What's bugging you this week?
Is it the fruit flies in your bananas? Is it the little black bugs in your African violets? Or is it the thought of all those dandelions that will soon spring forth in your front lawn? Would you use pesticides to get rid of any of these problems?
Many homeowners consider a quick fix with a spray of chemical or a good dousing of some kind of poison as the best way to rid themselves of the pests that share their environment. Others are trying to find new biochemically less toxic ways to keep the creepy crawlies and fast-growing pests out of their home and garden. All of us, the quick fixers and the environmentalists, soon find there are no easy answers.
"The world has to really think this through. We have to consider, what's our role in this?" says Margaret-Ann Armour, an associate dean of science at the University of Alberta who's done extensive research on pesticides and their disposal.
Armour spoke Wednesday at the Telus World of Science in Edmonton about the effects of various environmental toxins such as DDT and the herbicide 2,4-D. She balanced her discussion by also explaining the consequences of banning their use.
Lives saved
Too often the world has used lethal killers with little or no thought, Armour said, as she talked specifically about DDT.
Armour's statistics showed that in 1946, before the use of DDT, Sri Lanka had 2.8 million cases of malaria out of a population of 6.5 million. In 1963, with DDT in use, there were only 17 cases of malaria. In 1968, after the chemical was banned, there were one million cases of malaria and by 1969, 2.5 million cases. Last year, it was estimated that 655,000 people would die from malaria.
"The World Health Organization estimates that DDT saved 25 million lives," Armour said.
A chemist, Armour repeatedly stressed that she supports the 2006 Stockholm Convention initiative that advocated for the partial use of DDT inside homes in those countries plagued by malaria.
She also explained that last year, where it was allowed, there were repercussions to the entire food chain and inevitably to human health.
"You have DDT in your body. I have DDT in my body. Polar bears have been tested and they have DDT in their system," she said, adding that though DDT was never used in the Arctic, the substance moves globally on oil-coated dust particles blown on the wind.
"In every instance, for every pesticide, we have to think, what is this pesticide going to kill, not just now, but what is it going to change into that may be more or less toxic to animals or to humans?"
Home and away
Amour brought her message home by discussing the use of 2,4-D to kill broad-leafed weeds such as dandelions. The chemical is commercially sold as Killex.
Armour said she has learned to live with dandelions in her lawn, but argued that what she lives with and what the world can live with may be different. The main use for 2,4-D is for weed control in crops such as grain cereals, sorghum and rice. Increasingly, food quantity and food quality is a worldwide concern, not just for farmers, but also for every human.
The pesticide 2,4-D is not a carcinogen but it has been connected with endocrine disruption in humans.
"Endocrines involve our hormonal system. That means we should be concerned about the use of 2,4-D because of its effect on very young children. But before you say, 'ban it' you must consider how it affects others in the world, not just us," Armour said.
Plant variety
In previous years, Armour said, she used Malathion to kill bugs on her garden roses.
"But no more. Malathion is toxic to bees," she said.
Armour switched her gardening practices and now tries companion planting. She plants marigolds and garlic near her roses to discourage aphids. Mint, planted in pots also repels aphids and basil plants repel mosquitoes. Yarrow is said to attract aphid-eating ladybugs.
But Jim Hole of the Enjoy Centre said that instead of planting things to repel insects, gardeners need to turn the problem inside out and think of ways to attract beneficial insects.
"Instead of thinking about companion planting, think about adding diversity," Hole said. "Sure marigolds may keep some insects away but I don't advocate for plants because they keep out bugs. Instead, plant lots of diverse plants to attract beneficial predatory insects."
Homeowners and gardeners have to discover and examine their own level of tolerance regarding bugs, Hole said.
"So you have ants. You have to go back to why they bother you. If they are in your sidewalk, who cares? Is it because you are afraid of insects? Or maybe you want to get rid of them because you have feelings that you haven't done the job right and therefore you have ants? If ants are in your house, you have to trace where they come from and seal the house against them," he said.
As for dandelions, Hole said the gardener can choose to leave them alone, use 2,4-D or use a chemical called chelated iron to build up the soil. The invigorated soil means the grass will crowd out broad-leaved plants.
Hole said that maintaining a pesticide-free garden requires a three-pronged strategy of growing a varied number of species, attracting and then living with some insects and finally keeping the plants healthy and well tended in good soil.
"There is passion on both sides of this argument and sometimes it's too simplistic to say, 'I'm not going to use pesticides,'" he said.
"The thing is, for a person in America it's nice to worry about ospreys. If you were a person in the Third World whose child is in danger of dying from malaria, you would worry about that before you worried about the birds."
