I suppose there are different pollutants all the time, but the areas I'm familiar with (SF Bay and LA) have gotten much less polluted in the last few decades, at least by how they look and smell. I suspect our air and water is safer now than 20 years ago, and much safer than 40 years ago.
Solitary entertainment has grown drastically more engaging in the last few decades, and it seems reasonable to think that it has contributed to increased isolation and sedentary behavior.
Even though it's not absolutely certainly the cause of all ills in the world, I think it's worthwhile to be cautious about digital entertainment.
> I suppose there are different pollutants all the time, but the areas I'm familiar with (SF Bay and LA) have gotten much less polluted in the last few decades, at least by how they look and smell
I want to point out that pollution can be invisible. As a thought experiment - the amount of lead in your water it would take to permanently damage your brain would be invisible, untasteable, and miniscule. It's worth remembering how fragile we really are.
Is it water? Most water supplies only test for about 8-10 chemicals. Who knows? Is it the microplastics we eat?
As for why it would be worse now when our environment is getting better -- perhaps the damage is accumulating each generation (like sperm counts are going down each generation). There are a lot of cases where pregnant mother being exposed to something can have severe effects on the child, and sometimes even the grandchild (look up diethystylbestrol).
Anyways, this is just a hypothesis, but it seems to me it should be given as strong a starting consideration as anything else. I'm sure it's not too hard to take blood samples from a few thousand people to look for health correlations to these mood issues.
Humans might be fine with some form of pollution but not others, so "there's less trash and the factory isn't dumping glowing sludge into the bay" doesn't really rule out that there's some pollution that's less visible but problematic for a subset of people (or problematic when combined with other factors, e.g. veganism or listening to mumble rap).
The first thing I thought of when they said pollution in this context was plastics. That's something that people have an increasing exposure to that also has a history of chemicals that are hormone disruptors. I don't think it covers the entire increase. But it could be one of many factors on the longer scale (not just the shorter term increase).
Solitary entertainment has grown drastically more engaging in the last few decades, and it seems reasonable to think that it has contributed to increased isolation and sedentary behavior.
Even though it's not absolutely certainly the cause of all ills in the world, I think it's worthwhile to be cautious about digital entertainment.