Meta-study Points to Link Between Chlordane, Cancer
Chinese Health Study Confirms Chlordane Cancer Risk
Several studies over the past few decades have pointed to connections between exposure to certain pesticides and the incidence of non-Hodgkin’s lymphoma (NHL). A growing body of scientific evidence continues to link exposure to organochlorine pesticides (OCP) with cancer, specifically NHL.
Scientists with the Huazhong University of Science and Technology recently published, on May 17, 2016, a meta-analysis of several studies linking various OCPs to elevated NHL risk. The analysis, titled “Exposure to Organochlorine Pesticides and non-Hodgkin’s Lymphoma: a Meta-Analysis of Observational Studies (Mei),” draws an especially conspicuous connection between NHL and the pesticide chlordane.
The Mei analysis examined a number of studies investigating the links between NHL risk and exposure to five specific OCPs: DDT, DDE, HCH, HCB, and chlordane. The scientists collected data from 797 studies in a variety of published sources. The studies examined subjects from around the world, measuring the levels of OCPs in the study participants’ bodies and noting the prevalence of NHL. All together the meta-analysis consisted of 6,582 case subjects and 9,126 controls.
The Mei scientists and researchers concluded that one’s chance of developing NHL increases with exposure to OCPs.
“The results had suggested the body burden levels of OCPs, including DDE, HCH, chlordane and HCB, were significantly associated with increased risk of NHL,” the Mei study said. “The findings of our meta-analysis yielded a statistically significant association between exposure to OCPs and elevated risk of NHL.”
Not only were the OCPs considered cancerous, previous evidence showed they had adverse effects on the human immune system due to their immunotoxicity.
“Immune system dysfunction has been found to be the potential mechanism for the development of NHL,” the Mei study said. “The dysregulation or suppression of T-cell function and immunosuppression were mainly involved in the dysfunction of the immune system to induce NHL tumors.”
The Mei meta-analysis showed a particularly strong correlation between NHL and chlordane. Chlordane had the highest odds risk of NHL when adjusted for age and body-mass index (BMI) of all five OCPs included in the meta-analysis. In a subgroup analysis of OCPs in relation to NHL, scientists found a statistically significant link between chlordane exposure and NHL, with those exposed to the pesticide basically twice as likely to develop NHL.
Chlordane was sold in the United States from 1948 to 1988 as an insecticide. It was used in approximately 30 million households to protect homes from termites, as well as on crops including corn and citrus, and on lawns and domestic gardens.
Following the World War II building boom, home builders pumped thousands of gallons of chlordane into the ground in an effort to protect homes against termites. When the Formosan termite, an aggressive new breed, appeared in America in the 1960s, exterminators sought permits to use even stronger concentrations of chlordane to keep the bugs out of homes. This use eventually fell out of favor when it was discovered chlordane didn’t wipe out termite colonies. The chemical merely acted as a barrier, allowing termite colonies to flourish outside homes and eventually pierce the barrier through sheer numbers. Termites kept out of homes through chlordane use would also damage living trees outside the barriers.
The U.S. Environmental Protection Agency (EPA) banned all uses of chlordane in 1983 except for termite control. It was banned entirely by 1988. Chlordane breaks down very slowly and sticks strongly to soil particles, remaining in the environment for many years. Air tests in government housing found 10 to 15 times the minimal risk levels of chlordane, 32 years after the last chlordane treatment.
Velsicol Chemical Corporation, headquartered in Rosemont, Illinois, was the only manufacturer of chlordane. The company agreed to stop selling chlordane for consumer use in 1987, but continues to export the chemical overseas. According to a Mother Jones report, the company decided to “phase out” chlordane manufacturing, citing market pressures. Trade names for chlordane include Chlor-Kil, Chlortox, Corodane, Gold Crest, Kilex, Kypchlor, Niran, Octachlor, Synchlor, Termi-Ded, Topiclor, Chlordan, Prentox and Penticklor. The chemical was part of many pesticide products sold in home improvement stores and also used by exterminators.
Private equity firm Arsenal Capital Partners acquired Velsicol in 2005. The company also manufacturers flame retardants, food additives and plasticizers.
Chlordane is highly fat soluble, meaning humans can ingest it via eating high-fat foods from animals contaminated with the pesticide and then unknowingly store the chemical in their fat cells. It is excreted slowly from the body and bio-accumulates in body fat with age. The Mei study found age and body mass index to be positive factors for NHL and chlordane exposure.
“High lipophilicity of OCPs was hypothesized to lead to an increased risk among individuals with higher BMI,” the meta-analysis said.
All five of the OCPs saw a higher risk for NHL when adjusted for both age and BMI, with chlordane showing the largest adjusted, statistically significant odds risk. Those exposed to chlordane were well over twice as likely to develop NHL when adjusted for either age or BMI.
If you believe your recent non-Hodgkin’s lymphoma diagnosis might be related to exposure to chlordane or other organochlorine pesticides, please contact the trial attorneys of Allen Stewart, P.C. The firm has decades of combined experience in helping those who have developed cancer due to toxic exposure.