Bear in mind that the denominator is plastic pollution. Most plastic waste does not directly pollute the environment. If it is not recycled then it goes to landfills or incineration. Not ideal, but at least the damage is contained. (The bulk of ocean plastic comes from the rivers of poor countries without proper waste management.)
The issue with tyre microplastics is that it’s all but impossible to channel the waste. It’s the same with synthetic fabric: just washing it creates pollution that’s really hard to control.
Tyre dust vacuum car, just add HEPA filter:
Filtering clothes washer wastewater is even easier.
Yes the washer wastewater should be easy in theory. But to filter the really small particles you’d need an expensive HEPA-equivalent filter that has to be regularly changed. Needless to say, none of this is happening in practice.
Filtering tyre dust is always going to be a haphazard proposition. This interesting contraption notwithstanding.
(The bulk of ocean plastic comes from the rivers of poor countries without proper waste management.)
This might be true for places nearer to shore, but studies have found the great Pacific patch to be mostly discarded fishing gear by weight.
Yes I’ve seen this factoid too, but I struggle to see how it could be true. We’re comparing theoretically non-disposable kit from individual boats with the output of a large number of massive rivers in countries with populations of hundreds of millions (in particular Indonesia and Philippines) and a terrible habit of dumping trash in waterways. The amount reaching the ocean must by definition be huge.
Of course, the main problem with discarded fishing nets is not that they are plastic but that they destroy the ecosystem by design. Maybe the two harms have been conflated.
I also struggle with it, but the research I’ve seen is that it’s the majority by weight. Microplastics wouldn’t get picked up, so they’d be really hard to be weighed.
Then again, these big pieces will be shedding microplastics all the time so maybe they’re contributing to it as well.
Either way, we’ve got two problems: Plastic runoff from rivers and fishing gear disposal. And both, I think, could be solved by simply providing cash for people who can verifiably dispose of plastics. Check out some nets and floats and line, check in a certain amount and you get money back. Because people are greedy and stupid we need to incentivize cleaning things up.
