A comprehensive and continuous pesticide

screening during one growing season in five

small Swiss streams

Eawag: Rahel Comte, Simon Mangold, Heinz Singer, Simon Spycher, Christian Stamm

Oekotoxzentrum: Marion Junghans, Miriam Langer

FOEN: Manuel Kunz

Cantons: BE, BL, TG, TI, VS

VSA: Tobias Doppler, Irene Wittmer

August 31 2017 - York 2017 – Pesticides Behaviour in Soils, Water & Air

Time period

covered [M]

Goal

# substances

sampling

interval [d]

14 10 6 2

Single grab

sample

200

150

100

50

2

4

6

8

10

12

≈ 400

2 min during rain events

8 months

≈

213 PPP

March- August

0.5-day composite

samples

250

Getting closer to exposure relevant for aquatic organisms in small streams

Location of 5 Small Streams

0

0.1

0.2

0.3

0.4

3/ 10/ 17/ 24/

Water level [m] Continuous series of half-day composite samples

Half-day sample Pooled samples

Reduction of 1800 half-day samples to

119 half-day samples and 130 pooled samples analyzed with Online-SPE LC-HRMS/MS

April 2015

Sample Selection on the Example of the Weierbach

Pre

cip

itation [m

m/1

2 h

]

0

10’000

30’000

50’000

40

30

20

10

0

Weierbach

Sum

of P

PP

concentr

ations [ng/L

]

0

500

1’500

2’500

3’500

60

40

20

0

Canale Piano di Magadino

Mrz Apr Mai Jun Jul Aug Sep

High Concentration Peaks, High Variance

Doppler et al. (2017): Aqua & Gas, 4, 46-56

Comprehensive View on Eschelisbach

[ng/L]

Spycher et al. (in preparation)

Assessment of Concentrations

Environmental Quality Standards (EQS)

• Acute and Chronic EQS based on exotoxicological data

• Chronic EQS compared to 14 d time weighted averages (twa)

• acute EQS to measured concentrations

• 𝑅𝑄 =𝐶

𝐸𝑄𝑆 𝑅𝑄 > 1 Risk for sensitive organisms

• 32 different PPP exceeding EQS (from a total of 128 detected

compounds)

8

Comparison with Quality Standards

# of half-days with single substance concentrations > acute and chronic QS

• Acute EQS-exceedances not only due to higher time resolution,

because with 14-d time weighted averages 8 a.s. > acute QS

% of time ≥ 1

exceedances 6 43 24 92 22 92 0 10 41 86

Mooskanal Weierbach Eschelis-

bach

Canale P.

di M.

Tsatonire

Ac. Chr. Ac. Chr. Ac. Chr. Ac. Chr. Ac. Chr.

Herbicide 0 140 64 868 7 112 0 28 134 420

Fungicide 0 0 35 168 25 140 0 0 17 56

Insecticide 19 84 39 476 61 504 0 0 2 168

Classification of substances by primarily affected group of organisms

(i.e., trophic level)

For each sample RQs are summed according to the classification

Risks for Different Groups of Organims

Plants Vertebrates

Invertebrates

Junghans M., Kunz P. & Werner I. (2013): Aqua & Gas, 5, 54-61

Gustavsson M. (2017): Sci. Total Environ., 598, 973–983

Eschelisbach: Highest Risk for Invertebrates

Langer et al. (2017): Aqua & Gas, 4, 58-68

Su

m o

f c

hro

nic

RQ

Plants

Invertebrates

Vertebrates

Eschelisbach: Active ingredients with RQ > 0.1

Vertebrates

Plants

Invertebrates

Different Perspectives: Active ingredient (< 1% of measurements with exceedance) vs.

stream (92% of time with elevated risk)

"Historic" View (2005-2012)

Vertebrates

Plants

Invertebrates

Vertebrates

Plants

Invertebrates

28 most frequently sampled a.s. in Switzerland (Moschet et al. 2014: ES&T, 48, 5423−5432)

Scenarios for Acute Risk Quotients

All active ingredients (89 compounds)

Vertebrates Plants

Invertebrates

Same but with 2-week composite samples

Historic view (28 most frequently measured) with 2 –week composite samples

WFD with 2-week composite samples (3 PPP detected)

Vertebrates Plants

Invertebrates

Vertebrates Plants

Invertebrates

Vertebrates Plants

Invertebrates

Wittmer, Stamm, Singer, Junghans 2014: Beurteilungskonzept für Mikroverunreinigungen aus diffusen Einträgen

Substance Selection by Guideline for diffuse sources (38 a.s.)

Vertebrates Plants

Invertebrates

Relevance for Swiss River Network

Daten: swisstopo (Art. 30 GeoIV): 5704 000 000 / DHM25@2003

reproduced with permission of swisstopo / JA100119

Conclusion

• Large variety of a.s. and high concentration peaks in small streams

• Chronic EQS exceeded in all examined streams, in some cases almost

during entire monitoring campaign. Considerable variability among streams

• The pollution we «see» depends on the choice of substance AND the

sampling strategy

• A suited monitoring strategy can provide ecotoxicologically relevant

information and help to reduce the variability of PPP-monitoring data

Acknowledgements

Special thanks to all colleagues from cantonal authorities and

Federal Office of the Environment for funding.

Thank you for your attention! Photograph: Kim Jae-Sun

Additional Slides

- NAWA Spez 2015: ≈ 10 a.i

- NAWA Spez 2012: ≈ 15 a.s.

- RÜS ?

Small vs. medium sized streams

Number of active ingredients required to cover 90% of sum of concentrations

Pre

cip

itation [m

m/1

2 h

]

0

10’000

30’000

50’000

40

30

20

10

0

Weierbach

Sum

of P

PP

concentr

ations [ng/L

]

0

500

1’500

2’500

3’500

60

40

20

0

Canale Piano di Magadino

Mrz Apr Mai Jun Jul Aug Sep

High Concentration Peaks, High Variance

Doppler et al. (2017): Aqua & Gas, 4, 46-56

Occasionally Elevated Concentrations

without Rain Event

Mar Apr May Jun Jul Aug Sep0

1000

3000

5000

Meto

lachlo

r-C

oncentr

ation [ng/L

]

40

30

20

10

0

Pre

cip

itation [m

m/1

2 h

]