No, we can't be sure. There's a lot of diseases that we don't know the cause of, for example. Cancers, dementia, Alzheimer's, etc. There is a possibility that the rates of those diseases are higher because of plastics. Plastic pollution also accumulates, there was a lot less plastic in the environment a few decades ago. We add more faster than it gets removed, and there could be some threshold after which it becomes more of an issue. We might see the effect a few decades from now. Not only on humans, but it's everywhere in the environment now, affecting all life on earth.

You're not arguing in a way that strikes me as intellectually honest.

You're hypothesizing the existence of large negative effects with minimal evidence.

But the positive effects of plastics and social media are extremely well understood and documented. Plastics have revolutionized practically every industry we have.

With that kind of pattern of evidence, I think it makes sense to discount the negatives and be sure to account for all the positives before saying that deploying the technology was a bad idea.

I agree that plastics probably do have more positives than negatives, but my point is that many of our innovations do have large negative effects, and if we take them into use before we understand those negative effects it can be impossible to fix the problems later. Now that we're starting to understand the extent of plastic pollution in our environment, if some future study reveals that it's a causal factor in some of our diseases it'll be too late to do anything about it. The plastic is in the environment and we can't get it out with regulation anymore.

Why take such risks when we could take our time doing more studies and thinking about all the possible scenarios? If we did, we might use plastics where they save lives and not use them in single-use containers and fabrics. We'd get most of the benefit without any of the harm.