According to Wikipedia it's the biggest environmental health risk factor that may kill 8.8 million people annually (March 2019), which definitely puts it up the

According to Wikipedia it's the biggest environmental health risk factor that may kill 8.8 million people annually (March 2019), which definitely puts it up there, but hypertension probably still kills more people (9.4 mil, 2010). It's hard to compare an environmental risk factor with actual diseases, but I don't think you can really argue that it's the biggest "health crisis" by any metric. Anxiety for example is still the most debilitating disease worldwide. It's still pretty bad though, which I didn't realize before looking into it, but the usual suspects are still worse in terms of health.