Post on 28-Mar-2015
Risk Assessment Risk Assessment United Creosoting SiteUnited Creosoting Site
TXTX
Anuradha Desai , Alex Figaro, Wei-Chun LinAnuradha Desai , Alex Figaro, Wei-Chun Lin
Hazard Hazard IdentificationIdentification
Risk Risk CharacterizationCharacterization
Toxicity Toxicity AssessmentAssessment
Exposure Exposure AssessmentAssessment
OutlineOutline
OverviewOverview
Problem at the siteProblem at the site
objectives of Risk Assessmentobjectives of Risk Assessment Site BackgroundSite Background Identification of COCsIdentification of COCs Exposure AssessmentExposure Assessment Toxicity AssessmentToxicity Assessment Risk CharacterizationRisk Characterization
Site BackgroundSite Background
United Creosoting SiteUnited Creosoting Site Size 100 acresSize 100 acres Located at Conroe, TexasLocated at Conroe, Texas Operated a wood Operated a wood
preserving facility at the preserving facility at the sitesite
Site DescriptionSite Description 13000 people live within 2 miles of the site.13000 people live within 2 miles of the site. Land use pattern Land use pattern Distribution companyDistribution company Sisco Construction companySisco Construction company Tangle wood east subdivision – residential area, Tangle wood east subdivision – residential area,
supports about 225 residents.supports about 225 residents. Site holds two waste lagoons which are now filledSite holds two waste lagoons which are now filled 35,000 cubic yards of contaminated soil in the two filled waste lagoons and in the residential area. 43,000,000 gallons of contaminated ground water
United Creosoting SiteUnited Creosoting Site
Site historySite history 1946-1972 Operated as a wood treatment facility1946-1972 Operated as a wood treatment facility 1972 Facility was closed and was redeveloped for 1972 Facility was closed and was redeveloped for
light industrial use and a residential area was light industrial use and a residential area was
built adjacent to it.built adjacent to it. 1980 County excavated soil from the site to use as a 1980 County excavated soil from the site to use as a
fill along roads in the area. Subsequent fill along roads in the area. Subsequent
investigation revealed contamination at the siteinvestigation revealed contamination at the site 1983 EPA proposed the site for NPL1983 EPA proposed the site for NPL 1984 Remedial investigation begun1984 Remedial investigation begun
Site History Contd…..Site History Contd…..
1986 EPA issued a record of decision for temporary1986 EPA issued a record of decision for temporary
remedy.remedy. 1989 EPA issued a second record of decision for1989 EPA issued a second record of decision for
removing the contaminants from the soil.removing the contaminants from the soil. 1990 Remedial action began on residential properties1990 Remedial action began on residential properties 1993 Remediation of residential properties was 1993 Remediation of residential properties was
completecomplete 1994 Remedial action began on industrial property1994 Remedial action began on industrial property 1999 Remedial action was completed1999 Remedial action was completed
Site contaminants and operationsSite contaminants and operations
Principal pollutantsPrincipal pollutants Pentachlorophenol (PCP)Pentachlorophenol (PCP) Polycyclic aromatic hydrocarbons (PAHs)Polycyclic aromatic hydrocarbons (PAHs) Chlorinated Dioxins (CDDs)Chlorinated Dioxins (CDDs) Chlorinated furans (CDFs)Chlorinated furans (CDFs)
Site OperationsSite Operations
Treatment of wood under pressure with preservative Treatment of wood under pressure with preservative
chemicals like PCP and creosote.chemicals like PCP and creosote.
Identification of chemicals of concernIdentification of chemicals of concern Sampling locationsSampling locations Tanglewood east division (Residential)Tanglewood east division (Residential) Industrial area of the siteIndustrial area of the site Sampling MediaSampling Media Soil (surface and subsurface)Soil (surface and subsurface) SedimentsSediments GroundwaterGroundwater BiotaBiota AirAir Criteria for screeningCriteria for screening ToxicityToxicity Concentrations in the mediaConcentrations in the media PathwayPathway Fate and transport characteristicsFate and transport characteristics
Chemicals of concernChemicals of concern
Non CarcinogensNon Carcinogens AcenaphtheneAcenaphthene Pentachlorophenol(PCP)Pentachlorophenol(PCP) DibenzofuranDibenzofuran PyrenePyrene NaphthaleneNaphthalene
CarcinogensCarcinogens Benzo-a-pyreneBenzo-a-pyrene Benzo-a-anthraceneBenzo-a-anthracene ChryseneChrysene HxCDDHxCDD HxCDFHxCDF HpCDDHpCDD HpCDFHpCDF PeCDDPeCDD OCDFOCDF OCDDOCDD
Exposure Assessment
Characterization of exposure settingCharacterization of exposure setting Nearest drinking water well is 1.8 miles southeast Nearest drinking water well is 1.8 miles southeast
of the siteof the site Shallow water bearing zone is 25 feet deep and is Shallow water bearing zone is 25 feet deep and is
not used at presentnot used at present Water bearing used for supply is 100 feet deepWater bearing used for supply is 100 feet deep Potentially exposed populationPotentially exposed population Residents (Tanglewood east division)Residents (Tanglewood east division) Onsite workersOnsite workers Workers involved in remediationWorkers involved in remediation
Pathway AnalysesPathway AnalysesSourceSource United Creosoting United Creosoting
facilityfacilityUnited Creosoting United Creosoting facilityfacility
MediaMedia Surface SoilSurface Soil Subsurface SoilSubsurface Soil SedimentSediment
Transport in the Transport in the mediamedia
Contamination Contamination through waste through waste lagoonslagoons
Contamination Contamination through waste through waste lagoonslagoons
Exposure pointExposure point Tanglewood east Tanglewood east division division
Industrial area Industrial area around the sitearound the site
RouteRoute DermalDermal IngestionIngestion
Dermal Dermal IngestionIngestion
Potential Potential ReceptorsReceptors
ResidentsResidents Onsite workersOnsite workers
Remedial workersRemedial workers
Exposure Quantification Exposure Quantification Residential Area (surface soil)Residential Area (surface soil)
Chemicals of ConcernConcentration
1990 Mg/KgConcentration 1985
Mg/KgRBC Mg/Kg/day
Acenaphthene 0.67 2600 3.70E+03
Pentachlorophenol (PCP) 37 150 1.50E+02
Pyrene 160 2800 3
Naphthalene 0.076 ND 2.30E+03
Benzo(a)anthracene 35 2000 1.20E+02
Benzo(a)pyrene 72 650 6.20E-01
Chrysene 97 2000 6.20E-02
PeCDD 0.004 0.0073 6.20E+01
HxCDD 0.203 0.0076 NA
HpCDD 1 0.72 NA
OCDD 2.8 6 NA
HxCDF 0.053 0.14 NA
HpCDF 0.137 0.89 NA
OCDF 0.42 1.5 NA
Exposure QuantificationExposure QuantificationIndustrial area (Subsurface soil)Industrial area (Subsurface soil)
Chemicals of ConcernConcentration (1990) Mg/Kg
Concentration (1985) Mg/Kg RBC Mg/Kg/day
Acenaphthene 220 860 3.30E+04
Dibenzofuran 190 930 1.70E+03
Pentachlorophenol (PCP) 96 1100 1.00E+01
Pyrene 620 1600 3.20E+04
Naphthalene 67 1200 2.10E+02
Benzo(a)anthracene 34 180 2.3
Benzo(a)pyrene 13 5 0.23
Chrysene 35 130 2.30E+02
PeCDD ND 0.021 NA
HxCDD 0.003 0.007 NA
HpCDD 0.072 0.41 NA
OCDD 0.383 0.24 NA
HxCDF 0.005 0.018 NA
HpCDF 0.046 0.037 NA
OCDF 0.066 0.012 NA
Groundwater – (Onsite & vicinity of the Groundwater – (Onsite & vicinity of the residential area)residential area)
Chemicals of ConcernConcentration 1985 Mg/L GW StdsMg/L
Acenaphthene 490 3.70E-02
Pentachlorophenol (PCP) 0.22 5.00E-02
Dibenzofuran 410 1.00E-02
Pyrene 450 1.80E-02
Naphthalene 1,200 3.30E-01
Benzo(a)anthracene ND 1.00E-02
Benzo(a)pyrene ND 1.00E-02
Chrysene ND 1.00E-02
PeCDD 1.80E-06 NA
HxCDD 2.90E-06 NA
HpCDD 6.60E-05 NA
OCDD 4.80E-04 NA
HxCDF ND NA
HpCDF ND NA
OCDF ND NA
Exposure Assessment Contd….Exposure Assessment Contd….
Exposure pathways evaluatedExposure pathways evaluated Ingestion of soil Ingestion of soil Dermal exposure to soilDermal exposure to soil Ingestion of sedimentsIngestion of sediments Dermal exposure to sedimentsDermal exposure to sediments Ingestion of groundwaterIngestion of groundwater
Pathways eliminatedPathways eliminated InhalationInhalation Ingestion of biotaIngestion of biota
Toxicity AssessmentToxicity Assessment Non CarcinogensNon Carcinogens PCPPCP
Detrimental effects on the liver, kidney, lungs, Detrimental effects on the liver, kidney, lungs, nervous system, immune system and GI tract.nervous system, immune system and GI tract.
PyrenePyrene
Attacks the kidney and liverAttacks the kidney and liver AcenaphtheneAcenaphthene
causes irritation to the skin and mucous membranecauses irritation to the skin and mucous membrane DibenzofuranDibenzofuran
Causes rashes, irritation to the skin, nose & throatCauses rashes, irritation to the skin, nose & throat NaphthaleneNaphthalene
Hemolytic anemia. Reduction in the appetite of Hemolytic anemia. Reduction in the appetite of childrenchildren
Toxicity Assessment Contd…Toxicity Assessment Contd…
CarcinogensCarcinogens Benzo-a-Pyrene (Class A carcinogen)Benzo-a-Pyrene (Class A carcinogen)
Associated with dermatotoxicity. Damage to Associated with dermatotoxicity. Damage to
reproductive system.reproductive system. Benzo-a-anthracene / Chrysene (Class 2 carcinogen)Benzo-a-anthracene / Chrysene (Class 2 carcinogen)
Target organs include liver, kidney and fat.Target organs include liver, kidney and fat. Chlorinated DioxinsChlorinated Dioxins
Anticipated to increase the cancer risk at Anticipated to increase the cancer risk at
background levels of exposure. At higher levels background levels of exposure. At higher levels they can cause serious skin diseases.they can cause serious skin diseases.
Risk CharacterizationRisk Characterization SmartRisk software was used to evaluate the cancer and SmartRisk software was used to evaluate the cancer and
the non cancer risk from the chosen exposure routesthe non cancer risk from the chosen exposure routes.. Input to the SmartRiskInput to the SmartRisk Concentrations of the COCsConcentrations of the COCs Slope factors and RfDs (For carcinonogens and non –Slope factors and RfDs (For carcinonogens and non –
carcinogens Respectively)carcinogens Respectively) AssumptionsAssumptions Use of TEFs for the compounds for which slope Use of TEFs for the compounds for which slope
factors/RfDs were not available primarily the Dioxins factors/RfDs were not available primarily the Dioxins and Furans.and Furans.
Groundwater ingestion – The fraction ingested was Groundwater ingestion – The fraction ingested was assumed to be 1 in 1000 of a litre. assumed to be 1 in 1000 of a litre.
Risk Characterization Contd….Risk Characterization Contd….Results Cancer and non cancer risk (1985)Results Cancer and non cancer risk (1985)
Exposure pathway Scenario Adult Child
CancerNon Cancer Cancer
Non cancer
Soil Ingestion Industrial 9.15E-04 1.64E-01
Residential 8.04E-03 1.94E-01 1.50E-02 1.81E+00
Dermal exposure to soil Industrial 3.07E-04 2.82E-02
Residential 3.03E-03 3.90E-02 3.80E-03 2.45E-01
Sediments Ingestion Industrial 2.52E-04 2.57E-03
Dermal exposure to sediments Industrial 1.85E-04 1.03E-03
Groundwater Ingestion Industrial 1.31E-10 1.81E-04
Results Cancer and non cancer risk: Results Cancer and non cancer risk: Sampling year 1990Sampling year 1990
Exposure pathway Scenario Adult Child
Cancer Non Cancer Cancer Non cancer
Soil Ingestion Industrial 7.77E-05 3.67E-02
Residential 4.00E-03 9.00E-03 7.54E-03 8.42E-02
Dermalexposure to soil Industrial 6.40E-05 6.04E-03
Residential 2.96E-03 2.61E-03 3.72E-03 1.64E-02
Cancer Risk Cancer Risk
Industrial scenarioIndustrial scenario
Adult – Soil Ingestion pathway -9.15e-4Adult – Soil Ingestion pathway -9.15e-4
Non cancer RiskNon cancer Risk
Industrial ScenarioIndustrial Scenario
Adult – Soil Ingestion pathway – 1.64e-1Adult – Soil Ingestion pathway – 1.64e-1
Cancer RiskCancer Risk
Residential ScenarioResidential Scenario
Adult – Soil IngestionAdult – Soil Ingestion – 8.04e-3 – 8.04e-3
Cancer RiskCancer Risk Residential scenarioResidential scenario
Child – Soil Ingestion – 1.5e-2Child – Soil Ingestion – 1.5e-2
Cancer RiskCancer Risk
ResidentialResidential
Adult – Dermal exposure to soil – 3.03e-3Adult – Dermal exposure to soil – 3.03e-3
Cancer RiskCancer Risk
Residential Residential
Child Dermal Exposure to soil – 3.83e-3Child Dermal Exposure to soil – 3.83e-3
Cancer RiskCancer Risk
IndustrialIndustrial
Adult – Dermal exposure to sediments – 1.85e-4Adult – Dermal exposure to sediments – 1.85e-4
Cancer riskCancer risk
IndustrialIndustrial
Adult – Soil Ingestion (1990) - 7.77e-5Adult – Soil Ingestion (1990) - 7.77e-5
Comparison of cancer risk for 1985 & 1990Comparison of cancer risk for 1985 & 1990AdultAdult
0.00E+00
1.00E-03
2.00E-03
3.00E-03
4.00E-03
5.00E-03
6.00E-03
7.00E-03
8.00E-03
9.00E-03
Risk
Soil Ingestion(industrial)
Soil Ingestion(Residential)
Dermal exposure(industrial)
Dermal exposure(Residential)
Scenario
Cancer Risk (Adult)
1985
1990
Comparison of cancer risk for child for Comparison of cancer risk for child for 1985 & 19901985 & 1990
0.00E+00
2.00E-03
4.00E-03
6.00E-03
8.00E-03
1.00E-02
1.20E-02
1.40E-02
1.60E-02
Risk
Soil Ingestion (Residential) Dermal exposure (Residential)
Scenario
Cancer Risk (Child)
1985
1990
Non cancer risk summaryNon cancer risk summaryFemales HI CoC
Pathway Scenario Adult Child Adult Child
Soil Ingestion Industrial 1.64E-01 No
Residential 1.94E-01 1.81E+00 No Yes
Dermal exposure to soil Industrial 2.82E-02 No
Residential 3.90E-02 2.45E-01 No No
Sediments Ingestion Industrial 2.57E-03 No
Dermal exposure to sediments Industrial 1.03E-03 No
Groundwater Ingestion Industrial 1.81E-04 No
Mortality rates observed during the year Mortality rates observed during the year 1981-891981-89
ConclusionsConclusions Ingestion and dermal exposure to contaminated soil and Ingestion and dermal exposure to contaminated soil and
sediments are potential exposure pathways for industrial sediments are potential exposure pathways for industrial workers as well as residents of Tanglewood east workers as well as residents of Tanglewood east subdivision.subdivision.
Ground water ingestion is not a pathway of concern.Ground water ingestion is not a pathway of concern. The non cancer risk is greatest for children for The non cancer risk is greatest for children for the soil ingestion pathway.the soil ingestion pathway. The cancer risk in the year 1990 for the The cancer risk in the year 1990 for the industrial workers has reduced considerably to what was industrial workers has reduced considerably to what was in the year 1985. in the year 1985. However residents are still a potential receptor population However residents are still a potential receptor population
for exposure to contaminated soil and sediment.for exposure to contaminated soil and sediment. The site posed a public health hazard in 1985.The site posed a public health hazard in 1985. However as of 1999 the site has been remediated and However as of 1999 the site has been remediated and
therefore may not pose a public health hazard at present.therefore may not pose a public health hazard at present.
ReferencesReferences
http://www.epa.gov/earth1r6/6pd/rcra_c/pd-o/midlhttp://www.epa.gov/earth1r6/6pd/rcra_c/pd-o/midlo.htmo.htm
http://www.atsdr.cdc.gov/HAC/PHA/ucc/ucc_toc.hhttp://www.atsdr.cdc.gov/HAC/PHA/ucc/ucc_toc.htmltml
http://risk.lsd.ornl.gov/cgibin/tox/TOX_select?selehttp://risk.lsd.ornl.gov/cgibin/tox/TOX_select?select=csfct=csf
http://www.epa.gov/iris/http://www.epa.gov/iris/