26 No. 1
Chemicals in Products: Safeguarding the Environment and Human Health
Royal Commission on Environmental Pollution
TSO (The Stationery Office), London, 2003
An abridged version of this review is published on page 25 of the print version of the January-February 2004 CI.
reviewed by John Duffus
This report carries with it a great deal of authority because it is produced by the Royal Commission on Environmental Pollution (RCEP). The RCEP is an independent standing body in the U.K., established in 1970 to advise Queen Elizabeth II, government, Parliament and the public on environmental issues. The Commission sees its role as reviewing and anticipating trends and developments in environmental policies, identifying fields where insufficient attention is being given to problems, and recommending action that should be taken. The Members of the Royal Commission on Environmental Pollution are drawn from a variety of backgrounds in academia, industry and public life. Members serve part-time and as individuals, not as representatives of organisations or professions.
Once the Commission has chosen a subject for study, it reviews the scientific, medical and technical literature, and invites written evidence from a large number of organisations and individuals, both lay and professional, and from the general public. Some witnesses are invited to give oral evidence. Additionally, the Commission may employ consultants and special advisers to assist it with studies. Visits to all parts of the United Kingdom give direct knowledge of environmental problems and solutions and, where necessary, the Commission visits other countries to see how they are dealing with a particular problem.
The findings and recommendations from a Commission study are published in a report such as the one being reviewed here. Aimed at a general readership, the Commission's reports are written so that no particular scientific or other expertise is needed to understand them. The reports are submitted to Queen Elizabeth II. By Her command, each report is then presented to Parliament, published by the Stationery Office, and made available from booksellers.
Most Commission recommendations are addressed to U.K. government Departments, and a U.K. government response to a Commission report is prepared and published by one or more of the relevant U.K. government Departments. The U.K. parliament is informed of the government response, usually a detailed paper setting out the Government's decision on each recommendation. A debate may follow, initiated by government or Opposition, depending on the degree of Parliamentary interest.
The present report starts from the premise that “after more than a century of chemicals production, and decades of legislation attempting to deliver environmental safety from these chemicals, we still do not have a good understanding of the fate and effects of chemicals in the environment”. The RCEP believes that “only a substantial paradigm shift will allow a start to be made to rectify this situation, and.........that such a start needs to be made now”. Hence, the objective of the report is to offer a new approach to chemicals assessment and management. A major question for the reviewer is therefore whether this objective has been attained. A question which puzzles the reviewer, and for which no answer is given in the report, is why the Royal Commission changed its focus from “Study on Long—Term Effects of Chemicals in the Environment”, the original title (see Appendix A), to “Chemicals in Products—Safeguarding the Environment and Human Health”, the current title. Personally, I should have found the originally proposed study more valuable than the present Report and I regret that it was not pursued.
The first important point to make about this Report is that it focuses on manmade synthetic organic chemicals. In doing this, it effectively ignores inorganic chemicals and even naturally occurring organic chemicals. This self-imposed limitation may be realistic in that it simplifies the problem faced by the Commission, but it is unrealistic in that it ignores the fact that environmental exposure to potentially toxic substances is not compartmentalised into synthetic or natural, organic or inorganic, air or water, soil or sediment, food or pharmaceutical etc. The ultimate logical objective of chemical safety regulation, however difficult to attain, ought to be broadbased regulation of exposure to all potentially toxic substances, of whatever kind and within all environmental media. To reach this objective requires bringing together existing piecemeal legislation within a single harmonized legislative approach. There are many practical reasons why this cannot be achieved easily but it ought to be the long term objective of both regulators and scientists.
Although this report is generally well written, occasionally ideas could be expressed better. For example, it says in paragraph 2.16, “ toxicity is not a single concept”. Toxicity may be expressed in many different ways but it is clearly a single concept which may be defined simply as “the capacity of a substance to cause injury to a living organism as a result of physicochemical reactions following exposure to the substance”. Lack of a definition of “toxicity” points to a major deficiency in the report and that is the lack of a glossary of specialised terms, many of which may be unfamiliar to Queen Elizabeth II, her ministers, her members of parliament and the general readership for whom the report is prepared. The lack of a glossary is particularly important where a term like “heavy metals” appears (paragraphs 2.71, 2.130, box 2f, and paragraph 5.21), since this term has no generally agreed definition (see www.iupac.org/publications/ pac/2002/7405/
As one might expect in such a complex document, there are also some debatable statements. For example “Pollutants can also adsorb onto solids, most importantly onto soil particles”. Is adsorption onto soil particles really more important than adsorption onto other particles such as those forming sediments? Most of the world is covered with water and, underneath the water, with sediment. Methylmercury became a problem after being produced in anaerobic sediments. Radionuclides absorbed to sediments in the Irish Sea may move with the sediments up the west coast of Scotland and also out of the sea onto shore and into the air as the particles dry. Bottom dwelling organisms may absorb pollutants directly from sediments. Other aquatic organisms may absorb pollutants from sediment particles in the water, making the pollutants available to their predators, and ultimately to human beings. Since prioritisation is a key part of chemical regulation, assessment of the relative importance of environmental compartments is as important as the relative importance of potentially toxic substances. This is especially so for well planned and effective monitoring which the RCEP wishes to encourage.
True but very misleading statements are to be found at the beginning of paragraph 2.75 - “Metals are elements and, therefore, not subject to decomposition. On the other hand, organic chemicals do degrade........” These statements are true but the comparison is not valid since it does not compare like with like. Organic chemicals are mainly made up of the elements, carbon, hydrogen, nitrogen, and oxygen, which, like all other elements, including metals are not subject to decomposition. All elements may exist in different forms and compounds (chemical species) which have varying properties of toxicity and decomposition. Thus, each substance should be assessed for regulation on the basis of its own particular properties. Unfortunately it has become customary to consider elements other than carbon, such as metals or semimetals, as giving generic toxic properties to all the possible forms (chemical species) in which they may exist. Thus, it is generally assumed that, in any form, the semimetal arsenic (referred to as a metal in paragraph 2.132) is poisonous, although it has long been known that, in arsenobetaine, arsenic may be consumed in large amounts in shellfish without harm. On the other hand, most of the very toxic compounds that we know, for example cyanide(CN) and carbon monoxide(CO), are carbon compounds but carbon is never considered to be toxic (nor are nitrogen and oxygen, although both can kill).
In paragraph 2.118, reference is made to increasing concern about the impact of large amounts of veterinary and other medicines currently entering the environment. It is pointed out that a recent UK study showed environmental risk ratios of more than one for 60 compounds tested, representing the majority of pharmaceutical sales by volume. The Royal Commission rightly expresses concern that these highly biologically active chemicals were not subject to systematic regulatory monitoring of their environmental fate and effects.
Perhaps the most important point raised by this report is the question of the applicability of computational techniques to the screening of chemicals for their potential for cause adverse environmental and health effects. The appeal of this approach in terms of ease of use and speed and in terms of the possible reduction of animal testing is clear. No-one can doubt that, in theory, “it should be possible to develop........high throughput computational systems to augment and eventually replace current screening methods for environmental safety”. The question is when. The methods used to predict pharmacological properties from structure apply successfully to organic molecules and to direct application to a very few mammalian species. We are not in any position to apply these methods to predicting the effects of organic substances on most of the enormous range of species in any natural environment or to predicting the consequences of effects on ecosystem relationships. At best, we are only at the beginning of applying such techniques to the environmental fate and effects of inorganic substances.
For complete risk assessment of environmental effects of chemicals, computational techniques for screening chemicals for their potential to cause adverse environmental and health effects must be combined with computational models for predicting their environmental fate. Models for predicting environmental fate of non-ionic organic compounds are quite well developed and are currently used in assessing exposure to such compounds in different environmental compartments. However, they do not work well with ionisable compounds and they cannot predict movement through the environment associated with biological transformations since much is still to be learned about these. It will be a long time before we have the requisite knowledge, especially with the current political emphasis on research that favours relatively short term commercially viable projects.
The Royal Commission also has more faith in the current value of “in vitro” techniques than I do. In paragraph 4.60 of their report, they say “It is axiomatic that the effects of virtually any new chemical upon a biological system can be detected at the cellular level”. If this were so, then it should be possible to predict the nature of a tissue, of an organ, a whole organism or even an ecosystem from any component cell. Such predictions cannot be made because we cannot yet predict the properties of higher systems from those of their components. Knowing all about the Roman alphabet does not enable us to predict much about Latin, English, or any other of the languages which may be constructed from it, still less about their literature. In vitro tests are extremely useful in screening for serious, biochemically well defined adverse effects such as DNA damage but they can never eliminate the need for whole organism tests.
Another example of poor use of terminology, reflecting the need for a glossary, occurs in paragraph 4.77, where we find reference to “Environmental epidemiology (the study of nonhuman populations)”. According to Last's “A Dictionary of Epidemiology”, 4th Edition, which is the accepted international authority on such matters (prepared for the International Epidemiological Association), environmental epidemiology is “The study of health effects on populations of exposure to physical, chemical and biological agents external to the human body, and of immediate and remote social, economic, and cultural factors (e.g., urbanization, agricultural development. energy production / combustion) related to these physical, chemical and biological agents.” This definition refers to human populations and so we have a possibility of confusion. Subsequently, this possibility is realised when the Royal Commission says “We recommend......environmental epidemiological studies of human and animal populations......“. Without a clear definition, it is difficult to know what this means in practice.
In paragraph 4.100, we find the following statement. “Risk assessment can be expensive, and funding saved by avoiding much of the need for expensive testing and assessment procedures could become available for monitoring.” This is a complicated statement and needs to be carefully analysed. Risk assessment is essentially a desktop exercise and therefore is not inherently expensive. Obtaining the data required may be expensive but it may also be very inexpensive. For example, in the extreme, if use of a given substance will always be totally contained, I need no other information to say categorically that the risk of using that substance is zero. The cost of obtaining relevant data varies on a case by case basis and generalisations about it should be avoided. Whether transferring funds from testing to monitoring is a more effective way of using these funds to ensure chemical safety is debatable. A great deal of monitoring has been carried out over the years and it is arguable whether it has achieved as much as premarket testing and regulation in protecting human health and the environment. Indeed, the great examples of recognition of the environmental dangers of chemicals come from public concerns generated not by monitoring but by relatively unstructured observation of declining bird populations such as led to identification of the long-term food web effects of DDT or such as led to the identification of Minamata disease from methylmercury or of imposex from tributyltin oxide. The worst aspect of monitoring is that, like epidemiology, detectable contamination and/or harm must occur before it can produce results which lead to action. To quote the RCEP's own opening quotation from R.P.Riger - “....it seems to me that if you wait until all the frogs and toads have croaked their last to take some action, you've missed the point.....”.
As already explained, this document is aimed at U.K. government and in it the Royal Commission recommend that that “the U.K. government establish a chemicals safety co-ordination unit.......by transferring resources (staff and budgets) from existing organisations dealing with chemicals safety to the Environment Agency”. Since the Environment Agency has authority only in part of the U.K., namely England and Wales, and not in Scotland and Northern Ireland, this will clearly cause constitutional problems. The Health and Safety Executive, which has U.K. wide authority, would seem to be a much more appropriate body to undertake this responsibility.
Finally we reach the recommendations to the U.K. government. Here I shall comment on only a few major points. The Royal Commission recommends (recommendation 9) that standards for prioritising chemicals for regulation should be reviewed regularly, “taking into account public views'. How assessment of public views is to be done should be indicated, as the final results obtained depend upon the methods used. In any survey of public views, there is always a tendency for activists opinions to be given more significance than they deserve.
Recommendation 15 is as follows. “Where synthetic chemicals are found in elevated concentrations in biological fluids such as breast milk and tissues of humans, marine mammals or top predators, regulatory steps should be taken to remove them from the market immediately”. This begs the question - “What is an elevated concentration?” For a new synthetic chemical, any concentration found will be an elevated concentration since the substance could not have been there before it was synthesised. Thus, valuable synthetic chemicals may be banned from use on the basis of the presence in biological fluids of only a few molecules which do not pose any risk. If the chemical is essential as a pesticide to control a disease such as malaria, immediate removal from the market before a good substitute is found may result in many people dying unnecessarily. Loose wording of recommendations such as this can kill.
Recommendation 29 is another that requires clearer definition. It says that “The chemicals safety co-ordination unit should publish its strategic approach to research setting out the steps it will take to ensure that it will be possible to predict with adequate confidence the fate and effects of synthetic chemicals released into the environment”. Unfortunately, “adequate confidence” is not defined. The fugacity model developed by Don Mackay of Trent University, Canada, is used in various forms to predict the fate of un-ionised synthetic chemicals in the natural environment and subsequently to predict possible harmful effects. This model is adequate for many purposes, but is it adequate for the Royal Commission? I have no way of knowing from their Report.
Recommendation 31 is one of the main recommendations but again is unclear without a glossary of key terms. The recommendation is that “The chemicals safety co-ordination unit, in co-ordinating monitoring as recommended, should direct effort towards reconnaissance monitoring and environmental epidemiology, using an integrated approach to detecting the presence or possible effects of chemicals in the environment as part of its risk management programme”. In order to find a definition of reconnaissance monitoring, I had to go to number 41 in the list of references for Chapter 4. This is a very unusual way to quote a definition. The definition given is: “Reconnaissance monitoring aims to determine what chemicals are present in the environment and whether a change in the health status or function of the ecosystem, the quality of a habitat, the functional integrity of an ecological community or the level of harm to individuals or populations of organisms in the environment is due to chemicals or attributable to some other cause”. This sounds to me very like a definition of “ecotoxicology” since it goes well beyond monitoring. I have already commented on the confusion as to the nature of environmental epidemiology. It seems to me that this recommendation can be expressed simply as “increase research in ecotoxicology and apply the resulting knowledge effectively in guiding risk management”.
Moving on through the recommendations, we come eventually to a section entitled “Towards Environmentally Sustainable Products”. This has a preamble starting with the following general statement - “Substitution of hazardous substances with others of lower hazard should be a central objective of chemicals policy”. This is superficially attractive but fails to consider some relevant factors. For example, it may be that lower hazard is also associated with lower effectiveness, for example for pesticides or fire retardants. Alternatively, effective use of low hazard substances may require use of much larger amounts (with large exposures leading to harmful doses) and more risky processes. So the generalisation in the preamble may, if implemented, lead to more harm being caused with hazard-based substitution than without. What should have been recommended was risk substitution, not hazard substitution, but this has not been properly considered in the RCEP report although we do have the vague recommendation “The UK government should adopt substitution as a central objective of chemicals policy”.
The RCEP report argues for better information about chemicals on the market, more intelligent testing, better use of monitoring, a concerted push for early European legislation, and a strong move towards substitution, underpinned by economic instruments and an improved liability regime, incorporating full articulation of public values. With the provisos which I have indicated above, these recommendations are unexceptionable but the question remains - has the objective of the report “to offer a new approach to chemicals assessment and management” really been achieved? In my opinion, it has not. The approach suggested, “based extensively on computational approaches to hazard assessments” is not new. Regulatory toxicologists have considered similar approaches for some time but have generally concluded that such methods are only practicable under certain clearly defined and limited conditions. Much more research is required before they can become applicable to all the possible scenarios that may occur in the natural environment. Similarly, the recommendation of more effort in “reconnaissance monitoring” and “environmental epidemiology” needs supporting evidence that these activities would be cost effective. As argued above, the most that can be expected from these approaches is limitation of damage. Although there will be cases where limitation is the best we can achieve, the main objective should always be prevention of harm.
As a broad general review of the regulation of the safe use of chemicals and its scientific background, this is a very clearly written and useful document, available free on the RCEP website and at a very reasonable price as an A4 paperback. Perhaps the binding of the paperback could be better since the copy I have been reading began to fall to pieces before I had finished. Apart from the lack of a glossary of specialised terms, the main weakness in the document lies in the inadequacy of some of the key recommendations. This may reflect the lack of experience in fundamental regulatory toxicology in the membership of the RCEP. Although they consulted widely and well, the RCEP have perhaps undervalued some of the problems identified here because there was no professional ecotoxicologist on the committee. I think that lack of a good ecotoxicologist is a serious deficiency in an important committee with the remit of advising on environmental pollution.
last modified 8 January 2004.
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