Lecture 28: Macroplastics & Microplastics

Question 1

What is the great acceleration of human activity?

Answer 1

Due to industrialization, all aspects of human civilization have increased:
- population
- gdp
- water use
- motor vehicles

Question 2

What is rafting of marine species?

Answer 2

When marine species (barnacles, worms, molluscs) attach themselves to floating objects to move around

Question 3

What effect does ocean litter have on marine rafting?

Answer 3

Marine species now attach themselves to floating trash which enables raft dispersal to hugely increase

Question 4

What are microplastics?

Answer 4

Small (<5mm) polymer particles including beads, pellets, flakes, and fibres.

Question 5

Where do microplastics come from?

Answer 5

• Fragments of larger plastic debris
• manufactured for industrial use (microscopy/biotech)
• manufactured fpr domestic use (cosmetics/textiles)

Question 6

What do we know about microplastics found in the St Lawrence?

Answer 6

• most originate from cosmetics (due to size, shape, chemical composition)
• some originated from industrial sources
• microbeads occur pretty much everywhere
• rivers can act as a sink for microplastic pollution.

Question 7

Ex: if the avg person uses 1.5g of toothpaste per brushing (24.8M ppl in Canada) and 35% of toothpaste contains 3% polyethylene, how much plastic is flushed?

Answer 7

1.5g * 2 (twice per day) * 24.8M people * 0.35 * 0.03 = 781,200 g/day (285 tonnes/year)

Question 8

What is the concern of microplastics ended up in waterways?

Answer 8

small enough to be ingested by animals (can affect their physiology and behaviour) –> can also contain toxins/contaminants that affect the animals and possible humans through marine seafood consumption