Public employee unions, in their defense, say politicians have unfairly made them into simplistic bogeymen, responsible for problems that have myriad causes. Not all government workers receive generous pensions, they note.

Government and other scientists have identified hundreds of chemicals that are linked to diseases in small concentrations and that are unregulated in drinking water or policed at limits that still pose serious risks.

Union leaders argue that pension shortfalls account for a proportionally tiny portion of governments' financial problems, and by all accounts, there are plenty of parties to blame for the growth in payrolls and obligations.

Charles Duhigg Quotes