Hormone-disturbing environmental chemical toxins, Danish Environmental Protection Agency

Greenland

Hormone-disturbing environmental chemical toxins

A new biochemical test method shows the effect on human cell function of having slowly degradable organic environmental chemical toxins in the blood. Laboratory analyses show clear dioxin-like activity and effects on the hormone balance in blood specimens from 140 greenlanders.

It has been proven many times that the environmental chemical toxins dioxin, PCB, DDT and the nine other members of the socalled "dirty dozen" affect birds and mammals. Now, the effect of these organic dioxin-like and hormone like substances has been tested in humans. The results show that these substances - which accumulate easily in animals and humans because they are fat-soluble - can affect the hormone balance and thus fertility, growth, the brain and the immune system. The risk of disturbances is thought to be greatest at the foetal stage.

The results have been obtained by researchers using the new method on a number of blood specimens from Greenland. What is new - and revolutionary - is that, with a relatively simple biochemical method, it is now possible to evaluate the effect on human cell functions of having problem environmental chemical toxins in the blood. The method is at the same time so sophisticated that the total effect of the accumulated toxins in a blood specimen can be measured directly through tests on human cells or mouse cells. By observing the cell culture we can see whether the toxins affect vital functions in the cells, such as the ability to receive hormonal influences.

Inhibition of the function of natural hormones

Researchers have used the new method to analyse 70 blood specimens for the effect of the dioxin-like substances in human blood directly on a cell culture system. The blood came from 70 people in six districts of Greenland (Upernavik, Ilulissat, Nuuk, Nanortalik, Ammassalik and Scoresbysund). The researchers describe the level of effect on the cell systems as worrying.

With the method for determining the hormonal effect of problem substances, the natural hormones have to be separated from the accumulated problem substance with hormone like effect. This is the only way a blood specimen from a human being can be analysed for the effect of environmental chemical toxins on a human cell culture system.

70 other blood specimens, taken in the Ammassalik district, showed clear inhibition of the function of the natural hormones - in the cell cultures used, of course. The method thus gives only an indication of the damage the substances can cause in the body in the longer term.

The results are statistically significant, i.e. scientifically reliable.

The results are danger signal

The method was developed at the Institutes of Environmental Medicine at the University of Southern Denmark and Aarhus University. One of the researchers behind the method, Eva Bonefeld-Jørgensen, Senior Lecturer at the Institute for Environment and Occupational Medicine at Aarhus University, says:

"It will take a whole generation before we know how the children of these people will be affected. The method gives a clear signal - in this case a danger signal - that can be transferred to other population groups with the same load levels."

Eva Bonefeld-Jørgensen presented the results at the AMAP 2 conference in Tromsø from 21 to 24 January 2002. At this conference 175 researchers from the eight Arctic countries gathered to discuss the impacts of heavy metals and "the dirty dozen" on Arctic environments.

With the signing of a new convention by 92 countries in Stockholm in May 2001, "the dirty dozen" were internationally banned. That was a pleasing and historic global event. However, it will take several generations for the impact from "the dirty dozen" to die away, and, on top of that, it emerged at the conference in Tromsø that there are not just 12, but at least 16 of these problem substances. Besides that, there are the relatively new brominated fire retardants, which are still being used in computers and elsewhere. Their impact is in many ways similar to that of "the dirty dozen".