The U.S. Environmental Protection Agency, acting in response to a lawsuit by NRDC, reinstated a rule to protect the public from the more than five tons of mercury pollution discharged each year from dental offices across the nation. Mercury can disrupt brain function, harm the nervous system, and is especially harmful to pregnant women, babies, and young children—even at tiny levels of exposure. The EPA issued the Mercury Effluent Rule on December 15, 2016, but withdrew it in January after President Trump took office. This illegal, senseless withdrawal prompted NRDC to sue. Instead of trying to defend its decision in court, the EPA just reinstated it. Good move.