Y Devos

Environmental impact indices: Environmental impact indices:

DISCLAIMER: This presentation does not reflect the view of EFSADISCLAIMER: This presentation does not reflect the view of EFSA

Environmental impact indices: Environmental impact indices:

what do they reveal and not?what do they reveal and not?

RR maize symposium: the European perspectiveRR maize symposium: the European perspective

2222--24 March 201024 March 2010

Yann Devos (PhD) – Junior Scientific Officer

GMO Unit – EFSA

[email protected]

1. Introduction

� Aim

– Assess and compare environmental impact of herbicide regimes

applied in genetically modified herbicide tolerant (GMHT) maize

with those used in its conventional counterpart

Residual

Residual + foliar

2sowing pre-emergence emergence 1 leaf stage;

3-4 cm height

2 leaf stage;

3-4 cm height

4 leaf stage;

4-10 cm height

40 cm height 60 cm height

GLY

GLY GLY

Residual + foliar

5-6 leaf stage;

10-15 cm height

Residual

Residual

Residual + foliar

Residual + GLY

1. Introduction

� Environmental impact indices

– Pesticide Occupational and Environmental Risk Indicator

(POCER) → Vercruysse & Steurbaut (2002)

• Maize: Devos et al (2008)

– Environmental Impact Quotient (EIQ) → Kovach et al (1992)

• Maize: Leroux et al (2006); Kleter et al (2007); Brookes & Barfoot • Maize: Leroux et al (2006); Kleter et al (2007); Brookes & Barfoot

(2008)

• Soybean: Kleter et al (2007); Bonny (2008); Brookes & Barfoot

(2008)

• Cotton: Brookes & Barfoot (2008)

• Oilseed rape: Brimner et al (2005); Kleter et al (2007); Brookes &

Barfoot (2008)

3

2. POCER → Vercruysse & Steurbaut (2002)

� Pesticide Occupational and Environmental Risk Indicator

(POCER) – modules

– Annex VI of Directive 91/414/EEC

• 3 modules for human health (non-dietary exposure)

– Risk to pesticide operator

– Risk to worker– Risk to worker

– Risk to bystander

• 7 modules for the environment

– Persistence in soil

– Risk of ground water contamination

– Acute risk to aquatic organisms

– Acute risk to birds

– Acute risk to bees

– Acute risk to earthworms

– Risk to beneficial arthropods 4


(POCER) – formula

– For each module → risk is estimated via risk indices (RI)

Risk index Estimated exposure / toxicity ratio

Pesticide operator IE / AOEL [IE=internal exposure; AOEL=acceptable operator exposure level]

Worker (DE x Ab ) / (AOEL x BW) [DE=dermal exposure; Ab =dermal absorption


Worker (DE x AbDE) / (AOEL x BW) [DE=dermal exposure; AbDE=dermal absorption

factor; BW=body weight]

Bystander (DE x AbDE + I x AbI) / (BW x AOEL) [I=inhalation exposure]

Persistence 10[((DT50/90)-1) x 2] ) [DT50=half-life]

Groundwater PEC / 0.1 [PEC=predicted environmental concentration in groundwater]

Aquatic organisms PEC / MTC [MTC=maximum tolerable concentration]

Birds (10 x PEC) / (LC50 x BW)

Earthworms (10 x PEC) / LC50

Bees AR / (50 x LD50) [AR=application rate]

Beneficial arthropods (RC – 25) / (100 – 25) [RC=reduction of control capacity]5



(POCER) – calculations

– Integration of RI into total risk indicator

• Describe extent to which a chosen trigger is exceeded as a

numerical dimensionless value

– Step 1 – define lower (LL) and upper limit (UL) for each RI– Step 1 – define lower (LL) and upper limit (UL) for each RI

– Step 2 – calculate relative RI, LL and UL & log-transform

– Step 3 – determine exceedence factors (EF)

» EF values ≤ 0 are scored as 0 → low risk

» EF values ≥ 1 are scored as 1 → high risk

» EF values between 0 and 1 → intermediate risk

– Step 4 – calculate total risk = ∑ EF values ranging between 0 and 10

» Assumption: all components are equally important

6

2. POCER → Devos et al (2008)

� Herbicide regimes in conventional maize

– 3 different strategies to control annual/perennial grasses and

broadleaf weeds (abbreviated as CON)

• Pre-emergence of crop

• Early post-emergence, ideally in 2-4 leaf stage of maize

• Sequentially, • Sequentially,

– where a combination of herbicides with soil (residual) activity is

applied pre-emergence

– followed by a mixture of post-emergence herbicides with foliar

activity

– Farmers use a combination of <3-4> active substances

– 13 typical herbicide regimes (Flanders; Belgium)

• Time of application; dose; activity; weed spectrum

7


� Herbicide regimes in RR maize

– Different strategies to control annual/perennial grasses and

broadleaf weeds (e.g., Dewar, 2009)

• Single or sequential application of GLY only, without relying on

pre-emergence herbicides

• Use of GLY in combination with other herbicides, especially • Use of GLY in combination with other herbicides, especially

residual herbicides applied pre-emergence

• Use of GLY in a single application in combination with other

post-emergence herbicides with residual activity

– 10 GLY-based herbicide regimes

• Single vs. sequential application; dose; application timing;

presence/absence of residual herbicide

• RR composition = 360 g/l

8



– 3 regimes:

• Single application of GLY only (abbreviated as GLY)

• Application dose rates (g/ha):

– 720 → medium efficacy (Soukup et al, 2008)

– 900 → medium efficacy (Leroux et al, 2006)– 900 → medium efficacy (Leroux et al, 2006)

– 1080 → medium efficacy (Phipps and Park, 2002)

– 4 regimes:

• Sequential application of GLY only (abbreviated as GLY)

• Application dose rates (g/ha)

– 900 + 450 = 1350 → high efficacy (Leroux et al, 2006)

– 720 + 720 = 1440 → high efficacy (Monsanto)

– 900 + 900 = 1800 → high efficacy (Leroux et al, 2006; Monsanto)

– 1080 + 1080 = 2160 → high efficacy (Soukup et al, 2008;

Monsanto) 9



– 3 regimes:

• Single application of GLY in combination with herbicides with

residual activity (abbreviated as GLY+)

• Application dose rate (g/ha)

– GLY (1080) + acetochlor (2100) → high efficacy (Soukup et al, 2008; – GLY (1080) + acetochlor (2100) → high efficacy (Soukup et al, 2008;

Monsanto)

– GLY (1080) + herbicide with residual activity (full dose rate)

» S-metolachlor

» Terbuthylazin

» Dimethenamid-P

10


� Results – human health

– 3 modules

• Risk to pesticide operator

– EF CON = [1.00]

– EF GLY = [0.54-0.78]

– EF GLY+ = [1.00]– EF GLY+ = [1.00]

• Risk to worker

– EF CON/GLY/GLY+ = [0.00-0.37]

• Risk to bystander

– EF CON/GLY/GLY+ = [0.00]

– If used alone, GLY has lower impact on pesticide operator than

other herbicide regimes tested

– Risk to worker and bystander is low and transient

11


� Results – environment

– 7 modules

• Persistence in soil

– EF CON/GLY/GLY+ = [0.00-0.03]

– Half lives ≤ 90 days considered low

• Risk of ground water contamination• Risk of ground water contamination

– EF CON/GLY/GLY+ = [0.18-0.33]

– Risk of ground water contamination low due to rapid adsorption in

soil of GLY

• Acute risk to aquatic organisms

– EF CON = [0.47-1.00]

– EF GLY = [0.00]

– EF GLY+ = [0.38-1.00]

– GLY has low acute toxicity to fish, Daphnia and algae

12


� Results – environment

– Acute risk to birds / bees / earthworms / beneficial arthropods

• EF CON/GLY/GLY+ = [0.00]

• Low acute toxicity to birds, bees, earthworms and beneficial

arthropods

� Overall conclusion� Overall conclusion

13

0,0

0,5

1,0

1,5

2,0

2,5

3,0

Human health Environment Total

Exce

ed

en

ce f

act

or

(EF

)

va

lue

s

POCER modules

CON

GLY

GLY+

3. EIQ → Kovach et al (1992)

� Environmental Impact Quotient (EIQ) – components and

calculations

14

3. EIQ → Leroux et al (2006)

� EIQ-methodology applied to RR maize in Canada (Québec)

15

3. EIQ → Kleter et al (2007)

� EIQ-methodology applied to GMHT crops in US

– 2004; pesticide use survey data of National Center for Food and

Agricultural Policy (NCFAP); percent change

– Proportional EIQ/ha reduction of 39% in maize

16

0 20 40 60 80

Canola

Cotton

Maize

Soybean

% decrease GM vs. conventional

Ecology impact, EI/A

Consumer impact, EI/A

Farmworker impact, EI/A

Total impact, EI/A

Pesticide use, lbs ai/A

3. EIQ → Brookes & Barfoot (2008)

� EIQ-methodology applied to GMHT maize globally

– 1997-2006; pesticide use survey data from US, Canada, South

Africa & Argentina

17

3. EIQ → Bonny (2008)

� EIQ-methodology applied to GMHT soybean in US

– 1990-2006; pesticide use survey data of US Department of

Agriculture (USDA)

Period Field EIQ

1994-1996 29.2

2001 20.4

18

2001 20.4

2002 23.8

2006 25.7

3. EIQ → Brookes & Barfoot (2008)

� EIQ-methodology applied to GMHT soybean in Romania

– 2000-2003; data from Brookes (2005)

19

4. What environmental impact indices do not

reveal?

– (see e.g., Cerdeira & Duke, 2006, 2010; Dewar, 2009, for

comprehensive reviews)

• Weed control efficacy & weed management flexibility

• Impact due to the adoption of conservation tillage practices

• Impact on human health due to pesticide residues

• Impact of GLY metabolites (e.g., AMPA)• Impact of GLY metabolites (e.g., AMPA)

• Risk to mammals

• Weed resistance evolution to GLY

• Weed spectrum shifts

• Impact on farmland biodiversity

• Impact on microorganisms and soil functions

• …

20

5. What environmental impact indices do

reveal?

� Useful tools

– as indicators of environmental impact of pesticides

– to compare/rank pesticides based on environmental impact

� Herbicide regimes in maize cropping systems

– GLY-based herbicides have a better environmental profile

compared to those applied in conventional maizecompared to those applied in conventional maize

– Addition of herbicides other than GLY in RR maize

reduces/cancels beneficial effect, depending on application

dose rate of additional herbicide

21

6. Thank YOU for your attention!

� Acknowledgments

– Dirk Reheul & Mathias Cougnon & Robert Bulcke

• University of Ghent; Department of Plant Production

– Sofie Vergucht & Walter Steurbaut

• University of Ghent; Department of Crop Protection

– Geert Haesaert– Geert Haesaert

• University College of Ghent; Department of Plant Production

– Gijs Kleter

• RIKILT; Institute of Food Safety; Wageningen University and

Research Center

22

Y Devos

Education

Transcript of Y Devos