6. Emerging Contaminants

Question 1

What are emerging contaminants? (2)

Answer 1

• Chemicals that are being manufactured for the first time
• Chemicals that have not historically been considered as contaminants, but now are

Question 2

Why were some chemicals not considered contaminants historically, but now are?

Answer 2

Because information now suggests that they are of concern.
Could be due to:
- widespread exposure
- persistence
- bioaccumulation
- toxicity data

Question 3

Why did we not know that these emerging contaminants that weren’t considered contaminants historically were contaminants?

Answer 3

• little data available
• analytical methods lacking

Question 4

Classes of emerging contaminants (7)

Answer 4

• pharmaceuticals
• personal care products
• nanomaterials
• flame retardants
• plasticizers
• rare earth elements
• microplastics

Question 5

What do we need to do more research on for emerging contaminants? (5)

Answer 5

• analytical methods development
• environmental occurrence
• sources and source pathways
• transport and fate
• ecological effects

Question 6

What do flame retardants do?

Answer 6

Flame retardants reduce the impact that fires have on people, property, and the environment

Question 7

Where are flame retardants found? (6)

Answer 7

• in home insulation
• in carpet padding made with recycled foam
• in upholstered furniture containing polyurethane foam
• in plastic casing of electronics
• in dust
• in some baby products (high chairs, diaper-changing pads)

Question 8

Examples of chemicals that have been used as flame retardants (4)

They are all toxic and bioaccumulate

Answer 8

• asbestos
• PCB
• brominated flame retardants (BFRs) (e.g. PBDEs - polybrominated diphenyl ethers)
• organophosphate flame retardants (OPFRs)

Question 9

Where are organophosphate flame retardants still used?

Answer 9

In furniture

Question 10

What are microplastics? (dimension)

Answer 10

smaller than 0.5mm

Question 11

What are nanoplastics? (dimension)

Answer 11

smaller than 100nm

Question 12

How can microplastics cause toxicity ? (4)

Answer 12

• physical (e.g. blocking gills, filling up your digestive tract so you feel full)
• tissue invasion leading to cellular stress
• leaching and toxicity of chemical constituents of plastics (e.g. UV absorbents)
• toxicity of chemicals that become stuck to the surface of microplastics