1、API PUBL*LibLO 95 m 0732290 0542008 231 = HEALTH AND ENVIRONMENTAL SCIENCES DEPARTMENT API PUBLICATION NUMBER 461 O JANUARY 1995 Critical Review of Draft EPA Guidance on Assessment and Control of Bioconcentratable Contaminants in Surface Waters American Petroleum Institute API PURL*4bLO 95 m 0732290
2、 0542009 178 m Critical Review of Draft EPA Guidance on Assessment and Control of Bioconcentratable Contaminants in Surface Waters Health and Environmental Sciences Department API PUBLICATION NUMBER 461 O PREPARED BY: JERRY M. NEFF, PH.D.* ARTHUR D. LITTLE, INC. ACORN PARK CAMBRIDGE, MA 02140 APRIL
3、1994 * CURRENT ADDRESS: BATELLE OCEAN SCIENCES LABORATORY, 397 WASHINGTON STREET, DUXBURY, MA 02332 American Petroleum Institute API PUBLm4blO 95 0732290 0542030 77T FOREWORD API PUBLICATIONS NECESSARILY ADDRESS PROBLEMS OF A GENERAL NATURE. WITH RESPECT TO PARTICULAR CIRCUMSTANCES, LOCAL, STATE, AN
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7、HE PREPARATION OF THIS REPORT - Alexis E. Steen, Health and Environmental Sciences Department MBERS OF llE BIOMONITORING TASK FORCE Philip B. Dom, Ph.D., Shell Development Company W. Raymon hold, Ph.D., Exxon Biomedical Sciences, Inc. Shiv Baloo, Amoco Oil Company Janis M. Farmer, BP America Researc
8、h and the tissue residue option. Procedures for assessing sediments are also included. In the tissue residue option, tissues of aquatic organisms in the receiving water are analyzed for residues of bioconcentratable organic chemicals. If the concentrations of any chemicals in tissues are above permi
9、ssible levels, the sources of the chemicals are traced by target analysis and the chemicals are limited in the point sources. In the effluent option, representative samples of the effluent are analyzed for chemicals that bioconcentrate. If any bioconcentratable chemicals are detected in the effluent
10、 at concentrations above a threshold value, a determination (based on a bioconcentration model) is made as to whether bioaccumdation by fish and shellfish in the receiving waters could occur at levels that might pose a health hazard to human consumers of the fishery products. This report presents a
11、critical review of methods proposed in the DBG with particular emphasis on their suitability for assessing bioconcentratable chemicals in National Pollution Discharge Elimination System (NPDES) permitted effluents from oil refineries, petroleum marketing terminals, and crude oil production activitie
12、s. The major focus of this review was on the effluent option. As defined in the DBG, bioconcentratable Chemicals are nonpolar (unionizable) organic chemicals with a log octanoYwater partition coefficient (log kW) of 3.5 or higher and a concentration in the fmal effluent of 100 ng/L (parts per trilli
13、on) or higher. The most abundant potentially bioconcentratable chemicals in NPDES-permitted oil industry effluents are saturated and aromatic hydrocarbons and related heterocyclic compounds. Halogenated organics, phthaiate esters, pesticides, and other potentially bioconcentratable compounds of ES-
14、1 API PUBLU4bLO 95 m 0732290 0542037 244 m major environmental concern usually are absent, present as trace contaminants, or are analytical artifacts. Therefore, any assessment of bioconcentratable chemicals in oil industry effluents should focus on hydrocarbons. The guidance proposed by the EPA for
15、 identifjhg and quantifj4ng bioconcentratable organic chemicals in NPDES-permitied effluents does not provide a sound basis for predicting bioaccumulation of toxic chemicals in the edible tissues of fish and shellfish. A great many conservative assumptions are made in deriving screening parameters f
16、or each stage of the assessment. The net result is an extremely conservative, overprotective, estimate of potential bioaccumulation and tissue residue concentrations in fishery products consumed by man. Because of the multiple conservative assumptions, tissue residues are likely to be overestimated
17、by as much as two to three orders of magnitude. This over-estimation is particularly true for hydrocarbons, which are the potentially bioconcentratable chemicals most frequently encountered in oil industry effluents. These chemicals are absorbed poorly from the gut of aquatic animals and man and are
18、 metabolized and excreted rapidly. Hydrocarbons do not biomagniQ in aquatic food webs. In the effluent option, effluent samples are collected from point source discharges and analyzed by a high pressure liquid chromatography (HPLC) method that produces three fractions of nonpolar organic chemicals w
19、ith different ranges of log kW between 3.5 and 8.2. Each fraction is analyzed by gas chromatography/mass spectrometry (GCMS) to identifi and quantifi individual bioconcentratable chemicals. Various screening steps are then performed for each chemical identified to determine if it poses a hazard and
20、may require subsequent regulatory action. The initial screen identifies bioconcentratable chemicals of concern based on log KW, concentration in the whole effluent, and initial dilution in the mixing zone of the outfall. Chemicals that do not pass the first screen are evaluated by regression models
21、that relate log kW to bioconcentration factor (BCF). Predicted concentrations of chemicals in tissues of aquatic animals are evaluated with respect to the risk of harm to human consumers of fishery products from the vicinity of the waste water outfall. Aithough the effluent option provides a means f
22、or identifiing and quantifj4ng potentially bioconcentratable chemicals in oil industry effluents, the extraction, cleanup, and analyticai methods may degrade many hydrocarbon analytes and produce a variety of artifacts. Reverse ES-2 API PUBL*4bLO 95 m 0732290 O542038 LBO m searches of mass spectral
23、libraries probably will produce tentative identifications for many chemicals for which no physical/chemical or toxicological data are available. It will not be possible to determine if these chemicals pose a health hazard to humans at the concentrations at which they occur in the effluent. The compl
24、ex screening process is so conservative that nearly all chemicals in fraction 1 and all chemicals in fractions 2 and 3 will not pass the initial screen and will require additional assessment if their individual concentrations in the full-strength effluent are 100 ngL or higher and the allowable init
25、ial dilution of the effluent in the mixing zone of the discharge is 100-fold or less. The screening analysis is time-consuming and expensive. Because it contributes little to identifj4ng chemicals that should or should not be listed in Report 2, it should be eliminated. Concentration decision points
26、 for water, tissues, and sediments are set unrealistically low, particularly for saturated and polycyclic aromatic hydrocarbons (PAHs). Natural background concentrations of hydrocarbons of the types found in oil industry effluents are likely to be similar to or higher than the decision point concent
27、rations, particularly in sediments (5 pgkg dry wt.) and tissues (5 pgkg wet wt.). The decision point concentrations are very near the detection limits of available analytical methods for most chemicals of concern in oil industry effluents. This will result in a high variance in measured concentratio
28、ns near the decision points and lack of confidence in the value of the decision point concentrations. However, the main weakness of the effluent option, as discussed in greater detail in the following sections of this review, is the uncertainties about many of the assumptions used to mathematically
29、link (model) the relationship between concentrations of a bioconcentratable chemical in an effluent and concentrations of that chemical in the edible tissues of an animal living in the receiving water environment. The models assume that there is an equilibrium among concentrations of bioconcentratab
30、le chemicals in the receiving water, sediments, food organisms, and aquatic animals consumed by man in the receiving water environment. This is almost never the case. Concentrations in a receiving water environment of chemicals derived from a point-source effluent are continuously varying on both te
31、mporal and spatial scales. Animais, particularly motile ones, are nearly always actually exposed to time-averaged concentrations of the chemicals of concern that are much lower than the concentrations ES-3 API PUBL*4bLO 95 9 0732290 0542019 017 9 predicted by conventional dilution models. The kineti
32、cs of partitioning of nonpolar organic chemicals among water, sediments, food organisms, and consumer organisms is poorly understood, particularly under conditions of highly variable concentrations in solution in the aqueous phase. Wide differences in the ability of food chain organisms to metaboliz
33、e and excrete hydrocarbons (Stegeman, 198 1 ; Stegeman and Kloepper-Sams, 1987), the most abundant bioconcentratable compounds in oil industry effluents, further complicates prediction of net bioaccumulation in aquatic animals consumed by man. The technical basis for calculating values for BCFs usin
34、g a log some are lost from the organism by active or passive means as rapidly as they enter the tissues. The food route of exposure to toxic chemicals is important only for those chemicals that are accumulated from the water and are retained in the tissues of fish and shellfish species consumed by h
35、umans, and that can be absorbed in significant amounts through the human gut. 1-1 API PUBL*4610 95 O732290 0542022 bOL As part of the chemical-specific approach to toxics control, EPA (1 991 b) has developed draft guidance on the “Assessment and Control of Bioconcentratable Con taminants in Surface
36、Waters (March 1991).“ This document, referred to subsequently as the DBG (draft bioconcentration guidance), provides guidance for identifying and monitoring nonpolar organic chemicals in effluents that have the greatest potential to bioaccumulate in aquatic food chains leading to humans. The major g
37、oal of bioconcentration assessment is to protect humans from consumption of toxic quantities of contaminated fish and shellfish products. The DBG describes: Analytical chemical procedures to identi and quantify bioconcentratable pollutants in environmental samples (water, sediments, tissues of aquat
38、ic animals), Methods for deriving criteria for aquatic organisms and receiving waters, and Approaches for the control of these pollutants from point sources. EPA has not yet developed guidelines to be used by NPDES-permitting authorities to identify point dischargers or to set priorities for identis
39、ling dischargers that will be required to perform an assessment for bioconcentratable chemicals in NPDES-permitted effluents. EPA has asked for public comment on selection of point-source dischargers for assessment. The final guidance document will provide recommendations for the selection process.
40、The DBG describes two approaches for assessing bioconcentratable contaminants in effluents and receiving waters: 1) the tissue residue option, and 2) the effluent option. It also includes procedures for assessing sediments. In the tissue residue option, tissues of aquatic organisms in the receiving
41、water are analyzed for residues of bioconcentratable organic chemicals. If the concentrations of any chemicals in tissues are above permissible levels, the sources of the chemicals are traced by target analysis and the chemicals are limited in the point sources. In the effluent option, representativ
42、e samples of the effluent are analyzed for chemicals that bioconcentrate. If any bioconcentratable chemicals are detected in the effluent at concentrations above a threshold value, a determination (based on a bioconcentration model) is made as to whether bioaccumulation by fish and shellfish in the
43、receiving waters could occur at levels that might pose a health hazard to human consumers of the fishery products. 1-2 API PUBL*4bLO 95 W 0732290 0542023 548 The objective of this review is to evaluate the proposed methods and underlying assumptions for assessing bioconcentratable contaminants in pe
44、troleum industry effluents. The main focus of this review is on the effluent option and its application to “DES-permitted effluents from oil refineries, petroleum product marketing terminals, and oil/gas production platforms (produced water discharges). However, there will be some general evaluation
45、 of the suitability of the tissue residue option for evaluating oil industry effluents. The review will, in general, discuss and evaluate the different aspects of the DBG in the order in which they appear in the draft guidance document. 1-3 API PUBLS4bLO 95 0732290 0542024 484 Section 2 CHEMICALS WI
46、TH BIOCONCENTRATION POTENTIAL IN PERMITTED EFFLUENTS FROM OIL INDUSTRY OPERATIONS INTRODUCTION NPDES-permitted, treated effluents from oil refineries, petroleum product marketing terminals, and oilgas production platforms (produced water) often contain low or trace concentrations of a wide variety o
47、f chemicals. Some of the nonpolar (unionizable) chemicals in these effluents have a strong potential to bioconcentrate, as defined in the DBG. The DBG criteria for identifying potentially bioconcentratable organic chemicals are: concentration in the effluent greater than 100 ng/L (0.1 pg/L or parts
48、per billion); and log octanovwater partition coefficient (log Kow) greater than 3.5. The concentration criterion is the lowest concentration at which adequate quantification can occur with the analytical methods proposed in the DBG. The value of 100 ng/L also is the approximate solubility in fiesh w
49、ater of a nonpolar organic chemical with a log Lw of about 8.2 (Brggemann and Altschuh, 1991), the highest log KO, used in the bioconcentration assessment. The log KW criterion was based on the observation that nonpolar organic chemicals with log KOw values lower than 3.5 do not bioconcentrate to any great extent in aquatic organisms. Only organic chemicals that meet the above criteria are considered. Metals and polar (ionizable) organic chemicals were not considered in the DBG. This section of the review provides a summary of the published scientific literature on the ident
