Hazard vs. risk analysis a vital distinction to make

Editor’s note: This editorial is updated from an earlier version to address the terminology of hazard versus risk, and is a correction of the print version.

The tug-of-war between conclusions based on hazard versus risk studies continues.

The most recent example is the University of Saskatchewan study that shows that canola seed coated with imidaclophrid — a type of neonicotinoid — can affect songbirds.

The study found that songbirds showed significant loss of body mass, lethargy, loss of appetite and disorientation when they eat coated seed.

That surely requires a closer look. No one wants to see birds affected in such a manner.

It’s alarming, but the study used what’s known as the “hazard-based” approach — what otherwise is known as laboratory conditions.

On the Prairies, imidacloprid is mainly used on wheat crops to control wireworm. As manufacturer Bayer points out, other studies that are risk-based — that is, using conditions closer to reality — show birds aren’t interested in imidacloprid-treated seeds when other food is available because of the repellent properties of the seed coating.

So, when birds are out in the field, they will look for other sources of food, rather than unhappily ingest seeds coated with imidacloprid and other compounds.

We’ve also seen this hazard-versus-risk debate play out in the use of glyphosate in farmers’ fields.

The World Health Organization said in 2015 that glyphosate is “probably carcinogenic to humans” — using the hazard-based approach. But other organizations, including the Canadian Food Inspection Agency, looked at conditions that were closer to the real world — the risk-based approach — and concluded that glyphosate is “unlikely to pose a carcinogenic risk to humans from exposure through diet.”

Still, the herbicide barely survived in Europe recently because Germany supported its continued use at the last minute, much to the chagrin of France, where President Emmanuel Macron has promised to ban glyphosate within three years, despite reputable studies that show it is safe when used as recommended.

Lab tests versus real-world conditions is an important debate.

Hassan Azia, associate dean of academic affairs at the College of Arts and Sciences and director of biomedical science at Qatar University, recently wrote a paper on this debate. In this case, he was looking at human behaviour, but his paper shows his observations of field-versus-laboratory research are applicable pretty much across the board.

In a paper published in April, Azia noted that, “whilst field research offers contextual data on settings, interactions, or individuals, controlled laboratory research is basic, repeatable.”

He concluded that “the most fruitful overall research approach is usually to use both: laboratory and field research.

“The results of controlled experiments produce new approaches or hypotheses to be tried and investigated in the field. Conversely, observations in the field produce new hypotheses to be tested by controlled experiments.”

Health Canada has proposed phasing out imidacloprid over three or five years. A decision on that proposal is pending.

It’s important to note there is no alternative chemical replacement to imidacloprid at the moment, though possible alternatives might be on the way.

If Health Canada is going to move on imidacloprid, it could consider restrictions only in regions where there is a real world problem. This would be a practical approach. New studies could then determine the effect of the restricted regions versus where it’s still being used.

That way, the full spectrum of science — hazard and risk — would be the determining factor in any further action.


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