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Oil spills: Regulation and biotechnology
Oil spills: regulation and biotechnology Guest editorial Ronald M. Atlas University of Louisville, Kentucky, USA Current Opinion in Biotechnology 1992, 3:220-223
Introduction
remain in residual oil by the time bioremediation programs can b e implemented for oil spill treatment.
Several recent oil spills have brought bioremediation to the forefront as an almost 'green' biotechnological approach to the treatment of oil spills. At the same time that the potential of bioremediation is being recognized, scientific and regulatory uncertainties are constraining these applications of biotechnology to the environmental cleanup of petroleum pollutants. When considering the use of bioremediation or any other cleanup technology, it is necessary to conduct risk analyses as well as cost-benefit determinations. In most cases, marine oil spills are left to natural weathering, a process that includes significant biodegradation, which alters the chemical composition of the oil, and removes its toxic and ecologically harmful components. Only w h e n oil from marine spills affects shorelines or shallow nearshore environments are significant cleanup efforts made and the use of bioremediation considered. Of the options available for cleanup, bioremediation is perhaps the least invasive and closest to the natural process. Yet, in spite of the fact that bioremediation is simply an acceleration of the natural biological weathering process, many scientists and regulators controlling the cleanup process feel that the best course of action is to avoid any treatment, because of the ecological impact any human activity has and the physical damage that will inevitably accompany any cleanup effort.
Currently, the regulatory framework for recombinant microorganisms worldwide does not permit the fullscale application of genetically engineered microorganisms to the environment. The United States Environmental Protection Agency (USEPA) is about to issue its proposed rules for the deliberate release of genetically modified microorganisms that are regulated by the Toxic Substances Control Act but these regulations will have more immediate and greater effects on field testing than on full-scale application. The specific testing requirements, if these regulations are adopted, would preclude the use of any recombinant organism for oil spill cleanup. Local municipality regulations, as well as the lack of uniform multi-national regulations, further restrict the potential for using recombinant microorganisms in oil spill bioremediation. Although regulatory restriction of the use of genetically modified organisms appears to be a significant block to effective oil spill bioremediation, this is not, in fact, so. Because almost all petroleum hydrocarbons, apart from the asphaltenes, are readily degraded b y naturally occurring microorganisms, the ability to use genetically modified organisms is not critical. This is in contrast with the recalcitrance of chlorinated hydrocarbons and xenobiotics to biodegradation by indigenous microorganisms, which allows such compounds to persist at contaminated sites. Minimal effort is currently aimed at engineering better hydrocarbon-utilizing strains that could outcompete and perform better than indigenous microbial populations.
Recombinant microorganisms for treating oil spills Although the first patent for a recombinant microorganism was issued to A. Chakrabarty and the US General Electric Company for a hydrocarbon-degrading bacterium, it is unlikely that any genetically engineered microorganism will ever be used for the bioremediation of an oil spill. The engineered bacterial strain patented by Chakrabarty degrades low molecular weight aromatic hydrocarbons, and not those that
Seeding with naturally occurring non-indigenous microorganisms Numerous companies have isolated and commercially produced hydrocarbon-degrading microorganisms, and are currently marketing these products as the solution to oil spill pollution. Most of the cultures being marketed are mixtures of undefined species. They are
Abbreviations BPAC--Bioremediation ProductAssessmentCorporation; NETAC--National Environmental TechnologyAssessmentCorporation; USEPA--UnitedStatesEnvironmentalProtection Agency.
220
© Current Biology Ltd ISSN 0958-1669
Oil spills: regulation and biotechnology Atlas 221 typically obtained by primary enrichment culture and grown on media containing petroleum hydrocarbons. In most cases the claims of success at seeding oil spills to enhance the rate and extent of hydrocarb o n biodegradation are greatly exaggerated. Removal within 2/1 48 hours is not a realistic goal in areas that have received heavy concentrations of oil. Complete biodegradation of crude oil is impossible because all crude oils contain some asphaltic hydrocarbons that are recalcitrant. Yet in each of the recent major oil spills, vendors have pressed these claims. The result is a reluctance on the part of oil companies, governmental regulatory authorities, and academic scientists serving as expert consultants, to believe the claims of any seed culture vendor, and a d e m a n d for independent verification. In the aftermath of the Exxon Valdez oil spill in 1989, USEPA funded an effort to develop standardized test protocols to determine the efficacy of bioremediation products. This effort is being carried out b y the US National Environmental Technology Assessment Corporation (NETAC) of the University of Pittsburgh. Tiered testing protocols, including laboratory, microcosm, and field tests, have b e e n dev e l o p e d to determine whether bioremediation agents are effective and safe for application in divergent settings, varying from o p e n water oil spills to mangrove s w a m p s contaminated with oil. The draft NETAC protocols have b e e n used by other nations, including Saudi Arabia, to develop test protocols for other situations. Additionally, a product testing service, the Bioremediation Product Assessment Corporation (BPAC), has b e e n formed to certify the effectiveness and safety of bioremediation agents. Both BPAC and NETAC aim to further biotechnology by bringing bioremediation products to the field. Should BPAC fail to independently verify the effectiveness of a product, this is likely to restrict the acceptance for application by on-site regulatory coordinators, w h o have control over the technologies used to clean up oil spills. It is unlikely that any product that has not b e e n tested and demonstrated to be effective will be used. Even if rigorous government-supported tests show seeding or application of other bioremediation technologies to b e effective, current regulatory frameworks may still not permit them. Local and regional authorities, as well as a myriad of national government agencies, exercise control over the treatment of oil spills. The Alaskan State Government, through its Department of Environmental Conservation, initially took the position that there could b e no introduction of nonindigenous microorganisms following the Exxon Valdez oil spill. They went as far as to rule that the transfer of a liter of water containing microorganisms from the shoreline in one part of Prince William Sound to the shoreline of an island in another part w o u l d constitute the introduction of non-indigenous organisms and would, therefore, not be permitted. Later, they reexamined that policy and permitted field testing by the USEPA of seed cultures on small test plots. The national environmental protection agency of Saudi Arabia took a similar conservative stand on the introduction
of non-indigenous microorganisms, insisting that cultures should be tested in contained facilities which could be disinfected, to ensure that no pathogenic microorganisms entered the environment as a result of seeding with cultures to treat an oil spill affecting their coastal region. In contrast, the State of Texas actively sought approval for full-scale field application of seed cultures following several relatively small coastal spills. The regulatory framework in operation in USEPA Region VI, which includes the Texas Gulf of Mexico coast, is extremely liberal with regard to the application of seed cultures and therefore encourages companies to bring microbial cultures to full-scale commercial operation. The failure to demonstrate conclusive benefit from the first seed inoculations of the Texas coastal spills has led to public calls from within the National Oceanic and Atmospheric Administration for the withdrawal of the bioremediation option for on-site remediation coordinators. These calls further confuse the regulatory acceptability of bioremediation.
Bioaugmentation by fertilizer application Even the low technology application of bioremediation, using fertilizers to enhance the biodegradative activities of indigenous microbial populations, is subject to uncertain regulatory hurdles. When fertilizers were considered for the bioremediation of the Exxon Valdez spill, a series of statutes had to be considered with regard to the potential impact of the fertilizers. The first of these considerations was the potential impact on Native American artifacts, which are protected b y specific state statutes. The second was the protection of marine mammals which are also specifically protected b y statute. Concerns about h u m a n health, fish, ecological processes, and so on, were the responsibility of a variety of federal and state agencies with regulatory authority. These agencies attempted to coordinate their differing missions. Although fertilizers have b e e n routinely applied for years in agricultural settings and, in fact, are routinely a d d e d to salmon rearing areas in Alaska to enhance the algal productivity that supports fish growth, approval was not immediately given for the use of fertilizers to stimulate oil biodegradation. Instead, extensive regulatory obstacles had to be passed. Both the efficacy of fertilizer application for the stimulation of oil biodegradation and the lack of significant toxicity at concentrations p r o p o s e d for bioremediation, had to b e demonstrated. A major problem was the lack of predetermined, specified e n d points for performance standards. Toxicity must b e considered as part of a risk analysis and all treatments have ecological impact. The question is whether that impact is acceptable relative to t h e benefit of removing the oil pollutants. Efficacy must b e viewed with regard to h o w much oil is r e m o v e d and h o w fast that removal is achieved. For oil spills, there
222
Regulatory affairs are no performance standards for such cleanup methods. There is no definition of h o w clean is 'clean'. In the Alaskan situation, it was felt that bioremediation was inadequate because some contaminating hydrocarbons would not be biodegraded and would be left as a residue. Some groups proposed the removal of oil-contaminated rocks and their replacement with clean rocks from other regions. Others felt that bioremediation was an extension of a natural process and hence a use of nature's solution to remove oil pollutants. These differing views each had to be considered before the regulatory authorities would grant approval for fertilizer application in oil spill bioremediation. In the treatment of oil spills, potential benefits demonstrated in the laboratory or even in microcosms are considered inadequate and full-scale field demonstration is necessary. In the case of the Exxon Valdez spill permission was granted for a field demonstration of bioremediation. Through the Technology Transfer Act, Exxon and the USEPA agreed to a joint effort, with the field demonstration performed by USEPA researchers from several laboratories. The benefits revealed by the field demonstration had to be viewed by regulators and by the public as significantly greater than any risks of environmental impact. Meetings with local fishing groups, Native Americans, and numerous environmental activist groups had to be held to gain political acceptance for bioremediation, before the various regulatory bodies would consider giving their approval. Given the patchy oil distribution over the rocks of the Prince William Sound shoreline, it was difficult to demonstrate with statistical confidence that any treatment would be effective, especially as there was only a short period of time in which to make decisions before full field applications would have to be started. Although there was dramatic visual evidence (a white w i n d o w in the rectangular field plots) within a few weeks following fertilizer application to test plots on selected areas of the Prince William Sound shoreline, supporting chemical analyses were not available within the time frame n e e d e d to make regulatory decisions. Several months after the spill, interim approval was given for the application of oleophilic and slowrelease fertilizers. Before approval o n this interim basis was granted, extensive tests were conducted to ensure that the levels of nitrogen-containing fertilizers to be applied would not cause eutrophication. Additionally, extensive tests were conducted to assess both acute and chronic toxicity. The toxicity tests were centered on the oleophilic fertilizer Inipol EAP 22. Values for ammonia toxicity from past literature were used to assess the risk associated with applying water-soluble, slow-release inorganic fertilizers. A single surrogate fish, such as the rainbow trout which is typically used to assess toxicity, was not acceptable to the Alaska Department of Environmental Conservation for toxicity testing of Inipol EAP 22, and hence several series of tests had to be run with indigenous fish species as well as with several invertebrates. Each
time the relative safety of the oleophilic fertilizer was established, n e w questions were asked about the potential effects on yet other species or other life stages of those organisms that had already been used in toxicity tests. Having b e e n given interim approval late in the summer of 1989, Exxon were able to treat 70 miles of shoreline several months after the spill by bioremediation with a combination of oleophilic and slow-release fertilizers. Winter storms failed to wash all of the oil from the contaminated shorelines and so further bioremediation was proposed in the second summer after the spill. As only interim approval had been granted previously, m u c h of the approval process had to be repeated. A n u m b e r of regulatory bodies again o p p o s e d the application of fertilizer for bioremediation without extensive new tests. Interim approval was again granted with a mandated monitoring program to be conducted jointly by Exxon, the Alaskan Department of Environmental Conservation, and the USEPA. Fertilizer application for bioremediation was to continue only if the initial monitoring tests demonstrated that the treatment was effective even for biodegradation of subsurface hydrocarbon contaminants. The treatment proved to be effective and bioremediation continued with periodic additions of fertilizer to contaminated shorelines throughout the affected shoreline of Prince William Sound during the summer of 1990. Even though approval was given for the use of bioremediation by the on-site coordinator, not all regions contaminated with oil could be treated because of differing regulatory jurisdictions. For example, shorelines under the authority of the US Park Service were treated only with slow-release fertilizers because of the ruling by that agency that oleophilic fertilizers were not natural chemicals and, hence, could not be applied to national park lands. Thus, regulatory standards governing areas affected by oil spills are not consistent. Each contaminated shoreline requires a different approach to gain regulatory approval for the use of bioremediation. Different local indigenous organisms need to be considered w h e n assessing potential toxicities, and different philosophies toward environmental protection must also be considered w h e n proposing the use of any technology, including bioremediation for environmental cleanup.
Conclusion As there is no definition of h o w clean is 'clean' following an oil spill, regulatory uncertainty necessarily occurs regarding acceptable performance criteria for bioremediation. For bioremediation to b e c o m e an effective technology there must be agreement on performance criteria. Regulatory agencies should establish uniform requirements and standards for the remediation of oil pollution. Surrogate test organisms for testing risk-based ecological effects are n e e d e d and
Oil spills: regulation and biotechnology Atlas standardized tests are necessary to verify the claims of commercial cultures for oil spill bioremediation. Contingency plans must b e made prior to spills that include consideration of regional differences. While the use of genetically engineered microorganisms for oil spill bioremediation is blocked b y regulation, this is not a major problem as the use of such organisms is not scientifically supported as necessary. Bioremediation of oil pollutants can be achieved for the most part by environmental modification (nutrient and oxygen supplementation) and b y the activity of naturally occurring microorganisms.
References and recommended reading Case History Compendium. Washington, DC: Applied Biotreatment Association; 1989. ATLAS RM, BARTHAR: H y d r o c a r b o n B i o d e g r a d a t i o n a n d Oil Spill Bioremediation. Adv Microbial Ecol, 1992: in press.
22. In Proceedings o f the 1991 International oil Spill Conference. Washington DC: American Petroleum Institute, 1991:577-581. MANGAN KS: University o f T e x a s M i c r o b i o l o g i s t Seeks to P e r s u a d e Skeptical Colleagues that Bacteria Could be Useful i n Cleaning Up Major o i l Spills. Chronicle of Higher Education 1990, 37(3):A5-A9. MEANS AJ: Observations o f a n Oil Spill B i o r e m e d i a t i o n Activity i n Galveston Bay, Texas. Seattle: US Department of Commerce, National Oceanic and Atmospheric Administration, National Ocean Service; 1991. PRINCE R, CLARKJR, LINDSTROMJE: Bioremediation Monitoring Program. Joint Report of EXXON, the USEPA, and the Alaskan Department of Environmental Conservation, Anchorage, Alaska; 1990. PRITCHARD PH, COSTA CF: EPA's Alaska Oil Spill Biorem e d i a t i o n Project. Environ Sci Technol 1991, 25:372-379. VENOSA AD, HAINES JR, NISAMANEEPONG W, GOVING R, PRADHAM S, SIDDIQUE B: S c r e e n i n g o f Commercial Inocula for Efficacy i n E n h a n c i n g Oil Biodegradation in a Closed Laboratory System. J Hazardous Materials 1991, 28:131-144. ZITRIDES TG: B i o r e m e d i a t i o n 1990, 12:59~0.
C o m e s o f Age. Poll Engin
HALVORSON HO, PRAMERD, ROGULM (EDS): Engineered Organisms in the Environment.. Scientific Issues. Washington DC: American Society for Microbiology; 1985. LADOUSSE A, TRAMIER B: Results o f 12 Years o f Res e a r c h i n Spilled Oil Bioremediation: Inipol EAP
RM Atlas, Department of Biology, University of Louisville, Louisville, ICY 40292, USA.
223
Introduction
remain in residual oil by the time bioremediation programs can b e implemented for oil spill treatment.
Several recent oil spills have brought bioremediation to the forefront as an almost 'green' biotechnological approach to the treatment of oil spills. At the same time that the potential of bioremediation is being recognized, scientific and regulatory uncertainties are constraining these applications of biotechnology to the environmental cleanup of petroleum pollutants. When considering the use of bioremediation or any other cleanup technology, it is necessary to conduct risk analyses as well as cost-benefit determinations. In most cases, marine oil spills are left to natural weathering, a process that includes significant biodegradation, which alters the chemical composition of the oil, and removes its toxic and ecologically harmful components. Only w h e n oil from marine spills affects shorelines or shallow nearshore environments are significant cleanup efforts made and the use of bioremediation considered. Of the options available for cleanup, bioremediation is perhaps the least invasive and closest to the natural process. Yet, in spite of the fact that bioremediation is simply an acceleration of the natural biological weathering process, many scientists and regulators controlling the cleanup process feel that the best course of action is to avoid any treatment, because of the ecological impact any human activity has and the physical damage that will inevitably accompany any cleanup effort.
Currently, the regulatory framework for recombinant microorganisms worldwide does not permit the fullscale application of genetically engineered microorganisms to the environment. The United States Environmental Protection Agency (USEPA) is about to issue its proposed rules for the deliberate release of genetically modified microorganisms that are regulated by the Toxic Substances Control Act but these regulations will have more immediate and greater effects on field testing than on full-scale application. The specific testing requirements, if these regulations are adopted, would preclude the use of any recombinant organism for oil spill cleanup. Local municipality regulations, as well as the lack of uniform multi-national regulations, further restrict the potential for using recombinant microorganisms in oil spill bioremediation. Although regulatory restriction of the use of genetically modified organisms appears to be a significant block to effective oil spill bioremediation, this is not, in fact, so. Because almost all petroleum hydrocarbons, apart from the asphaltenes, are readily degraded b y naturally occurring microorganisms, the ability to use genetically modified organisms is not critical. This is in contrast with the recalcitrance of chlorinated hydrocarbons and xenobiotics to biodegradation by indigenous microorganisms, which allows such compounds to persist at contaminated sites. Minimal effort is currently aimed at engineering better hydrocarbon-utilizing strains that could outcompete and perform better than indigenous microbial populations.
Recombinant microorganisms for treating oil spills Although the first patent for a recombinant microorganism was issued to A. Chakrabarty and the US General Electric Company for a hydrocarbon-degrading bacterium, it is unlikely that any genetically engineered microorganism will ever be used for the bioremediation of an oil spill. The engineered bacterial strain patented by Chakrabarty degrades low molecular weight aromatic hydrocarbons, and not those that
Seeding with naturally occurring non-indigenous microorganisms Numerous companies have isolated and commercially produced hydrocarbon-degrading microorganisms, and are currently marketing these products as the solution to oil spill pollution. Most of the cultures being marketed are mixtures of undefined species. They are
Abbreviations BPAC--Bioremediation ProductAssessmentCorporation; NETAC--National Environmental TechnologyAssessmentCorporation; USEPA--UnitedStatesEnvironmentalProtection Agency.
220
© Current Biology Ltd ISSN 0958-1669
Oil spills: regulation and biotechnology Atlas 221 typically obtained by primary enrichment culture and grown on media containing petroleum hydrocarbons. In most cases the claims of success at seeding oil spills to enhance the rate and extent of hydrocarb o n biodegradation are greatly exaggerated. Removal within 2/1 48 hours is not a realistic goal in areas that have received heavy concentrations of oil. Complete biodegradation of crude oil is impossible because all crude oils contain some asphaltic hydrocarbons that are recalcitrant. Yet in each of the recent major oil spills, vendors have pressed these claims. The result is a reluctance on the part of oil companies, governmental regulatory authorities, and academic scientists serving as expert consultants, to believe the claims of any seed culture vendor, and a d e m a n d for independent verification. In the aftermath of the Exxon Valdez oil spill in 1989, USEPA funded an effort to develop standardized test protocols to determine the efficacy of bioremediation products. This effort is being carried out b y the US National Environmental Technology Assessment Corporation (NETAC) of the University of Pittsburgh. Tiered testing protocols, including laboratory, microcosm, and field tests, have b e e n dev e l o p e d to determine whether bioremediation agents are effective and safe for application in divergent settings, varying from o p e n water oil spills to mangrove s w a m p s contaminated with oil. The draft NETAC protocols have b e e n used by other nations, including Saudi Arabia, to develop test protocols for other situations. Additionally, a product testing service, the Bioremediation Product Assessment Corporation (BPAC), has b e e n formed to certify the effectiveness and safety of bioremediation agents. Both BPAC and NETAC aim to further biotechnology by bringing bioremediation products to the field. Should BPAC fail to independently verify the effectiveness of a product, this is likely to restrict the acceptance for application by on-site regulatory coordinators, w h o have control over the technologies used to clean up oil spills. It is unlikely that any product that has not b e e n tested and demonstrated to be effective will be used. Even if rigorous government-supported tests show seeding or application of other bioremediation technologies to b e effective, current regulatory frameworks may still not permit them. Local and regional authorities, as well as a myriad of national government agencies, exercise control over the treatment of oil spills. The Alaskan State Government, through its Department of Environmental Conservation, initially took the position that there could b e no introduction of nonindigenous microorganisms following the Exxon Valdez oil spill. They went as far as to rule that the transfer of a liter of water containing microorganisms from the shoreline in one part of Prince William Sound to the shoreline of an island in another part w o u l d constitute the introduction of non-indigenous organisms and would, therefore, not be permitted. Later, they reexamined that policy and permitted field testing by the USEPA of seed cultures on small test plots. The national environmental protection agency of Saudi Arabia took a similar conservative stand on the introduction
of non-indigenous microorganisms, insisting that cultures should be tested in contained facilities which could be disinfected, to ensure that no pathogenic microorganisms entered the environment as a result of seeding with cultures to treat an oil spill affecting their coastal region. In contrast, the State of Texas actively sought approval for full-scale field application of seed cultures following several relatively small coastal spills. The regulatory framework in operation in USEPA Region VI, which includes the Texas Gulf of Mexico coast, is extremely liberal with regard to the application of seed cultures and therefore encourages companies to bring microbial cultures to full-scale commercial operation. The failure to demonstrate conclusive benefit from the first seed inoculations of the Texas coastal spills has led to public calls from within the National Oceanic and Atmospheric Administration for the withdrawal of the bioremediation option for on-site remediation coordinators. These calls further confuse the regulatory acceptability of bioremediation.
Bioaugmentation by fertilizer application Even the low technology application of bioremediation, using fertilizers to enhance the biodegradative activities of indigenous microbial populations, is subject to uncertain regulatory hurdles. When fertilizers were considered for the bioremediation of the Exxon Valdez spill, a series of statutes had to be considered with regard to the potential impact of the fertilizers. The first of these considerations was the potential impact on Native American artifacts, which are protected b y specific state statutes. The second was the protection of marine mammals which are also specifically protected b y statute. Concerns about h u m a n health, fish, ecological processes, and so on, were the responsibility of a variety of federal and state agencies with regulatory authority. These agencies attempted to coordinate their differing missions. Although fertilizers have b e e n routinely applied for years in agricultural settings and, in fact, are routinely a d d e d to salmon rearing areas in Alaska to enhance the algal productivity that supports fish growth, approval was not immediately given for the use of fertilizers to stimulate oil biodegradation. Instead, extensive regulatory obstacles had to be passed. Both the efficacy of fertilizer application for the stimulation of oil biodegradation and the lack of significant toxicity at concentrations p r o p o s e d for bioremediation, had to b e demonstrated. A major problem was the lack of predetermined, specified e n d points for performance standards. Toxicity must b e considered as part of a risk analysis and all treatments have ecological impact. The question is whether that impact is acceptable relative to t h e benefit of removing the oil pollutants. Efficacy must b e viewed with regard to h o w much oil is r e m o v e d and h o w fast that removal is achieved. For oil spills, there
222
Regulatory affairs are no performance standards for such cleanup methods. There is no definition of h o w clean is 'clean'. In the Alaskan situation, it was felt that bioremediation was inadequate because some contaminating hydrocarbons would not be biodegraded and would be left as a residue. Some groups proposed the removal of oil-contaminated rocks and their replacement with clean rocks from other regions. Others felt that bioremediation was an extension of a natural process and hence a use of nature's solution to remove oil pollutants. These differing views each had to be considered before the regulatory authorities would grant approval for fertilizer application in oil spill bioremediation. In the treatment of oil spills, potential benefits demonstrated in the laboratory or even in microcosms are considered inadequate and full-scale field demonstration is necessary. In the case of the Exxon Valdez spill permission was granted for a field demonstration of bioremediation. Through the Technology Transfer Act, Exxon and the USEPA agreed to a joint effort, with the field demonstration performed by USEPA researchers from several laboratories. The benefits revealed by the field demonstration had to be viewed by regulators and by the public as significantly greater than any risks of environmental impact. Meetings with local fishing groups, Native Americans, and numerous environmental activist groups had to be held to gain political acceptance for bioremediation, before the various regulatory bodies would consider giving their approval. Given the patchy oil distribution over the rocks of the Prince William Sound shoreline, it was difficult to demonstrate with statistical confidence that any treatment would be effective, especially as there was only a short period of time in which to make decisions before full field applications would have to be started. Although there was dramatic visual evidence (a white w i n d o w in the rectangular field plots) within a few weeks following fertilizer application to test plots on selected areas of the Prince William Sound shoreline, supporting chemical analyses were not available within the time frame n e e d e d to make regulatory decisions. Several months after the spill, interim approval was given for the application of oleophilic and slowrelease fertilizers. Before approval o n this interim basis was granted, extensive tests were conducted to ensure that the levels of nitrogen-containing fertilizers to be applied would not cause eutrophication. Additionally, extensive tests were conducted to assess both acute and chronic toxicity. The toxicity tests were centered on the oleophilic fertilizer Inipol EAP 22. Values for ammonia toxicity from past literature were used to assess the risk associated with applying water-soluble, slow-release inorganic fertilizers. A single surrogate fish, such as the rainbow trout which is typically used to assess toxicity, was not acceptable to the Alaska Department of Environmental Conservation for toxicity testing of Inipol EAP 22, and hence several series of tests had to be run with indigenous fish species as well as with several invertebrates. Each
time the relative safety of the oleophilic fertilizer was established, n e w questions were asked about the potential effects on yet other species or other life stages of those organisms that had already been used in toxicity tests. Having b e e n given interim approval late in the summer of 1989, Exxon were able to treat 70 miles of shoreline several months after the spill by bioremediation with a combination of oleophilic and slow-release fertilizers. Winter storms failed to wash all of the oil from the contaminated shorelines and so further bioremediation was proposed in the second summer after the spill. As only interim approval had been granted previously, m u c h of the approval process had to be repeated. A n u m b e r of regulatory bodies again o p p o s e d the application of fertilizer for bioremediation without extensive new tests. Interim approval was again granted with a mandated monitoring program to be conducted jointly by Exxon, the Alaskan Department of Environmental Conservation, and the USEPA. Fertilizer application for bioremediation was to continue only if the initial monitoring tests demonstrated that the treatment was effective even for biodegradation of subsurface hydrocarbon contaminants. The treatment proved to be effective and bioremediation continued with periodic additions of fertilizer to contaminated shorelines throughout the affected shoreline of Prince William Sound during the summer of 1990. Even though approval was given for the use of bioremediation by the on-site coordinator, not all regions contaminated with oil could be treated because of differing regulatory jurisdictions. For example, shorelines under the authority of the US Park Service were treated only with slow-release fertilizers because of the ruling by that agency that oleophilic fertilizers were not natural chemicals and, hence, could not be applied to national park lands. Thus, regulatory standards governing areas affected by oil spills are not consistent. Each contaminated shoreline requires a different approach to gain regulatory approval for the use of bioremediation. Different local indigenous organisms need to be considered w h e n assessing potential toxicities, and different philosophies toward environmental protection must also be considered w h e n proposing the use of any technology, including bioremediation for environmental cleanup.
Conclusion As there is no definition of h o w clean is 'clean' following an oil spill, regulatory uncertainty necessarily occurs regarding acceptable performance criteria for bioremediation. For bioremediation to b e c o m e an effective technology there must be agreement on performance criteria. Regulatory agencies should establish uniform requirements and standards for the remediation of oil pollution. Surrogate test organisms for testing risk-based ecological effects are n e e d e d and
Oil spills: regulation and biotechnology Atlas standardized tests are necessary to verify the claims of commercial cultures for oil spill bioremediation. Contingency plans must b e made prior to spills that include consideration of regional differences. While the use of genetically engineered microorganisms for oil spill bioremediation is blocked b y regulation, this is not a major problem as the use of such organisms is not scientifically supported as necessary. Bioremediation of oil pollutants can be achieved for the most part by environmental modification (nutrient and oxygen supplementation) and b y the activity of naturally occurring microorganisms.
References and recommended reading Case History Compendium. Washington, DC: Applied Biotreatment Association; 1989. ATLAS RM, BARTHAR: H y d r o c a r b o n B i o d e g r a d a t i o n a n d Oil Spill Bioremediation. Adv Microbial Ecol, 1992: in press.
22. In Proceedings o f the 1991 International oil Spill Conference. Washington DC: American Petroleum Institute, 1991:577-581. MANGAN KS: University o f T e x a s M i c r o b i o l o g i s t Seeks to P e r s u a d e Skeptical Colleagues that Bacteria Could be Useful i n Cleaning Up Major o i l Spills. Chronicle of Higher Education 1990, 37(3):A5-A9. MEANS AJ: Observations o f a n Oil Spill B i o r e m e d i a t i o n Activity i n Galveston Bay, Texas. Seattle: US Department of Commerce, National Oceanic and Atmospheric Administration, National Ocean Service; 1991. PRINCE R, CLARKJR, LINDSTROMJE: Bioremediation Monitoring Program. Joint Report of EXXON, the USEPA, and the Alaskan Department of Environmental Conservation, Anchorage, Alaska; 1990. PRITCHARD PH, COSTA CF: EPA's Alaska Oil Spill Biorem e d i a t i o n Project. Environ Sci Technol 1991, 25:372-379. VENOSA AD, HAINES JR, NISAMANEEPONG W, GOVING R, PRADHAM S, SIDDIQUE B: S c r e e n i n g o f Commercial Inocula for Efficacy i n E n h a n c i n g Oil Biodegradation in a Closed Laboratory System. J Hazardous Materials 1991, 28:131-144. ZITRIDES TG: B i o r e m e d i a t i o n 1990, 12:59~0.
C o m e s o f Age. Poll Engin
HALVORSON HO, PRAMERD, ROGULM (EDS): Engineered Organisms in the Environment.. Scientific Issues. Washington DC: American Society for Microbiology; 1985. LADOUSSE A, TRAMIER B: Results o f 12 Years o f Res e a r c h i n Spilled Oil Bioremediation: Inipol EAP
RM Atlas, Department of Biology, University of Louisville, Louisville, ICY 40292, USA.
223