Chemical risk assessment – ecosystem services

Background

Assessing the risks of chemicals to man and the environment is based on the concept of comparing exposure to chemicals with their respective hazardous properties. However, there are differences in the criteria for deciding whether the level of exposure represents an acceptable or unacceptable risk. For man, decision criteria are focused on protecting the individual and regulations are applied relatively consistently around the globe. For the environment, protection goals are less clearly defined and not applied consistently in regional regulations. Regional environmental policies seem to take a cost-benefit approach to environmental impacts. There are two possible extremes for doing this: i) a precautionary approach aiming for zero release of chemicals into the environment; ii) uncontrolled release with no effective management to mitigate impacts. Most environmental regulatory schemes adopt an approach somewhere between these extremes. For example, some effects on individuals may be accepted if the population is unaffected or if it recovers from episodic exposure. For this approach to make sense, protection goals need to be suitably defined. Reviews of current regulations indicate that protection goals are only generally defined leaving a lack of clarity on how to achieve such protection.

Discussion of current chemical regulation schemes has led to calls for changes in the way environmental toxicity thresholds are derived. The use of limited species toxicity tests and application factors is tenuously linked to protection goals and could be over-protective in some cases or under-protective in others. Given that there are relatively few examples of major impacts e.g. TBT, DDT, from the thousands of chemicals in commerce, it may be that the current approach tends to be over-protective. This could be restricting the societal benefits of chemicals. On the other hand the uncertainties in the approach may underestimate effects, for example, in potentially sensitive ecosystems such as coastal marine reefs or in assessing endocrine disruption of chemical mixtures.

In addition to discussions for changes in current risk assessment schemes, there are policy discussions ongoing on the use of ecosystem services in setting protection goals. Examples include the Millennium Ecosystem Assessment, the European Commission strategy on biodiversity and ecosystem services, the UK National Ecosystem Assessment (UK NEA), the EFSA Guidance on a harmonised framework for pesticide risk assessment and the identification and evaluation of pesticide risk management options. This growing interest in using ecosystem services to help define and communicate protection goals will inevitably influence chemical regulation. Therefore, it is timely for the chemical industry to engage in this topic in order to determine and influence developments.

The TF should investigate a new risk assessment paradigm based on a structured framework for identifying which ecosystem services might be affected by chemicals, setting protection goals and then assessing relevant risk assessment schemes. We propose to follow and expand the recently published EFSA framework applied to pesticides (1).

The expected duration is 1 year and will involve 3 phases:

Phase 1 – Develop a Framework for the chemical industry applicable to all sectors by considering the following:

  • Description of key exposure scenarios and ecosystems including continuous and intermittent exposures, seasonality in receiving environments, spatial differences and scales.
  • Identification of the main stressors driving ecological status.
  • Establishment of current and potential uses of the environment in terms of ecosystem services. What does the local society use?
  • Definition of spatially explicit protection goals. Use case examples to exemplify, e.g. direct discharge of untreated sewage and no-impact scenarios for down the drain chemicals in different regions. Prioritise/select case examples for phase 2.
  • Identification of key service providing units. What are their attributes/dimensions?

Phase 2 – Case studies to show how the framework would be used:

  • Receiving environments to include freshwater, marine, soil.
  • Exposure scenarios to include down the drain (pharmaceuticals, home and personal care products representing constant exposure), episodic exposure in terrestrial and aquatic environments (pesticides), intermediate exposure scenarios (biocides?), multiple sources of exposure from industry value chains (e.g. oil and/or mining companies).
  • Also consider multiple stressors to explore relative contributions of chemicals to overall ecosystem stress.

Phase 3 Recommendations on how Risk Assessments Schemes need to be evolved:

There is scope to incorporate greater ecological relevance in risk assessment in order to achieve protection goals, e.g. population metrics, community structure. If the ecotoxicological community is about to develop more ecologically relevant paradigms for chemical risk assessment, we should combine the approach with consideration of the ecosystem services we wish to protect.

Terms of reference

  • Critically evaluate the proposed risk assessment framework developed following the ECETOC workshop and assess its utility as an interim approach for regulatory assessment of chemicals.
  • Develop suitable guidance and trigger values to enable the decision tree to be used and test the utility of the scheme using suitable case studies.
  • Provide guidance on study design to provide the appropriate quality of data needed for the risk assessment framework to function within a regulatory decision making system.

Outcome: April 2016

Ecosystem Services and Chemical Risk Assessment: ECETOC task force investigates the applicability of the EFSA framework for developing specific protection goals for a wide range of chemicals.

IN A NUTSHELL

Ecosystem goods and services are the benefits we (humans) get from nature. They include provisioning services, e.g. from crops that provide food and fibre, regulating services, e.g. the plants growing in river basins that retain water and thereby reduce flooding, supporting services, e.g.  the microbial communities involved in nutrient cycling and soil formation and cultural services, e.g. the aspects of ecosystems that provide spiritual, recreational and educational benefits.

Environmental landscapes are multifunctional but the range of services they provide is largely dependent on how they are managed. Managing for some services limits the delivery of others, e.g. draining land to increase agricultural yields increases food production but reduces flood alleviation. Understanding how ecosystems provide services and the trade-offs between them helps authorities decide where and how the ecosystem services needed to benefit society can be provisioned.

In addition to helping manage landscapes and communicate the benefits people gain from the environment, the ecosystem services concept also has relevance for how we assess the potential impacts of commercial chemicals that are released into the environment. It means that we can focus our assessments of potential impacts on the types of plants and animals providing the services in each type of habitat. For example, the most important species to protect in agricultural land used to grow crops would include the crop species themselves, species that control pests and diseases, microbes that breakdown organic matter to form soil or recycle nutrients, and so on. A different list of key species would come from woodlands where, although trees may be harvested for timber, they are also important in regulating water, air quality and climate. Insects, birds and mammals involved in pollination, seed dispersal and pest and disease control are all important in maintaining a thriving woodland. In principle, these spatial differences in service-providing species means we could change our basis for making chemical risk assessments from protecting all species everywhere at all times, which is the most common approach in current chemical regulation, to a more environmentally representative assessment based on types of land and water body use.

Recently, the European Food Safety Authority (EFSA) developed a framework to identify ecosystem services potentially affected by (agro)chemicals, such as pesticides, for setting specific protection goals and guiding environmental risk assessment. An ECETOC Task Force has investigated the applicability of the EFSA framework for developing habitat-specific protection goals for a wide range of other chemicals using four case studies spanning a range of different emission scenarios and habitats. The selected case studies were: i) oil refinery wastewater exposure in estuarine environments; (ii) oil dispersant exposure in marine environments; (iii) chemicals in consumer products (home and personal care and pharmaceuticals) discharged via sewers to expose a wide range of ecosystems (terrestrial and aquatic); (iv) persistent organic pollutant exposure in remote (pristine) environments. The case studies demonstrated that, with some modifications and development, the EFSA framework could be used to identify and prioritise ecosystems and services that are most at risk from a broad range of chemical exposure scenarios. Prioritised habitats with their associated plants and animals could then form the focus for further risk assessment and/or investigation to assess if control measures are adequate.

The document has been published as ECETOC Technical Report no.125: Chemical Risk Assessment – Ecosystem Services, and can be read online and downloaded at http://www.ecetoc.org/publication/tr-125-chemical-risk-assessment-ecosystems-services/

Further Articles Published:

Maltby L, Jackson M, Whale G, Ross Brown A, Hamer M, Solga A, Kabouw P, Woods R, Marshall S. 2016. Is an ecosystem services-based approach developed for setting specific protection goals for plant protection products applicable to other chemicals? Sci Total Environ 580:1222-1236 [Open Access] Doi: 10.1016/j.scitotenv.2016.12.083

Brown AR, Whale G, Jackson M, Marshall S, Hamer M, Solga A, Kabouw P, Galay-Burgos M, Woods R, Nadzialek S, Maltby L. 2016. Towards the Definition of Specific Protection Goals for the Environmental Risk Assessment of Chemicals: A Perspective on Environmental Regulation in Europe. Integr Environ Assess Manag 2016 Aug 10. Doi: 10.1002/ieam.1797. [Open Access]

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