Through the chair, thank you very much for that. Dr. Rochman would be able to complement any response I might offer.
I will say that, in general terms, we feel as though 80% of ocean pollution comes from land-based activities. There's no question that plastics and microplastics are entering waterways throughout our terrestrial environments and paddling to the sea. They're heading down to the sea, where we suffer the consequences.
In terms of the source of microplastics in particular, we're very concerned about waste-water treatment plants that discharge liquid effluent containing microplastics. In Vancouver, we have five major waste-water treatment plants. One of those, the largest, releases an estimated 30 billion particles of plastic every single year. That represents less than 5% of the microplastics that enter the plant. Much of that is from our clothing. We lose 10 million fibres every time we wash a single load of laundry, and that enters the waste-water stream.
Ninety-five per cent of those fibres are retained as solid waste and redistributed under federal policy, CCME policy and provincial legislation as biosolids. They're spread onto farmlands, in mining reclamation and in silviculture. Those plastics are not degraded. We now have microplastics throughout our farms. They will ultimately drain slowly but steadily into our waterways, where they can affect spawning salmon and other wildlife downstream.
Big sources on land are absolutely associated with our activities as humans.
