Research on environmental toxins and cancer

Chlorinated, organic compounds are heavily biodegradable chemical substances that can cause harm to health. The study investigates the relationship between cancer and organochlorins using samples from the Janus serum bank.
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Background and purpose

In this project, the level of two groups of organochlorines, DDT and PCB, is analysed in samples from the Janus serum bank. The results of the laboratory analyzes are used to calculate the risk of developing several different cancers:

  • Breast cancer
  • Leukemia
  • Non-Hodgkin Lymphoma
  • Multiple myeloma
  • Endometrial cancer
  • Ovarian cancer
  • Prostate cancer
  • Melanoma
  • Cancer of the brain
  • Pancreatic cancer
  • Testicular cancer
  • Liver cancer
  • Thyroid cancer

The collection for Janus Serum Bank started in the 1970s, and the samples are therefore ideal for investigating levels of pollutants such as PCBs and DDT, which were banned in Norway in the 1970s and 80s. Serum samples from just over 2,000 individuals with different types of cancer have been analysed, in addition to samples from a healthy control group of just over 1,000 people.

Organochlorins are a group of organic compounds that contain at least one chlorine atom. The substances have different build-up and very different chemical properties. Some organochlorins have been shown to be carcinogenic, and some are endocrine disruptors. It is questioned whether this may increase the risk of hormone-related cancers such as breast cancer, endometrial cancer and prostate cancer.

DDT (dichloro-diphenyl-dichloroethane) is chlorinated hydrocarbon that was widely used in agriculture, and for fighting malaria from the 1940s. The substance was banned in Norway in 1970, although the deepening of spruce trees to combat spruce weevils was allowed at the reforestation schools until 1989. It breaks down very slowly in nature, and is highly toxic (Great Medical Encyclopedia)

PCBs (polychlorinated biphenyls) were used commercially from the 1930s in a number of industries, and were used in electrical appliances, transformers, capacitors, sealants, paints, and as adhesives around insulated glass windows. The substance is oil-like and burn-proof, and was therefore used as hydraulic oil in underground mines, aircraft and smelters.

PCBs were banned from use and trading in Norway in 1980. Much of the original amount is now out of use, but only about half of the PCBs that have been taken out have been handled properly. The rest may have ended up in ordinary landfills, or in nature. The substance breaks down slowly and dissolves into fat. This means that PCBs accumulate in the food chain, and humans and predators are therefore particularly vulnerable. It can be passed on to the next generation through breast milk, via the womb to the fetus, and via egg circulation (


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