Ecotoxicology, 13, 377–398, 2004 2004 Kluwer Academic Publishers. Manufactured in The Netherlands.
International Trends in Bioassay Use for Effluent Management ELIZABETH A. POWER1,* AND RUTH S. BOUMPHREY2, 1
Azimuth Consulting Group Inc., 218-2902 W. Broadway, Vancouver, Canada. V6K 2G8 2 Environment Agency, Howbery Park, Wallingford, Oxfordshire OX10 8BD, UK
Abstract. The use of effluent bioassays in various international jurisdictions is reviewed, resulting in an analysis of themes and trends in: regulatory use, different uses of bioassays in meeting protection goals, different types of bioassays, bioassay test variability, statistical design, use of effluent bioassays to predict receiving environment effects, and uptake of effluent bioassay testing by developing countries. Current effluent bioassay use by jurisdictions in North America, the European Union, and Asia/Pacific is described. The historical trend for many jurisdictions has been to start with chemical hazard-based systems, then add effluent bioassays (first lethal, then sublethal measures) and then use receiving environment evaluations to predict or measure impacts. For jurisdictions adopting effluent bioassays over the past decade, policies about the use of in vivo vertebrate tests appear to be influencing the types of bioassays that are used and there is also a trend towards micro-scale tests. In countries where regulations relating to effluent management do not require effluent bioassays, uptake of bioassays is relatively slow. Good practice for effluent bioassay applications can only be defined with regard to the regulatory regime, as differences between jurisdictions (e.g., hazard-based versus risk-based regimes, policies on in vivo vertebrate testing) will result in different choices. Keywords: effluent bioassay; whole effluent testing (WET); direct toxicity assessment (DTA); effluent regulation; whole effluent assessment
Introduction The intent of this review paper is to set the international context for the following papers in this series on the Direct Toxicity Assessment (DTA) Programme. The uses of bioassays in effluent assessment are well-studied and in many countries bioassays are a standard tool for characterising effluent quality. Keeping the numerous reviews on effluent bioassays in mind—what value will this paper add to the field of effluent bioassay use? This paper reviews the use of bioassays in *To whom correspondence should be addressed: Tel.: 1-604-730-1220; E-mail:
[email protected] Current address: Natural Environment Research Council, Polaris House, North Star Avenue, Swindon, Wiltshire SN2 1UY, UK.
effluent management by describing regulatory applications of aquatic bioassays in various jurisdictions. We will analyse international trends in the application of effluent bioassays to evaluate how they support management objectives. Terminology One confusing difference to address is terminology, because a wide range of terms is used to describe effluent bioassays. In the United States (US), the term ‘Whole Effluent Toxicity’ (WET) is used, referring to whole organism bioassays for endpoints related primarily to mortality, growth and reproduction. In Canada, the term ‘effluent toxicity test’ is generally used but does not carry a specific meaning. In the UK and Australia, the term
378 Power and Boumphrey ‘Direct Toxicity Assessment’ (DTA) is used, meaning bioassays in general, covering both effluent and receiving environment sample testing. In some European countries, the term WET is used but it can be applied more broadly than in the US, for example to include bioaccumulation, biodegradation and persistence testing. The term ‘Whole Effluent Assessment’ (WEA) has become increasingly common in Europe since this is term that the Oslo and Paris Commission (OSPAR) has adopted (OSPAR Commission, 2000), generally meaning some combination of toxicity, bioaccumulation, and persistence assessment, but can also include other ‘combination’ measures such as biological oxygen demand (BOD), adsorbable organic halogens (AOX), and total organic carbon (TOC). The German term ‘Integrating Controlling of Effluents’ (ICE) and the Dutch term ‘Whole Effluent Environmental Risk’ (WEER) may also cover the use of effluent bioassays. Since this paper is a review of international approaches, covering jurisdictions with different terminologies, we will generally use the generic term ‘effluent bioassay’.
Previous reviews on effluent bioassays There have been numerous reviews of effluent bioassays and their uses but we did not identify any peer-reviewed international reviews of effluent bioassay use. There have been numerous synthesis points on the use of effluent bioassays in the US. Examples include the 1982 Society of Environmental Toxicology and Chemistry (SETAC) ‘Pellston’ workshop (Bergman et al., 1986), the 1995 Pellston workshop (Grothe et al., 1996), and the work of the SETAC Foundation for Environmental Education WET Expert Advisory Panel (SETAC, 1999). A review of applications of toxicological data, including those for effluent management, is provided in Environment Canada (1999), which looks at trends in both testing and regulatory use. It compares and contrasts the Canadian approach to that used in the United States (US). From a European perspective (with the notable exception of Germany), there has been a shorter history of whole effluent testing for regulatory purposes, and hence fewer synthesis reviews. Tinsley et al. (2004) and Wharfe et al. (2004) summarise
the development of effluent bioassay testing for the UK, describing bioassay use before and after uptake by the DTA Demonstration Programme. Also, in 1999, SETAC-Europe held a meeting in Edinburgh (Effluent Toxicology: A European Perspective). More recently, Oslo and Paris Commission (OSPAR) has become a focus for the development and exchange of effluent bioassay information in Europe. An OSPAR review document (OSPAR Commission, 2000) has summarised the uses of bioassays in effluent assessment in many European countries and a WEA Intersessional Expert Group (IEG) has been established under OSPAR to take forward further development of effluent bioassays. For example, this group has recently produced draft reviews of genotoxicity test methods for effluent assessment and whole effluent persistence and bioaccumulation test methods used by contracting parties (OSPAR Commission, 2001). The use of effluent bioassays is still in its infancy in Australia compared to Europe and North America (ANZECC and ARMCANZ, 2000). However, several institutions have developed protocols and carried out a significant amount of research utilising effluent (and receiving environment) bioassays, for both government and industry. Development of protocols in Australia has generally been on a regional or site-specific basis. This is almost certainly a result of the absence of a formal national approach to DTA development, with specific institutions developing protocols to suit particular regions and purposes. New Zealand has completed the development of standard testing protocols as summarised in ANZECC and ARMCANZ (2000). Finally, an annual review issue of the SETAC journal (Environ. Toxicol. Chem. 19(1), 2000) was devoted to whole effluent toxicity testing and several papers summarised the state-of-the-art (e.g., Chapman, 2000; de Maagd, 2000; Sarakinos et al., 2000). Although American contributions dominate this review issue, it included authors from, for example, Australia, China, The Netherlands and the UK.
State of current practice The approach used for information collection was to conduct a conventional literature review and
International Bioassay Use for Effluent Management 379 then augment that with telephone interviews, use of listservers and direct correspondence with researchers in various jurisdictions. This review is restricted to effluent bioassays and focuses on the regulatory and management aspects of their use, as opposed to technical aspects. Summary tables to describe the current roles of effluent bioassays in various jurisdictions have been prepared for North America (Table 1), for European Union (EU) Member States with developed effluent bioassay programmes (Table 2), Australia and New Zealand (Table 3) and other nations for which only limited information could be found (Table 4). These tables were developed to compare and contrast effluent bioassay practices and to help us identify trends and links to regulatory/management objectives that are discussed in the following sections. Before discussing the specific findings of this review, a general observation is that access to documentation about effluent bioassays and their regulatory uses was variable between jurisdictions, making consistent review of the issues across jurisdictions difficult (hence, the tables have different formats). In particular, it was difficult to access information from developing countries. From the review of current practice, themes or trends emerge which are discussed in this section. When we started this paper, we wanted to describe ‘best practice’, but it quickly became apparent that this cannot be done in isolation from specific regulatory or management objectives of effluent bioassay use. Therefore, we attempt to describe trends for effluent bioassay use in the context of various regulatory/management regimes.
The regulatory use of effluent bioassay data varies between different jurisdictions Regulation of effluents can take many different forms depending on the stated regulatory objectives. Whitehouse (2001) identifies different types of standards that can be used for different environmental protection goals and describes the advantages and disadvantages of each type. Internationally, he describes two types of situations where bioassay-based standards have been applied. These are:
(1) standards designed to protect the quality of the receiving environment (‘point of contact’ standards), and (2) standards designed to reduce emissions to the environment, e.g., based on load (‘point of entry’ standards). The first of these should be viewed as a standard based on a site-specific risk assessment, i.e., the bioassay standard or limit is designed to be protective of the receiving environment and may take account, for example, of the sensitivity of the receiving environment or the available dilution. They are designed to meet water quality objectives for any particular site. These standards are often expressed as permissible toxicity in effluents using specific tests and endpoints. The second of these, sometimes referred to as emission limit values or load values, is designed to promote the use of ‘best available technology’ for a specific industry sector, regardless of the receiving environment. These latter standards restrict overall load releases and may be thought of as a hazardbased standard. This approach is consistent with recent Ministerial meetings of the OSPAR Commission (1998) where near-zero environmental concentration targets for hazardous substances were agreed upon. This OSPAR decision influences EU regulatory regimes for effluent control and, as described previously, OSPAR supports the development of effluent bioassays. The OSPAR review (OSPAR Commission, 2000) uses this difference in regulatory intent as the main way of classifying different countries’ approaches to effluent bioassay controls. Stortelder and de Guchte (1995) present a detailed description of trends arising from the use of these two approaches. These distinctions are used in Tables 1–3 to describe existing effluent management frameworks. It should be noted that some, if not most, regulatory regimes (e.g., EU, US, Canada as summarised below) may require both approaches. In the EU Integrated Pollution Prevention and Control (IPPC) Directive (96/61/EC), industry is required to use best available techniques and to meet the water quality requirements of the receiving environment. For example, Germany combines a set of chemical properties and sum parameters with a set of bioassays (fish, daphnia, algae, luminescent bacteria, elimination). Discharge toxicity levels depend on the type of waste water and best available technol-
380 Power and Boumphrey Table 1. State of current regulatory use of effluent bioassays in North America Characteristic of effluent bioassays
United States
Canada
Entry point to applying effluent bioassays1
Regulatory requirement under Clean Water Acta
Regulatory requirement under general provisions of Fisheries Act as well as for specific industry-specific sections (e.g., Fisheries Act, Pulp and Paper Effluent Regulations; Metal Mining Effluent Regulations [MMER])
Management framework2
Primarily source control, but augmented by receiving environment bioassays in some situationsa and states
Primarily source control but, for some industries in some situations, receiving environment bioassays may be required
Phyla used3
Algae, invertebrate and fisha
Algae, macrophyte, invertebrate and fish (depending on permit, maybe only one of these)b
Bioassay endpoints4 Effluent bioassay data use5
Acute and chronica Statutory/enforceable requirement
Acute and sublethalb Statutory/enforceable requirement (in most cases under effluent permits)b,c,d Part of a Environmental Effects Monitoring (EEM) framework for some industriesb,c,d Not required for many sewage dischargese
Consequence of effluent bioassay non-compliance6
WET test data are used for National Pollutant Elimination Discharge System (NPDES) permit development and for determining compliance with permit toxicity limitsa Toxicity reduction/toxicity identification evaluations (TIE/TRE) legally mandated in some states, pending problems with bioassay compliance
Legally enforceableb Toxicity reduction/toxicity identification evaluationc not legally mandated, but supported as voluntary measure (part of compliance promotion)e
Percentage of effluent discharges tested using bioassays in this jurisdiction7
Over 6500 permits in USA (1995) have WET monitoring, or WET limits or bothf
Industrial surface discharges: 80% have bioassays as compliance point; most of the remainder use bioassays for monitoringe Sewage discharges:
