Do you really think that China would not have industrialised if not for Western companies? Nothing about China's history shows that that's remotely true.
In fact, outsourcing was only possible because of the various industrial plans that China had put in place in the 1960s, 1970s, and 1980s, all of which prioritised building equivalent capacity to what existed in the West and the USSR.
Moreover, China was destroying its environment in the 1950s already, long before it even allowed real trade with the West.
Let's treat countries as responsible actors in their own right, not as mere non-independent reactors to Western actions.
Not quite to the same extent, or nearly as late. China's Four Pests campaign, for instance, ran from 1958 to 1962 and was ecologically disastrous.
Meanwhile, in the US you already had strong conservationist movements starting up, leading to the creation of the EPA by 1970.
While China finally adopted some environmental protections in 1979, it wasn't until the late 1980s/early 1990s that they could override industrial development in key situations
While Ranch Hand was indefensible and US leaders should have been prosecuted for it, the scale of it is minuscule compared to the ecological damage of the Four Pests campaign.
In fact, outsourcing was only possible because of the various industrial plans that China had put in place in the 1960s, 1970s, and 1980s, all of which prioritised building equivalent capacity to what existed in the West and the USSR.
Moreover, China was destroying its environment in the 1950s already, long before it even allowed real trade with the West.
Let's treat countries as responsible actors in their own right, not as mere non-independent reactors to Western actions.