It checks out compared to countries without these issues, so 15 years to me sounds exaggerated, especially if we're talking about areas close to each other.
Such a huge shortening normally involves heavy metal pollution of the drinking water and soil.
It would be nice if the article had mentioned this issue. A metastudy of lots of bad correlational studies is just garbage in garbage out. So, did they address the issue?
There are ways round it, by the way. As a recent review said:
"it is unclear why federal ISAs that are the input into all regulatory analyses tend not to incorporate the emerging body of evidence on the effects of air pollution on health outcomes from the economics literature despite the additional rigor imposed by the emphasis on causal inference."
https://www.annualreviews.org/docserver/fulltext/resource/15...
Having the study at hand is nice of course, but environnemental factors being alleviated through money and discriminatory policies is rampant enough I don't get the surprise.
People using high quality water filters or straight buy clean water tanks in areas where tap water is bad, getting better indoor air filtering, blocking construction of pollution sources to move them further away (near poorer areas) in the county, redlining/manipulateing zoning rules to make it systematic etc.
It's a old as humans.