Working through all my observations of beach litter my focus is drawn to the length of time that our litter will last on our beaches and floating in the seas.
The time line for the existence of litter into the future is something I am grappling to understand. Figures vary hugely for instance on many educational websites for schools covering organic waste such as Oranges & bananas Orange peel upto 2 years cigarette butts 1-5 years, plastic coated paper 5yrs, plastic bags 10-20years, nylon fabric 30-40yrs, aluminum cans 80-100 years glass bottles 1million years, plastic bottles indefinitely. Other sources predict little breakdown of tough plastics (boxes etc) in 10’s of thousands of years. Such figures are generalised projection estimates for degrading in the environment.
Many scientific organisations are trying to shed light on biodegrading of different materials specifically in the marine environment , one such research body is published by the Center for Microbial Oceanography: Research and Education (C-MORE) in Honolulu, USA, they have calculated an estimate below with which I intend to use over the next few days as I set about trying to date how long the litter on our beaches will exist with the help of pupils and residents along the coast.
Marine Debris Biodegradation Time Line
Item |
Time to degrade |
|
Paper towel |
2-4 weeks |
|
Newspaper |
6 weeks |
|
Cardboard box |
2 months |
|
Waxed milk carton |
3 months |
|
Apple core |
2 months |
|
Cotton gloves |
1-5 months |
|
Wool gloves |
1 year |
|
Plywood |
1-3 years |
|
Painted wooden sticks |
13 years |
|
Photo-degradable beverage holder |
6 months |
|
Plastic beverage holder |
400 years |
|
Plastic bags |
10-20 years |
|
Plastic bottle |
100 years |
|
Glass bottle and jars |
undetermined |
|
Disposable diapers |
50-100 years |
|
Tin can |
50 years |
|
Aluminium can |
200 years |
|
Monofilament fishing line |
600 years |
|
(Mote Marine Laboratory, 1993) |