A new study says just because something is organic doesn't mean it is better for the environment than a synthetic product -- as far as pesticides go, anyway.
The report out of the University of Guelph in Ontario, Canada finds that some organic pesticides can have a more damaging environmental impact than conventional pesticides because the organic products are inherently less effective.
"The consumer demand for organic products is increasing partly because of a concern for the environment," said Rebecca Hallett, one of the study's authors. "But it's too simplistic to say that because it's organic it's better for the environment. Organic growers are permitted to use pesticides that are of natural origin and in some cases these organic pesticides can have higher environmental impacts than synthetic pesticides often because they have to be used in large doses."
The study, which is published in the journal PLoS ONE, involved testing six pesticides -- four synthetic and two organic -- and comparing their environmental impact and effectiveness in killing soybean aphids.
"We found the mineral oil organic pesticide had the most impact on the environment because it works by smothering the aphids and therefore requires large amounts to be applied to the plants," said Hallett.
Another problem -- the organic products also killed ladybugs and flower bugs, which are important regulators of aphid population and growth. These predator insects reduce environmental impact because they naturally protect the crop, reducing the amount of pesticides that are needed, she added.
"Ultimately, the organic products were much less effective than the novel and conventional pesticides at killing the aphids and they have a potentially higher environmental impact," she said. "In terms of making pest management decisions and trying to do what is best for the environment, it's important to look at every compound and make a selection based on the environmental impact quotient rather than if it's simply natural or synthetic. It's a simplification that just doesn't work when it comes to minimizing environmental impact."