As reported by the Associated Press last week, U.S. EPA has adopted a new airborne lead standard.  U.S. EPA selected a standard at the lower range of those being considered.  The new standard is ten times more stringent than the old standard.  As was reported:

The new limit – 0.15 micrograms per cubic meter – is the first update to the lead standard since 1978, when it helped phase out leaded gasoline. It is 10 times lower than the old standard, which was 1.5 micrograms per cubic meter.

EPA estimates that 18 counties in a dozen states across the country will violate the new standard, requiring state and local governments to find ways to further reduce lead emissions from smelters, metal mines and other sources.

Here are is a good graph and pie chart showing the reductions in lead and sources responsible for remaining airborne lead:






The graph on the right shows airborne lead levels have decreased by 94% since U.S. EPA banned lead from gasoline and took other measures.  The pie chart to the right shows the largest remaining contributor to airborne lead levels is leaded aviation fuel.  However, this would not explain why some counties have such high lead levels.  This can only be explained by factories or sources in those counties.

U.S. EPA’s monitoring data that shows only 18 counties in the entire country violate the strengthened lead standard.  Compare that to the ozone and fine particle air quality standards where 30 counties in Ohio alone violated the standard.  This may be due in part to the inadequate monitoring network that exists for measuring airborne lead levels.

Once again Cuyahoga County gets the dubious distinction of being listed as one of the few counties in the country to violate the new lead standard.  However, a closer look at EPA lead monitoring shows Cuyahoga barely over the standard.  EPA data says airborne lead levels are .16 micograms per cubic meter and the standard is .15.  

Ohio’s highest lead levels are in Fulton County with reading at .52 micrograms per cubic meter.  The highest in the Country are in Jefferson County, Missouri with a reading of 2.26 micrograms per cubic meter, about 15 times higher than the new standard. 

Placed into context, Cleveland should not face much of a challenge in meeting the new airborne lead standard.  This is good news to an area that has faced the greatest challenge in the state in meeitng ozone and fine particle standards.