1、 Ame ri can Petroleum Ins titute BIOACCUMULATION: HOW CHEMICALS MOVE FROM THE WATER INTO FISH AND OTHER AQUATIC ORGANISMS Health and Environmental Sciences Department Publication Number 4656 May 1997 STDmAPIIPETRO PUBL ib5b-ENGL 1997 0732270 0565044 840 One of the most significant long-term trends a
2、ffecting the future vitality of the petroleum industry is the publics concerns about the environment, health and safety. Recognizing this trend, API member companies have developed a positive, forward-looking strategy called STEP: Strategies for Todays Environmental Partnership. This initiative aims
3、 to build understanding and credibility with stakeholders by continually improving our industrys environmental, health and safety performance; documenting petformance; and communicating with the public. API ENVIRONMENTAL MISSION AND GUIDING ENVIRONMENTAL PRINCIPLES The members of the American Petrol
4、eum Institute are dedicated to continuous efforts to improve the compatibility of our operations with the environment while economically developing energy resources and supplying high quality products and services to consumers. We recognize our responsibility to work with the public, the government,
5、 and others to develop and to use natural resources in an environmentally sound manner while protecting the health and safety of our employees and the public. To meet these responsibilities, API members pledge to manage our businesses according to the following principles using sound science to prio
6、ritize risks and to implement cost-effective management practices: To recognize and to respond to community concerns about our raw materials, products and operations. To operate our plants and facilities, and to handle our raw materials and products in a manner that protects the environment, and the
7、 safety and health of our employees and the public. To make safety, health and environmental considerations a priority in our planning, and our development of new products and processes. To advise promptly, appropriate officials, employees, customers and the public of information on significant indu
8、stry-related safety, health and environmental hazards, and to recommend protective measures. To counsel customers, transporters and others in the safe use, transportation and disposal of our raw materials, products and waste materials. To economically develop and produce natural resources and to con
9、serve those resources by using energy efficiently. To extend knowledge by conducting or supporting research on the safety, health and environmental effects of our raw materials, products, processes and waste materials. To commit to reduce overall emission and waste generation. To work with others to
10、 resolve problems created by handling and disposal of hazardous substances from our operations. To participate with government and others in creating responsible laws, regulations and standards to safeguard the community, workplace and environment. To promote these principles and practices by sharin
11、g experiences and offering assistance to others who produce, handle, use, transport or dispose of similar raw materials, petroleum products and wastes. Bioaccumulation: How Chemicals Move from the Water into Fish and Other Aquatic Organisms Health and Environmental Sciences Department API PUBLICATIO
12、N NUMBER 4656 PREPARED UNDER CONTRACT BY: JAMES N. HUCKINS JIMMIE D. Pm JAMIN THOMAS MIDWEST SCIENCE CENTER 4200 NEW HAVEN ROAD COLUMBIA, MO 65201 U.S. DEPARTMENT OF INTERIOR MAY 1997 American Petroleum Institute STD-API/PETRO PUBL 4bSb-ENGL 1777 = 0732290 05b504b bL3 FOREWORD API PUBLICATIONS NECES
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16、means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission from the publishe,: Contact the publisher, API Publishing Services, 1220 L Street, N. U!, Wmhington, D.C. 20005. Copyright 6 1997 American Petroleum Institute iii STD-API/PETRO PUBL 4bSb-ENGL 1777
17、m 0732270 0565047 557 m ACKNOWLEDGMENTS THE FOLLOWING PEOPLE ARE RECOGNIZED FOR THEIR CONTRIBUTIONS OF TIME AND EXPERTISE DURING THIS STUDY AND IN THE PREPARATION OF THIS REPORT API STAFF CONTACT Alexis E. Steen, Health and Environmental Sciences Department MEMBERS OF THE BIOMONITORING TASK FORCE Ph
18、ilip Dom, Shell Development Company, Chairperson Raymon Arnold, Exxon Biomedical Sciences, Inc. Marie BenKinney, Moble Oil Corporation Janis Farmer, BP American R (2) low water solubility or hydrophobicity due to the lack of polar functional groups; and (3) structural stability resulting in environm
19、ental persistence (years instead of days). Finally, chemicals of moderate molecular weight and size (Le., molecular weight of about 350 and molecular breadth of less than 1 O Angstroms), and lacking ionizable functional groups have a greater tendency to bioaccumulate. Environmental Related Factors A
20、s suggested earlier, the environmental presence of chemicals that meet most of the aforementioned criteria does not always lead to high degrees of bioaccumulation. This attenuation of bioaccumulation is often due to low residue bioavailability. For bioaccumulation to occur, a molecule must make cont
21、act with a biomembrane and move through the membrane to lipid-rich storage sites. The amount of chemical making contact with an organisms absorbing membranes is dependent not only on its environmental concentration in the bulk water phase (includes particulates), but also on the fractional amount th
22、at is available for uptake (Le., the bioavailable fraction). This bioavailable fraction usually corresponds with the fraction of chemical that is truly dissolved in water. Lipophilic or bioaccumulative chemicals also have high affinities for particulate organic carbon in suspended and bed sediments
23、because the organic carbon associated with sediments has some of the same chemical characteristics as lipid. Most of the mass of a highly lipophilic contaminant in an aquatic system is usually not dissolved in the water but rather is sorbed on particulate organic carbon. The desorptive release of a
24、lipophilic residue from sediment organic carbon can be very slow, thus significantly reducing the amount of chemical available for bioaccumulation. However, the slow release of sediment-sorbed contaminants in areas where contaminant inputs have declined is often the major source of trace levels of b
25、ioconcentratable compounds. ES-3 Another factor that greatly affects the potential of a compound to bioaccumulate is its environmental stability or persistence. The effects of environmental degradation processes (e.g., hydrolysis, photolysis and microbial degradation) on contaminant molecules typica
26、lly result in more hydrophilic (water-loving) or polar products, which have lower bioaccumulation potentials than did the parent compounds. Some exceptions to this outcome do exist, especially under conditions of low oxygen. However, the overall effect of these degradation processes is to reduce par
27、ent compound concentrations and organism exposure time, thereby decreasing the amounts of residues bioaccumulated. Oraanism Related Factors Lipophilic contaminants are accumulated by aquatic organisms from water via respiration, and from ingested food or sediments. Bioconcentration (uptake from wate
28、r) is generally viewed as the predominant route of uptake for most chemicals (including most PAHs) by aquatic organisms. Because liters of water per day are ventilated across the gill membranes of fish, the gill is generally the principal point of contaminant entry into an aquatic organism. The assi
29、milation efficiencies of a variety of lipophilic compounds by this route range from about 20 to 90% of the contaminant residues present in ventilated water. Diet is more likely to be the major route of uptake when chemicals are persistent and have high K, (Le., greater than IO5). This is especially
30、true for the top predators (aquatic and terrestrial) of a food chain. The assimilation efficiency of lipophilic chemicals across the gut is dependent on the quality of the ingested materials. If ingested materials are largely nondigestable, such as most natural sediment organic carbon, then the like
31、lihood of gastrointestinal uptake is diminished. Gut assimilation efficiencies for a series of lipophilic chemicals, from high quality fish food (e.g., animal or plant tissues), have been shown to range from about 50 to 85%. Note that lipid content of the consumer organism has little or no effect on
32、 dietary and respiratory uptake rates of chemicals but it does affect the ultimate capacity of an organism to accumulate a chemical. ES4 STD-API/PETRO PUBL i.lbSb-ENGL 1777 0732290 05bS055 b2b = Bioaccumulation occurs only if the rate of a chemicals uptake exceeds the rate of its elimination. In aqu
33、atic organisms, depuration of many lipophilic chemicals occurs passively across the gills. This route of elimination appears to be most important for nonpolar compounds that are not biotransformed. The rates of elimination for these compounds are generally inversely related to their kW. In many orga
34、nisms (especially mammals, birds, and aquatic vertebrates), both the enzyme system known as the cytochrome mixed-function monooxygenase (MFO) system, and the aryl hydrocarbon hydroxylase system are responsible for the biotransformation of a variety of lipophilic compounds, especially the PAHs. Remem
35、ber that biotransformation products are typically more hydrophilic and have much more rapid elimination rates then their parent compounds. In fish, birds, and mammals, most MFO activity is localized in the liver and the route of elimination of the more hydrophilic metabolites is by the bile. Althoug
36、h the MFO system effectively detoxifies and reduces the bioaccumulation of many contaminants, certain PAHs and alkanes can be transformed to intermediates that are more toxic (including carcinogenic) than the parent compounds. The ability to eliminate accumulated PAH residues by all processes varies
37、 among species according to the following general trend: mammals fishes crustaceans bivalve molluscs. The typically low elimination rates of PAH and other contaminant residues by bivalves, which leads to high bioaccumulation, accounts in part for their popularity as sentinel or biomonitoring organis
38、ms. Food Chain Related Factors Biomagnification is the increase in the bioaccumulation factors (BAFs) of certain chemicals in organisms occupying sequentially higher trophic positions in a food chain. This phenomenon occurs because of the following sequence of events. As lipids of contaminated prey
39、are digested in the gut of predators, the capacity of the digestate ES-5 STD-API/PETRO PUBL Lib5b-ENGL 1777 0732270 05b505b 5b2 (due to its increased polarity) to retain nonmetabolized lipophilic contaminants is reduced, resulting in the net transfer of these chemicals to the predators lipid-rich ti
40、ssues. Then, assuming that the predator continues to consume numerous prey, the rates of uptake by the diet can exceed the rate of elimination, resulting in contaminant concentrations higher than those that would be found in the predators fatty tissues at equilibrium. If this animal is, in turn, con
41、sumed by a predator of higher trophic level, a further magnification in residue concentrations can occur. In cases where the predators are fish-eating birds and mammals having high consumption rates of contaminated fatty prey and limited elimination pathways, biomagnification can result in residue c
42、oncentrations that are 100-fold higher than the equilibrium values. BIOACCUMULATION ASSESSMENT Three approaches are being considered by EPA to assess the presence of bioconcentratable or bioaccumulative substances (not covered by water quality criteria) in surface waters and effluents. These approac
43、hes are the tissue residue measurement option, effluent measurement option, and sediment assessment option. In this primer, only the salient features of these options are covered and an evaluation of each is provided. Also, the use of transplanted bivalve molluscs and lipid-containing semipermeable
44、membrane devices (SPMDs) is examined as alternative options for the determination of bioaccumulative chemicals. Tissue Residue Opt ion The tissue residue approach involves measuring the concentrations of contaminants in tissue samples of indigenous organisms from receiving water sites and comparing
45、these values with those in similar organisms collected from relatively uncontaminated control sites. The tissue residue measurement approach is environmentally realistic. However, the same or similar species may not be collectible at the test and referencekontrol sites, there are potential differenc
46、es in the residence time of the test organisms at the sites, there are differences in the abilities of different organisms to ES-6 STD-API/PETRO PUBL 4bSb-ENGL 1997 0732290 05b5057 4T7 eliminate contaminants, and costs of tissue collection and analysis are high. These factors limit the certainty and
47、 practicality of the tissue residue option. Effluent Opt ion This approach involves the collection of samples of effluent water, the extraction of the organic chemicals from the water, and the separation and analysis of the bioconcentratable chemicals in the extracts. The effluent separation procedu
48、re is designed to sort the results of the initial screening analysis in order to determine which of the contaminants pose a hazard. The bioconcentration factors (BCFs) of those compounds identified in the effluent that appear to pose a hazard are estimated from log k-log BCF relationships or obtaine
49、d from measured values of BCFs in the literature that followed accepted standards for fishes and saltwater bivalve molluscs. The effluent assessment option does not allow detection of all bioconcentratable chemicals that may be present in aquatic organisms. The approach is fairly robust for chlorinated hydrocarbons but may fail to detect many PAHs because of the likelihood of acid-mediated PAH degradation during sample cleanup. Other limitations include analytical interferences from the hydrocarbons often present in refinery effluents, lack of sensitivity of the anal
