We also need to acknowledge that most of the substances that Mr. Michaels discusses have legitimate and valuable uses in our modern technology and to the extent that they contribute to the protection that our technology provides us against disease and pestilence, they have value to us. To willy-nilly ban use of those compounds is to inflict harm on humanity. DDT, for example is a compound that has great value and which suffered a slanderous attack that caused its banishment.

All of the compounds (except second hand tobacco smoke) that Mr. Michaels names have important uses; we should be certain of their danger before we restrict their use. There will always be legitimate debate among scientists who study toxicity. To characterize all of those who urge that we collect sufficient information before sacrificing useful technology as being engaged in “manufacturing doubt” is as slanderous as it is irresponsible. Such behavior is not science; it is blind advocacy.

I believe that it is possible that unjustifiable banning of substances has caused us more harm than the continued use, at excessive exposure rates has caused.

Ortho-toluidine (commonly called OTO) is an interesting example. At the relatively high exposure rates that might exist in manufacturing plants, it might cause bladder cancer. One use of OTO is to measure the chlorine concentration in the water in public swimming pools. Pool operators place a few drops of an OTO solution into a transparent vial that contains a few milliliters of water. Once the test is complete, it is common for the pool operator to empty the vial into the swimming pool. Does Mr. Michaels claim that causes bladder cancers among the swimmers? Of course not. Do we believe that the incidence of water-borne disease among swimmers would increase if the banning of OTO were to make it impossible to maintain the proper chlorine level in swimming pools? I do.

In my opinion, Mr. Michaels is being hysterical about the possible harm that modern technology presents to us and is underrating the importance of those compounds.

Mr. Michaels cautions us to be skeptical about the reports of scientists who receive industry funds. Rightfully so, we should be skeptical of all science; skepticism is the sine qua non of science. Mr. Michaels should add that we also must be skeptical of the reports of activists who receive funding only if they frighten enough members of the public to generate donations.

“Manufacturing scientific uncertainty” exists in other venues, such as the never-ending war by fundamentalist religious creationists against evolution - see, for instance, http://en.wikipedia.org/wiki/Dover_trial. The creators of “intelligent design” creationism have no science to contribute to the discussion, but they work very hard to sow the seeds of doubt against evolution, which is the cornerstone of modern biology.