I don't doubt that Chinese authorities want to solve this problem. The problem isn't a lack of will on the part of their Government; the problem is a lack of established infrastructure to deal with relatively nuanced issues like industrial chemicals. You're asking a country that is rapidly transitioning to modernity—perhaps faster than any other large country ever in history—to get all these things right faster than anyone else ever did.
We shouldn't stop pressuring China to do better, but the best thing we can do is good science, good measurements and helping them to solve the problem for themselves.
(Disclaimer: this post was written with an eye to Cunningham's Law. I'm a total layperson and I would be interested to hear observations from someone with expertise in this field.)