12:41 p.m. on June 23, 2008 (EDT)
The big problem, to partially answer trouthunter's question, is that the risks are in almost all cases unknown, despite huge efforts to determine them beforehand, until products have been in the field for a long time. In many cases, the risks may only affect a small number of people who may have particular genetic make-up. For example, millions (probably billions) of people use NSAIDS for pain relief (aspirin, ibuprofen, naproxin, others), and have done so for hundreds of years (aspirin was originally derived from willow bark, which had been used as a folk remedy for possibly thousands of years). A few people take massive amounts intentionally or accidentally and die. A few people, like my spouse, are allergic to NSAIDS (we discovered this by accident, when after years of occasional use of aspirin, ibuprofen, and naproxin, our son discovered her semi-conscious. when we got her to the ER, her blood pressure was 60/30. She spent 6 days in intensive care before she recovered). Should all NSAIDS be withdrawn from the market?
Some negative consequences are like the "butterfly" phenomenon (the tiny disturbance of a butterfly flapping its wings can, in principle, propagate and intensify, resulting ultimately in a hurricane). How do you foresee which butterfly will cause a hurricane?
We ingest lots of toxins every day in our food, water, and the air we breathe. The body (for the vast majority of people) tolerates and rejects these toxins just fine. But above a certain amount, a given toxin can be deadly, produce cancer, promote heart problems, or a number of other negative consequences. As an example, fat-soluble vitamins are vital to health. But in too large a quantity (how large is that?), they can be fatal.
When I was growing up (yeah, I know, I am still not grown up), we were told that since the body does not generate its own vitamin D and exposure to sunlight does trigger the generation of D, we should get healthy tans. At this point in my life, I am visiting the dermatologist every few months to get pre-cancerous lesions removed (and recently a squamous cell and a basal cell, both malignant). So, should we ban sunlight? How much sunlight triggers skin cancers?
A few centuries ago, women were told to ingest a certain amount of arsenic daily, because it gave a pale complexion, which was a sign of the upper class, who did not have to get out in the sun to work. We know that arsenic is a poison, of course.
A serious problem a few decades ago was children, especially babies, being seriously burned when their nightclothes came close to flames. So it was viewed as a huge benefit that children's night clothes were coated with fire retardant and fireproofing. It was in fact demanded and mandated by law. Then after a number of years of this practice, it was discovered that the chemicals were toxic and caused developmental problems. So now the retardants are banned.
DDT was hailed as a miracle product that virtually eliminated malaria and yellow fever (mosquito-borne diseases) in many countries and in large parts of the US. Yet it had the side effect of thinning the shells of eggs of a number of raptors, something which did not show up until after some 40-50 years of use.
Right now, there is a huge battle going on over developmental medical treatments that promise to treat fatal illnesses. At what point in the testing should they be made available for patients who have these 100% fatal diseases?
The point is - when a product is being developed, some of the risks are immediately apparent, but many (most) are not until the product is in the field being used by millions of people. Life is a risk (to be only slightly facetious, being born is the major cause of death). You always are trading the risks for the rewards. Only the risks frequently do not show up until long after the rewards become apparent.
