1、 Chemical Human Health Hazards Associated With Oil Spill ResponseRegulatory Analysis and Scientific AffairsPUBLICATION NUMBER 4689AUGUST 2001CHEMICAL HUMAN HEALTH HAZARDSASSOCIATED WITH OIL SPILL RESPONSEPrepared for theAmerican Petroleum Institute1220 L Street, NWWashington, DC 20005Prepared byEvan
2、 C. ThayerAnita George-AresRobert T PlutnickRuth A. KaufmanExxon Biomedical Sciences, Inc.Mettlers Rd. CN 2350East Millstone, NJ 08875-2350August 2001FOREWORDAPI PUBLICATIONS NECESSARILY ADDRESS PROBLEMS OF A GENERAL NATURE.WITH RESPECT TO PARTICULAR CIRCUMSTANCES, LOCAL, STATE, AND FEDERALLAWS AND
3、REGULATIONS SHOULD BE REVIEWED.API IS NOT UNDERTAKING TO MEET THE DUTIES OF EMPLOYERS,MANUFACTURERS, OR SUPPLIERS TO WARN AND PROPERLY TRAIN AND EQUIPTHEIR EMPLOYEES, AND OTHERS EXPOSED, CONCERNING HEALTH AND SAFETYRISKS AND PRECAUTIONS, NOR UNDERTAKING THEIR OBLIGATIONS UNDERLOCAL, STATE, OR FEDERA
4、L LAWS.NOTHING CONTAINED IN ANY API PUBLICATION IS TO BE CONSTRUED ASGRANTING ANY RIGHT, BY IMPLICATION OR OTHERWISE, FOR THEMANUFACTURE, SALE, OR USE OF ANY METHOD, APPARATUS, OR PRODUCTCOVERED BY LETTERS PATENT. NEITHER SHOULD ANYTHING CONTAINED INTHE PUBLICATION BE CONSTRUED AS INSURING ANYONE AG
5、AINST LIABILITYFOR INFRINGEMENT OF LETTERS PATENT.All rights reserved. No part of this work may be reproduced, stored in a retrieval system, or transmitted by anymeans, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission from thepublisher. Contact the publ
6、isher, API Publishing Services, 1220 L Street, N.W., Washington, D.C. 20005.Copyright 2001 American Petroleum InstituteACKNOWLEDGMENTSThe following people are recognized for their contributions of time and expertise during thepreparation of this report:API STAFF CONTACTThomas Purcell, Regulatory Ana
7、lysis and Scientific AffairsMEMBERS OF THE OIL SPILL SCIENCE AND TECHNOLOGY WORK GROUPDavid Fritz, Chairperson, BPDan Allen, Chevron North America E however , the shor t -t er m heal th hazar ds t ohuman heal t h f r om pet rol eum spil l s have not been discussed in det ai l (AP I , 1997). It is im
8、portant to understand potential hazards associated with an oil spill so that efforts can bemade to reduce acute health impacts, particularly during emergency response. The potentialhealth hazards from a petroleum spill depend on many factors, the most important are the: Chemical and physical propert
9、ies and composition of the petroleum product; Environmental conditions both during and after the release; Location and types of tasks performed by the oil spill workers; Control measures used to minimize worker exposure.The objective of the report is to identify the potential chemical health hazards
10、 and provideinformation on exposure to spilled petroleum products. The report is not intended to be used as afield guide during cleanup operations following a spill. Physical hazards, such as slips, trips,falls, fire, and explosion are important, but are not discussed in this report.Hazard identific
11、ation is the first step in the process of linking scientific information abouthazards (risk assessment) to the decision-making process (risk management) during which thesehazards are mitigated. Figure 1-1 shows the elements of risk assessment and risk managementand highlights the risk assessment pro
12、cess covered in this report.Hazard identification is defined as the process of determining whether exposure to an agent cancause an increase in the incidence of a health condition (EPA, 1992). In order to identify theoverall health hazards, the toxicological properties of each petroleum constituent
13、were reviewed1-2Research Risk Assessment Risk ManagementFigure 1-1. Elements of Risk Assessment and Risk Management (modified from NRC 1993).due to the poor health hazard information available on oils as a whole. Information used tocompile this summary includes toxicology databases, case histories o
14、f oil spill drills and actualincidents, as well as model data. Little relevant information on exposure to oil spill responders isavailable in the literature. Factors evaluated include chronic and acute toxicity by the two majorroutes of exposure (dermal and inhalation), and the component concentrati
15、ons in the commonpetroleum products. These factors are summarized in Table 2-1.The following topics are discussed: Identification of the most commonly spilled petroleum products; Review of their overall potential health hazards as well as those associated with theircomponents of concern; Summarizati
16、on of the relevant environmental fate of petroleum products; Additional considerations related to health hazard assessment.This document is intended to provide general guidance for oil spill response planning.Therefore, conclusions reached may not apply to all situations. Actual health concerns may
17、varyEvaluation of publichealth, economic, social,political consequencesof control options.Decisions and actions.Laboratory and fieldobservations ofadverse effects andexposures tohazards.Hazard Identification(Does the hazard orsafety threat cause anadverse effect tohuman health/safety?)Exposure-Respo
18、nseAssessment (What isthe relationshipbetween themagnitude of exposureand the probability ofoccurrence?)Field measurements,observations,estimated exposures.Development ofcontrol options.Exposure Assessment(what exposures arecurrently experiencedor anticipated underdifferent conditions?Risk Character
19、ization(What is the estimatedincidence of the adverseeffect in a givenpopulation?)1-3depending upon product composition, environmental conditions, worker training, and otherfactors. Where potential exposures are uncertain, air monitoring and/or conservative protectivemeasures are recommended.2-1Sect
20、ion 2ENVIRONMENTAL FATE AND EXPOSURE CONSIDERATIONSThis section describes the environmental fate processes and provides a brief overview of someconsiderations that need to be included in discussions about potential exposure. The informationfound in this section is based on referenced literature (F i
21、ngas, 1994, 1995; GE SAMP, 1993;Koons and Jahns, 1992; Mielke, 1990; NRC, 1985, 1989). A more complete description of theenvironmental fate and effect processes are found in the Fate and Environmental Effects of OilSpills in Freshwater Environments (API, 1999).ENVIRONMENTAL FATEIntroductionWhen oil
22、is released into the environment, numerous processes begin to affect the environmentalfate of oil components and the chemical-physical properties of the oil. The composition andphysical/chemical properties of crude oil and refined products are variable; therefore, no twocrude or refined oils will be
23、have exactly the same in the environment. In addition,meteorological and oceanographic conditions will affect the movement and weathering of oil.Spreading, drift, evaporation, dissolution, and dispersion are processes that begin immediatelyonce oil is spilled. Figure 2-1 illustrates these processes.
24、 One process can occur at a greaterrelative magnitude than another process. For example, in the early phases of an oil spill,spreading occurs at a greater rate than oil drift. Dispersion of oil occurs at a greater magnitudethan dissolution since only small amounts of oil components are soluble in wa
25、ter.Emulsification, sedimentation, biodegradation, and photooxidation can occur within the first dayof a spill, but these processes are not as predominant as spreading, evaporation, and dispersion.Some of the fate processes, for example, evaporation, may be most relevant to human healthexposure. Oth
26、er processes, such as photooxidation and sedimentation, are not importantdeterminants of human exposure. The major processes are discussed here to provide a generalunderstanding of the environmental fate of spilled oil.2-2Figure 2-1. Processes Acting on Spilled Oil (Exxon, 1985)SpreadingS pr e adi n
27、g is vari a bl e , depending on the t y pe of oil spi l l ed. I f a light oi l is spil l e d, it begi ns tospr ead imm e di a t el y and r a pi d l y. I n the hour s fol lowi n g a spi ll , as the layer of oil thins, the rat e of spr eadi n g decreases. Som e oi ls, generall y those wi t h a speci f
28、i c gr avi ty gr eater t h an 1.0 and thosewit h a pour poi n t gr eater t h an the am bi e nt wat e r temper ature, t end to for m lumps and may si nkr at h er than spr ead. S pr e adi ng is cont r ol l ed by oi l vol u m e, vi scosi ty, and surf ace t ensi o n. Sur f ace tensi on and vi scosi tyva
29、r y wi t h tem p eratur e and t ype of oi l . As surf ace t ension increases, spreading becomes less rapid.Weather i ng di mi n i shes spr e adi ng by r educi ng oi l vol u m e and i ncr easi n g oi l densi t y and viscosit y . High vi s cosi t y oi ls spread sl owl y whi le l o w vi s cosi t y oi l
30、 s spread m o re r a pi d l y. T h e type of oil det er m i nes t he rate at which col d wat er t em p er a t ures increase oil vi scosi ty and, t h us, sl o w thespr eadi n g of oi l as well as t h e rate at whi c h hi g her wat er t emper at u res enhance oi l spr e adi ng. 2-3However , r el ati v
31、e t o other cont r ol li ng fact ors, the eff ect s of am bi ent t emper at ure on spr eading areusual ly negl i gi bl e for oi ls, except for high viscosit y oil s such as Bunker C. An oil sl ick contains areas of variable thickness. Under relat ively calm conditi ons, oil sli ckstypically may have
32、 a thick ( 1 mm) ar ea sur rounded by a more extensive thin ( 10 mm) area. Thethi ck por tion contains the greatest vol ume of oil ( approximatel y 90%) while the t hin portion of thesli ck contains the balance. The thin area, however , repr esents 80% t o 90% of the total slick area. L ocal physica
33、l fact ors m ake predicti ons of spr eading di f fi cul t. Wave and wind act ion m odif y oil spr eadi ng. Nat ur al surf ace conver gences (ar eas where curr ent s meet ) or diver gences (ar eas whereadj acent cur r ents m ove i n dif fer ent dir ecti ons) may cause accum ul at i ons or separ at io
34、ns of oi l. As ar esul t, wi ndr ows (st reaks) and oil patches may occur. Spr eading is an i m port ant det erm inant f or r at es of dissol ut ion, di spersion, and photooxi dat ion of oi l. DriftT he com bined acti on of wi nd, sur face curr ent s, and waves causes t he oi l sli ck t o dri f t. P
35、r edi ct i onof sl ick dri f t is necessary f or spil l r esponse pl anni ng and operati ons. Sl ick dri ft is l ar gel yi ndependent of spil l vol ume, spr eadi ng, or weatheri ng. However , a “thick“ sl ick dri f ts f ast er t han a“thin“ sli ck, because wi nd inter acti on is i ncr eased wit h t
36、hi cker oi l i n com pari son t o t hi nner oi l .T herefor e, t he thicker port ions of t he sl ick oft en form the leadi ng edge of an advancing spi ll . Localcondi ti ons such as river outf low, nearshore st ructures, or t he pr esence of surf ace debr is can al soaff ect sli ck dr if t. Evaporat
37、ionE vaporat ion is one of the pri mar y weather ing processes invol ved i n the r emoval of oi l f rom thesea. E vapor ati on begi ns im medi ately upon r elease of oi l and is especi al l y domi nant dur ing the f i rstf ew days of a spi ll . Dur ing evaporat ion, volati l e hydr ocarbon component
38、 s f rom the oi l sl ick escapet o the atm osphere. In t he fi rst f ew days f oll owi ng a spil l, li ght crude oi ls can lose up t o 75% of t heir volume due to evaporati on. Medium cr ude oi ls and heavy crude oi ls may lose up to 40% and10% , respect i vely, of their vol ume t hrough evapor at i
39、on. 2-4Crude oi l is a compl ex m i xt ur e contai ni ng numerous component s wit h dif fer ent vol at il i ti es. Lower m ol ecul ar wei ght com ponents are gener al ly t he most volat il e. T hese component s, such as benzeneand t ol uene, evapor ate r api dl y, typi cal ly i n l ess t han one day
40、. As evaporati on pr oceeds, t he oi l becom es enri ched in non- vol at il e com ponents, higher m ol ecular wei ght hydr ocar bons, andcom pl ex ni tr ogen- sul fur- oxygen com pounds. As low mol ecular wei ght com ponents evapor at e, the physi cal pr oper ti es of the rem ai ni ng oi lchange. F
41、or exam pl e, speci fi c gravi t y and viscosit y of the oil wil l i ncr ease. These changes wi l lt end to retar d the rat e of spreadi ng and evaporat ion. DissolutionDissolut ion is the transf er of sol ubl e hydr ocarbons f rom a sl ick or di spersed oi l int o solut ion inwat er . Di ssoluti on
42、 begi ns im mediatel y af ter a spil l. T he concentr ati on of sol ubl e com ponents i n crude oi l is low, about 10 to 30 ppm . Low m ol ecularwei ght com ponents t end t o be mor e sol uble t han hi gher m olecul ar wei ght component s. The m or epol ar ar om at i c component s ( benzene, tol uen
43、e, xyl enes) t end t o be mor e sol uble t han al kanes (up t oC5) . I n addi ti on, som e of the sul fur -contai ni ng component s and sal t s pr esent i n crude oi l are watersol uble. S ince only a very sm al l fract ion of an oi l sli ck di ssol ves, it is unli kel y that di ssoluti on si gni fi
44、 cant l yaff ects oi l weather i ng. Al though evaporati on occur s mor e rapidly t han di ssol ut i on, dissolut ion isan im por tant pr ocess under condi ti ons when evapor at ion is mi nim al . For example, evapor at ion i snot l ikely t o occur when oi l dr opl et s are di sper sed or when oil i
45、 s trapped under or in ice. DispersionOil can enter wat er natur al ly, wit hout chem i cal enhancem ent, as disper sed dropl ets. The di ameter of di spersed dr oplet s gener al ly ranges fr om 10 t o 100 m m . Di sper si on makes i t dif fi cul t to inter pr et oil concentr ati ons in wat er ( e.
46、g., solubl e oil ) measured beneat h sl i cks. T he di ff icult y li es insepar at i ng water- sol uble component s of oi l from neat oi l droplets pr ior to anal ysi s. Most oil i n t he2-5wat er column under a sli ck is beli eved to be disper sed dropl ets r at her t han t rul y di ssolvedhydrocar
47、 bons. Oil com posit i on, sl i ck t hickness, oi l -wat er inter faci al tensi on, and t ur bul ence ar e factors af fecti ngoil disper si on. Cr ude oi ls and ot her pet rol eum product s cont ai n ni t rogen, sulf ur, and oxygen- containi ng compounds t hat act as sur f ace act ive agent s (surf
48、act ants) . Natural sur factant s inpet roleum tend to r educe the oi l -wat er inter faci al tensi on al lowi ng the oil t o disper se m or e r eadil y. T ur bulence enhances oi l dispersi on by i ncreasi ng the int er act ion bet ween the oi l and water layer s;t herefor e, di sper si on is gr eat
49、er wher e ther e i s high wave energy. Breaki ng waves may ent rai nf ragm ent s of the sl i ck i nto t he upper wat er colum n. The l ar ger , mor e buoyant oi l dr opl et s maysur face and coalesce wit h t he sl ick, whil e small er oi l dropl ets are incor porated i n the wat er col um n. Dispersi on al so occurs i n t he absence of br eaking waves. Oi l dropl ets i n t he water col um n wil lconti nue t o disperse under condi ti ons of tur bulent mi xi ng and cur rents. Use of chem i caldispersant s dur ing spi ll response operati ons all ows disper si on to occur at much lo
