The loosening of rules around spreading sewage sludge – potentially laced with pharmaceuticals like Viagra – on Ontario farm fields has critics sounding the alarm about potential health risks.
While the sludge, a mix of household and industrial waste, has been used as a crop fertilizer for years, recent regulatory changes have made it easier for farmers to use.
The province insists any pharmaceuticals found in the sludge are at levels that meet safety standards, but critics are crying foul.
“It so does not make sense to allow the kinds of contaminants that are routinely in sewage sludge ... onto our farm fields, to allow them to be put on pasture land where cows graze that give us milk,” said Maureen Reilly of the group Sludge Watch.
“We have pink-ribbon campaigns to stop breast cancer, but we’re deliberately putting poisons on our foods.”
Some 35 to 45 per cent of the municipal biosolids generated in Ontario – 300,000 dry tonnes – are applied to agricultural land. The bulk of the sludge is distributed to farmers for free.
Sludge was recently classified as a nutrient, and the management of its use shifted to the Ministry of Agriculture from the Ministry of the Environment. That means it’s classified as a type of manure instead of treated under waste management rules.
That means it’s harder to track where the sludge is being spread, and also lets it be applied at higher levels, Ms. Reilly said. Environmentalists find that highly concerning given the Walkerton water tragedy and outbreaks – some deadly – of E. coli, salmonella and Listeria.
While there may not be exhaustive research done on the direct impact of food grown in sludge, anecdotal evidence suggests people who live near farm fields fertilized with sludge have gotten ill, as have their animals, Ms. Reilly said.
Just because the resources aren’t always there to fully investigate the complaints it doesn’t mean they shouldn’t be taken seriously, she added.
“People who live near sludge spreading do report illnesses,” she said.
The most common complaints include irritated nasal passages, headaches, lethargy, rashes, vomiting and fevers.
In the U.S., there is a 38-month waiting period before a farmer can harvest if using sludge. Quebec and Nova Scotia don’t allow one of the types of sludge spread in Ontario to be used on their fields.
NDP health critic France Gelinas, whose hometown of Sudbury recently received a $10-million federal grant to process its sludge into fertilizer, says that while some sludge may be safe it’s not all created equal, and those distinctions need to be studied.
Sudbury is a mining town, she notes, and its mines use the same sewers as households do.
“The concentration of heavy metal, the concentration of mine residue in Sudbury sludge is way higher than it would be (elsewhere),” Ms. Gelinas said.
“If you’re next to a big hospital then you would have whatever’s being flushed down the drain in the hospital, from people being sick to... well, you get the idea.”
She would like the government to impose a moratorium on the use of sludge on farm fields until more is done about its potential health effects.
No new study has been financed by the provincial government to look at the issue, she added, and yet the province has paid municipalities to turn sludge into fertilizer.
“It’s very one-sided, even though we don’t have the science to tell us that the sludge is safe,” she said.
Provincial agriculture Minister Ted McMeekin said there was ongoing research to evaluate the benefits and assess any potential risks of using sludge as a nutrient source for crops, and the regulatory requirements and strict standards governing its use reflect the latest scientific knowledge.
“Research to date has shown that the concentration of a variety of pharmaceuticals found in run-off from biosolids-treated fields is significantly lower than levels that would cause any known health or environmental effects,” he said.
“As an added level of protection, waiting periods of up to 15 months are required before fruit and vegetable crops may be harvested after treated sewage biosolids are applied.”