More than a quarter century after working in a chemical factory in the Soviet Union, employees of the plant still have some of the highest blood levels of dioxins ever recorded, according to a report in the September issue of the Journal of Occupational and Environmental Medicine.
Dioxins have been linked to several types of human cancer, including lymphomas and lung cancer.
Many countries now ban the use or manufacture of weed killers called phyenoxy herbicides, but in previous decades, many people were exposed to potentially harmful chemicals in plants that made the herbicides.
Dr. John Jake Ryan, of Health Canada in Ottawa, and Dr. Arnold Schecter, of the State University of New York in Binghamton, collected blood samples in 1992 from people who worked at one such factory in Ufa, Bashkortostan, during the 1960s.
At the time, Bashkortostan was part of the Soviet Union.
More than 25 years later, levels of dioxins and closely related chemicals were 10 to 30 times higher in the workers than in people who lived in the surrounding area but did not work at the plant, the researchers reported.
In fact, the levels were higher than ever recorded in most other samples collected elsewhere in the world.
The results of the study show "that early production workers worldwide were exposed to high amounts of dioxin-like compounds before there was recognition of the health risk and implementation of precautionary measures," the authors wrote.
But plant workers were not the only ones exposed to the toxic chemicals, the report indicates.
Children of the workers and administrative personnel, who presumably would not have had much contact with chemicals in the plant, also had higher blood levels of dioxins than the general population.
by Virginia Sutcliffe