Sludge Watch ==> Univesity Prof Warns Against Use of Sludge on Farmland

[Maureen Reilly]

http://www.communitypress.ca/ArticleDisplay.aspx?e=955376&auth=Bill+Tremblay


March 24, 2008
University professor warns against use of sludge on farmland
Bill Tremblay
The Community Press
Trenton Ontario Canada

Trenton – The use of sludge in farming is allowing toxins to enter food 
sources, says a university professor who has studied the effects of 
chemicals and toxic metals in soil and how they could pose a threat to the 
environment and food chains.

"I estimate there are 10 to 15 metals in sludge that could be harmful," Dr. 
Murray McBride of Cornell University said during a public forum held at St. 
Peter’s School in Trenton March 19.

McBride delivered a presentation on sludge and its effects during the forum, 
hosted by the National Farmers Union, Quinte Watershed Cleanup, Canadian 
Organic Growers, and the Safe Water Group.

McBride is a professor of soil chemistry in the Department of Crop and Soil 
Sciences at Cornell University in Ithaca, New York.

"The application of sludge is not sustainable," McBride told the crowd of 60 
people who attended the forum. "Eventually soil will reach a point where it 
can't take any more."

Sludge is a concentrate left over from sewage treatment which is used as a 
low-cost nutrient-rich fertilizer. In Ontario, 300,000 tonnes of sludge is 
applied to farmer's fields per year. In every case study, the use of sludge 
has shown an increase in soil dioxin levels. Increased levels of cadmium, 
lead and mercury have been found as well which are harmful to people. 
Molybdenum levels have also increased which can cause disease in livestock.

"If you have a farm that's applying sludge, and you are grazing dairy cows, 
there is a good chance some of the contaminants are making their way into 
products from your farm," McBride said.

McBride explained that contaminants in sludge enter the soil which are then 
passed on to plants and livestock and through them to the consumer of the 
products.

"Health effects are long-term and difficult to prove," McBride said. "A 
long-term study would have to be done, and realistically that will never 
happen."

Conducting a study on the effects of the toxins on humans would be 
"virtually impossible," McBride said, because of the cost of the research. 
The effects could include cancer and damage to reproductive health.

"If you are not going to be able to say the product is reasonably safe, then 
you have to keep the toxins out of the food chain," McBride said. "We can't 
wait to see if there is a problem down the line."

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Methods of safely disposing of sludge seem to be non-existent and the damage 
the substance causes to soil is nearly irreversible, he said.

"I have had some luck using willow shrubs to drain the contamination," 
McBride said.

Bob Orrett, an organic farmer in Trent Hills, said sludge is widely used in 
the Quinte area.

"There are a lot of people who are concerned about it being applied near 
their homes," said Orrett, who chaired the forum.

Orrett said there is local concern about air-born toxins causing sickness, 
and contaminants entering water sources.

"I have several friends who are farmers that use sludge," Orrett said. "It's 
not a topic we normally talk about."