Is "consensus science" always correct?

For instance, "consensus scientific opinion" in the U.S. right now seems to favor the notion that water fluoridation is "safe and effective." Yet, back in the early 1940's the "consensus opinion" from the medical community, including the American Dental Association, was that fluoride was a poison, and that laws should be enacted to remove as much of it as possible from our food and water supplies. So what changed? The latest report from the NRC (a research arm of the National Academy of Sciences) is now saying as little as 4 parts per million of the stuff can cause thyroid problems, osteoarthritis, and possibly even osteosarcoma in male children, if consumed over a long period of time. In other words, it looks like the pendulum is swinging back to the notion that fluoridation is NOT "safe and effective" after all. Other substances like leaded gasoline, ddt, and most recently Celebrex, have also fallen by the wayside. So why do the media still invoke "consensus science" so often?

Is "consensus science" always correct?
I can understand the confusion. But here's how it works:


First of al, you need to understand what a "scientific consensus "means. It is NOT simply that scientists decide and agree. When a new idea is put forward--and has enough evidence to support it to seem plausible, scientists start subjecting that idea to eveery test they can think of. And (this is important) alll scientific tests are designed to "falsify" the idea. A scientific consensus that an idea is correct is reached only after every possible test anyone can think of has been made--and the idea still stands up.





Now, given that , you might ask, how (except very, ery rarely) could an idea be wrong? The answer is that it is very rare. But, two other factors are at work. One is that the public--and most science reporting--doesnt distinguish between the findings scientists publish while a scientific debate is underway over an new idea and the findings that reflect the eventual consensus. That's what happened with the "change in views' in the 40s and 50s about flourine. People reported the scientific thinkinng as fact--even though the "jury was still out." We see the same thing today (only worse). I guarantee you that if you watch "health news" for a few days, you will see at least one interview with a scientist and the scientist is talking about work that "indicates we may be able to (X)." If you listen to the scientist--its clearly a preliminary finding. Listen tothe reporter, it is presented as established fact.





The second problem is that ALL scientific statements (e.g. flourine is safe) includes the statement "under the stated conditions" the statement is true. Scientists don't usually bother to say this explicitly--its so basic to science that its not necessary--and our scince education in this country has gotten so bad that most people dont know this.





So (as here) 20 or 40 years down the road, things can change. Today we can make far more precise measurements, know more about the chemistry and biology--and have the ability via computers to do analysis impossible even a decade ago. So--ongoing research shows that under some conditions that couldn't be tested back then, flourine poses a (slight) danger. And those conditions are rare themselves (Of course, the pop science reporters don't get around to making this part clear).





So-was the earlier science "wrong." NO. First of all, their original model still holds--its jsut been expanded with new information.





Second, (with respect to biological issues) safety is relative. Almost ANYTHING has some risk--and can cause harm in some cases, however rare. Which doesn't stop pharma companies from saying "x is "proven safe")--nor (leaving aside their hype) should they.





Flourine is still as safe as it ever was--and that is VERY safe (in very low concentrations--high concentrations ARE poisonous). But again--safety is always relative. And flourine is safe COMPARED TO other substances used to purify water, etc. That does not mean absolute safety--which does not exist.





BTW--that current report about flourine is preliminary--its not been confirmed yet anywhere to the extent needed to establish a scientific consensus. Wait about 5-10 years. Right now its a definate possibility of a firm maybe.
Reply:The consensus is frequently wrong. But it is up to the person claiming the consensus is wrong to prove it wrong.
Reply:Using ultimate terms like always and never are usually wrong...times and science changes therefore my answer is NO.
Reply:The one with the loudest voice or biggest grant wins.
Reply:Because without it, Al ('I invented the Internet') Gore wouldn't have a prayer of convincing people that 'Global Warming' is happening chiefly because of man.





Doug
Reply:the reason that the consensus scientific opinion is used so often is to place the least risk. If we didn't do it there may be many more terrible medications released to men and women around the globe. It works just like Congress, congress takes a vote on national and international political and military decisions, and these scientists take a vote on medical, bacterial, etc decisions. These are just one more group of people that are in place to protect us, regardless of if they accomplish that or not. So no "consensus science" is only correct if the least damage comes from their decisions.