ENVIRONMENTAL HEALTH RISK ASSESSMENT D1

ENVIRONMENTAL HEALTH RISK ASSESSMENT D1

Please read the following excerpt of an article. When completed, just state your opinion of it and whether or not you agree with Roger Bate. Fear and Precaution: A Lethal Mix? By Roger Bate By every objective measure such as infant mortality and life expectancy, westerners are healthier today and exposed to fewer and lesser hazards than ever before. Yet, it seems that living longer and having few immediate, material concerns means that we have the luxury of contemplating long-term theoretical hazards. Survey after survey show that some people worry so much about the future that they believe that new technologies and products should not be permitted until it is known for certain they won’t endanger health and environment. Precaution has become their categorical imperative: thou shalt not tolerate even the risk of a risk. I recently tried mild ridicule to attack this modern urge to ‘banish by survey’ by conducting my own survey about whether water (called dihydrogen monoxide or DHMO in the survey) should be banned by the EU. My survey explained that DHMO had many nasty effects such as contributing to acid rain and being a constituent in cancerous cells. Despite the extravagant claims of harm, very few got the joke, and 76% of Londoners thought water should be banned. It has been gratifying to have reports flood in from academic departments around Europe with results similar to my own. London University geographers scored a mind-numbing 86%, whereas German economists did best at 40%, perhaps because many economists are cynics, and assumed correctly that there was something fishy about the survey. The UK Science Minister, John Battle, even used the survey result in his speech to the annual UK Chemical Industry Association Dinner, to make the point that a true fact (water is found in cancerous cells) can lead some people who are scientifically illiterate to make a false conclusion (water is dangerous). However, the survey had a more subtle counter-intuitive aim, which was to show that even a substance required by every living creature can be dangerous. Of course, to ingest a fatal amount of water is very difficult, unless one drowns, but it is possible. A more obvious example of substances essential at low doses but poisonous at high doses are vitamins. For example, it would be relatively easy to poison oneself on vitamin A, but one could not live without a small amount of it. The notion that the dose makes the poison has been known for centuries but seems to be forgotten in modern health and environmental regulation. I recently edited a book* with the explicit aim of showing that modern regulations are based on the erroneous assumption that because something is dangerous at high doses it also causes harm at low doses. This is akin to knowing that a temperature of 200 degrees Celsius can cause severe burns, and concluding that temperatures of 20 degrees are likely to be dangerous. As the numerous experts in ‘What Risk?’ demonstrate, there is a threshold below which the defense mechanisms and metabolic processes of human beings can cope perfectly well. For example, there are 19 known carcinogens in coffee, yet normal consumption is not a concern. However, if coffee were discovered today it would probably be banned by some health agencies, since coffee provides worse test results than many banned synthetic chemicals. When the basis for much current regulation was laid some 40 years ago, the science was insufficiently clear to show whether there were safe thresholds for modern carcinogens. Today, the evidence shows that safe thresholds exist, yet the policies remain based on the old science. When regulators are confronted with this evidence their response is often to say, ‘At least we are reducing some risks’. However, every attempt to reduce risk involves a trade-off, and concentrating on minuscule risks may increase our exposure to more real threats. * Reference: Bate, R. (2000). Life’s Adventure: Virtual Risk in a Real World. Elsevier: Great Britain. pp. 131-132.)