The federal government has announced its intention to ban single-use plastics as early as 2021.
Less than 10 per cent of plastic used in Canada is recycled.
Trudeau said it is "tough" trying to explain the problem to his own children.
In April, a carcass of a pregnant sperm whale washed up in Italy with 22 kilograms (49 pounds) of plastic in its stomach.
Studies and real-world experience suggest, for example, that while banning plastic grocery bags obviously decreases their use, it simultaneously increases the use of such things as plastic garbage bags, which are thicker, paper bags and cotton bags.
Canada's decision comes following the establishment of an Ocean Plastics Charter announced by Trudeau at the G7 conference a year ago.
The government said it will also aim to introduce standards and targets for companies that manufacture plastic products or sell items with plastic packaging so they become responsible for their plastic waste.
At least 100 undigested boba pearls found in girl's stomach
Most people would either recommend eating bubble tea pearls by the pound or are completely weirded out by their chewy texture. In China, a teenage girl was hospitalized after doctors found over 100 bubble tea balls trapped inside her stomach.
Canada's biggest advantage as a producer of plastics is its abundant cheap natural gas feedstock and that won't change under the proposed ban, said Ashish Chitalia, principal analyst for polyolefins for consultancy Wood Mackenzie. That compares with current world demand of roughly 100 million barrels daily.
In Toronto, Environment Minister Catherine McKenna announced the ban surrounded by people holding photos of garbage-strewn beaches and oceans, and turtles and birds entangled in plastic waste and fishing nets.
Canada said it was waiting until 2021 to allow for a "science-based" decision on exactly which plastics "are harmful to the environment and human health".
Eight years ago, the ACT banned single-use plastic shopping bags - and now the territory is taking aim at a range of other single-use plastics.
The proposals are expected and are generally supported by the sector, which is seeing a five-year high in capital spending this year thanks in part to incentive programs by federal and provincial governments, said Isabelle Des Chenes, executive vice-president of the Chemistry Industry Association of Canada.
Microplastics often come from larger plastics breaking down. Without a change in policy, the amount of annually discarded plastic materials will reach a value of $11 billion by 2030, the government said. This represents up to $8 billion per year in lost value and wastes valuable resources and energy.
"Copol International is a forward-thinking business that's developing biodegradable food packaging", Trudeau said.
Recycling, he said, would not only cut down on pollution but would help produce 42,000 jobs in the recycling and recovery businesses. May had urged other Commonwealth countries to follow suit, but at the time Trudeau was reluctant to make that promise.