(Beyond Pesticides, November 15, 2011) Research published in the online edition of Environmental Health Perspectives finds that exposure to certain pesticides elevates the risk of non-Hodgkin’s Lymphoma (NHL). The study, “A Prospective Study of Organochlorines in Adipose Tissue and Risk of non-Hodgkin’s Lymphoma,” finds a positive correlation between levels of the organochlorine pesticides DDT, cis-nonachlor, chlordane, and their breakdown products in human fat tissue and the often deadly form of cancer.
The researchers from the Danish Cancer Society’s Institute of Cancer Epidemiology conducted a case-cohort study using a prospective Danish cohort of 57,053 persons enrolled between 1993 and 1997. Within the cohort they identified 256 persons diagnosed with NHL in the population-based nationwide Danish Cancer Registry and randomly selected 256 sub-cohort persons. The research team measured concentrations of eight pesticides and ten polychlorinated biphenyl congeners (PCBs) in fat tissue collected upon enrollment.
The results indicate a higher risk of NHL in association with higher fat tissue levels of DDT, cis-nonachlor and oxychlordane, but shows no association with PCBs. Because the tissue samples were taken up to 15 years prior to the cancer diagnosis, the research suggests that exposure to these organochlorines increases the risk of NHL later in life and strengthens the theory that there is an environmental factor in contracting the disease.
While most organochlorine pesticides are banned or restricted, they still continue to cause problems decades after their widespread use has ended. This study reinforces the need for a more precautionary approach to regulating pesticides and industrial chemicals. Once released into the environment, many chemicals can affect health for generations, either through persistence in the environment or long-term changes to the genetic code of humans and other animals.
Non-Hodgkin’s lymphoma is cancer of the lymphoid tissue, which includes the lymph nodes, spleen, and other organs of the immune system. According to the American Cancer Society, a person has a 1 in 50 chance of developing non-Hodgkin’s lymphoma. Most of the time, this cancer affects adults. However, children can get some forms of lymphoma. High-risk groups include those who have received an organ transplant or who have a weakened immune system. This type of cancer is slightly more common in men than in women.
Organochlorine pesticides have previously been linked to a number of adverse effects on human health, including birth defects and diabetes. This study illustrates how the health impacts of pesticides can be often subtle and delayed, and pesticides once considered to pose “acceptable” risks are continuing to affect public health. In response to the growing evidence linking pesticide exposures to numerous human health effects, Beyond Pesticides launched the Pesticide-Induced Diseases Database to capture the range of diseases linked to pesticides through epidemiologic studies. The database, which currently contains hundreds of entries of epidemiologic and laboratory exposure studies, is continually updated to track the emerging findings and trends.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.