Prometheus 6

In a 1978 memo, the EPA said sludge "contains nutrients and organic matter which have considerable benefit for land and crops" despite the presence of "low levels of toxic substances."

But in the late 1990s the government began underwriting studies such as those in Baltimore and East St. Louis using poor neighborhoods as laboratories to make a case that sludge may also directly benefit human health.

Meanwhile, there has been a paucity of research into the possible harmful effects of heavy metals, pharmaceuticals, other chemicals and disease-causing microorganisms often found in sludge.

Sludge tested as lead-poisoning fix
By JOHN HEILPRIN and KEVIN S. VINEYS, Associated Press Writers
Sun Apr 13, 6:54 PM ET

Scientists using federal grants spread fertilizer made from human and industrial wastes on yards in poor, black neighborhoods to test whether it might protect children from lead poisoning in the soil. Families were assured the sludge was safe and were never told about any harmful ingredients.

Nine low-income families in Baltimore row houses agreed to let researchers till the sewage sludge into their yards and plant new grass. In exchange, they were given food coupons as well as the free lawns as part of a study published in 2005 and funded by the Housing and Urban Development Department.

The Associated Press reviewed grant documents obtained under the Freedom of Information Act and interviewed researchers. No one involved with the $446,231 grant for the two-year study would identify the participants, citing privacy concerns. There is no evidence there was ever any medical follow-up.

Comparable research was conducted by the Agriculture Department and Environmental Protection Agency in a similarly poor, black neighborhood in East St. Louis, Ill.

The sludge, researchers said, put the children at less risk of brain or nerve damage from lead. A highly toxic element once widely used in gasoline and paint, lead has been shown to cause brain damage among children who ate lead-based paint that had flaked off their homes.

The researchers said the phosphate and iron in the sludge can bind to lead and other hazardous metals in the soil, allowing the combination to pass safely through a child's body if eaten.

The idea that sludge — the leftover semisolid wastes filtered from water pollution at 16,500 treatment plants — can be turned into something harmless, even if swallowed, has been a tenet of federal policy for three decades.