Royal Commission on Environmental Pollution

Comments from KEMI National Chemical Inspectorate
on the scoping of the Chemicals Study

Thank you for the opportunity to comment on the Royal Commission on chemicals, as explained in your letter of 19 October 2000. We have in Sweden given considerable thought to similar matters in recent years. On the policy side, there has been a government bill two years ago, accepted by Parliament last year, giving general objectives for a chemicals policy. These have been detailed by two government investigations. One of these was carried through with the participation of members of our Parliament. This implies that when it will be treated by Parliament in the spring of 2001, there is a high likelihood its proposals will by and large be accepted. You will find its conclusions on chemicals on page 25 of:

http://www.hallbarasverige.gov.se/pdf/miljomal-eng-sammanf-sou2000_52.pdf

The environmental effects depend on a very large number (thousands) of substances. Substances that are long-lived (decades to centuries) in the environment and travel long distances (thousands of kilometers) are taken up by humans in an almost invariant fraction of the amount released to the environment, irrespective of the substance.

Below you will find the arguments behind these hypotheses. I would be most delighted if you would find them worthy of consideration. Please feel free to post this letter on the website if you find it worthy of a broader publication.

Comments from G Bengtsson

1.     The environmental effects depend on a very large number (thousands) of substances.

In the attached PowerPoint file you will find some arguments on page 3 onwards (can be opened as Note pages) which lead me to believe that thousands of substances contribute to the total exposures. This is from a lecture I gave about 3 years ago. My arguments are very simplistic and I would appreciate if you could help me find the pitfalls in them.

In support of my belief of a large number of substances of concern, I only have scattered evidence. Gwynne Lyons' recent breast milk compilation quoted hundreds of contaminants in breast milk. Åke Bergman's Renco project identified about 40 halogenated and phenolic compounds in the human body, but additionally many substances of unknown structure. Åke's team recently identified more than 100 phenolic substances in salmon blood. I have heard environmental chemists say that broadly, if you look for a substance you will find it.

One of the possible ways of tearing my simplistic view to pieces would be if there were very selective mechanisms that would strongly narrow down the range of substances in the environment which can reach the human body. Do you know of any such mechanisms, and if so, would similar mechanisms apply also to lower organisms in the environment?

2.    Substances that are long-lived (decades to centuries) in the environment and travel long distances (thousands of kilometers) are taken up by humans in an invariant fraction of the amount released to the environment, irrespective of the substance.

These thoughts originated many years ago while I was working with radioactive substances. I discovered that for four radionuclides (isotopes of cesium, ruthenium, strontium, and iodine), the fraction of a release to water that passes any human body before going to a sink was very similar (1 to 10 in a million) (G Bengtsson: Judging the long-term acceptability of radioactive waste disposal practices from the radiation protection point of view and other perspectives. OECD Nuclear Energy Agency Seminar on Interface Questions in Nuclear Health and Safety, OECD NEA Paris 1985).

Changing field to chemicals in 1995, I tested the hypothesis that this would also hold for long-lived chemical substances. To my surprise, the same fraction applied for a range of very different substances (Dioxin, Aldrin+dieldrin,Toxaphene, HCB, Chlordane, Cd, PCB, DDT, Pb, Cr). The details are given in the attached Adobe pdf file. If the hypothesis would hold true over a broader range of substances, it might be used for prioritisation, as indicated in the file.

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