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PUBLIC HEALTH ASSESSMENT

POPILE, INCORPORATED
EL DORADO, UNION COUNTY, ARKANSAS


Sediment

On-site sediment samples were collected during the RI in February and March 1992 from the same two locations(SW-4 and SW-5) where the surface water samples were taken (see Figure 6).

Analytical results from the sediment samples (Table 6) indicated the presence of several PAHs and phenols. However, the phenols concentrations did not exceed ATSDR's comparison values. The sediment samples were notanalyzed for metals. The sampling data indicate that site contaminants have been transported along surface drainagepaths.

Table 6.

Contaminant Concentrations in On-Site Sediments
Contaminant Concentration
Range -
ppm (mg/kg)
Sample
Date
ReferenceComparison Value
ppm
(mg/kg)
Source
PAHs
Phenanthrene0.15J2/92,3/921None  
Benzo(b/k)fluoranthene1.1J 2/92,3/921None  
Benzo(a)pyrene1.3J2/92,3/9210.1CREG
Indeno(1,2,3-cd)pyrene5.2J2/92,3/921None  
Benzo(g,h,i)perylene0.19J2/92,3/921None  
Total PAHs1.38 - 8.032/92,3/921None  
B(a)P Equivalents0.0 - 1.932/92,3/9210.1CREG
Phenols
2-Chlorophenol1.00 - 1.702/92,3/921300RMEG
3-Methylphenol0.280 - 1.40 2/92,3/9213,000RMEG
PentachlorophenolND2/92,3/9216CREG

Ambient Air

Ambient air samples were collected during the August 1990 site investigation. Samples were gathered usingAnderson Model PS-1 High Volume Air Samplers at seven locations (as shown in Figure 5) on the site and aroundthe site perimeter. (The perimeter air samples are considered off-site samples and are discussed in the Off-SiteContamination section of this document.) The samples were analyzed for selected semi-volatile organic compounds(anthracene, phenanthrene, fluoranthene, and pentachlorophenol) and TCDD equivalents.

As shown in Table 7, all four of the semi-volatile compounds were detected along with low levels of TCDDequivalents. The air concentrations were generally highest on the north and central areas of the site and somewhatlower at the northern end of the site.

Table 7.

Contaminant Concentrations in On-Site Ambient Air Samples
Contaminant Concentration
Range -
µg/m3
Sample
Date
Reference Comparison Value
µg/m3 Source
PAHs
Phenanthrene 0.57 - 0.87 8/90 1 None  
Anthracene 0.03 - 0.05 8/90 1 None  
Fluoranthene 0.30 - 0.56 8/90 1 None  
Total PAHs 0.898 - 1.44 8/90 1 None  
PHENOLS
Pentachlorophenol 0.24 - 1.2 8/90 1 None  
DIOXINS/FURANS
TCDD Equivalents 0.00000006 -
0.00000476
8/90 1 None  

B. Off-Site Contamination

Sludge

As previously discussed, samples of waste sludges were collected in May 1991 from areas east of the railroad tracks. The samples taken east and southeast of the clearing (samples 3S and 4S) and those from across Bayou de Loutre(samples 9S-14S) are considered "off-site" samples for the purposes of this health assessment (see Figure 4). Theanalytical results from these samples are discussed below.

As shown in Table 8, the sludge samples contained the PAH compounds benzo(b)fluoranthene, benzo(k)fluoranthene,and benzo(a)pyrene and several metals, including arsenic, cadmium, chromium, and lead. The contaminantconcentrations were generally similar to those found in on-site sludge samples. In addition, the metals present were atlevels similar to background soil concentrations for the eastern U.S. (7), except for lead, which was elevated. Thesludge arsenic levels exceeded the applicable ATSDR comparison value.

Table 8.

Contaminant Concentrations in Off-Site Waste Materials (Sludges)
Contaminant Concentration
Range -
ppm (mg/kg)
Sample
Date
ReferenceComparison Value
ppm
(mg/kg)
Source
PAHs
Benzo(b)fluorantheneND - 1.65/911None  
Benzo(k)fluorantheneND - 9.65/911None  
Benzo(a)pyreneND - 13.05/9110.1CREG
Total PAHsND - 24.25/911None  
B(a)P EquivalentsND - 14.15/9110.1CREG
METALS
Arsenic0.56 - 15.75/9110.4CREG
Cadmium0.24 - 0.505/91110EMEG
Chromium2.1 - 33.35/911300RMEG
Lead4.5 - 8305/911None  

Surface Soil

Off-site soil samples (Figure 4, samples 2, 15-17, and 21-23) were collected outside the site perimeter in May 1991 inconjunction with the 1990-1991 Removal Action. Although the depth of the samples was not reported, the July 1992EPA Risk Assessment refers to them as "surface soil samples". Therefore, the May 1991 samples will be considered"surface" soil samples for the purposes of this public health assessment.

Analytical results from the surface soil samples (Table 9) indicated the presence of several PAHs, metals, and dioxins. The contaminant levels were generally similar to the levels measured in the 1991 on-site surface soil samples. Inaddition, the concentrations of metals were similar to background concentrations for the eastern U.S. (7).

Table 9.

Contaminant Concentrations in Off-Site Surface Soil
Contaminant Concentration
Range -
ppm (mg/kg)
Sample
Date
ReferenceComparison Value
ppm
(mg/kg)
Source
PAHs
PhenanthreneND - 0.585/911None  
Benz(a)anthraceneND - 2.45/911None  
ChryseneND - 3.35/911None  
Benzo(b)fluorantheneND5/911None  
Benzo(k)fluorantheneND - 3.65/911None  
Benzo(a)pyreneND - 2.05/9110.1CREG
Indeno(1,2,3-cd)pyrene1.3 - 2.05/911None  
Dibenzo(a,h)anthraceneND - 0.575/911None  
Benzo(g,h,i)perylene1.0 - 1.25/911None  
DIOXINS/FURANS
HxCDD (total)0.00040 -0.008995/9110.00011CREG
TCDD Equivalents0.00002 -0.001345/9110.00005EMEG
METALS
Arsenic0.76 - 13.75/9110.4CREG
Cadmium0.23 - 0.285/91110EMEG
Chromium2.0 - 1395/911300RMEG
Lead6.1 - 1105/911None  

Groundwater

Off-site groundwater samples were collected from Monitoring Well No. 14 (MW-14) which was installed in March1992 during the RI field activities. This well was designated as a "deep" monitoring well in the RI report since it isscreened at a depth of 43-53 feet below ground surface. As shown in Figure 7, MW-14 is located northeast of the siteacross Bayou de Loutre (approximately 350 feet), and is considered to be downgradient of the site.

Groundwater samples from MW-14 were analyzed for VOCs, PAHs, and phenols, but not for metals. Nocontaminants were detected in the samples from MW-14, except acenaphthene, which was reported at a very lowlevel. However, it is possible that acenaphthene was not actually present in the groundwater samples since thereported concentration was an "estimated" value. These and other sampling results suggest that groundwatercontamination downgradient of the site does not extend beyond Bayou de Loutre.

No other off-site groundwater data were found during the development of this document. However, as previouslydiscussed, data from Monitoring Wells 8, 9, and 11, located along the south and southwest site boundary, indicate thatgroundwater contamination is not likely to extend significantly upgradient of the site.

Surface Water

Surface water samples were collected from Bayou de Loutre upstream and downstream of the site during the October1989 SA and during the Feb.-Mar. 1992 RI. Sample points 71 (SA) and SW-1 (RI) were located just upstream of thesite near the South West Road bridge, while sample points 72 (SA) and SW-2 (RI) were just downstream of therailroad bridge. RI sample point SW-3 was situated approximately 1000 feet downstream of the railroad bridge. Thelocations of the SA and RI surface water samples are shown in Figures 5 and 6, respectively.

Except for toluene and xylene, which were detected at very low levels, no organic contaminants were found in any ofthe RI surface water samples. In the SA samples, low levels of three volatile compounds were present, possibly as aresult of laboratory contamination. As shown in Table 10, several metals were found in the SA and RI surface watersamples. However, the levels measured were generally similar upstream and downstream of the site with a fewexceptions. These included arsenic, lead, and thallium which were found in greater concentration just downstream ofthe railroad tracks.

Table 10.

Contaminant Concentrations in Off-Site Surface Water (Bayou de Loutre)
Contaminant Concentration
Range -
ppb
Sample DateReferenceComparison Value
ppbSource
METALS
AntimonyND - 9810/8913LTHA
Arsenic3 - 240B10/89; 2/92, 3/9210.02CREG
Beryllium3.0B - 6.0B2/92, 3/9210.008CREG
Chromium7.0B - 2210/89; 2/92, 3/921None  
Lead2 - 52B10/89; 2/92, 3/921None  
Thallium93B - 204B2/92, 3/9210.4LTHA

Sediment

Sediment samples were collected during the 1989 SA and 1992 RI from the same locations in Bayou de Loutre wherethe surface water samples were taken. One additional sediment sample (no. 20) was taken during the SA justupstream of the railroad bridge (see Figures 5 and 6).

As shown in Table 11, substantial levels of PAHs and dibenzofuran were found in the sediment samples. Severalmetals were present at levels similar to background soil levels for the eastern U.S., except for thallium, which waselevated (7). Phenols were also found in some samples but, for the most part, their concentrations did not exceedapplicable ATSDR comparison values. It should be noted that some PAHs and phenols, especiallypentachlorophenol, from the RI were reported to be present at levels higher than those shown in Table 11. This isbecause the table does not include analytical data flagged with a "R" qualifier by the EPA data validation program,signifying that the data were "rejected and unusable for any purpose" (1).

The most heavily contaminated sediment samples were those collected near the railroad bridge, just downstream ofwhere site drainage historically entered the Bayou. The samples taken upstream and far downstream of the northernend of the site were relatively uncontaminated. These findings suggest that surface drainage from the site has resultedin contamination of sediments in the Bayou at the northern end of site. In addition, the sampling results indicate thatmany site contaminants, especially PAHs and phenols, entering the Bayou from seepage or surface drainage areadsorbed by suspended solids and subsequently deposited in the bottom sediments.

Table 11.

Contaminant Concentrations in Off-Site Sediments (Bayou de Loutre)
Contaminant Concentration
Range -
ppm (mg/kg)
Sample DateReferenceComparison Value
ppm
(mg/kg)
Source
PAHs
Naphthalene3.37D - 15010/89; 2/92, 3/921,3None  
Phenanthrene0.382D - 32010/89; 2/92, 3/921,3None  
Benz(a)anthracene0.801D - 2910/89; 2/92, 3/921,3None  
Chrysene0.25 - 3110/89; 2/92, 3/921,3None  
Benzo(b)fluoranthene0.271D - 1110/89; 2/92, 3/921,3None  
Benzo(k)fluoranthene0.217D - 1510/89; 2/92, 3/921,3None  
Benzo(a)pyrene0.258D - 9.610/89; 2/92, 3/921,30.1CREG
Total PAHs19.4 - 1,38010/89; 2/92, 3/921,3None  
B(a)P Equivalents0.392 - 15.410/89; 2/92, 3/921,30.1CREG
PHENOLS
4,6-Dinitro-2-methylphenolND - 1.1J2/92, 3/921None  
DIOXINS/FURANS
Dibenzofuran47 - 13010/891,3None  
2,3,7,8-TCDDND2/92, 3/9210.00005CREG
TCDD Equivalents0.0000 - 0.005210/89; 2/92, 3/921,30.00005CREG
METALS
Arsenic1.0 - 24.5B10/89; 2/92, 3/9210.4CREG
Beryllium0.63B - 110/89; 2/92, 3/921,30.2CREG
CadmiumND - 1.32/92, 3/92110EMEG
Chromium5.9 - 5010/89; 2/92, 3/921,3300RMEG
Copper2.5B - 1710/89; 2/92, 3/921,3None  
Lead7.0 - 14.810/89; 2/92, 3/921None   
Thallium36.1 - 41.92/92, 3/9214RMEG

Ambient Air

Ambient air samples were collected near the southern/southwestern site perimeter during the August 1990 siteinvestigation. The locations of the these two sampling stations (PS6 and PS32) are shown in Figure 5.

As shown in Table 12, contaminant levels detected in the perimeter samples, which were located in the generaldirection of the residences along South West Avenue, were significantly lower (except for anthracene) than the levelsfound in the samples from the central and northern areas of the site.

Table 12.

Contaminant Concentrations in Off-Site (Perimeter) Ambient Air Samples
Contaminant Concentration
Range -
µg/m3
Sample
Date
ReferenceComparison Value
µg/m3Source
PAHs
Phenanthrene0.02 - 0.058/901None   
Anthracene0.048/901None  
Fluoranthene0.02 - 0.048/901None  
Total PAHs0.095 - 0.118/901None  
PHENOLS
Pentachlorophenol0.208/901None  
DIOXINS/FURANS
TCDD EquivalentsND -0.000000208/901None  

C. Toxic Chemical Release Inventory

The Toxic Chemical Release Inventory (TRI) is a series of files for the reporting years of 1987,1988, 1989, and 1990 which contain information on estimated annual releases of toxic chemicalsto the environment (air, water, land, or underground injection) by certain industries and is basedon data collected by the EPA.

To identify facilities that could contribute to the air, surface water, and soil contamination nearthe Popile, Inc. site, ATSDR searched the 1987, 1988, 1989, and 1990 TRI. This search revealedthat various toxic chemicals had been released to land, surface water, groundwater, and air byindustries in the El Dorado area. However, it cannot be determined from the TRI informationwhether these releases have contributed to contamination at the site or whether individuals in thesite area have been exposed to contaminants from the releases. Therefore, the results from theTRI search will not be considered further in this health assessment.

D. Quality Assurance and Quality Control

Information reviewed for this health assessment, including laboratory reports and data summarysheets, indicate that appropriate quality assurance/quality control (QA/QC) measures weregenerally followed during the previous data collection, handling, and analysis activities at the site. RI/FS documents, for example, report that samples, including duplicates, blanks, and rinsates,were collected and analyzed in accordance with the QA requirements of the RI/FS Sampling andAnalysis Plan.

At the time the RI/FS report was prepared, standard validation of the RI/FS lab data had not beencompleted. However, the majority of the data (referred to as QTM data) had been electronicallyvalidated by the EPA Computer Aided Data Review and Evaluation Program (CADRE). Approximately 0.5 percent of the VOC results, 19 percent of the PAH results, and 17 percent ofphenol results were rejected during the CADRE validation (1), and, therefore, were not used inthe development of this public health assessment. The rejection of QTM data, especially datafrom samples with potentially high concentrations of contaminants, may cause some exposures tobe underestimated. In addition, lack of validation of the remaining data (referred to as SAS data),increases the uncertainty of the estimated exposures.

QA/QC measures were also employed during the October 1989 Site Assessment activities.Specifically, samples were collected, packaged, shipped, and analyzed in accordance with EPAContract Laboratory Program (CLP) guidelines and the specifications of the SA Sampling QA/QCPlan. In addition, the resulting laboratory data were reportedly validated by EPA Region VI,Environmental Services Division (3).

E. Physical and Other Hazards

No significant physical hazards were observed at the site during the September 1992 ATSDR sitevisit. However, moving timber trucks and freight trains, which frequently pass by the site, couldrepresent a minor hazard to individuals walking around the site perimeter.


PATHWAYS ANALYSES

To determine whether individuals in the site area are exposed to site-related contaminants, ATSDR evaluates theenvironmental and human exposure components that lead to human exposure. This pathways analysis consists of fiveelements: a source of contamination; environmental medium in which the contaminants may be present or maymigrate; points of human exposures; routes of human exposure such as inhalation, ingestion, and dermal absorption;and a receptor population. The first three elements represent an environmental pathway and the last two elementsrepresent a human exposure pathway.

ATSDR identifies an exposure pathway as completed, potential, or eliminated. Completed exposure pathways requirethat the five elements listed in the previous paragraph exist and indicate that exposure to a contaminant has occurredin the past, is currently occurring, or will occur in the future. Potential exposure pathways require that at least one ofthe five elements is missing but could exist. Potential pathways indicate that exposure to a contaminant could haveoccurred in the past, could be occurring now, or could occur in the future. An exposure pathway can be eliminated ifat least one of the five elements is missing and will never be present. Completed and potential exposure pathwaysmay also be eliminated when they are no longer likely to exist or are not significant.

Completed and potential exposure pathways for the Popile, Inc. site are summarized in Table 13 of this section. Estimates of the number of exposed individuals for completed exposure pathways and the number of potentiallyexposed individuals for potential exposure pathways is shown in Tables 14 and 15, respectively. The discussion thatfollows these tables includes only those pathways that are believed to be important or relevant to the site. However,exposure pathways that have been eliminated are also discussed.

Table 13.

Completed and Potential Exposure Pathways
Pathway NameExposure Pathway ElementsTime
SourceMediumPoint of ExposureRoute ofExposureExposedPopulation
Completed Exposure Pathways
Worker-WasteMaterialWood-treatmentchemicals andwaste materials Source chemicals; waste materials;
soil;
groundwater
Wood treatment areas;
waste disposal areas;
contaminated soil areas
Skin contact
Ingestion
Inhalation
Facility employees;
site workers
Past
Surface Water/SedimentSite drainage;stormwaterrunoff; seepagefrom wasteimpoundmentsSurface Water;SedimentsBayou de Loutre Skin contact
Ingestion
Recreationalusers of Bayoude Loutre (eg.fishermen /waders Past
Present
Future
Potential Exposure Pathways
Ambient AirFugitive dusts;gaseous vaporsAirSite areas and siteperimeterInhalationSite workersPast
Surface SoilOn-sitecontaminatedsoilsSurface SoilContaminated soilareas Skin contact
Ingestion
Site visitors /trespassers Past
Present
Future
Private WellsContaminatedsoil /groundwaterGroundwater Nearby residences or businesses (downgradient of the site) where private wells are used;
future on-site industrial or residential drinking water wells
Ingestion
Skin contact
Inhalation
Nearbyresidents;future siteworkers orresidentsFuture
FishSurface water /sedimentcontamination(from sitedrainage;stormwaterrunoff; seepagefrom wasteimpoundmentsFishResidences or otherplaces where fish areeatenIngestionBayou deLoutre fisheaters Past
Present
Future

Table 14.

Estimated Populations for Completed Exposure Pathways
ESTIMATED EXPOSED POPULATIONS THAT ARE AFFECTED BY A COMPLETED EXPOSURE PATHWAY*
EXPOSED POPULATIONS COMPLETED EXPOSURE PATHWAY FOR:
Location Est.
Number
VOCs
(ex. toluene)
PAHs
(ex. benzo(a)-pyrene)
Phenols
(ex. pentachloro-phenol)
Furans/
Dioxins
(ex. dibenzo-furan)
Heavy Metals
(ex. lead)
Former facility employees and site workers Not knownWorker-WasteMaterial Worker-Waste Material;
Ambient Air
Worker-Waste Material;
Ambient Air
Worker-Waste Material;
Ambient Air
Worker-WasteMaterial
Recreational users of Bayou de Loutre Not known Surface Water/
Sediment
Surface Water/
Sediment
Surface Water/
Sediment
Surface Water/
Sediment
Surface Water/
Sediment
* Refer to Table 13 for summary of completed exposure pathways.

Table 15.

Estimated Population for Potential Exposure Pathways
ESTIMATED POTENTIALLY EXPOSED POPULATIONS THAT ARE AFFECTED BY A POTENTIAL EXPOSUREPATHWAY*
POTENTIALLY EXPOSED
POPULATIONS
POTENTIAL EXPOSURE PATHWAY FOR:
Location Est.
Number
VOCs
(ex. toluene)
PAHs
(ex. benzo(a)-pyrene)
Phenols
(ex. pentachloro-phenol)
Furans/
Dioxins
(ex. dibenzo-furan)
Heavy Metals
(ex. lead)
Site visitors/
trespassers
Not
known
Surface SoilSurface Soil;Surface Soil;Surface Soil;Surface Soil
Persons whoconsume fishfrom Bayou deLoutre Not
known
Not likelyFishFishFishFish
Nearby residents or business persons (downgradient of the site);
Future site workers or residents
NotknownPrivate WellsPrivate WellsPrivate WellsPrivate WellsPrivate Wells
* Refer to Table 13 for summary of potential exposure pathways.

A. Completed Exposure Pathways

Worker-Waste Material Pathway

Previous studies and environmental sampling indicate that chemicals such as creosote and pentachlorophenol thatwere used in wood treatment operations on the Popile site, and waste materials, such as sludges and wastewater, fromthe operations have contaminated site soils and groundwater, with a number of contaminants including VOCs, PAHs,furans/dioxins, phenols, and metals.

Former employees of the wood treatment facility were likely exposed to site contaminants from the handling, spillage,and disposal of creosote and pentachlorophenol; from handling and disposal of waste materials (such as wastewaterand sludge); and from contact with contaminated media such as soil. Exposure to site contaminants could haveoccurred through skin contact, inhalation, and incidental ingestion. The maximum duration of exposure is estimatedto be 35 years since the wood treatment operations began in 1947 and ended in 1982. Actual exposure, however,could have been significantly less depending on how long a worker was employed at the site. The number ofemployees exposed to site contaminants and the extent of exposure and contaminant uptake cannot be estimated withthe information available.

Field workers and other personnel who participated in any of the past site investigations, sampling events, or removalactivities may have been exposed to site contaminants of concern via skin contact, inhalation, and incidental ingestionof waste materials and contaminated soils. However, available information suggests that appropriate personalprotective equipment were utilized as necessary during the various site activities. Therefore, any exposure of theseindividuals to site contaminants was likely insignificant.

Surface Water/Sediment Pathway

Contaminants found in on-site waste materials and soils, including PAHs, phenols, furans/dioxins, and metals, havealso been detected in Bayou de Loutre sediments. Furthermore, contamination has been observed and measured inon-site drainage ditches that emptied into the bayou. In addition, some VOCs and metals present in on-sitegroundwater have also been found in the bayou surface water.

Contamination in Bayou de Loutre was found mostly near the north end of the site where site drainage enters thebayou. These findings and other available information suggest that contaminants from the site have been transportedby drainage, surface runoff, and flooding into the bayou. For example, in 1984 liquids removed from the threesurface impoundments were dumped onto the site drainage area, and in 1989 or 1990 a major flood inundated the siteand allowed contaminated soils and waste materials to drain into the bayou. In addition, since groundwatercontamination at the site is estimated to extend to the bayou, it is possible that contaminants have been transported intothe bayou through groundwater seepage.

As previously discussed, Bayou de Loutre is reportedly used for wading, fishing, and possibly waterfowl hunting, ona seasonal basis. Individuals who participate in these activities where the bayou passes the north end of site are likelyexposed to contaminants in the surface water and sediments. Past, present, and future exposure is possible throughskin contact and incidental ingestion. Since few contaminants other than metals were found in the bayou's surfacewaters and since most site contaminants, such as PAHs, phenols, and dioxins/furans, tend to concentrate in the bottomsediments, exposure to sediments is likely a much more significant exposure pathway.

B. Potential Exposure Pathways

Ambient Air Pathway

As previously discussed, several semi-volatile organic compounds (anthracene, phenanthrene, fluoranthene, andpentachlorophenol) and dioxin congeners (represented as TCDD equivalents) were detected in ambient air samplescollected at the site in August 1990. The contaminant air concentrations were generally highest on the interior of thesite and lowest along the southern and southwestern site boundary (in the direction of the residences on South WestAvenue). Apparently, no analysis for VOCs was conducted and, therefore, it is not known if VOCs were present inthe ambient air samples.

Field personnel present during the August 1990 site investigation may have been exposed to the contaminantsdescribed above via inhalation of vapors and/or fugitive dust. These individuals may also have inhaled other aircontaminants, such as VOCs, that were not sampled for. The significance of this potential exposure pathway isdifficult to determine because 1) the number of contaminants sampled for was small, and 2) it is not known ifrespirators were worn by the on-site personnel. In addition, it is not known if individuals living near the site, such asthe residents along South West Avenue, were exposed to air-borne contaminants since no air samples were collectedin any off-site residential mareas. However, based on the contaminant levels measured in the August 1990 airsamples along the southern and southwestern site perimeter, it is unlikely that off-site residents were significantlyexposed to airborne contaminants.

Since the August 1990 air samples were taken prior to the 1990-1991 EPA removal action, it is not known whateffects the removal actions had on contaminant levels in ambient air. Specifically, since no other air monitoring dataare available, it is not known whether the number or concentration of air contaminants increased during the removalactions. Therefore, we cannot determine if an air exposure pathway existed during that period of time.

At present, the site is well vegetated with little evidence of surface contamination. Thus, it is unlikely that anysignificant air exposure pathways currently exist.

Surface Soil Pathway

Wide-spread contamination of surface soils on and around the Popile site was documented by previous siteinvestigations. Contaminants found in site surface soils included PAHs, pentachlorophenol, dibenzofuran, and metals. Surface soils were likely contaminated as a result of spills and leaks of wood-treatment chemicals, such aspentachlorophenol and creosote; on-site storage and disposal of liquid and solid wastes; and transport of suchchemicals and waste materials by drainage, flooding, and surface runoff from site areas such as the old surfaceimpoundments, facility area, and sludge pit.

Individuals who accessed the site in the past, such as site investigation personnel, fisherman, hunters, or children, mayhave been exposed to surface soil contaminants through ingestion and dermal contact. For small children, soilingestion can be an important exposure pathway due to their frequent hand-to-mouth contact. However, due to theremoteness of the site and the small number of nearby residences, it is unlikely that young children enter the site on afrequent basis.

During the Sept. 1990 - Aug. 1991 removal action, soils from areas of heavy contamination, such as the oldimpoundment area, were excavated and much of the site was covered with a one to two foot layer of clean soil. Atpresent, the site is generally well-vegetated with little evidence of surface contamination except for a few small areasof creosote-tainted soil and wood debris. In addition, the site, which is currently fenced and gated, is not believed tobe frequently accessed. Therefore, exposure to contaminants in site surface soils should not be significant.

Private Wells

As previously discussed, shallow groundwater at the Popile site had been found to be contaminated with VOCs(benzene and toluene), PAHs, pentachlorophenol, dibenzofuran, and metals (including arsenic, chromium, and lead). The highest contamination levels at the site were found in the vicinity of the old impoundment area and the oldtreatment facility area, and immediately downgradient of the soil disposal cell. These findings and other availableinformation indicate that contaminants were transferred to site groundwater from overlying soils and waste materialsthrough direct contact and infiltration/seepage.

The nearest private drinking water well is located on South West Avenue, approximately 3/4 mile south/southwest ofthe site (6). Other nearby residences along South West Avenue may also have private wells, even though they arereported to be on public water. These residences are considered to be upgradient of the site and, therefore, areunlikely to affected by groundwater contaminants from the Popile site. No private well sampling data are available,however, to confirm this.

Some private wells may also exist downgradient (northeast) of the site. However, there are currently no knownprivate wells located within the zone of groundwater contamination which likely extends to Bayou de Loutredowngradient of the site. Nevertheless, private wells downgradient of the site could potentially be affected by thegroundwater contamination plume if it moves further off-site. Therefore, users of such wells could be exposed in thefuture to groundwater contaminants via ingestion, inhalation, and/or skin contact. However, the levels of groundwatercontaminants in the future and the number of individuals potentially exposed cannot be determined. Also, it should benoted that any future groundwater remediation actions may minimize or eliminate these potential exposures.

It is possible that the Popile site could eventually be developed for industrial or residential uses, or it could be leftabandoned. Under an industrial scenario, exposure to groundwater contaminants, through ingestion (drinking) andpossibly dermal contact, could occur in the future if a shallow production well was installed on-site. Under aresidential scenario, future exposure could be possible, through ingestion (drinking), dermal contact, and inhalation(during showering), if the upper aquifer was used a source of potable water. However, as previously mentioned,future site remediation actions could reduce or eliminate these potential exposures.

As previously discussed, the nearest public water supply wells are located within 2 miles of the site and are operatedby the City of El Dorado. In addition, Parkers Chapel Rural Water System has public supply wells 2 to 3 miles fromthe site. All of these wells are screened in the deep El Dorado aquifer, 700 to 800 feet below ground surface (6). Incontrast, groundwater contamination at the Popile site likely extends less than 1/4 mile downgradient of the site and isbelieved to be confined to the shallow Alluvium/Cockfield aquifer. Moreover, contaminant movement into deeperaquifers at the site is restricted by a thick, continuous clay layer located approximately 39 to 57 feet below groundsurface (see earlier discussion). Therefore, it is unlikely that any public water supply wells will be impacted bygroundwater contamination from the site.

Fish Pathway

As previously discussed, PAHs, phenols, furans/dioxins, and metals from the site have contaminated sediments inBayou de Loutre. The areas of greatest sediment contamination are located near the north end of the site, justdownstream of where surface runoff from the site enters the bayou. Some of the sediment contaminants, includingpentachlorophenol, furans/dioxins, cadmium, and copper, are known to bioconcentrate in fish tissue. Thus, it ispossible that some sediment contaminants are present in fish living in Bayou de Loutre. (Note: During the September1992 ATSDR site visit, numerous fish were observed swimming in the bayou at the north end of the site.) As such,individuals who fish in Bayou de Loutre near the site and eat their catch could be exposed to site-related contaminants. The number of individuals potentially exposed is unknown; however, it has been reported that up to 100 people perweek may fish the bayou during the March through September fishing season. In addition, since no fish data areavailable to confirm the presence of fish tissue contaminants, the significance of this exposure pathway cannot bedetermined.

C. Eliminated Exposure Pathways

It is possible that wild game, such as duck and deer, have come into contact with site contaminants through ingestionof contaminated water or foodstuffs (e.g., plants, fish). Individuals who hunt and consume such game couldpotentially be exposed to contaminants in the game meat. However, based on available information, ATSDR believesthat such exposures are extremely unlikely and, therefore, has eliminated this pathway from further discussion.


PUBLIC HEALTH IMPLICATIONS

A. Toxicological Evaluation

Introduction

Health effects resulting from the interaction of an individual with a hazardous substance in the environment dependon several factors. One is the route of exposure: that is, whether the chemical is breathed, consumed in food or water,or whether it contacts the skin. Another factor is the dose to which a person is exposed, and the amount of exposuredose that is actually absorbed. Mechanisms by which chemicals are altered in the environment, or inside the bodyonce absorbed, are also important. Much variation in those mechanisms exists among individuals.

ATSDR has developed a Minimal Risk Level (MRL) for contaminants commonly found at hazardous waste sites. The MRL is an estimate of daily human exposure to a contaminant below which non-cancer, adverse health effects areunlikely to occur. MRLs are developed for different routes of exposure, like inhalation and ingestion, and for lengthof exposure, such as acute (less than 14 days), intermediate (15 - 364 days), and chronic (365 days or greater). If anATSDR MRL is not available as a health comparison value, then EPA's Reference Dose (RfD) is used. The RfD is anestimate of daily human exposure to a contaminant for a lifetime below which (non-cancer) health effects are unlikelyto occur (7).

For the Popile, Inc. site, environmental contaminant data, especially off-site data and data from former site operations,are limited or non-existent regarding many of the completed exposure pathways; therefore, ATSDR is unable toevaluate the potential of these exposures for producing adverse health outcomes. The completed exposure pathwaysdiscussed are our best estimate of possible scenarios based upon what we know about the history of the site.

ATSDR has determined that adults and children using the waters of Bayou de Loutre near the Popile, Inc. site forrecreational purposes are likely being exposed to several contaminants in the surface waters and sediments. Eachcontaminant will be discussed. To estimate the exposure dose, it was assumed that 100 milligrams (mg) of sedimentwould be ingested each day, with an exposure time of three days out of the week. The exposure was estimated forthree months out of the year. For ingestion of surface waters, we adjusted the typical ingestion rate of two liters perday for an adult and one liter per day for a child, to a more realistic level of 50 milliliter (ml) [0.05l]. This incidentalingestion rate is estimated for individuals wading in the bayou near the site.

ATSDR has determined that former employees of the wood treatment facility were likely exposed to sitecontaminants. Lack of historical environmental data (taken during time site was in operation) makes it difficult toaccount for media contamination levels and routes of exposure which may have resulted in significant exposure tocontaminants originating from the site. For the purpose of this discussion it was assumed 100 mg of solidcontaminated material (i.e. soil, sediment, sludge) and 0.05l of contaminated surface waters were ingested by the siteemployees. The exposure time was estimated to be five days per week for 50 week out of the year. This exposurescenario assumes that contaminant levels were the same as those found during the site assessment conducted by EPAin October 1989.

ATSDR has prepared toxicological profiles for many substances found at hazardous waste sites. Those documentspresent data and interpret information on the substances. Preparers of this public health assessment have reviewed theprofiles for the contaminants of concern at Popile, Inc.

Table 16 lists the contaminants of concern at the Popile site that will be further discussed in the health assessment. These contaminants include 1) those for which the estimated exposure dose exceeds the applicable health guideline, 2)those which have no health guidelines, and 3) those which are classified as carcinogens or probable carcinogens.

Table 16.

Comparison of Estimated Exposed Dose to Health Guidelines for Individuals Exposed to On-Site and Off-Site Contaminants
ContaminantExposure
Medium
Health Guideline (mg/kg/day)
ValueSourceExceeded by
Estimated
Exposed
Dose
ArsenicSurface Water
Surface Soil
Sludge
Sediment
0.0003RfDNo
DioxinsSurface Soil
Sediment
0.000000001chronic MRLYes
LeadSludge
Surface Soil
Surface Water
Sediment
N/AN/A
PAHsSurface Water
Surface Soil
Sediment
Sludge
0.002RfD (naphthalene)No
PentachlorophenolSurface Water
Surface Soil
0.001intermediate MRLYes

Arsenic

ATSDR estimated the arsenic exposure doses that workers might have received from the incidental ingestion ofsurface water, sludge and soil. ATSDR also estimated the arsenic exposure doses that adults and children mightreceive or have received from the incidental ingestion of surface water and sediments (in the bayou). All exposuredoses were below levels of concern, and, therefore, no adverse health effects are expected to be seen in adults orchildren as a result of ingestion of media contaminated with arsenic.

Epidemiologic studies of people exposed to arsenic in Taiwan indicate that exposure to arsenic is associated with skincancer (9). Based on that and other studies, the EPA considers arsenic a human carcinogen. The EPA has calculated acancer unit risk factor, which can be used to estimate the probability of excess cancer risks from a lifetime of exposure to arsenic. Adverse non-cancer health effects are not expected to be seen in former workers at the site.

If the site is developed in the future for residential or commercial/industrial use, and on-site wells are utilized tosupply drinking water, the concentration of arsenic in the groundwater could pose a threat to human health.

Dioxins

ATSDR estimated the dioxin exposure doses that workers have received from the incidental ingestion of surface soil. ATSDR also estimated the dioxin exposure doses that children and adults might have received from the incidentalingestion of sediments in Bayou de Loutre near the Popile, Inc. site. Although the exposure doses calculated areslightly above the comparison value (chronic MRL), no adverse health effects are expected as a result of ingestion ofmedia contaminated with dioxin.

The human evidence for 2,3,7,8-Tetrachlorodibenzo-p-Dioxin (TCDD) alone is inadequate to demonstrate or reflect acarcinogenic hazard, although certain herbicide mixtures containing dioxin as an impurity provide limited evidence ofcausing cancer in exposed humans. Based on the positive evidence in animal studies, dioxin is probably carcinogenicin humans (10). Due to insufficient data, ATSDR is unable to evaluate the carcinogenic risk to humans due toexposure to dioxin at this site at the concentrations found in the contaminated media.

Lead

ATSDR estimated the lead exposure doses that workers might have received from the ingestion of sludge, surfacesoil, and surface water. ATSDR also estimated the lead received from the incidental ingestion of surface water andsediments (in the bayou). All exposure doses are below levels of concern, and therefore, no adverse health effects areexpected to be seen in adults or children as a result of ingestion of media contaminated with lead.

Lead is a naturally occurring bluish-gray metal found in small amounts in the earth's crust. Exposure to lead isparticularly dangerous for unborn children and young children because of their greater sensitivity during development(11). The Centers for Disease Control and Prevention (CDC) has set the limit for blood lead levels in children at 10µg/dl. The American Academy of Pediatrics has concluded that lead continues to be a significant hazard to the healthof children in the United States (12). ATSDR has no MRLs and EPA has no RfDs for lead. No blood lead levelswere taken for individuals associated with or potentially associated with the site. Although it is not possible todetermine whether adverse health effects would occur at the estimated dose of lead ingested due to lack of healthguidelines for comparison, there was probably limited exposures to lead in on-site groundwater at this site in the past.

If the site is developed in the future for residential or commercial/industrial use, and on-site wells are used to supplydrinking water, the concentration of arsenic in the groundwater could pose a human health hazard.

Polycyclic Aromatic Hydrocarbons

ATSDR estimated the polycyclic aromatic hydrocarbon (PAH) exposure doses that workers might have received fromthe ingestion of sludge, surface water and sediment, and surface soil. ATSDR also estimated the PAH exposure dosesthat adults and children might receive or have received from the incidental ingestion of sediment (in the bayou). Allexposure doses are below the level of concern, and, therefore no adverse, health effects are expected to be seen inadults or children as a result of ingestion of media contaminated with PAH.

No information is available from human studies to determine health effects resulting from exposure to specific levelsof the individual PAHs, although inhalation and skin exposure to mixtures containing PAHs has been associated withcancer in humans (13).

If the site is developed in the future for residential or commercial/industrial use, and on-site wells are utilized tosupply drinking water, the concentration of PAHs in the groundwater could pose a threat to human health.

Pentachlorophenol

ATSDR estimated the pentachlorophenol (PCP) exposure doses that workers might have received from the ingestionof surface soil and surface water.

The lengths of exposure to PCP and the levels that cause harmful effects in humans have not been well defined. Long-term exposure to low levels such as those that occur in the work-place can cause damage to the liver, kidney,blood, and nervous system. Only one report was found in the literature concerning adverse effects in humans ofingestion of PCP (14). Because we do not have enough reliable human exposure information, levels of exposure thataffect human health must be estimated from studies in animals. Based upon these animal studies, workers at the sitewould not be expected to develop adverse health effects at the concentration of PCP present in the contaminatedmedia. There is no apparent increased risk for cancer at the levels of PCP present in the surface water and surface soils.

If the site is developed in the future for residential or commercial/industrial use, and on-site wells are used to supplydrinking water, the levels of PCP present in the groundwater could pose a human health hazard.

B. Health Outcome Data Evaluation

Health outcome data were not evaluated for this site because the population of concern is a very small (less than 200). This would make it very unlikely that any health effects due to the site could be detected. In addition, no previoushealth studies on the population near the Popile, Inc. site were identified during the gathering of data and informationfor this public health assessment. No community concerns were expressed regarding any possible health outcomes.

If health outcome data relevant to the Popile, Inc. site and the surrounding community should become available at alater date, ATSDR will evaluate its significance at that time.

C. Community Health Concerns Evaluation

We have addressed the community concern about health as follows:

  • What are the possible respiratory effects should harmful air emissions escape from the site during incineration?

    The Environmental Protection Agency in their Record of Decision (ROD) has decided to use on-sitebiological treatment (i.e., bioremediation) rather that on-site incineration to remediate contaminated site soils.


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