The thing is, new chemical compounds are being developed all the time for all kinds of applications. What you’re saying is not really “we should let sick people die rather that try to get a cure”, horrible enough as it is, but rather “let’s dump whatever shit we come up in the environment without testing its effect first”, and while things are bad currently, there is no depth to how worse things could get if we didn’t even bother trying to prevent the worst from happening
What you are proposing may seem nice, but any ethics committee would shut this down instantly, anywhere in the world.
But let’s imagine we can do this, somehow, and that all the ethical issues are resolved. Harvard might be able to grow their “thing”, or order it from some specialized company; how do you not condemn all research in developing countries?