UN Report States That Biodegradable Plastic Breakdown In Oceans Extremely Slowly
Biodegradable plastics are not degraded in the marine environment as previously expected to be, a United Nations report has found. This is contrary to popular belief of biodegradable plastic such as plastic bags and bottle being more susceptible to degradation.
According to the team of top environmentalists, who prepared the report, biodegradable plastics are not meant to solve the problem of ocean litter since most of the plastic content remains extremely durable for months.
Biodegradable plastics were once considered to be an alternative that could help reduce the tonnes of litter that settle down at the bottom of the oceans. However, the rate at which such self-degrading plastics break down primarily depend on the environmental conditions.
In fact, there is no scientific proof or evidence that biodegradation of such items could take place at a faster pace than any other non-biodegradable plastic made from unmodified polyethylene.
In a marine environment, UV irradiation is the primary weathering agent. While the radiation is quite pronounced along the shorelines of the sea or the ocean, its intensity decreases at the base. Therefore, plastic present along the shoreline degrades rapidly. However, the material present at the base of the ocean is subjected to "extremely slow" degradation due to reduced oxygen levels and temperature, in addition to decreased UV exposure.
According to the environmentalists, biodegradable plastics often require temperature around 122 Fahrenheit to completely break down into its individual constituents such as methane, carbon dioxide and water. This sort of temperature is usually present in industrial composters.
The team further believes that the "biodegradable" label itself encourages people to overuse them and pollute the water bodies. Such "microplastics" and the debris derived from low-density plastics tend to get distributed throughout the Antarctic and the Arctic with the help of water currents.
