Wednesday, July 25, 2012

Ocean Trash - It's Not What You Think

The Ocean Conservancy assembled nearly 600,000 volunteers recently to pick up trash from coastlines around the world. Considering that we are pelted nearly daily with "reports" about how much plastic packaging there is in the various garbage patches around the world, I was quite surprised by this graphic of the most commonly found items:
Cigarettes? The number one item by far was cigarettes, outnumbering plastic caps by almost a 2-1 ratio. I certainly didn't expect that.

The filters of most butts are made of cellulose di-/tri-acetate which has a specific gravity of about 1.3, which suggests that the butts sink rather than float and hence have a difficult time making their way to the great garbage patches.

The efforts to fight pollution are mostly based on visibility of the pollution. "Out of sight, out of mind" is never more true. The butts sink and it's tough to get people fired up about them, even though they are the most common type of ocean trash. But plastic packaging floats and is visible, and it will remain visible even if it is biodegradable. And that's why I don't believe biodegradable plastics will do anything to change public perception about plastic waste. As long as people can see the plastic waste on the coastline, the biodegradability will do nothing to change their perception of it.

Since plastic pollution is leading to cities banning bags and bottles, the same logic would lead us to also be considering a ban on cigarettes. Somehow I don't see that happening, as the tobacco industry is far more powerful than the plastics industry in lobbying against such bans.

4 comments:

Brandon said...

Cigarettes are a lot smaller than plastic bottles or tin cans though, something that the chart doesn't convey (the unlabeled axis looks like frequency).

I wonder how their impact compares vis a vis toxicity vs. sheer mass.

Anonymous said...

Regarding the impact of biodegradable plastics on perceived pollution/litter levels:

I would think that a biodegradable plastic would have a lower "steady-state" concentration than non-biodegradables? Or are you suggesting that the time-scale for biodegradation is still long enough (presumably for performance reasons?) that any effect on this "steady-state" concentration would be minimal?

Anonymous said...

Polylactic acid, aka PLA, will not biodegrade in the ocean any faster than regular plastic - it requires high heat to biodegrade. The commonest bioplastic is just a scam. Look it up if you doubt this.

John said...

Anonymous @ 2:15 -

You take a swipe at a lot of points in a small period of time!
Yes, "biodegradability" does have a "legal" definition, and in order to meet it, PLA needs to be composted, and generally in an industrial compost from what I've read - a home compost pile won't do it. Does that make it a scam? I am not so sure, as the PLA suppliers certainly are toeing the line carefully about what they claim. Does that prevent others from mistaking what is claimed and overhyping it's biodegradability? No, certainly not, and so that's where the "scam" comes from as I see it.

Regardless, PLA will biodegrade faster than other plastics such as PET or polystyrene, irrespective of the temperature.