Problem Formulation in Environmental Risk Assessment

for Genetically Modified Crops

Alan Gray

Centre for Ecology and Hydrology UK

“The genetic basis of unintended effects in modified plants” Ottawa, 14-15 January 2014

Problem Formulation in ERA for GM crops

In this talk: Take-home messages

Problem Formulation

“Unintended” environmental effects

Disclaimer: Any views expressed in this

presentation are mine and not necessarily shared by any organisation with which I am, or have been, associated

Problem Formulation in ERA for GM crops

Take-home messages (1) * Because ERA for GM crops deals almost

exclusively with the phenotype it considers all traits altered by transformation

* Traits have been characterised during

growing trials and product development * ERA thus embraces both intended and

‘unintended’ effects of transformation

Problem Formulation in ERA for GM crops

Main traits of interest in multi-site trials of GM plant and comparator

‘Regeneration niche’ traits seed development /yield,

shattering, dormancy, germination rates

‘Competitiveness’ traits seedling vigour, growth rate, days to flowering, plant height/yield, plant-insect/disease

interactions, etc

Problem Formulation in ERA for GM crops

Data from plant characterisation trials can be used to test several general hypotheses e.g. will the modified crop be more weedy or invasive than its non-modified counterpart Further data will be required to test hypotheses relating to intended effects (e.g. novel protein expression, effects on NTOs etc)

Problem Formulation in ERA for GM crops

Take-home messages (2) * ERA considers the collateral effects of cultivating a

GM crop on a large scale * Problem Formulation aims to identify which effects

may cause harm and to devise a plan to analyse the risk of the harm being realised

* Some outcomes of large-scale cultivation, negative

or beneficial, GM or non-GM, may be ‘unintended’ – Problem Formulation is designed to capture the potentially harmful ones

Common components of ERA frameworks (after Hill 2005)

1 HAZARD IDENTIFICATION

The “what could go wrong” step

2 EXPOSURE ASSESSMENT

The “how likely is it to happen” step

4 RISK CHARACTERISATION

The “what is the risk” step

3 CONSEQUENCES ASSESSMENT

The “would it be a problem” step

Simple schematic of ERA (after US EPA)

PROBLEM FORMULATION

(includes identification of assessment endpoints, risk hypotheses and

analysis plan)

EXPOSURE ASSESSMENT (levels and likelihood

of exposure)

RISK CHARACTERISATION

HAZARD ASSESSMENT (effects testing or

consequences assessment)

RISK ASSESSMENT

Risk characterization

Problem definition

Problem context

Risk evaluation conclusions

Risk treatment mitigation options & actions

Consequence of exposure

Likelihood of exposure

Com

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PROBLEM FORMULATION

The ‘ILSI’ framework

(Wolt et al 2010)

Problem context develops the

parameters and identifies constraints

for the ERA

Problem definition shapes the ERA into a tractable form for

analysis

Problem Formulation in ERA for GM crops

Problem Formulation starts with the identification of protection goals (environmental objectives defined by policy, law, statutes or guidelines)

From these we derive assessment

endpoints (explicit expressions of the environmental value to be protected – a valued ecological entity and its attributes e.g. ”beneficial insect abundance”

Problem Formulation in ERA for GM crops

Protection goal – conservation of insect pollinators

Assessment endpoint – the abundance of bumblebees

Protection goal – weed-free crops

Assessment endpoint – the abundance of in-field weeds

Problem Formulation in ERA for GM crops

We then generate an exposure scenario or pathway to harm (describing the link between the GM crop and the assessment endpoint, enabling characterisation of risk)

This pathway can be expressed as a set of risk hypotheses (tentative explanations taken to be true for the purpose of argument e.g. GMHT canola will not be a worse volunteer weed than conventional canola)

The process can be aided by conceptual models…

……..which may be simple

PATHWAY TO HARM RISK HYPOTHESES

HT soybean produces seed HT soybean does not produce seed

Seed disperses to natural habitats Seed does not disperse to natural habitats

HT soybean establishes in natural habitats

HT soybean does not establish in natural habitats

HT soybean persists and spreads more than non-HT counterpart

HT soybean does not persist and spread more than non-HT soybean

HT soybean displaces species or reduces valued species

HT soybean does not displace species or reduce valued species

ANAYSIS PLAN – Assess comparative performance of HT and non-HT soybean for unintended effects during product development (e.g. ‘weedy’ traits)

……or more complex

Sears et al. PNAS 98: 11937–11942, 2001.

Bt CornProduction and Distribution

Pollen CharacterizationBt expressionPollen Shed

Timing, Duration, IntensityEnvironmental Dispersal

MonarchOccurrence & Distribution

RegionLandscape

HabitatBehavior

OvipositionFeeding

MilkweedOccurrence and Distribution

RegionLandscape

Habitat

MonarchEffectLethal

Sub lethal

Environmental Exposure

Risk

Problem Formulation in ERA for GM crops

For definition of terms, framework etc…. Wolt JD, Keese P, Raybould AF, Fitzpatrick JW, Burachik M,

Gray AJ, Olin SS, Schiemann J, Sears M & Wu F (2010) Problem formulation in the environmental risk assessment for genetically modified plants. Transgenic Research 19:425-436

Also Raybould AF (2011) The bucket and the searchlight:

Formulating and testing risk hypotheses about the weediness and invasive potential of transgenic crops, Environmental Biosafety Research 9:123-133

Problem Formulation in ERA for GM crops

The steps in Problem Formulation can be expressed as four questions *

1 What do we not want to see harmed?

What must be protected? 2 Can we envision a way in which they

could be harmed? 3 How can we assess whether they are

likely to be harmed? 4 Does it matter?

*Gray AJ (2012) Collection of Biosafety Reviews http://www.icgeb.org/biosafety/publications/collections.html

Problem formulation in ERA for GM crops QUESTION PROBLEM FORMULATION

1 What do we not want to see harmed? What must be protected?

Identify assessment endpoints from protection goals

2 Can we envision a way in which they could be harmed?

Trace pathways to harm and develop conceptual models

3 How can we assess whether they are likely to be harmed?

Formulate risk hypotheses and devise analysis plans

4 Does it matter? Decide regulatory context

Problem Formulation in ERA for GM crops

For application and worked examples….. Gray AJ (2012) Problem Formulation in

Environmental Risk Assessment for genetically modified crops: a practitioner’s approach. Collection of Biosafety Reviews 6:10-65

Also Tepfer M, Racovita M & Craig W (2013) Putting

problem formulation at the forefront of GMO risk analysis. GM Crops and Food: Biotechnology in Agriculture and the Food Chain 4:1-6

Problem Formulation in ERA for GM crops

“Unintended” environmental effects * Large-scale cultivation of novel crops is likely to

have novel effects, arising from new varieties and/or changes in management

* Some effects will be unintended sensu unplanned but not unforeseen (e.g. evolution of pest resistance) and form part of the ERA

* Others may be unintended sensu unexpected * Problem Formulation aims to identify possible

harmful effects, providing a tool for decision making about the cultivation of the crop

Problem Formulation in ERA for GM crops

The challenge for ecology is to improve our understanding of the effects of agricultural

changes

For example the huge changes in grassland management in the UK (haystacks->bales->

silage ; permanent pasture -> temporary leys)

Problem Formulation in ERA for GM crops

….and in cereal and other arable farming (e,g. harvesting methods, spring-> winter crops)

….and in dairy and

beef production

Problem Formulation in ERA for GM crops

…..have been accompanied by declines in biodiversity (as indicated for example by a huge decline in some farmland bird species)

But agri-environment schemes

are indicating species need specific management to reverse these declines

(e.g. Hicks et al (2013) Aspects of

Applied Biology 121 Rethinking Agricultural Systems in the UK, pp 219-20)

Problem Formulation in ERA for GM crops

Not all unexpected effects are harmful - changes in cultivation of Canadian canola

with increase in HT varieties

1996 2006 Conventional Conservation No-till Source: Statistics Canada, Census of Agriculture 1996-2006 (with thanks to Phil Macdonald)