The Washington Department of Labor and Industries’ research unit, SHARP, has an excellent site for researching hazards and policies.
http://www.lni.wa.gov/Safety/Research/About/Related/default.asp

The Pump Handle — a Public Health blog
http://scienceblogs.com/thepumphandle/

 Hazards Magazine — a U.K. site
http://www.hazards.org/

Environmental Health and Safety program at the University of Massachusetts Lowell
http://www.uml.edu/ehs/default.html

The Hanford Challenge blog
http://www.hanfordchallenge.org/

The Coalition for Workplace Safety — Industry lobby
http://workingforsafety.com/

Unnatural Causes: Is Inequality Making Us Sick?
http://www.unnaturalcauses.org/