Lead in Baltimore - The True Story

 

By Sally Brown, University of Washington (April 29, 2008) 

 

The Associated Press has recently published a second story (note that the word story is generally used to describe a fictional narrative) on biosolids.  For the second article, they focused on a study conducted by Johns Hopkins University in cooperation with the Kennedy Krieger Institute.  The study was a field trial that tested the ability of Class A biosolids compost, produced in Baltimore, to reduce the bioavailability of lead in urban yards.  The study found that, including both dilution and actual reductions in bioavailability, after compost application the danger posed by the high lead was reduced by about 66%.  In addition to measured reductions in bioavailable Pb, the compost grew lush grass which made it much more difficult for the children at highest risk for lead exposure, to come anywhere near the soil.  This study was done as a follow up to a lab study.  In the lab study, a soil from Baltimore with total Pb of 2000 ppm was amended with a range of different biosolids products.  Changes in lead availability were measured using lab tests and an animal feeding study.  I know about that one, as I was the first author on it and did all of the analysis on the soils and the rat bones.  

An easy, environmentally friendly, cost effective solution to one of the inner cities' big problems?  Sounds good right?  Sounds like cities all across the country should be doing this.

Not according to the AP reporters.  In their story, sewage sludge was sprayed on the yards of poor people, a case of environmental injustice akin to when blacks in Alabama were left untreated for syphilis so that scientists could observe the progression of the disease.  This AP story has left the senator from Maryland as well as the senator from California calling for congressional hearings into this environmental injustice.  

Scientists from Johns Hopkins and Kennedy Krieger have responded to this noting that the 'sewage sludge' that was sprayed on the yards is actually a Class A compost made from biosolids, sawdust and wood chips that is for sale at the Home Depot.  It is the same material that was used at Camden Yards where the Baltimore Orioles play and at the White House where the President lives.  They point out that elevated Pb in urban soils is a real problem and that this is part of the work towards a solution.  

I was at a CASA conference last week and worked with some of the leaders of CASA to determine the best way to respond to this article.. They are very concerned about this.  I encouraged them to start a range of small scale programs with their Class A products to demonstrate that not only are the biosolids safe, they are great stuff.  Later in the week I was at the Tagro facility in Tacoma.  Talking to Gordon Behnke about this, he said that many of his customers had called to tell him what fools those AP reporters were and how angry they were at the distortions in their story.  The different levels of concern about this article as you travel from California up north are a testament to the success of many of the biosolids programs in the NBMA.