Thank you for giving me the opportunity--on very short notice, however--to talk about an old problem with known solutions, but perhaps a timely problem for Canada and for Quebec.
I'll make it very simple. If you look at the screen, I've subdivided into two groups all microscopic organisms using photosynthesis. I have what I've called the “other algae”. The algae are mostly harmless, I would say. They're generally useful. They're part of the normal food webs. They're filtered by zooplankton, which is in turn eaten by small fish, eaten by large fish. So they're a part of the normal food webs.
I've called my second group cyanobacteria, and they are often harmful. They're generally inedible. They don't participate as much in normal food webs. They confer a bad taste, a bad odour to water. What's important to us here today is that they may produce toxins, toxins that cause skin irritation and symptoms that are like gastroenteritis. Also, they may affect the nervous system. Because of that, public health departments are aware of cyanobacteria. In Quebec at least, when they observe toxins in the water, they generally close the body of water to most uses.
On my next slide, I have taken a few pictures in lakes and compared them on a scale, which is phosphorus concentration in the water. It goes from 2 to 20 micrograms per litre. And remember that 1 microgram per litre is a very small quantity. It's about one thimblefull in an Olympic-size pool, so it's a very tiny quantity.
Phosphorus is an essential element. Every living organism needs it. But it is also a limiting factor in lakes. It limits the growth of life in lakes. At 4 or 5 micrograms per litre, rocks begin to be slippery with algae growth. At 8 to 10 micrograms per litre, we begin to see nuisance aquatic plants. Above 15 or 20 micrograms per litre, the water tends to turn pea-soup green or broccoli-soup green, as you prefer, but there's clearly too much phosphorus.
In Quebec, in the Laurentian lakes where I work, we tend to see cyanobacteria at phosphorus levels ranging between 8 and 10 micrograms per litre, cyanobacteria developing toxins that close down all the uses of a lake.
It's important to note that cyanobacteria are a natural phenomenon, especially in the shallow lakes that have surrounding soils rich in phosphorus. I took that picture in Alberta. There has never been any human development on the watershed, but you can still see cyanobacteria in this lake. So it's a natural occurrence.
The natural phosphorus loads to lakes and rivers are generally small. But it is an essential element, as I said. Naturally, it comes from atmospheric fallout, wet and dry fallout. It also comes from streams. Phosphorus is lost by forests, wetlands, beaver impoundments, and so on. So these are the natural sources of phosphorus in aquatic systems, and phosphorus concentrations are naturally low.
With regard to phosphorus pollution, humans have increased a lot the phosphorus concentrations in many aquatic systems. It's not a recent problem, it's an old problem, and there are many causes for it. In decreasing order of importance, I would say the first cause is unsustainable agriculture. By that I mean agriculture that has always maximized crop yield but never looked at the quality of the receiving waters. Phosphate in household detergents is also still a big problem, as is industrial urban effluence, by which I mean outdated sewage treatment facilities. Those are very common in Quebec at least; I don't know about the other provinces in Canada. As well, the use of fertilizers on lawns and gardens, deficient septic systems, excessive forest clearance in watersheds, and excessive residential development on lakeshores are all potential important sources of excess phosphorus in aquatic systems.
Some of these sources will be hard to deal with. It will take generations to fix the problem. Some, like phosphates in household detergents, we could get rid of within a few months.
In terms of solutions for excessive phosphorus, there are long-term solutions and short-term solutions. I think in the next generation or two we'll have to revise our agricultural system--that is, what should we produce, how should we produce it, and what is the best way to produce it without affecting the receiving waters?
As an example, in Baie Missisquoi on Lake Champlain, you're looking at about 100 square kilometres of water that contains far too much phosphorus, far too much algae, and far too much cyanobacteria. All the uses of that water, including skiing and swimming, are forbidden.
Again, let's look at Baie Missisquoi. I'll focus on that little spot just to indicate what I mean by sustainable agriculture. Looking at this small spot, magnified, I think in the next generation we will have to combine agriculture, silviculture, and forestry on wide buffer strips. The present buffer strips are about five metres, and they're not even enforced. We should do silviculture and forestry on wide buffer strips in order to combine spots that lose nutrients with spots of nutrient sources, the forest, in order to minimize phosphorus and nitrogen fertilizer losses to rivers, streams, and lakes.
Phosphorus in dishwasher detergent is an important source that we could easily deal with. In 1972 the Canada-U.S.A. agreement on Great Lakes water quality limited phosphorus in laundry detergent to 2.2%. Apparently, and I don't exactly know the reason, dishwasher detergent slipped through the cracks, as far as I understand the problem.
I've fooled around in the last few years measuring phosphorus in dishwasher detergents. Remember that about 55% to 60% of households now have dishwashers. Dishwasher detergents are still full of phosphorus, especially these new gel caps that are widely advertised on TV right now. They are the richest in phosphorus. I've calculated very roughly that dishwasher detergents can contribute from 5% to 20% of the phosphorus load from the average household.
That's a fairly big number. And I'm being very conservative here; countries like Switzerland estimate on the higher side, that 20% of phosphates now come from dishwasher detergents.
Several American states and some European countries have completely banned phosphorus from all household products. Other states, such as Massachusetts, right now have bills in front of their legislatures.
Read this:
No household cleansing product which contains a phosphorus compound in concentrations in excess of a trace quantity...shall be distributed, sold, offered or exposed for sale at retail...or used in a commercial establishment in the commonwealth after July 1st, 2010.
This is what is coming elsewhere in the world.
I'm going to ask a question: why are we behind in Canada?
That's all. Thank you.