Sunlight breaks down plastic more than previously thought

More than 150 million tons of plastic waste pollutes the world’s oceans today and adds about eight million tons each year. Most of it sank to the sea floor, but nearly 400,000 tons of plastic is believed to be floating on the surface. Durable plastics are pulverized into microplastics by wave motions.

It’s so bad – it ends up in animals and humans. But many plastic bags in the ocean do not stand up to the microplastic scale. From American researchers Woods Hole Oceanographic Institute (WHOI) It was found that floating bags can be released even under 15,000 different, water-soluble materials under solar radiation.

According to WHOI researcher Colin B. Ward, sunlight can break down plastic into a single compound with a few compounds that can dissolve in water into tens of thousands of compounds. One has to think not only about the effects of plastic particles, but also about the transformation of these materials.

The effects of ecosystems are unknown

Anna Walsh, the study’s lead author, gained initial insights, Ward and other colleagues are now in a detailed analysis of the decomposition of plastic bags under sunlight. To this end, they examined the degradation of pure polyethylene compared to plastic films made from plastic bags, to which various additives such as calcium carbonate and titanium dioxide were added.

Scientists simulated decomposing under natural sunlight in water tanks in an open-air laboratory. The most powerful mass spectrum is am National High Magnetic Field Laboratory In Tallahassee, Florida, they were able to determine the number of different items after a few weeks of decomposition.

Plastic bags were inspected

Depending on the size and type of additives for pure polyethylene films, the amount of water-soluble decomposition material will vary considerably. In the case of pure polyethylene, researchers were able to find 9,000 different materials. Researchers have documented 15,000 items in plastic bags from Walmart, the largest American business group. “We don’t even know what effects all of these substances have on aquatic ecosystems or on biochemical processes such as the carbon cycle,” says Ward.

The ward sees rapidly decomposing plastic types – a positive effect against plastic flooding at first glance – very critically. Therefore more research is needed to determine the effects of degradation on ecosystems.

But this study clearly shows that the decay of plastic films depends on the type and size of the compounds. In principle, it is possible to create plastic films that degrade eco-friendly materials as quickly as possible. But it is much better, more effective and cheaper than this purely technical solution to avoid plastic waste and establish a controlled and closed recycling cycle.

(jle)