Lead’s omnipresence and persistence

High lead levels in soil around homes and a preschool near a battery recycling plant in Vernon, California have prompted state officials to issue health warnings and order testing in adjacent neighborhoods.  State toxic waste regulators report that initial results from almost 40 homes and two schools have led them to require Exide Technologies to create a plan to protect children and pregnant women living in affected homes, and to performexide additional testing. The plant, in operation for some 90 years, recycles 25,000 batteries a day.  Elected leaders, residents, and other officials have focused on Exide since the South Coast Air Quality Management District found its arsenic emissions to pose a cancer risk to 110,000 nearby residents.  Although soil testing failed to show high arsenic levels, it did evidence lead levels higher than the 80 parts per million that California uses as a trigger for further evaluation, ranging from a low of 95 parts per million to a high of 580 parts per million.  For more details, read here.

At the 2013 Ocean Sciences Meeting, scientists revealed new evidence of a different source of lead risks.  New maps show a mass of seawater infused with traces of the lead about 1000 meters deep in the Atlantic Ocean, surface waters with relatively high traces of lead flowing into the South Atlantic from the Indian Ocean, and another hot spot where the Mediterranean Sea empties into the Eastern Atlantic.  Science Magazine concluded that “Decades ago, the United States and Europe banned leaded gas and many other uses of the metal, but the pollutant’s fingerprint lingers on.”Pb_3D_scene

The maps are the result of an international collaboration to document the presence of trace metals and other chemicals in the world’s oceans called GeoTRACES.  Thus far, researchers have collected nearly 30,000 water samples at 787 study sites during some 30 cruises in the past few years.  The lead maps are the first to be released and show both past pollution and continuing contamination.  While lead levels in much of the Atlantic have dropped dramatically over the past few decades, due to the lead phase out in U.S. and European gas production in the 1970s (of which the deep sea mass is a historical artefact), continued use of leaded gasoline in Africa and Asia fuels the pollution found in the Indian Ocean.

This entry was posted in lead. Bookmark the permalink.

Comments are closed.