Janet F. Bornman

Co-Chair, Environmental Effects Assessment Panel (EEAP) of the Montreal Protocol

Curtin UniversityPerth, Western Australia 6845Janet.Bornman@Curtin.edu.au

1

Workshop on Hydrofluorocarbon (HFC) Management

Montreal Protocol

Paris, 11-12 July 2014

Hydrochlorofluorocarbons (HCFCs)

Ozone Depleting Substances (ODS)Greenhouse Gases (GHGs)

Hydrofluorocarbons (HFC)

Greenhouse Gases (GHGs)

2

The effect of HFC and HCFCs on the biosphere

Do they have an effect on the biosphere?

UV-generated hydroxyl radicals (OH), determine the atmospheric lifetime of climate-relevant compounds including: HFCs, HCFCs, CO, NOx, and SO2, methane ….

3

The effect of HFC and HCFCs on the biosphere

Levels of complexity

UV radiation, ozone, climate, health, environment

HCFCs enter the body by inhalation of air, or by skin contact: breathing difficulties, skin irritation, may affect other internal organs

Ground-level O3, aerosols

UV

NOx Volatile organic compounds

Premature mortality (annual, global) ~1.5 million from particulate matter (sulfate, nitrate, most organic aerosols)~0.5 million from O3 (OECD, 2013)

Agricultural losses of $12-21 billion (Avnery et al., 2011)Complex sensitivity to UV radiation and climate

Air quality and UV radiation

Documented: Effects of decreased O3 and increased UV radiation

Not yet well documented:How will the environment/biosphere be affected by increased O3 and decreased UV radiation?

And how will climate interactions modify the response?

5

Predicted likely decrease in tropospheric OH

Lower OH implies slower removal of many important gases:

HFCs, HCFCs, other VOCs, methane, NOx, SO2

Ozone and climate implications

Trifluoroacetic acid (TFA), a breakdown product of HCFCs and HFCs in the atmosphere

Readily deposits to the Earth’s surface through dry and wet deposition

Some of the new hydrofluoroolefins (HFO, unsaturated HFCs) as replacements for HFCs can lead to increases

in TFA (HFO TFA)

6

The effect of HFC and HCFCs on the biosphere

Salt lakes with no outflow, loss by evaporation only Microbiological

degradation in soil and water

TFA

HFCs, HFOs, and HCFCsCF3-CXyH

O

CF3-C-OH

O

CF2Cl-C-OH

• Strong acid, forms salts with minerals in soil

• Concentrations in flowing water are small

• Accumulation will occur in salt lakes, playas and in the ocean

TFA - Environments at risk

7

8

The effect of HFC and HCFCs on the biosphere

Trifluoroacetic acid (TFA)

Phytotoxic - negative effects on plant growth

But concentrations not sufficient for observed effects

 

Time (days)-10 0 10 20 30 40 50 60

Leng

th o

f w

ater

milf

oil (

cm)

0

5

10

15

20

25

30

35Control 100 μg/L 1,000 μg/L 30,00 μg/L 10,000 μg/L

No significant effects on plants, even at

high concentrations

9

TFA and TCA

Control

10

The effect of HFC and HCFCs on the biosphere

Trifluoroacetic acid (TFA)

Phytotoxic - negative effects on plant growth

But concentrations not sufficient for observed effects

 

Anthropogenic sources

Atmospheric degradation of some HCFC and HFCs

Atmospheric degradation of narcotics

Trifluoromethyl containing pesticides, aluminum production

 

Natural sources

Underwater hydrothermal vents (?)

11

Approximate concentrations of TFA

•Switzerland, Fresh water lakes, springs, rivers: ca 100 ng/L

•USA, Fresh water lakes, springs, rivers: 20 – 140 ng/L

•Europe, Rain water: 0 - 1.5 µg/L

•Oceans: 10 – 200 ng/L

Depositions of TFA largest during the growing seasons

Summary

• HCFC has potential negative health effects

• TFA is not bioaccumulative

• Risks to mammals, including humans, aquatic and terrestrial organisms: negligible

• TFA sources (natural and anthropogenic) and cycling through the biosphere should be considered for their environmental impacts

• Continuing monitoring of TFA in the environment may be required if HFOs are significantly increased to replace HFCs

12

Summary

WMO Assessment of Ozone Depletion (2007):

“TFA from the degradation of HCFCs and HFCs will not

result in environmental concentrations capable of

significant ecosystem damage.”

13