Salem Public Schools cancel outdoor activities as crews work to contain brush fires in Massachusetts WCVB BostonSmoke from fires in Massachusetts leads to unhealthy air quality north of Boston CBS BostonFire crews still working to contain dozens of brush fires across Mass. NBC BostonWhat is inversion smoke? Wildfires continue to impact air quality in Mass. NECNPolice urge residents to ‘avoid outdoor activity’ as 2nd Salem brush fire burns near golf course Yahoo! Voices