ASSESSING THE FATE AND EFFECTS OF MICROORGANISMS UNDER THE CANADIAN ENVIRONMENTAL PROTECTION ACT
Tom Edge
Biotechnology Section, Commercial Chemicals Evaluation Branch, Environment Canada, 351 St. Joseph Blvd., Hull, Quebec, Canada K1A 0H3, (819) 953-1666, fax (819) 953-7155
SUMMARY
A brief overview is provided of the approach being developed to assess the ecological fate and effects of microorganisms under the Canadian Environmental Protection Act (CEPA). The assessments will be based on information prescribed in notification regulations to be developed under the Act. The approach to assessment has been shaped by factors such as the need to assess a large number and variety of microorganisms, both naturally occurring and genetically modified, and the statutory requirements of CEPA. A working framework for ecological risk assessment of microorganisms under CEPA is outlined.
INTRODUCTION
Environment Canada and Health Canada are developing notification regulations for microorganisms under the Canadian Environmental Protection Act (CEPA). These regulations will provide for an environmental and human health assessment of microorganisms prior to their importation or manufacture in Canada. Microorganisms subject to notification will include both those which are naturally occurring and genetically modified. A more detailed overview of CEPA and the draft notification regulations was provided by Dr. Nigel Skipper, Environment Canada, earlier in this session.
The following paper provides a brief overview of the approach being developed for ecological risk assessment of microorganisms under the CEPA notification regulations. Two factors important in shaping this approach are described: (1) the number and variety of microorganisms that will be subject to notification and (2) the statutory requirements of CEPA. A working framework for ecological risk assessment of microorganisms is outlined.
THE NUMBER AND VARIETY OF MICROORGANISMS
A variety of commercial products composed of naturally occurring microorganisms are currently available for environmental applications such as degrading hydrocarbons or cleaning drains and grease traps. These products can contain microorganisms in a variety of formulations such as:
a pure culture;
a mixed culture that is a deliberate formulation of different pure cultures; and
a complex consortium of microorganisms.
Microorganism products that are mixed cultures consist of two or more different pure cultures. Consortia, on the other hand, consist of a complex group of microorganisms isolated from nature, such as a sewage sludge sample, where it is difficult or impossible to taxonomically identify the microorganism composition.
In order to get an indication of the microorganism products that might be used in bioremediation and that will be subject to assessment, a review was conducted of the microorganism products with a bioremediation-related use claim in the records of the Biotechnology Section, Commercial Chemicals Evaluation Branch, Environment Canada. These records have come over the last several years from proponents who have volunteered information on their products, or have provided this information when requesting an import permit from Agriculture and Agri-Food Canada. In some cases proponents described their products and identified the species composition. In other cases, there was little information provided on the composition of products. With the available information, microorganism products were categorized as either pure cultures, mixed cultures, or consortia. Where there was insufficient information to determine a category for a product, it was classified as "unknown". The results of this review are presented in Figure 1.
The review identified 338 products with a bioremediation-related use claim. Most of the products were mixed cultures. The mixed cultures contained anywhere from two to 10 or more different microorganism species that would each require notification. A wide variety of microorganisms were identified in these mixed cultures including, for example, Bacillus thuringiensis, Pseudomonas aeruginosa, Nitrosomonas europaea, Nitrobacter winogradskyi and Thiobacillus species. While there were fewer consortia products, it was suspected that a number of the "unknown" products were likely in this category. The consortia were often only characterized by their source of isolation such as municipal wastewater, livestock manure, compost or soil.
STATUTORY REQUIREMENTS OF CEPA
Under CEPA, information required for assessment is prescribed in notification regulations. This information must be provided by proponents. The information will be used, along with any other information available to evaluators, to assess the fate and effects of a microorganism and to identify any risk concerns. If no risk concerns are identified, importation or manufacture of the microorganism will be able to proceed after the end of the assessment period. If a risk concern is identified, a "suspicion of CEPA toxic" could be invoked, leading to a number of potential actions:
1. prohibition of importation or manufacture of the microorganism;
2. allowance of importation or manufacture, subject to specified conditions; and
3. prohibition of importation or manufacture pending submission and assessment of additional information.
These potential actions provide some flexibility to address risk concerns through specification of conditions on importation or manufacture, or by the proponent providing additional information to address the risk concern. However, the opportunity for provision of additional information is allowed only once.
ASSESSING FATE AND EFFECTS
The large number and variety of microorganisms that will need assessment, as well as the statutory requirements of the Act, have been important considerations in developing an approach to assessing the fate and effects of microorganisms under CEPA. A working framework for ecological risk assessment is provided in Figure 2. This framework was developed taking into consideration an Environment Canada contract report (Environmental Fate and Effects Data Requirements for Assessment of Unconfined Environmental Introductions of Microorganisms Under CEPA, Beak Consultants, Brampton, Ontario. October, 1994) and the U.S. Environmental Protection Agency/Environment Canada workshop on tiered testing schemes held in Arlington, Va, in January, 1994. The framework identifies an approach for assessing a number of ecological fate and effect endpoints. It requires that the information received in a notification be sufficient to address the endpoints and to identify risk concerns. A second assessment, if required, would focus on these risk concerns.
The variety of microorganisms likely to be notified under CEPA presents a considerable challenge for ecological risk assessment. Consortia, or mixed cultures containing unusual combinations of microorganisms, can raise complex issues for assessing ecological fate and effects endpoints. Some of these products contain microorganisms that are pathogens or that are involved in important biogeochemical cycles. For example, in an earlier session of this meeting, Dr. Alan Godfrey, Health Canada, provided data that identified a number of human pathogens in a consortium product used for drain cleaning (see page 216).
There is a need to identify appropriate ecological data requirements to enable assessment of the potential for toxin production or pathogenicity associated with a microorganism. A "hazard identification testing screen" is being developed under the draft CEPA notification regulations to assess the potential for adverse effects of a microorganism on plants, invertebrates and vertebrates. This screen would be used to assess microorganisms intended for widespread commercial use. Appropriate test methods to provide the data for this screen are being determined.
Figure 1. Types of microorganism products with a bioremediation-related use claim from records in the Biotechnology Section, Environment Canada. N = 338 microorganism products.
Figure 2. Working framework for ecological risk assessment of microorganisms under CEPA.