Non-sequitur, the presumption of free-markets does not conclude that everything is possible.
I'm glad you admitted that, now please stop using arguments that assume this is true. The free market cannot go about creating anything, thus the assumption that we haven't had the forensics to track this exact pollutant to this exact source because we don't have the property rights is unfounded, and needs to be dropped. We cannot prove where environmental damage comes from on a case by case issue, but we can prove where it comes from in general. Stop the "in general" and you prevent the specifics - and its very easy to do the latter.
Any thing can be a crave, desire or want. The toxic chemical itself may not fit into someones personal preferencefor need, but it could be a means to an end for a want or desire. The reason you may find some success in prohibition of toxic chemical's is because there are viable substitutes. When it comes to other crimes, there may or may not be a substitute, and sometimes if there is, the substitute is also prohibited. There are arguably some health/environmental improvements to abolishing things like DDT, but there are millions of African's suffering from Malaria who disagree with you. The unilateral decision to "ban" certain things carries unintended consequences. You may be familiar with news reports of a resurgence in a bed bug epidemic. In a report on the subject, the news is not promising. There may be some link to the resurgence with the ban of DDT, but even then it's not conclusive, but what they do know is there are other methods of fighting it it, but those pesticides are also banned. So, environmental protections may improve health and safety in some regards, but there are unintended consequences which may result in the loss of other modern comforts, hygene and health safety. It's not always completely black and white and the use of toxic chemicals needs to be analyzed on a case-by-case basis. There could very well be a way to use them in a win-win fashion by using them for certain benefits here and there, but shielding the environment and health of others from the ill effects as well. The market will allow us to figure out this balance.
As regards malaria (from wiki on DDT):
DDT was subsequently banned for agricultural use worldwide under the Stockholm Convention, but its limited use in disease vector control continues to this day and remains controversial.[5][6]
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Resistance has greatly reduced DDT's effectiveness
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Before DDT, malaria was successfully eradicated or curtailed in several tropical areas by removing or poisoning mosquito breeding grounds and larva habitats, for example by filling or applying oil to standing water. These methods have seen little application in Africa for more than half a century
So basically, we still do use it in limited, controlled quantities; the massive overuse of the chemical has actually made it less effective (thanks to the market); and there are various other, non-chemical ways to control mosquitos.
The same goes for other bugs. We've become reliant upon chemicals to do the work for us, when there are organic compounds that can do the same thing.
No, the market does not allow you to find that balance, in fact, the market has repeatedly shown that it creates a massive imbalance. We in fact do what you say with DDT, we use it in a controlled way, for specific reasons, and this is done without the market. I agree that everything is going to come down to individual analysis (which is why I haven't' said ban all industrial chemicals), but its quite obvious that certain chemicals are bad for the environment, bad for us, and just downright harmful. When there are other methods available, we should pursue those methods FIRST, because of their long-term effects. As it is, and as the market operates, chemicals are used first, and questions are asked later.
I mean, lets look at DDT. Imagine I contract a form of cancer thanks to exposure to DDT, thanks to farmers using the chemical on their fields. Right away, there'st he basic question of how to riddle down the cause of the cancer to DDT - that of itself is going to be extremely hard to prove, if it's possible at all. After
possibly ascertaining that the cause of my cancer is DDT, I would then have to trace the DDT back to its source, as well as assume that such exposure wasn't due to numerous sources, over the course of years. How am I going to do that? Seriously. It could be thousands upon thousands of farmers, hell, it could technically come from someone is China! Face it, its IMPOSSIBLE to go back, and prove that this or that person gave you cancer. The problem doesn't arise out of one individual use, it arises out of every individual use. It's a macro issue, not something the markets and the judicial system can easily prove, and provide justice for. The ONLY practical solution is government.