A US Senate committee is to hold hearings into a controversial experiment that involved spreading sewage sludge onto lawns in poor, black neighbourhoods.

In another development, the National Association for the Advancement of Colored People has called for criminal prosecutions over the experiment, conducted by Johns Hopkins university and the Department of Agriculture in 2000. It was designed to test whether spreading treated sewage around houses could bind to lead in the soil.

Spreading of processed waste is widespread in the US. In addition, lead in poor neighbourhoods is a big problem

The experiment was a success in terms of reducing the availability of lead. “Compost offers great promise for people to help themselves protect their children at low cost,” says the outcome report (released in 2005).

However it’s been less of a public relations success. And after Sunday’s AP story publicised the study the Environmental and Public Works committee is getting involved.

“Our hearing will include an investigation of the risks associated with application of sludge in neighbourhoods as reportedly took place in Baltimore,” said democrat Barbara Boxer, the committee’s chairman (AP).

This isn’t enough for the NAACP, which says the case has shades of the infamous Tuskegee experiment where researchers allowed syphilis to spread in the black community.

“Someone putting human waste and industrial waste in someone’s yard as a test? That sounds like Tuskegee all over again,” says Gerald Stansbury, president of Maryland NAACP (Baltimore Sun).

Rufus Chaney, a USDA researcher involved in the experiment, has been defending the work. He believes the lead was more of a risk than the sewage. “I am comfortable that the issues of soil and housing [lead] risks to the children were well-disclosed.,” he told the Baltimore Examiner.

However the Examiner also notes that a 2004 paper by University of Georgia researchers warns that more affluent neighbourhoods are starting to resist sludge spreading, meaning more is spread on vulnerable communities. It quotes the paper as saying: “One outcome of local bans is that land application of sewage sludge is being forced out of areas where residents have the political and economic resources to oppose the practice and into economically depressed areas.”

Image: Baltimore / Nasa Visible Earth