Effective public policy must be based on a clear understanding of the problem and its relation to other issues, as well as public needs and behaviour."...almost 50% of all wind borne litter escaping from landfills in Newfoundland and Labrador is plastic, much of it single-use plastic bags....
There's the problem, defined neatly.
The quote is from Municipalities Newfoundland and Labrador's campaign against plastic shopping bags.
Put the quote in a search engine on the Internet and you will turn up all sorts of places, including news stories, that use that phrase or a slight variation on it in coverage of the popular campaign to ban plastic bags from the province. Here's an example from The Telegram in 2017 and another a couple of days later that went province-wide.
One small question: what's the source for the statistic?