If there&#x27;s an environmental chemical cause, the 2006 REACH legislation in the EU should provide an interesting comparative study with the US:<p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Registration,_Evaluation,_Authorisation_and_Restriction_of_Chemicals" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Registration,_Evaluation,_Auth...</a><p>I don&#x27;t think I&#x27;d agree that air is less and less clean, incidentally. There have been big improvements in clean technology for cars and other vehicles, big reductions in the use of coal in developed countries, and so on.<p>And I doubt other environmental pollutants are significantly higher than they were in the age before serious environmental legislation (for instance, before the EPA was created)