BETHESDA, Md., June 15 (UPI) -- A U.S. study linked pesticides used in agricultural work to a pre-malignant condition, researchers said.
Lead author Dr. Ola Landgren of the National Cancer Institute, part of the National Institutes of Health, said monoclonal gammopathy of undetermined significance is characterized by an abnormal level of a plasma protein -- a pre-cancerous condition that can lead to multiple myeloma, a painful cancer of the plasma cells in the bone marrow. Multiple myeloma accounts for approximately 1 percent of all cancers.
The study of 678 people who apply pesticides, culled from a U.S. Agricultural Health Study of more than 50,000 farmers, found exposure to certain pesticides doubles one's risk of developing an abnormal blood condition called MGUS.
The blood of study participants, who were licensed to apply restricted-use pesticides, was assessed for MGUS prevalence. The median age of participants was 60 years -- range 30-94 years -- and all lived in either Iowa or North Carolina. Participants also completed questionnaires providing comprehensive occupational exposure information for a wide range of pesticides and exposures.
For comparison, data were obtained from a large MGUS-screening study conducted by the Mayo Clinic of 9,469 men from the general population in Minnesota similar in age, race and education.
The study, published in the American Society of Hematology, found that in the pesticide-exposed group, no MGUS cases were observed among those who were younger than age 50, but the prevalence of MGUS in those older than 50 was 6.8 percent -- or 1.9 times higher than the general population study group of men in Minnesota.