Mercury in western U.S. fish | D.C.’s water linked to elevated lead levels | Perchlorate in Japanese dairy milk | Nanotubes in the environment | News Briefs: A quiet brain-damage epidemic ` Climate cools economy ` Green pact for France ` Coastal pollution grows more dead zones ` Green learning curve ` Canada dumps CO2 targets | Germ fighter works as endocrine disrupter | Is EPA blocking clean coal technology? | Particulate matter from Chinese cooking