Impacts of Climate Change on Cycling, Accumulation and Feedbacks of Chemicals in Aquatic Ecosystems

Jordi DachsDepartment of Environmental Chemistry, IDAEA-CSIC, Barcelona, Catalunya,

Spain.

.

Introduction : Definition of POPs

Some chemicals represent an environmental risk

• 1- Persistence

• 2- Bioaccumulation

• 3- Long-range transport

• 4- Toxicity and exposure routes

• 5- Quantity produced / discharged to the environment

• 6- Other adverse effects: on atmospheric chemistry,…

Persistent Organic Pollutants

CG

CWCP

CAAir-WaterExchange

Water-Particle Partitioning

Gas-Particle Partitioning

Dry Deposition

Wet Deposition

Vertical Fluxes

Advection

Bioaccumulation

Continental Inputs

Atmospheric Transport

Degradation

Environmental fate of organic pollutants

Major permanent sinks: - Ocean interior (sediments, deep waters)- Atmospheric OH degradation

Influence of T on atmospheric concentrations

If temperature increases from 1 to 4°C degrees then:

Gas-phase concentrations of chemicals will increase between 20% (PCBs) to 100% (Nonylphenols).

1/Temp (K-1)

0.0033 0.0034 0.0035 0.0036

-1

0

1

2

Sandy Hook -ENPs

Jun Jul Aug Sep Oct Nov Dec Jan

0

10

20

30

40

Gas Phase

Aerosol Phase

Con

cent

rati

on(n

gm

-3)

Log

CG

( ng

m-3

)

1/Temp (K-1)

0.0033 0.0034 0.0035 0.0036

-1

0

1

2

Sandy Hook -ENPs

Jun Jul Aug Sep Oct Nov Dec Jan

0

10

20

30

40

Gas Phase

Aerosol Phase

Con

cent

rati

on(n

gm

-3)

1/Temp (K-1)

0.0033 0.0034 0.0035 0.0036

-1

0

1

2

Sandy Hook -ENPs

Jun Jul Aug Sep Oct Nov Dec Jan

0

10

20

30

40

Gas Phase

Aerosol Phase

Con

cent

rati

on(n

gm

-3)

Log

CG

( ng

m-3

) Nonylphenols

PCBs

Enhanced mobility and long range transport of chemicals

Log Cg = -9135/T + 31.7R2 = 0.88

(IPCC Synthesis Report 2007)

Influence of Temperature on environmental partitioning

Predicted percent change in air-water (H), octanol-air (Koa) and octanol-water partition coefficients associated to a 5°C increase for selected chemicals (from Macdonald et al. 2005).

air

water octanol

eq iA,

eq iO,OA

C C K

eq iw,

eq iO,ow

CC K

eq iw,

eq iA,AW

CC K H=

(IPCC Synthesis Report 2007)

How pollutants reach the Arctic and Antarctica?

Air-water gradient of PCB fugacity

(Gioia et al. J. Geophys. Res. 2008)

Case Study: POPs in the Arctic

(MacDonald et al. Sci. Total Environ. 2005)

Case Study: POPs in the Arctic

- MacDonald and coworkers have published the first comprehensive study on the implications of climate change on POP cycling and impact. This will modify:

- Atmospheric inputs of POPs/pesticides - Atmosphere-ocean gas exchange and delivery of ice-cover content

of POPs- Riverine inputs- Chemical partitioning and degradation of POPs.

- These changes are also linked to:- Altered food web structure- Food deprivation or shifts in diet- Altered migration pathways and invading species

-The literature suggests that there is a dynamic link between organochlorine compounds and disease and epidemics in wildlife arctic populations.

CG

CWCP

CAAir-WaterExchange

Water-Particle Partitioning

Gas-Particle Partitioning

Dry Deposition

Wet Deposition

Vertical Fluxes

Advection

Bioaccumulation

Continental Inputs

Atmospheric Transport

Degradation

Environmental fate of organic pollutants

Influence of trophic status on POP accumulation by biota

(- Berglund. O. Limnol. Oceanogr. 2003- Dachs, J. Hoff,R. S.J. Eisenreich, Environ. Sci. Technol. 2000.- Berglund, O., P. Larsson, G. Ewald, L. Okla. Ecology 2001)

Climate Change and Soil Respiration

(Nature 440, 165-171, 2006)

(Nature 439, 711-714, 2006)

(PNAS 101, 423-428, 2004)

(soot responsible for a quarter of global warming)

Net air-water exchange flux [pg m-2 d-1]Net air-water exchange flux [pg m-2 d-1]Wet deposition flux [pg m-2 d-1]Wet deposition flux [pg m-2 d-1]

Dry deposition flux [pg m-2 d-1]Dry deposition flux [pg m-2 d-1]

Atmospheric Deposition of PCBs to European Marine

Waters(PCB 153)

(IPCC Synthesis Report 2007)

Predicted precipitation changes in Europe

Wet deposition flux [pg m-2 d-1]Wet deposition flux [pg m-2 d-1]

CWT [ng m-3]

B PCB 180

dept

h [m

]

CWT [ng m-3]

A PCB 28de

pth

[m]

CWT [ng m-3]

B PCB 180

dept

h [m

]

CWT [ng m-3]

A PCB 28de

pth

[m]

[ng m-2 s-1]

FSINK PCB 180

depth

[m]precipitation

* 10-5[ng m-2 s-1]

FSINK PCB 180

depth

[m]precipitation

* 10-5

Importance of precipitation as a driver of water column chemical concentration variability

(Example: Adriatic Sea)

PCB 28

(Jurado et al. 2006, In press)

Elbe River Flood 2002

Re-distribution of Contaminants - Dioxins

Extreme Events and POP Remobilization

Behind broken dams Riverbanks

Elbe River Flood 2002

Re-distribution of Contaminants – Dioxins and other POPs

-In the Elbe River Flood, no significant increase was measured in levels of PCDDs/Fs and PCBs in river and floodplain sediments, with few exceptions.

- The 2002 flooding event did not result in a large-scale contamination of the areas affected by the floodwaters. However, the relatively high contamination levels in the floodplains represent the historic dimension of repeated floods events in upstream industrial regions.

- Repeated incidence of floods have the capacity to re-mobilize and re-distribute large amounts of contaminants and cause widespread contamination.

Soils Are an Important Environmental Reservoir of POPs

(Dalla valle, M., Dachs, J., Sweetman, A.J., Jones, K.C. Global Biogeochem. Cycles 2004.

Dalla valle, M., Jurado, E., Dachs, J., Sweetman, A.J., Jones, K.C. Environ. Pollut. 2005.)

180ºW 135ºW 90ºW 45ºW 0º 45ºE 90ºE 135ºE 180ºE

90ºN

60ºN

30ºN

0º

30ºS

60ºS

90ºS

0 20 40 60 80 100 120 140 160 180 200

Inventory in soil or ocean mixed layer / Inventory in atm boundary layer

PCB 101

0

20000

40000

60000

80000

100000

120000 -9

0-6

0-3

00

30

60

90

La

titu

de

Soil conc (pg/g dry wt)020000

40000

60000

80000

100000

120000

Total PCB usage (tonnes)

Soil Conc (pg g-1)

PCB usage (tn)

Soils Are an Important Environmental Reservoir of POPs

Influences of climate change

-The capacity of soils to accumulate and sequestrate atmospheric chemicals is a strong function of organic carbon quantity and quality, temperature, humidity….

- Changes in soil organic matter quality or quantity may affect chemical concentrations in soils.

- Underlying climate change processes that result in a change of soil use and management, can be expected to influence the storage capacity of “old” and “new” chemicals.

Climate fluctuations and atmospheric occurrence of POPs

- Changes in atmospheric circulation patterns and air-masses can induce changes in POP fate and impact.

-“Inter-annual variations of POPs air concentrations from the Great Lakes region and the arctic have been strongly associated with atmospheric low-frequency fluctuations, notably the North Atlantic Oscillation (NAO), the El Niño-Southern oscillation and the Pacific North American (PNA) pattern. This suggests interactions between climate variations and global transport and distribution of POPs” (Ma et al. Environ.

Sci. Technol. 2004).

CONCLUSIONS

- The influence of Temperature on environmental partitioning and rates of organic chemicals can be predicted with moderate uncertainty. These predictions suggest higher concentrations in the atmosphere.

- The impact of higher remobilization is complex due to multiple of interactions of trophic and physical processes.

- Extreme events may remobilize POPs and affect their impact.

- Pristine environments far from sources may be more exposed to anthropogenic chemicals.

- Little is known on how climate change will affect impact of chemicals to ecosystems.

- Legislation on POPs are based on scientific criteria for persistence, long range transport potential and bioaccumulation, which may need to be revised under climate change scenarios.

Anthropogenic perturbations of Coastal regions

(Dachs & Méjanelle. Estuaries and Coasts 2010)

Efecte dels contaminants orgànics en el cicle del C

- Hi ha multitud d’articles sobre efectes de contaminants individuals en organismes

- Hi ha molt poca feina feta sobre els efectes de les mescles reals de contaminants en els organismes

- L’ECO-toxicologia ha oblidat l’”ECO”?

- Poden els contaminants afectar el cicle del carboni mitjançant els seus efectes en fitoplancton i bacteris?

Pollutant effects on Phytoplankton

Pollutants effects on phytoplankton: Single chemicalCultures

Effects of phenanthrene on cultured phytoplankton

Pollutant effects on Phytoplankton: single chemicalNE Atlantic Ocean

Effects of phenanthrene on natural Atlantic Ocean phytoplankton

Pollutant effects on phytoplankton: mixturesNE Atlantic Ocean

Prochlorococcus sp Synechococcus sp Chlorophyll a

Non-polar organic

compounds

21 ± 6 27 ± 3 40 ± 22

Polar organic

compounds

23 ± 13 31 ± 12 36 ± 8

Mixtures of PAHs 661 ± 588 812 ± 262 2448 ± 8092

Phenanthrene

5020 ± 1230 5880 ± 1450 21340 ± 7090

Pyrene

3130 ± 1420 8590 ± 2110 35010 ± 16390

LC10 (Relative concentration at which abundance or chlorophyll a is reduced by 10%)

LC10 given as C/Ccontrol

(Echeveste et al. Chemosphere 2010)

Pollutant effects on Phytoplankton: Mixtures

0

8

16

24

32

40

1 10 100

C/CControl

De

ad

ce

lls

(%

)

25

28

31

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1 10 100

C/CControl

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ad

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(%

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1 10 100

C/CControl

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1 10 100

C/CControl

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ad

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75

1 1350

C/CControl

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ad

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lls

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6

12

18

24

30

1 1350

C/CControl

De

ad

ce

lls

(%

) Prochlorococcus sp Prochlorococcus sp Prochlorococcus sp

Synechococcus sp Synechococcus sp Synechococcus sp

Mixture of PAH Non-polar OrganicPollutants

Polar OrganicPollutants

(Echeveste et al. Chemosphere 2010)