1、 Risk-Based Screening Levels for the Protection of Livestock Exposed to Petroleum HydrocarbonsRegulatory Analysis and Scientific AffairsPUBLICATION NUMBER 4733JULY 2004Risk-Based Screening Levels for the Protection of Livestock Exposed to Petroleum HydrocarbonsRegulatory Analysis and Scientific Affa
2、irs DepartmentAPI PUBLICATION NUMBER 4733JULY 2004PREPARED UNDER CONTRACT BY:Mala Pattanayek and Bridgette DeShieldsBlasland, Bouck, and Lee, Inc.Petaluma, CaliforniaFOREWORDAPI publications may be used by anyone desiring to do so. Every effort has been made bythe Institute to assure the accuracy an
3、d reliability of the data contained in them; however, theInstitute makes no representation, warranty, or guarantee in connection with this publicationand hereby expressly disclaims any liability of responsibility for loss or damage resultingfrom its use or for the violation of any federal, state, or
4、 municipal regulation with which thispublication might conict.All rights reserved. No part of this work may be reproduced, stored in a retrieval system, ortransmitted by any means, electronic, mechanical, photocopying, recording, or otherwise,without prior written permission from the publisher. Cont
5、act the Publisher,API Publishing Services, 1220 L Street, N.W., Washington, D.C. 20005.Copyright 2004 American Petroleum InstituteACKNOWLEDGMENTSAPI would like to acknowledge the following people for their contributions of time and expertise during this study and in the preparation of this report:AP
6、I STAFF CONTACTHarley Hopkins, Regulatory Analysis and Scientic Affairs Department (RASA)MEMBERS OF THE PRODUCTION WASTE ISSUE GROUP (PWIG)Evan Sedlock, ChevronTexaco Energy Technology Company, PWIG ChairmanWORK GROUP MEMBERS AND REVIEWERSJeff Adams, BP America, Inc.Mickey Carter, ConocoPhillipsBill
7、y Clay, Vetta ConsultingMike Firth, ExxonMobil Biomedical SciencesJill Kerr, ExxonMobil CorporationMike Starrett, Oxy PermianRenae Magaw, ChevronTexaco Energy Technology CompanySara McMillen, ChevronTexaco Energy Technology CompanyKaren Christensen, ExxonMobil CorporationTOC-1Table of Contents Secti
8、on 1. Executive Summary 1-1Section 2. Introduction.2-1Section 3. Conceptual Site Model3-13.1 Receptor Evaluation. 3-13.2 Pathway Evaluation 3-13.2.1 Soil Ingestion . 3-13.2.2 Water Ingestion . 3-13.2.3 Direct Ingestion 3-33.2.4 Dermal Absorption. 3-33.2.5 Inhalation . 3-33.2.6 Plant Ingestion. 3-33.
9、3 Summary of the CSM for Livestock. 3-3Section 4. Toxicity Reference Values and Risk-Based Screening Levels4-14.1 Exposure Assessment . 4-14.2 Exposure Assumptions 4-64.2.1 Body Weight 4-64.2.2 Dietary Composition 4-74.2.3 Food Ingestion Rate 4-74.2.4 Incidental Soil Ingestion Rate (IRsoil) 4-74.2.5
10、 Water Ingestion Rate (IRwater) 4-84.2.6 Site Use Factor (SUF). 4-84.3 Effects Assessment 4-94.4 Crude Oil. 4-94.4.1 Development of Crude Oil TRVs for Livestock 4-94.4.2 Development of Crude Oil Drinking Water RBSLs and Soil RBSLs forLivestock 4-124.5 Benzene, Toluene, Ethylbenzene, and Xylene (BTEX
11、) 4-134.5.1 Development of BTEX TRVs for Livestock 4-134.5.2 Development of BTEX Drinking Water RBSLs and Soil RBSLs forLivestock 4-164.6 Polycyclic Aromatic Hydrocarbons (PAHs) . 4-164.6.1 Development of PAH TRVs for Livestock 4-164.6.2 Development of PAH Drinking Water RBSLs and Soil RBSLsfor Live
12、stock. 4-18Section 5. Uncertainty Analysis.5-15.1 Exposure Assumptions 5-15.2 Development of TRVs and RBSLs 5-1TOC-2Section 6. Analysis of Other Guidelines for Livestock Protection .6-16.1 Canada-Wide Standards (CWS; CCME 2000). 6-16.2 Alberta Environment (2001). 6-1Section 7. Summary .7-1Section 8.
13、 References 8-1Tables1. Exposure Assumptions for Livestock.4-22. Toxicity Studies for Mammals Exposed to Petroleum Hydrocarbons4-43. Whole Fresh Crude Oil TRVs and RBSLs for Livestock. 4-114. Benzene, Toluene, Ethylbenzene, and Xylene (BTEX) TRVs for Livestock 4-155. Benzene, Toluene, Ethylbenzene,
14、and Xylene (BTEX) TRVs andRBSLs for Livestock . 4-176. Polycyclic Aromatic Hydrocabon (PAH) TRVs for Livestock. 4-197. Polycyclic Aromatic Hydrocabon (PAH) TRVs and RBSLs for Livestock 4-208. Other Available Toxicity Values and Guidelines for Livestock 6-3Figure1. Conceptual Site Model for Livestock
15、 Exposed to Petroelum Hydrocarbons3-21-11. Executive SummaryLivestock may be exposed to accidental releases of petroleum hydrocarbons at or near exploration andproduction sites and, in these cases, there may be a need to estimate potential risks to these receptors. Aframework was developed to 1) det
16、ermine when livestock should be included in a risk evaluation and 2)estimate risks of petroleum hydrocarbon exposure to livestock. A conceptual site model (CSM) wasdeveloped to assess whether complete and significant exposure pathways for livestock exist at a site.To estimate potential risks in this
17、 screening-level risk assessment, toxicity reference values (TRVs) anddrinking water and soil risk-based screening levels (RBSLs) for petroleum hydrocarbons, including: crudeoil; benzene, toluene, ethylbenzene, and xylene (BTEX); and polycyclic aromatic hydrocarbons (PAHs)were developed for livestoc
18、k. TRVs and RBSLs were developed for the protection of a variety oflivestock including dairy cattle, beef cattle, calves, sheep, goats, camels, and horses.TRVs for petroleum hydrocarbons were based on available toxicity values from studies conducted onlivestock, if available, or on small mammals ext
19、rapolated to be protective of livestock evaluated in thisreport. RBSLs were calculated for the two complete and significant exposure pathways identified in theCSM, drinking water ingestion and incidental soil ingestion. Drinking water and soil RBSLs werecalculated based on the TRVs and the selected
20、exposure assumptions for the livestock.The TRVs and RBSLs developed for this framework were comparable to human health RBSLs as shownin the following table:Toxicity Reference Values (TRVs; mg/kg-bw/day)Livestock Crude Oil Benzene Toluene Ethylbenzene Xylene LMW PAH HMW PAHDairy Cattle 211 5.70 35.6
21、4.65 28.5 0.798 0.160Beef Cattle 211 5.95 37.1 4.86 29.8 0.833 0.167Calves 211 10.3 64.5 8.43 51.7 1.45 0.289Sheep 211 10.0 62.5 8.17 50.1 1.40 0.280Goats 211 11.8 73.6 9.62 58.9 1.65 0.330Camels 211 5.55 34.6 4.53 27.8 0.777 0.155Horses 211 5.67 35.4 4.63 28.4 0.794 0.159Drinking Water Risk-Based S
22、creening Levels (RBSLs; mg/L)Livestock Crude Oil Benzene Toluene Ethylbenzene Xylene LMW PAH HMW PAHDairy Cattle 1,199 32.4 202 26.4 162 4.53 0.907Beef Cattle 1,114 31.4 196 25.6 157 4.40 0.880Calves 293 14.3 89.5 11.7 71.7 2.01 0.402Sheep 855 40.5 253 33.1 203 5.68 1.14Goats 622 34.8 217 28.4 174 4
23、.87 0.974Camels 7,673 202 1,259 165 1,009 28.3 5.65Horses 2,763 74.3 464 60.6 371 10.4 2.081-2Soil Risk-Based Screening Levels (RBSLs; mg/kg)Livestock Crude Oil Benzene Toluene Ethylbenzene Xylene LMW PAH HMW PAHDairy Cattle 47,151 1,273 7,946 1,039 6,367 178 35.7Beef Cattle 44,894 1,266 7,901 1,033
24、 6,331 177 35.5Calves 44,894 2,198 13,715 1,794 10,990 308 61.5Sheep 20,095 953 5,949 778 4,767 133 26.7Goats 17,583 982 6,129 802 4,911 138 27.5Camels 69,522 1,829 11,412 1,492 9,144 256 51.2Horses 28,133 756 4,719 617 3,782 106 21.2mg/kg-bw/day = milligrams per kilogram body weight per day.mg/L =
25、milligrams per liter.mg/kg = milligrams per kilogram.LMW PAH = low molecular weight polycyclic aromatic hydrocarbon.HMW PAH = high molecular weight polycyclic aromatic hydrocarbon.2-12. IntroductionConsumption of petroleum hydrocarbons by livestock has been found to lead to a range of healthproblems
26、, including neurotoxicity (Coppock et al. 1995; Khan et al. 1995), fetal toxicity (Coppock et al.1995), damage to the gastrointestinal tract (Coppock et al. 1996), respiratory system, kidney, and liver(Meadows and Waltner-Toews 1979; Edwards 1985a; Coppock et al. 1995; Coppock et al. 1996; Stober196
27、2). Petroleum ingestion has also been linked to anorexia (Edwards and Zinn 1979), lethargy(Meadows and Waltner-Toews 1979; Edwards 1985b), and fatal poisoning in cattle (Edwards and Zinn1979; Meadows and Waltner-Toews 1979; Edwards and Gregory 1991).The purpose of this study was to develop toxicity
28、values and screening guidelines for evaluating risks tolivestock from exposure to petroleum hydrocarbons. This report addresses how to: (1) determinewhether livestock should be included in a risk evaluation, and (2) estimate risks of petroleum hydrocarbonexposures to livestock.In this report, the ap
29、proach used to develop toxicity values and screening guidelines for livestock frompetroleum hydrocarbon exposures was divided into two steps: The first step included evaluation of the potential for exposure through the development of aconceptual site model (CSM). The second step included development
30、 of Toxicity Reference Values (TRVs) and Risk-BasedScreening Levels (RBSLs) for the protection of livestock.This report focused on whole crude oil and its toxicologically important constituents (i.e. benzene,toluene, ethylbenzene, and xylene BTEX and polycyclic aromatic hydrocarbons PAHs). Metals ca
31、nalso be present in petroleum products, but they are generally not found at high enough concentrations toprovide a significant health risk (Magaw et al., 1999) and therefore metals are not addressed in this report.The approach presented herein is consistent with a screening-level risk assessment and
32、 used aconservative approach to determine potential risks to receptors by comparing exposure levels ofpetroleum hydrocarbons from a site to petroleum hydrocarbon threshold levels protective of livestock.Although threshold values for the protection of livestock have been developed by some agencies (e
33、.g.,Canadian Council of Ministers of the Environment CCME and Alberta Environment), these values areeither region-specific or cover limited constituents of petroleum hydrocarbons. In this study, a moregeneralized approach was used to develop conservative threshold values such as TRVs (i.e., toxicity
34、values) and RBSLs (i.e., guidelines) for petroleum hydrocarbons that can be used to characterize risks tolivestock across a variety of conditions.3-13. Conceptual Site ModelA conceptual site model (CSM) identifies complete and potentially complete exposure pathways andreceptors to be considered in a
35、 risk assessment. If no complete significant pathway(s) exist for exposureof livestock to petroleum hydrocarbons, a screening-level risk evaluation for livestock is not necessary.By definition, if there is little to no significant exposure to a potentially toxic compound, there is little tono likeli
36、hood of significant unacceptable risk to the receptor from that compound. A CSM was developedas presented in Figure 1 to assess the potential for exposures to livestock and the need for a riskevaluation. Components of a CSM generally include receptor evaluation and exposure pathwayevaluation, which
37、are described below.3.1 Receptor EvaluationLivestock that are potentially vulnerable to toxic effects of petroleum hydrocarbons include animals thatcould ingest significant quantities of soil, water, and/or food in oil-contaminated areas. Access to thecontaminated areas is key; cattle, sheep, goats,
38、 and horses that forage in pasture areas are more likely tobe potential receptors, while species that are raised in more confined and controlled conditions, such aschickens or pigs, would have less chance of exposure to petroleum hydrocarbons. Outside of the UnitedStates, other types of livestock an
39、imals may also be exposed to petroleum compounds, such as camels,llamas, oxen, etc. It was assumed that exposures to these receptors would be similar to those of typicallivestock in the United States based on similarities in body weights and feeding habits.3.2 Pathway EvaluationThe pathways by which
40、 livestock could be exposed to petroleum hydrocarbons are incidental soilingestion, water ingestion, and direct ingestion, inhalation, dermal absorption, and plant ingestion. Basedon available information, the primary exposure pathways considered significant in the exposure model asshow in the CSM (
41、Figure 1) included incidental soil ingestion, water ingestion, and direct petroleumproduct ingestion. Inhalation, dermal absorption, and plant ingestion were considered minor pathways forpetroleum hydrocarbons (CCME 2000). The exposure pathways listed above are described in more detailbelow.3.2.1 So
42、il IngestionSoil can comprise a substantial proportion of the livestock diet. Livestock may consume soil inadvertentlyduring grazing (Zach and Mayoh 1984; CCME 2000) or may intentionally ingest salty-tasting soil(Coppock et al. 1995). According to the CCME (2000), cattle are exposed to petroleum hyd
43、rocarbonsprimarily through consumption of contaminated soils, particularly during grazing. The authors state thatthe majority of petroleum hydrocarbon exposure in cattle is due to ingestion of surface soils.3.2.2 Water IngestionChronic exposure through drinking water can be a significant exposure pa
44、thway for livestock (CCME2000). The amount of water ingested by cattle varies according to age, physiological status (growth,fattening, pregnancy, lactation), diet composition, breed, size, and, for all animals, temperature(Agriculture and Agri-Food Canada 2001; National Research Council NRC 1988).3
45、-2Figure 1. Conceptual Site Model for Livestock Exposed to Petroleum HydrocarbonsRelease Secondary Source/Source Mechanism Transport Media Exposure Routes Dairy Cattle Beef Cattle Calves Sheep Goats Camels HorsesExposure pathway is complete; Exposure pathway is complete; Exposure pathway is complete
46、;Exposure is considered significant. However, exposure is not considered significant. Exposure is considered significant.TRVs and RBSLs were developed TRVs and RBSLs were not developed However, this pathway is site-specificfor this pathway in this report. for this pathway in this report. Therefore,
47、TRVs and RBSLs were not developed for this pathway in this report.Major Livestock ReceptorsLeaksDirect ContactVolatilizationRunoffPetroleum SourceSoilsSurface WaterDirect ContactIngestionAirDirect ContactIngestionDirect ContactIngestionInhalationPlant UptakePlant TissueIngestion3-33.2.3 Direct Inges
48、tionCattle may directly ingest crude oil and other petroleum compounds from pools of oil formed by leakingpipelines or storage tanks (Edwards and Zinn 1979; Coppock et al. 1995; CCME 2000) due to curiosity(particularly in young calves; Edwards 1985b), or to add salt to their diet (Edwards 1985b, Cop
49、pock et al.1995). Reported cases include steers consuming petroleum distillate, drinking from a slush pit, anddrinking petroleum from puddles near a tank battery (Edwards and Zinn 1979). Oil and natural gasindustry guidance (API 1997) and many regulatory agencies (e.g., the Railroad Commission of Texas1993) stress the importance of removing free-oil accumulations on the ground that animals couldpotentially ingest.3.2.4 Dermal AbsorptionDermal absorption of petroleum hydrocarbons in livestock is considered a minor exposure pathwaybecause of their thick coats (CCME 2000). While me
