"How will Oregon clean up diesel air pollution?" PBS NewsHour 1/31/2018

Excerpt

SUMMARY:  As many as 400 Oregon residents are estimated to die prematurely every year from exposure to diesel exhaust, a toxic carcinogen, and a contributor to climate change.  While new vehicles have emission requirements, there are no regulations for the older diesel engines still in use.  Special correspondent Cat Wise reports on the ways Oregon is trying to tackle the problem.