Till Bachmann, IER Stuttgart

NewExtWP4

"Multimedia impact pathways"

Presentation by Till M. Bachmann Villigen, 26 May 2003

Till Bachmann, IER Stuttgart

Introduction

• Objectives of WP:(according to description of work)– Site-dependent assessment of concentration levels

in soil and water compartments– Exposure assessment with respect to ingestion by

humans considering food chains– Total exposure assessment (ingestion + inhalation)– 'As far as possible' quantifying impacts and

damages

Introduction

Till Bachmann, IER Stuttgart

WATSON-Europe

• Acronym for: – Integrated WATer and SOil environmental fate,

exposure and impact assessment model of Noxious substances for Europe

• Box model for water and soil coupled to regional air quality model WTM (Windrose Trajectory Model) of EcoSense

EcoSense multimedia

Till Bachmann, IER Stuttgart

Atmosphericemissions

Background (natural+ anthropogenic)

Direct emissionsto water and soil

Sources ofsubstances

Regional scaleatmospheric models

Air model

Soils ofdifferent use

Soil &waterModel Sediment

freshGroundwater

Waterfresh

Watermarine

Sedimentmarine

Drinkingwater

Aquaticorganisms

Exposuremodel

Farmanimals

Human beingsinhalation exposure not shown

Plants

En

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men

tal f

ate

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EcoSense multimedia

Till Bachmann, IER Stuttgart

Top soils of:– Pastures– Arable land– Non-vegetated areas

(e.g. rocks, open cast mining)– Semi-natural ecosystems

Other compartments:– Freshwater bodies– Sediment

– Built-up areas– Glaciers

Spatial characteristics• Environmental media distinguished taking differences

in permeability, soil erosion and human (in)direct exposure into account

• These are:

about 11500 different compartments in 3400 base regions

EcoSense multimedia

Till Bachmann, IER Stuttgart

Temporal characteristics• Climatological annual average data for hydrology• Temporal resolution:

– Steady-state: for sustainability questions („Which concentration will occur in media and food if the current emissions are kept the same forever?“)

– Quasi dynamic: temporal concentration development in different media and food (‚quasi‘: only a substance‘s concentrations vary)

• Pulse emission: emission stops after a given time

– „Time to steady-state“: assessing when a certain percentage of the steady state solution will be reached (very persistent substances like heavy metals will only reach a steady-state after several hundred or even thousand and more years)

EcoSense multimedia

Till Bachmann, IER Stuttgart

Scenario• Case study: 1000 kg Pb/a emitted in Flanders

Scenario calculations

• Reference: European emissions in 1990 (UBA/TNO 1998)

• Exposure via inhalation and ingestion

Till Bachmann, IER Stuttgart

Concentration increment

Till Bachmann, IER Stuttgart

Collective dose of Pb - resultsScenario calculations

• Summed over national average exposures• Ingestion exposure only via milk, beef, cereals and potatoes

UWM (power plants)

WATSON

Inhalation 2.84 10-6 1.07 10-5

Ingestion 1.60 10-4 1.17 10-3

Total 1.63 10-4 1.18 10-3

Till Bachmann, IER Stuttgart

Collective dose of Pb - comparisonScenario calculations

• Similar to UWM: – Ingestion dose about two orders of magnitude larger than inhalation

• Dissimilar to UWM: – Dose levels: one order of magnitude higher

– Contribution of different paths (potato and rye!)

– Decreasing intake fraction over time

Till Bachmann, IER Stuttgart

• Two scenarios consideringCd and Pb emissions to Germany and tributary areas:– Atmospheric deposition only

(UBA/TNO 1998)– Plus direct releases into water

(UBA 2000; distribution: i) industry+municipal emissions: per capita, ii) diffuse emissions: area weighted)

• No background• Steady-state concentrations

Sustainability application• Case study for Germany

Scenario calculations

Till Bachmann, IER Stuttgart

• Policy standards (EU directive) with respect to lead:– Arable land: 50-300 mg/kg dry-weight

– Surface waters for drinking water abstraction: 0.05 mg/l

Results – environmental media – PbScenario calculations

concentration range at steady-state

standard exceedances [area %]

Standard min max unit emissions + backgrounda)

arable land 0.79 81.7 [mg/kg d.-wt.]

1.4 %b) 6.0 %c)

surface water

atm. dep. 8.7 10-4 1.2 10-2 [mg/l] 0 % n/a

+ water em. 1.2 10-3 1.7 10-2 [mg/l] 0 % n/a a) background: 17.0 ppm Pb in upper continental crust (Wedepohl, 1995)

time to steady-state for exceedance case: b) 11-24% and c) 11-35% (after 1000 years)

Till Bachmann, IER Stuttgart

• Policy standards with respect to lead:(Commission Regulation (EC) 466/2001 to Directive 2001/22/EC)

– milk consumption (infants): 0.02 mg/kg fresh-weight– meat consumption: 0.1 mg/kg fresh-weight

Results – food consumption – PbScenario calculations

concentration range at steady-state [mg/kg f.-wt.]

standard exceedances

[mass %]

Standard min max

milk 0.0021 0.037 0.9 %

meat 0.0038 0.067 0 %

Till Bachmann, IER Stuttgart

Conclusions

• Air-dispersion based EcoSense is extended to a multi-media exposure assessment tool

• WATSON offers many opportunities to calculate welfare losses via external costs as well as sustainability indicators in terms of long-term environmental media and/or food concentrations

• However, the use of exposure-response functions has not yet been possible due to lack of emission information as well as atmospheric modelling reasons related to PAHs and PCDD/Fs

Conclusion

Till Bachmann, IER Stuttgart

Thank you for

your attention!

Conclusion