Soil Picture Mostly Murky
Soil study in St. John's suggests we'll find contaminants if we look
The Issue: Better Grasp Would Be Helpful
Three years ago, the City of Calgary released an environmental
study of the picturesque suburban subdivision of
Lynnview Ridge where residents had become concerned
about a possible legacy of contamination left when an
Imperial Oil refinery closed there in 1975. Sure enough, the report
documented levels of lead and benzene exceeding soil quality
guidelines of the Canadian Council of Ministers of the Environment,
setting events in motion that would culminate in a home
buyout costing Imperial tens of millions of dollars.
Among the findings that prompted immediate alarm was a lead
concentration as high as 1,260 milligrams per kilogram (or parts
per million) of soil, nine times higher than the CCME guideline
of 140. Lynnview Ridge thus entered the environmental lexicon as
an example where soil contamination in excess of the CCME
guidelines had led to costly remediation and relocation. Lynnview
Ridge stands in contrast, it could be argued, to the Muggah Creek
situation where so-called made-in-Sydney guidelines have been
used to rebuff calls for relocation and general remediation in the
perimeter of the steel plant and coke ovens footprint.
"It's shocking, isn't it?" said Lynnview resident Brad Smith
when the report on his neighbourhood came out. "How many other
1,200 areas are there?" Actually, there could be quite a lot that we
just don't know about. That's one implication from the recent work
of scientist Trevor Bell and his team at Memorial University in
St. John's whose soil testing in the Newfoundland capital last
summer has raised new concern about urban soil contamination.
The Bell group took 260 soil samples, finding elevated levels of
metals in playgrounds, parks, school grounds, open areas and
residential properties around the city. Sixty per cent of the samples
exceeded CCME guidelines for lead, and 26 per cent also exceeded
the more forgiving U.S. Environmental Protection Agency's guideline
of 400 parts per million for soil in play areas.
For residential properties in the downtown core, the median
value (half were higher and half were lower) was 1,076, about 7.5
times the CCME guideline, which puts the oldest part of St. John's
within the ballpark that caused such a commotion in Calgary. Bell
notes that the 60 per cent of tests exceeding CCME guidelines in St.
John's compares to only 25 per cent in Victoria, B.C., the only other
major city to have such a study done.
The numbers for the St. John's core appear to indicate heavier
lead contamination than generally showed up in soil tests around
the Sydney cleanup perimeter.
Bell's work so far highlights lead, a known neurological health
risk to children, which is assumed to be ubiquitous in urban environments
thanks to leaded gasolines (banned only in the 1980s)
and paints, as well as coal-burning, some industrial processes and
natural occurrences of the metal in bedrock. However, Bell's team
did test also for other metals, finding samples exceeding CCME
guidelines for arsenic, barium, beryllium, chromium, copper, nickel
and zinc. Only cadmium and cobalt stayed under the CCME numbers.
What does it all mean? To some it suggests a need for comprehensive
soil testing throughout urban areas of the country. Governments
are not eager to open such a potential Pandora's Box but
there are sensible, low-cost measures that could be taken to minimize
exposure to environmental contaminants if people were
more aware of what's actually around them. No one's suggesting
that we relocate Toronto.
A better grasp of the distribution of potentially harmful metals
and other manmade chemicals in the soil, water and air of typical
urban neighbourhoods, and what that means for human health,
would provide a helpful context when environmental alarms, such
as over the tar ponds or New Waterford hospital renovations,
spring upon the public as things unique and unprecedented.