men.1

Any exposure to carbaryl or captan doubled the risk for multiple myeloma. DDT exposure increased the risk nearly 1.5-fold. Researchers did not observe statistically significant associations between increased multiple myeloma risk and the pesticides lindane, 2,4-Dichlorophenoxyacetic acid, and malathion.

“We looked at a number of different pesticides, including insecticides, herbicides, and fungicides. We saw a link between only 3 different types of pesticides and multiple myeloma,” said John Spinelli, PhD, department head and distinguished scientist of Cancer Control Research at the BC Cancer Research Centre in Vancouver, Canada. “Multiple myeloma is a fairly rare cancer and we don’t know much about the risk factors.”

A team of researchers led by Shelley A. Harris, PhD, of Cancer Care Ontario in Canada, and Laura Beane Freeman, PhD, of the National Cancer Institute (NCI) in Bethesda, Maryland, analyzed NCI studies conducted in the upper Midwestern United States in the 1980s and the Cross Canada Study of Pesticides and Health conducted in the early 1990s. These results come from an analysis of a subset of studies conducted in Iowa, Nebraska, and Canada, involving 547 farm workers with multiple myeloma, and 2700 healthy participants.