plastic pollution

Question 1

Facts

Answer 1

8 million tonnes of plastic gets in the oceans per year

Question 2

Microplastics

Answer 2

small plastic particles
primary microplastics- manufactured for use as small particles e.g. microbeads in toothpastes, cosmetics
secondary microplastics- particles produced by breakdown of larger plastic materials- litter, clothing

Question 3

Sewage sludge

Answer 3

formerly routinely dumped at sea
now used as a soil improver for agricultural systems on a very large scale, especially in the UK
sludge application delivers microplastics to soils- up to 15,000 particles/kg reported
stabilisation or large scale transport to aquatic systems both possible
microplastics have been shown to reduce fitness of soil invertebrates

Question 4

How do different polymers behave in different environmental conditions?

Answer 4

some less dense than water/sea water, some more dense
gather biological fouling, and properties change
durable but gradually break own
degrade with light weathering
contain some potentially dangerous substances but can absorb others in the environmen.

Question 5

How could intake or ingestion of small plastic particles could potentially damage a filter feeding organism?

Answer 5

satiation- feeding restricted or stopped by sensing food particles as prey
obstruction of digestive tract or gills by plastics particles
inflammation in tissues (digestive tissues or gills) in contact with microplastics
exposure of contaminants- harmful chemicals associated with plastic
absorption of nanoplastics- potential retention of tissues

Question 6

What are the risks?

Answer 6

uptake by biota- potential risk to ecosystems
human ingestion- seafood, water, air
little knowledge of toxicology- lab studies on biota often concentrations which are not environmentally relevant
risks likely to increase over time
nanoplastics scarcely understood

Question 7

United Nations resolution (Dec 2017)

Answer 7

aims to:
eliminate marine litter in the long term
urges counties to take action by 2025, to “prevent and significantly reduce marine pollution of all kinds” and “encourages” them to “prioritise policies” that “avoid marine little and microplastics entering the marine environment”
over 50 countries have signed up voluntarily to #CleanSeas campaign since its launch in Feb 2017

Question 8

Progress

Answer 8

plastic bag charges
microbeads ban 
restrictions on straws 
disposable cutlery
research funds 
UN 'Clean Seas' scheme
UK Environment Bill 2021