SCOTT FALLON / NORTHJERSEY.COM – New Jersey’s air quality still gets failing grades for smog, but in recent years it has gotten far better in one facet.

The amount of microscopic particles of soot that can trigger heart attacks and aggravate asthma has plummeted due in large part to coal-fired power plants closing and older diesel trucks being taken off the road.

But this week, for the second time in less than a year, New Jersey has been blanketed with soot from smoke that traveled 3,000 miles across the continent from enormous wildfires that have engulfed drought-ravaged western states …