The numbers game : international guidelines for chemical safety / by Emmanuel Somers

T he English physicist Lord Thompson declared in 1889: "When you can measure what you are speaking about, and express it in numbers, you know something about it." A century later this neatly expresses the basic premise of regulatory agencies and the credo that is increasingly emphasised in our numerate techno- logical world. National regulatory agencies that have the responsibility for control- ling hazardous chemicals need a number to give reality to a regula- tion, standard, guideline, or even a recommendation. Whatever the regulatory action, a number pro- vides the reference point for enforcement, surveillance and subsequent monitoring. The number enables us to make a judgement as to what is safe - or, more correctly, what is judged an acceptable or tolerable risk - as opposed to what is negligent or criminal. There may not be a significant increase in risk between driving a motor car at 58 and 62 kilometres per hour, but 60 kph can provide a sensible reference point for public safety. The chosen number should, of course, be both enforceable and amenable to change as the scientific knowledge on which it is based develops. At best, the number will be an approximation for health protection. In no sense can it be considered to give an absolute guar- antee of freedom from risk . Whether a government chooses to enforce compliance with health and safety requirements through the force of Jaw and prosecution, or through gentler routes of persuasion and recommendations, the essential flow-path of health protection is invariably: Investigation - Criteria - Standards - Regulations - Enforce- ment and Compliance. That is to say, investigation and research lead to an evaluation of the health hazards , formulated as criteria. From these criteria, health standards are derived, which are in turn converted to a legislative reality when promulgated as regulations . The final stage is enforcement of these regulations. The control loop is completed by monitoring the A shadow on young lives: how can we measure the point where fumes become health risks? Fortunately public opinion - epitomised by these young New York demonstrators (right) - is increasingly alerted to the potential dangers of chemical pollution. Photos L Sinnan © and WHO/J. Mohr WORLD HEALT H, December 1988 13 effectiveness of regulations, so that if they are not achieving the original intention, the cycle of investigation and regulation must be repeated once more. Ideally, such measures relate achievements to needs. It is at the criteria stage that the role of international evaluation is so critical. Few countries have the resources or expertise to assess the health risk on all the multitude of chemicals to which we are exposed. The cost of testing and evaluating chemicals is so high, and skilled personnel so scarce, that it is incum- bent on all of us to share limited resources and avoid overlap and duplication . Even for those that have the ability, the necessary objectivity and consistency can only be given in the international forum . Consistency of testing and evalu- ation helps to make data obtained in different countries comparable and acceptable and - in the final analysis - encourages both interna- tional trade in chemicals and the harmonisation of control measures . In view of the key role played by international cooperation in evalu- ating the risks from chemicals, let us consider how valuable the Interna- tional Programme on Chemical Safety (IPCS) has been in meeting this challenge. Established in 1980 as a cooperative venture of ILO, UNEP and WHO, the I PCS is required, as the first of its objectives, to prepare evaluations of the risk to human health and the environment from exposure to chemicals. In response, its wide range of publica- tions have included 75 Environ- mental Health Criteria documents, with another 39 in preparation; 11 simplified Health and Safety Guides, with another 54 in prepar- 14 Cleaning up a French beach after the shipwreck of a supertanker canying erode oil. Chemical spills tend to be less spectacular - and may be much more dangerous to health. Photo L Sinnan © ation; and the planned publication of some 400 of the even more concise International Chemical Safety Cards this year and next. The IPCS can draw on more than 28 years of studies by WHO, in collabo- ration with the Food and Agricul- ture Organization (FAO), in which the toxicity of food additives, conta- minants, and pesticide residues in food have been assessed . It has set maximum residue levels for 140 pesticides to date. Modest resources This is a remarkable achievement, particularly in the light of the modest resources available to the IPCS. Modest , that is , when compared to the cash spent on similar work by even middle-rank countries. The question remains how these outputs of IPCS are act ually used by WHO's member states . The fruits of many days of committee work and even longer resea rch by high- ranking consultants are not intended for academic or encyclo- poedic purposes . They are to be used in the practical application of public safety measures, for they represent the best available interna- tional knowledge on each chemical's safety. The health risk evaluations of pesticides and food additives carried out by the Joint FAO/WHO Corn- The numbers game. mittees are translated into regula- tory implementation through the Codex Alimentarius, with its 129 member states. In this fashion , the IPCS evaluations have an enormous economic impact on the world's food and agriculture production and trade. Summaries of Accept- ances of Codex Food Standards, including food additives, and Codex Maximum Limits for Pesticide Residues are published by the Codex Alimentarius Commission. These publications give the specific details of the manner in which countries choose to accept the recommendations. In general, it may be said that all of them accept the derived Acceptable Daily Intakes. The same uniformity does not apply to Maximum Residue Limits (MRLs) for pesticides, where many developed countries have derived their own limits based on local estimated intake. Most developing countries, lacking a strong regulatory infrastructure, tend to accept the Codex MRLs as a basis for commodity trade. The extent to which other IPCS products are used by countries as a basis for their chemical safety pro- grammes is largely a matter of supposition, although a survey of Environmental Health Criteria documents showed nearly half of the respondents claiming that the publications were being used for policy-making. Certainly, many would judge that , in developed countries, few regulatory decisions are taken on chemical problems without prior consultation of these documents at some stage, since they provide a peer-reviewed, unbiased evaluation of the dose-effect rela- tionship. The ultimate regulatory option is then developed from this scientific base. Developing countries may be more liable to accept with- out question the risk evaluations produced by developed countries. It is undisputable that, from mer- cury to mirex, from the PCBs to tetrachloroethylene, from mycotox- ins to toluene diisocyanates, the IPCS publications provide us with the basis and the rationale for regulating actions. In all our coun- tries, the public and the media have become ever more watchful of their officials as the spirit of g!asnost in the chemical field spreads. On the other hand , WHO's sound reputation is eagerly accepted as a talisman of objectivity and authority throughout the world. More and more, the importance of interna- tional guidelines for chemical sa fety is being recognised . • W ORLD HEALTH , December 1988