Johns Hopkins raps AP story on lead experiment

For about 20 years, Dr. Michael Klag has used a fertilizer made from Milwaukee municipal sludge on azaleas and yew shrubs at his suburban Baltimore home. And Klag, dean of the Johns Hopkins School of Public Health, says he's never had any question about its safety.

But in the past few weeks, he has found himself reassuring the public about a similar product, a compost made with treated municipal sewage sludge in Baltimore. Johns Hopkins researchers spread it on nine yards in poor black Baltimore neighborhoods in an experiment eight years ago.

That's become a cause for outrage among some politicians and others who have called for an investigation. The trigger was an Associated Press story in April that raised questions about the Baltimore experiment and whether there has been adequate testing to determine if sludge is safe.

The AP story described the Baltimore experiment, which was done in areas with high lead levels in soil and high rates of lead poisoning in children. Researchers reported that adding the compost to the dirt could cut the risk from lead by reducing the metal's ability to be absorbed by the body.

But the AP story described concerns about whether using treated sludge in such an experiment is itself hazardous.

In response, the Maryland NAACP asked the state attorney general to investigate the study. Sen. Barbara Mikulski and Rep. Elijah Cummings, both D-Md., asked for a federal investigation. And Sen. Barbara Boxer, D-Calif., cited the Baltimore study and said a committee she chairs will investigate the risks of using such material in neighborhoods.

Klag says the AP story was "inaccurate and misleading" because it gave the sense that "somehow we targeted vulnerable families for use of a product that we would never, ever consider using ourselves. It's just not true."

The sites of the experiment were chosen for their high lead levels, not to take advantage of people who lived there, Klag said.

And while the AP story said families in the Baltimore experiment weren't told of safety disputes and health complaints regarding use of treated sludge on land, Klag's school says it doesn't know of any research suggesting the compost itself poses a known risk to people.

"We used a commercial, off-the-shelf product that's highly regulated by both the federal and the state governments" and used widely at all levels of society, Klag said.

Mike Silverman, the AP's senior managing editor, said the story suggested the compost could be riskier than has been shown so far.

"It is a subject of scientific debate," Silverman said. "Many researchers believe the compost is safe, but there are some who believe it may be dangerous and should be studied further.

"The original AP story leaned too heavily on the latter view. That was unbalanced, and it created a distorted impression about the level of risk in the Baltimore experiment."

The compost, sold under the brand name Orgro, also contains wood chips and sawdust. It has been applied on virtually every golf course within 50 miles of Baltimore's composting plant, according to the company that operates the plant. It was also used several years ago on the the grounds of the vice president's official residence, according to a spokeswoman for the vice president's wife, Lynne Cheney.

Peter Lees of Johns Hopkins, one of the researchers involved in the 2000 experiment, said he wasn't aware of any question "from anybody anywhere" about using the compost at that time.

"It was a product you could get at Home Depot (and) garden stores," he said. "It met federal and state standards, so I guess at that point, what's the question?"

In technical terms, the compost contains "Class A biosolids," meaning it's been treated to cut germs to undetectable levels, and is rated "exceptional quality," indicating it meets certain requirements for heavy metal content. It's approved for use on lawns and home gardens.

Experts contacted recently by the AP generally said they didn't consider such material to be dangerous.

Klag said the AP story didn't clearly distinguish the compost from a different category of material, Class B treated sludge, which has been the object of some health concerns. Class B material can still have detectable levels of germs and isn't approved for lawns or home gardens. It's used to fertilize farmland, reclaim surface mines, cover landfills and help forested areas regrow after fire or erosion damage.

The AP story said there's been a lack of research into possible harmful effects from spreading treated sludge on land. It quoted the chairman of a National Academy of Sciences committee that looked into the practice as saying more safety studies are needed, and that sludge contains "potential pathogens and chemicals that are not in the realm of safe."

Related topic galleries: NAACP, Academic Progress, Standards, Environmental Pollution, Government, National Government, Metal and Mineral

• CONSTRUCTION

• ACCOUNTING

• DIAGNOSTIC TECH

• DRIVERS

• ADMINISTRATIVE ASSISTANT

• View all Top Jobs