PUBLIC HEALTH ASSESSMENT
BOSSIER CITY, BOSSIER PARISH, LOUISIANA
In this section, the contaminants of concern are listed. ATSDR and SEET evaluate these contaminants in the subsequent sections of the public health assessment and determine whether exposure to them has public health significance. ATSDR and SEET select and discuss these contaminants based upon the following factors:
1. Concentrations of contaminants on and off the site.
2. Field data quality, laboratory data quality, and sample design.
3. Comparison of on-site and off-site concentrations with background concentrations, if available.
In the following sections and in the data tables in Appendix B, the listed contaminant does not mean that it will cause adverse health effects from exposures. Instead, if the contaminants listed are greater than their comparison values, then they will be evaluated further in the public health assessment.
The data tables include the following abbreviations:
- CREG = Cancer Risk Evaluation Guide
- RMEG = Reference Dose Media Evaluation Guide
- EMEG = Environmental Media Evaluation Guide
- LTHA = USEPA's Lifetime Health Advisory for Drinking Water.
- ppm = parts per million
- ppb = parts per billion
Comparison values used during the preparation of a public health assessment are contaminant concentrations in specific media used to select contaminants for further evaluation. Environmental Media Evaluation Guides (EMEGs) are media-specific comparison values, based on ATSDR's minimal risk levels, that consider body weight and inhalation/ingestion rates. Reference Dose Media Evaluation Guides (RMEGs) are similar to EMEGs, but are based on EPA's reference doses. Reference doses are estimates, with safety factors built in, of the daily, life-time exposure of human populations to a possible hazard that is not likely to cause harm to the person. Lifetime Health Advisory for Drinking Water (LTHAs) are lifetime exposure levels for drinking water at which adverse, noncarcinogenic health effects would not be expected to occur. Cancer Risk Evaluation Guides (CREGs) are estimated contaminant concentrations causing insignificant excess cancer risk in persons exposed over a lifetime. They are calculated from EPA's cancer slope factors.
Based on field observations, and land usage, the site was divided into six zones of historical use. These zones are delineated in Figure 2 and described below. The on-site areas most affected by wood treating operations are the former wood treatment area and adjacent impoundment, the old railroad spur along the southern boundary of the site, and the former site drainage ditch.
Zone 1 includes the eastern end of the site which was unused during most of the operational life of the facility.
Zone 2 was used for wood cutting and shaping and for the storage of untreated or white wood.
Zone 3 was primarily used for treated wood storage.
Zone 4 includes the main drainage ditch to the south of the wood treatment area and the probable impoundment at the eastern end of the property.
Zone 5 lies south of the site drainage ditch along an old railroad spur of the Kansas City Southern Railroad Line.
Zone 6 is the former wood treatment and chemical storage area.
In 1985, LDEQ took on-site soil samples from depths ranging from the surface to 90 inches. Samples were analyzed for PAHs, Polychlorinated Biphenyls (PCBs), and metals (Table B-1). The maximum contaminant concentrations were found between 18-36 inches. The maximum arsenic, copper, and chromium concentrations were 4,500 ppm, 1,545 ppm, and 1,020 ppm respectively. The total B(a)P equivalent is 461 ppm. The maximum PCP concentration was 916 ppm.
In 1989, LDEQ collected eighteen surface soil samples (0-2") on-site and analyzed then for PAHs, PCP, and metals. Those contaminants sampled are presented in Table B-2. The maximum concentrations of the metals, arsenic, copper, and chromium were 164 ppm, 195 ppm, and 420 ppm respectively. The maximum B(a)P equivalent concentration was 61 ppm, and concentrations of PCP were not found above the comparison value of 6 ppm.
During 1989, LDEQ collected 42 subsurface soil samples from 0-19 feet in the inactive area, treated wood storage area, process area, and the drip out area. The concentrations which were detected from subsurface soils on-site are presented in Table B-3. Three of these samples were duplicates for quality assurance and quality control purposes. Subsurface conditions on-site from 0 - 19' depths were assessed by visual observation, odor, and chemical analyses of selected samples.
In 1993, confirmatory subsurface soil sampling was conducted by LDEQ to determine the remaining concentrations of any contaminants after remediation. Twenty-five samples were taken. When an excavated area no longer showed evidence of contamination, LDEQ sampled the first 6 inches of soil. The depths of these samples varied from 1-14 feet according to the depth of the excavation. The excavated areas were filled with clean soil.
The confirmatory soil samples on-site were analyzed for metals, PAHs, and PCP. Table B-4 indicates the results of the confirmatory soil sampling on-site. The maximum metal concentrations were 23 ppm, 65.5 ppm, and 65.1 ppm for arsenic, copper, and chromium, respectively. The maximum concentration of B(a)P equivalents was 226 ppm and the highest concentration of PCP was 41 ppm. Dibenzofuran was detected in the confirmatory soil sample analyses at a maximum concentration of 500 ppm.
In March 1989, three sediment samples were taken by LDEQ for the remedial investigation. The first sample, SED-1, was taken from the main ditch just prior to exiting the site, the second sample, SED-2, was taken in the ditch on-site which drains to the main ditch outside the fence, the third sample, SED-3, was taken inside the fence in a ditch on-site which drains to the main ditch. These sediments were collected from 0 - 2" at these locations and were analyzed for metals, PAHs, and PCP (Table B-5). The maximum B(a)P equivalent concentration was 102 ppm. Maximum concentrations of arsenic, copper, and chromium were 4.6 ppm, 21 ppm, and 30 ppm, respectively. The maximum concentration of PCP was 260 ppm.
During 1989, surface waters on-site were sampled for metals, PAHs, and PCP by LDEQ. Two surface water samples were collected in drainage ditches. Most constituents were not detected. Only arsenic (at 0.021 ppm) was detected above the ATSDR drinking water comparison value in sample SW-2.
Surface water runoff was sampled again from February-July 1992. A total of 100 water samples were taken and analyzed for total suspended solids and the metals copper, chromium, and arsenic.
Several samples showed the presence of arsenic, some near the EPA drinking water standard which is 0.050 ppm. The maximum arsenic concentration was 0.044 ppm. Only one sample showed chromium above its detection limit (0.05 ppm) with a concentration of 0.07 ppm.
Subsurface water and dirt underlying the Bossier City area are part of two main geologic features, the Red River Alluvium and the Wilcox Group. The Alluvium extends from the ground surface to approximately 100 feet below the ground surface. The first 20 feet of the Alluvium is made up of clay materials while the next 80 feet is comprised of sand and gravel. The production of groundwater is small in the Red River Alluvium, and it is not used as a drinking water source. Seven boreholes were drilled during the 1989 remedial investigation to determine the stratigraphy of the site. The alluvium fills with water from rain events and, therefore, its hydraulic gradient may change with precipitation.
The groundwater in the Alluvium underneath the site is contaminated. During on-site excavation, waste was observed to extend below the water table, placing contaminants in direct contact with the shallow aquifer in the Alluvium zone. Excavations below the water table were not completed.
Beneath the alluvium, the Wilcox Group is encountered. It consists of gray, cohesive, interbedded clays, silty clays, silty sands, and sands. There are peat and lignite seams dispersed throughout. The sands of the Wilcox Group are fine grained and composed of quartz.
Six monitoring wells (MW-1 through MW-6) were installed in the alluvium at the site during the Spring of 1989. Wells MW-3, MW-4, MW-5 and MW-6 were installed in shallow boreholes at depths of 28-38 feet which were completed for stratigraphic definition at the site. The other two wells, MW-1 and MW-2, were installed at depths varying from 14.9 to 35 feet below ground surface in the Red River Alluvium. Groundwater from the alluvium was sampled in each well and analyzed for metals, PAHs, volatile organic compounds (VOCs), polychlorinated biphenyls, and pesticides in 1989 and 1994.
Only one well, MW-5, indicated contamination with PAHs, PCP, VOCs, and heptachlor. Table B-6 summarizes the data collected from the monitoring well in 1989 and 1994[2,6]. The pentachlorophenol, naphthalene, and PAHs may be site-related, but the benzene and heptachlor are most likely urban background levels[7,8]. These two contaminants of concern would not ordinarily be associated with a creosote site. No trend could be determined between the 1989 and the 1994 sampling, so it is not known if the contaminant levels are decreasing or increasing over time. The vertical and horizontal extent of contamination in MW-5 is also not known. but the sandy nature of the alluvium and underlying Wilcox Group would make migration possible.
The annual prevailing winds for the area are from the south 22% of the time and usually in the speed class of 8-12 mph (Louisiana Office of State Climatology). On February 14-15, 1990, ambient air monitoring for PAHs was conducted by LDEQ during preliminary trenching of potentially affected soil at the Lincoln Creosote Site. One upwind sample and three downwind samples were collected each day in the vicinity of the trenching area. The upwind samples were collected to determine background air concentrations. The downwind samples were collected to determine if site contaminants are being released into the air as a result of the site activities.
Results indicated that all of the air samples collected on February 14-15, 1990, were below detectable limits for PAHs. No metals were sampled. The analyses of the limited data showed the absence of any increase in downwind values during these activities indicating that the trenching events did not result in off-site migration of PAHs. Because the sampling occurred over a two-day period, the results do not represent the PAH concentrations that might occur over time.
On-site air sampling also occurred in 1992, before remedial activity, and the PAHs listed in Table B-7 were present at that time. During remediation activities from February through September of 1994, over 200 air samples were taken by ERM-Southwest, under LDEQ supervision. Tests were conducted for metals, PAHs, and PCP. Arsenic was detected in six samples and chromium was detected in four samples. The maximum levels for both these metals were above comparison values. Copper was detected in 185 samples at a maximum value of 0.567 ppm. The maximum total PAH concentration detected on-site was 55.97 ppm during remediation. Almost all air samples had one or more PAHs detected. Pentachlorophenol was found in two samples at 0.004 ppm and 0.009 ppm. The contaminants detected are detailed in Table B-8.
Surface (that is 0-6 inches) and Subsurface (this is 6-24 inches) Soils
The results of a 1992 EPA Expanded Site Inspection indicated the presence of wood treating contaminants including PAHs, PCP, copper, chromium, and arsenic in off-site soils around the site. As a result, Joslyn implemented an off-site investigation of nine residential yards, one playground and two off-site ditches under LDEQ supervision in February 1994.
Of the contaminants detected, elevated concentrations of site-related PAHs were found in off-site areas with a maximum benzo(a)pyrene equivalents at 334 ppm (See Table B-9). Other contaminants including PCP, copper, chromium, and arsenic were also found in off-site soil, but these were detected above background levels much less frequently.
An Expanded Site Inspection/Remedial Investigation (ESI/RI) was conducted by EPA during June-July 1994 to determine the extent of off-site contamination in areas around the site and around ditches that drained the site. Based on the ESI/RI results, the estimated area of site-related PAHs soil and sediment contamination extended through the North Park Apartment complex and near approximately 70 residential homes, primarily on Bardot Road and Northside Drive. EPA performed remediation on yards having B(a)P equivalents at levels greater than 3.0 ppm.
Part of the sampling work plan was to determine background levels of site contaminants away from the site and off-site study areas. Background samples totaling 69 (including duplicate samples) were taken at 20 locations off-site at depth of 0-2 feet. The samples were taken in areas that were not impacted by site contaminants. However, these samples were located at residential and commercial areas having a similar level of development as the site. Semi-volatiles were found in 28 of the 69 background soil samples collected. Semi-volatiles were found in 13 of the 23 samples taken from 0-6 inches. Several PAHs found at the Lincoln Creosote site were also found in background samples including, anthracene, benzo(a)anthracene, benzo(a)pyrene, benzo(b)fluoranthene, benzo(g,h,i)perylene, benzo(k)fluoranthene, chrysene, fluoranthene, indeno(1,2,3-cd)pyrene, phenanthrene, and pyrene. The upper 95% level for the concentration range for each contaminant was taken as the background level.
A total of 431 (including 36 duplicate samples) soil samples were collected at 129 locations from 0-2 feet in the off-site study areas for analysis of semi-volatiles and metals. Dioxins and furans were measured in 10% of the samples. The number of samples at each depth is as follows: 0-0.5 feet, 142 samples; 0.5-1.0 feet, 144 samples; 1.0-1.5 feet, 54 samples and 1.5-2.0, 55 samples.
The levels of metals in surface and subsurface soil were not elevated. A total of 23 metals were analyzed, but the ones of greatest concern associated with the site are arsenic, chromium, and copper. These metals were in the preservatives used for on-site wood treatment. Though mercury and lead are not site-related contaminants, they are presented in the data summary table because of their public health importance. The only metal found above its comparison value was arsenic. The background level for arsenic was also above the comparison value of 0.5 ppm.
Residential Yard Sampling
The contaminants above comparison values for residential yards' soils were arsenic (maximum, 15.60 ppm), benzo(a)pyrene (maximum, 4.20 ppm) and benzo(a)pyrene equivalents (maximum 6.07 ppm. These maximum values were all found at the subsurface level (See Table B-10).
In residential yards, all samples had dioxins and furans levels below detection limits except for one sample with a total dioxin level of 0.0253 ppb. The highest detection limit for residential yard sampling was 0.019 ppb. ATSDR comparison value for dioxins in residential soil is 1 ppb (0.001 ppm).
Northpark Apartment Complex Sampling
North Park Apartment complex soil samples had a maximum benzo(a)pyrene [B(a)P] equivalent concentration of 23 ppm, a maximum B(a)P concentration of 12 ppm, and a maximum arsenic concentration of 27.4 ppm. All three of these contaminants were above their comparison values and had their maximum concentrations in subsurface soil (See Table B-11). In the North Park Apartment complex, the highest concentrations of PCP in surface and subsurface soils were 4.10 ppm and 8.90 ppm, respectively. The comparison value for PCP is 6 ppm. None of the samples taken from the North Park Apartment complex had dioxin or furans above the detection limit. The highest detection limit was 0.40 ppb (0.0004 ppm).
During the off-site investigation conducted by ERM-Southwest for Joslyn, both surface and subsurface soils were collected from a playground in the vicinity of the site. Two surface soils were sampled at depths ranging from 0-6" below the ground from the playground at the intersection of Bardot Lane and Northside Drive. For the surface soils, no PAHs were detected, except for benzo(g,h,i)perylene which had a maximum concentration of 0.48 ppm. One subsurface soil sample was collected from the playground at depths ranging from 12 - 24". Only two PAHs were detected; indeno(1,2,3-cd)pyrene at 0.46 ppm and benzo(g,h,i)perylene at 1.2 ppm.
Sediment/Soil in Off-Site Ditches
Wood-treating waste and contaminated surface-water runoff were transported off-site through drainage ditches originating on-site. Consequently, contaminants have been found in soil and sediments in and around these ditches. Some of these ditches were covered up during construction activities but others are still accessible.
Throughout the site's 50 year history, the direction of several ditches has been changed. The three main ditches transporting site contaminants off-site are the 1936 Drainage Pathway Ditch, the 1950 Joslyn Ditch, and the Site Main Ditch. The Site Main Ditch is in the southern portion where wood treatment and processing occurred. The ditch runs in a northeasterly direction until it intersects with the 1936 Drainage Ditch. The 1936 ditch is no longer operational. This ditch originates south of the site traversing northeasterly across the site and continuing between Northside Drive and Bardot Road.
The 1950 ditch picks up drainage from several ditches converging at the northeast corner of the site including a ditch that flows easterly from Benton Road and continuing behind the North Park Apartment complex. This ditch still drains water in this manner.
Unlike the 1950 Joslyn Ditch which was covered with concrete by the city in the 1980's, portions of the 1936 ditch along Montgomery Lane were not improved. Limited amounts of soil contamination were found in the unimproved ditch near the site which included a few scattered, black, creosote fragments on the banks.
A total of five samples were taken from these ditches and two from the northeastern section of the front ditch running alongside Montgomery Lane during June-July 1994 as part of the expanded site and remedial investigations. Only PAHs and pentachlorophenol were presented above detection limits. The maximum concentrations were 4.67 ppm for B(a)P equivalents and 0.74 for PCBs. No metals or dioxins were found in any of these samples (See Table B-12).
Background soil and sediment samples were taken from ditches at depths ranging from 0 - 6". Three sediment samples from ditches (Bossier Civic Center Ditch, Shed Road/KCS Railroad Ditch, and Benton Road/Tilman Road Ditch) were collected and one background soil sample was collected from the Bossier City Water Plant by ERM-Southwest for Joslyn. The samples were collected in areas that are remote from the site and could not have been affected by site operations.
During remediation work on the Montgomery Lane ditch in June 1996, EPA unearthed significant amounts of creosote material. EPA scraped several inches of surface soil off the top of the ditch which revealed creosote contamination at deeper soil depths. EPA excavated soils from the ditch until a depth was reached which revealed no visual contamination. The results of the two confirmatory samples taken from the ditch after the clean up, showed B(a)P equivalents at 2 ppm and 4 ppm respectively. SEET requested additional sampling be done in both ditches to determine if the remedial efforts were adequate.
On April 8, 1997, LDEQ along with SEET representatives visited the site to perform additional sampling of the two ditches in question. Three sampling locations in the exposed sediments of each ditch were chosen approximately 50 feet apart. One sample from 0-6 inches and another from 6-12 inches were taken from each sampling location.
In the ditch directly behind the North Park Apartment Complex, sampling results indicated non-detectable levels of PAHs. The ditch running along Montgomery Lane had levels of 3 ppm for one sample and below 3 ppm for the remaining two. Further sampling revealed a PAH level of 15 ppm in the sample closest to the drainage outlet of the ditch. The sample prompted a request for a remedial action.
In October 1997, one of the PRPs, the Joslyn Corporation, placed a geotextile membrane along the bottom of this ditch for 1200 feet, then placed 4-6 inches of crushed rock atop this liner to eliminate any direct contact with sediments underneath. This remedy will be maintained by the City of Bossier.
Groundwater - Monitoring Wells
There are no monitoring wells off-site for the Lincoln Creosote site.
Groundwater - Private Wells
Most residents of this area obtain their drinking water from the Bossier City Water System which uses the Red River as its source. However, a private drinking water well is located 0.4 miles north of the site. There are some school and residences including apartment complexes, trailer parks, and private homes which receive their drinking water from private wells within the City limits. The depths of the screened interval for these wells were not known.
Sampling of one residential well about 0.4 mile north of the site occurred in 1992. No wood-treating contaminants were detected. Data collected during 1989 for the remedial investigation indicated that groundwater flow beneath the site is easterly-northeasterly direction. The private well was located north of this site.
Surface water run-off, that may exist if flooding occurs during heavy rain, exits the site to the east and flows through a concrete lined ditch toward Macks Bayou approximately 3/4 of a mile from the site. Macks Bayou joins Cooper Bayou and empties into the Flat River. There has been no off-site surface water sampling.
No ambient air monitoring was conducted off-site.
The analyses and conclusions presented in this public health assessment are based on the data contained in the reports submitted to the EPA and LDEQ. The validity of the conclusions drawn are determined by the accuracy and reliability of the referenced information. The contractors at this site, upon review of the analyses, state that all the data are acceptable and reliable. Holding times were met and chain of custody documentation was properly maintained for all soil and water samples. The laboratory QA/QC parameters were generally within acceptable ranges.
The drainage ditches both on-site and off-site present physical hazards since they may fill with water and possibly flood during heavy rainfall. No other hazards are present because the Lincoln Creosote Site is fenced.
For nearby residents the Agency for Toxic Substances and Disease Registry (ATSDR) and theSection of Environmental Epidemiology and Toxicolgy (SEET) will evaluate the environmentaland human components that lead to human exposure. This pathway analysis consists of fiveelements: a source of contamination, transport through an environmental medium, a point ofexposure, a route of human exposure, and a receptor population.
ATSDR categorizes an exposure pathway as a completed or potential exposure pathway if theexposure pathway cannot be eliminated. Completed pathways require that the five elements existand indicate that exposure to a contaminant has occurred in the past, is currently occurring, orwill occur in the future. Potential pathways, however, require that at least one of the fiveelements is missing, but could exist. Potential pathways indicate that exposure to a contaminantcould have occurred in the past, could be occurring now, or could occur in the future. Anexposure pathway can be eliminated if at least one of the five elements is missing and will neverbe present. Table 1 identifies the completed exposure pathways, and Table 2 identifies thepotential exposure pathways. The discussion that follows these two tables incorporates onlythose pathways that are important and relevant to the site. The exposure pathways that have beeneliminated are also discussed.
Information obtained from residents during the public availability outreach session in April 1996, suggest that some residents may have had significant contact with the site in the past (SeeAppendix D). About 25% of the residents attending the session reported being on the LincolnCreosote site property before the fence was installed. Residents closer to the site spoke moreoften about visiting the site in the past than residents who lived farther from the site.
The site and adjacent ditch were used for playing. Some residents said that when they werechildren they played in the sawdust and dirt piles, and rode bikes on-site. Some residents saidthat they visited the site to collect crawfish and pick blackberries. The site has been remediated and a 6-foot chain-linked fence was installed around the site in 1989 . There is no significant evidence that the site is currently being trespassed on.
A completed exposure pathway existed in the past. Residents and children trespassed on the site. Industrial workers worked at the wood treatment plant when it was operational. Contaminants found in the on-site soil that residents, children and workers could have been exposed to include chromium, copper, arsenic, lead, PCP, and PAHs.
Exposure could have occurred through ingestion, dermal contact or both. Since children playingon-site in the past have been reported by residents around the site, it is likely that children may have ingested contaminated soils from the site. Adults were also reported to have visited the site to collect fruit berries and catch crawfish. It was also discovered during the Public Availability Session, that some pregnant women may have gone on-site and had contact with the soil. (Appendix D). Exposures to contaminants may have occurred in the past on-site. Currently, the site is cleaned up, fenced, and covered by fresh dirt and vegetation limiting exposure to soil on site.
Off-site ditches around the North Park Apartment complex were found to be contaminated withcreosote material. These ditches received site contaminants in the past though neither ditch wasa main drainage pathway. The ditches have served as play areas for children. Residents reportedcrawfishing in the ditches when there were heavy rains.
The ditch behind the North Park Apartments contained a few (3-4) scattered clumps of creosotematerial. During the Office of Public Health's (OPH's) public availability session in 1996(Appendix D), residents had complained that the back ditch was dirty, malodorous, and wasmaking their children sick when they played in it. The City scrapped the soil off the top of theditch. After the ditches were scraped, two areas containing small amounts of creosote materialwere excavated until no contamination was observed. This ditch is not covered or concreted. The ditch running parallel to Montgomery Lane was significantly contaminated. Soil at a depthof 2 feet was removed unless contamination was found at deeper levels. This ditch is lined andcovered with a gravel layer, preventing exposure to contaminants beneath.
A completed past exposure pathway exists for any child who may have played with the sedimentsand for people who crawfished in the drainage ditches on and off site. Exposure may haveoccurred through ingestion and dermal contact with PAHs. Levels of other site contaminantswere not found to be elevated in the ditches. Levels of contaminants may have been higher inthe past before the ditches were improved (excavated, covered, and/or concreted) by the city. Exposure to contaminants in the off-site drainage ditches may have occurred in the past.
A completed exposure pathway for air existed before the site was remediated, and during siteremediation. This was indicated by chemical concentrations detected during 1992. On-siteworkers at the wood preserving plant were exposed through inhalation to PAHs, PCP, arsenic,and chromium, if respirators were not in use.
During excavation of site soils, higher levels of site contaminants were detected in the air. On-site air monitoring was performed during removal of the contaminated soil to assess if there were any on-site air releases. The facility is no longer operational and has been remediated, therefore this exposure is no longer likely.
No off-site air data was collected. The exact levels of air contaminants traveling into nearbyresidential neighborhoods are not known. However, during on-site air monitoring approved bythe Louisiana Department of Environmental Quality (LDEQ), levels of polynuclear aromatics(PNAs), PCP, total suspended particulates, and the heavy metals copper, chromium, and arsenicwere evaluated. During the time frame evaluated, none of these exceeded the OSHA PermissibleExposure Limits (PELs).
|Pathway Name||Source||Media||Point of Exposure||Route of Exposure||Exposed Population||Time|
|Lincoln Creosote||soil||Lincoln Creosote||dermal ingestion||workers |
|Lincoln Creosote residential yards, playgrounds, ditches||soil||Lincoln Creosote||dermal ingestion||residents, children, gardeners, or anyone working in the contaminated soils||past |
|Lincoln Creosote||sediment||drainage ditches on-site||dermal ingestion||residents, children playing in ditches, workers||past|
|Lincoln Creosote||sediment||drainage ditches off-site||dermal ingestion||residents, children playing in ditches||past |
|Lincoln Creosote||air, fumes and dusts||Lincoln Creosote||inhalation||workers on-site||past|
Surface Water Pathway
A potential exposure pathway exists for area residents or children coming in contact with any of the surface waters that drained from the site in the past, present, and in the future. Since the site was remediated, the level of contaminants that would run off the site have decreasedsignificantly. Because so few surface water samples were taken in ditches, surface water cannotbe eliminated as a potential exposure pathway.
A potential exposure pathway exists for individuals that consumed biota such as crawfish or fish from the drainage ditches around the Lincoln Creosote Site. The fish and crawfish have not been sampled. Therefore contamination has not been confirmed in the biota. However, the sediments in the ditches surrounding the site are contaminated.
During the excavation of off-site residential yards, an exposure pathway via inhalation may have existed. EPA took measures to reduce air contaminants during the remediation of residentialyards and during the remediation of the North Park Apartment complex grounds. Therefore, exposures were not likely to be significant. However, no air sampling was performed off-site, so it is not possible to estimate the level of exposure.
Residents near the site are served by the municipal water supply from the City of Bossier whichreceives its water from the Red River. There are private wells supplying drinking water toresidents in private homes, trailer parks, and apartment complexes within the City limits. Thereare also some schools that rely on private wells for their water supply. Because no off-sitegroundwater monitoring or residential well testing occurred, groundwater cannot be eliminated asa potential exposure pathway.
The site is fenced that was remediated during 1992 and 1993. Therefore current exposure to on-site water, on-site drainage ditches (sediments), and on-site air are all eliminated as exposure pathways.
|Pathway Name||Source||Media||Point of Exposure||Route||Exposed Population||Time|
|surface water||Lincoln Creosote||surface water||drainage ditches that surround the site||dermal||children playing in ditches||past |
|biota||Lincoln Creosote||crawfish fish||drainage ditches||ingestion||consumers of fish and crawfish||past |
|Lincoln Creosote||site remediation||residences, |
residents in adjacent apartments off-site,
|groundwater||Lincoln Creosote||water||residential wells||dermal ingestion||residents who use wells for drinking water||past |
Health effects could result from exposures to site contaminants. People can only be exposed to a site contaminant if they come in contact with it. In order to understand health effects that may be caused by a specific chemical, three factors affecting how the human body responds to exposure need to be considered. These factors include the exposure concentration, the duration of exposure, and the route of exposure. Lifestyle can affect exposure duration and likelihood.Individual characteristics of each human such as age, sex, nutritional status, and overall healthcan affect how a contaminant is absorbed, distributed, metabolized or eliminated from the body. Together, these factors determine the individuals's response to chemical contaminants and whathealth effects may occur for that individual.
To evaluate health effects, ATSDR has developed a Minimal Risk Level (MRL) forcontaminants commonly found at hazardous waste sites. The MRL is an estimate of daily humanexposure to a contaminant below which non-cancerous, adverse health effects are unlikely tooccur. MRLs are developed for each route of exposure, such as ingestion and inhalation, and forthe length of exposure, such as acute (less than 14 days), intermediate (15 to 364 days), andchronic (greater than 365 days). For determining possible exposures to contaminants in soil,contaminant levels in the surface soil are used. Cancer risk is calculated using USEPA's cancerslope factors and our exposure assumptions. These are theoretical risks, based on conservative(i.e. protective) assumptions.
The exposure scenarios for children were based on an older child (7 years or older) visiting thesite to play before the site was fenced off and a young child (1-6 years old) playing incontaminated soil in off-site ditches, yards, and around the North Park Apartment complex. Itwas assumed that young children would be better supervised and would not wander onto the site. For adults, one scenario was for a site employee who worked in the yard for approximately 25years or more and the other scenario was for an adult resident living near the site whooccasionally visited the site for recreational purposes over a lifetime.
Factors such as duration of exposure, age, and body weight are used to help estimate the amountof contaminant that might have entered a person's body. For example some young childrenbetween the ages of 1-6 years old are known to put everything in their mouth (pica behavior). This behavior increases their chances of being exposed to soil contaminants. The assumptionsfor exposure calculations for a young child are a body weight of 10 kilograms (approx. 22pounds), with an ingestion rate of 5,000 mg of soil per day. The assumptions for an older child(7 years or older) are a body weight of 16 kilograms (approx. 35 pounds) and a soil ingestion rateof 200 milligrams per day. The adult assumptions are a body weight of 70 kilograms (approx. 150pounds), and a soil ingestion rate of 100 milligrams per day. In addition, the maximumconcentration found in a particular media was used for calculating risks and doses, so a worsecase scenario was evaluated.
The factors used to evaluate possible durations of exposure are broad estimates. An adultworker, employed on-site when the plant was operational, was assumed to spend a five of sevenday work week (70% of his/her time) on-site. It was assumed that an adult resident living nearthe site would not spend more than one of seven days (15% of his/her time) on the site. Childrenwere given a maximum estimation of three of seven days (43% of their time) on-site, and youngchildren were assumed to spend time outdoors everyday in residential yards.
Arsenic is found naturally in soils and rocks. Commercial products containing arsenic include:wood preservatives, pesticides, paints, and leaded gasoline. Certain industrial activities release arsenic such as desulfuring of gases and/or fossil fuels, the burning of preserved wood, and metal alloy production. Arsenic has had medical uses: antiparasiticals, antisyphilis drugs, and many other, older formulations.
Arsenic was detected in on-site surface soils at levels that were a cause for health concern. Arsenic is a known human carcinogen. Arsenic ingestion has also been reported to increase therisk of cancer in the liver, bladder, kidney, and lung. Because of this fact, and the exposurescenarios for on-site workers, there may have been a slightly increased risk of cancer foremployees who worked on-site for several years.
Arsenic was also detected in surface water on-site, and in air on-site during remediation, but at lower levels not expected to produce carcinogenic health effects. Beyond the conditions for site workers, exposures to arsenic in on-site surface soils may have occurred in the past to adults who trespassed on the site and to children or teens who may have wandered or played on the site before remediation. No health effects are expected from this exposure.
The remediation efforts have prevented this exposure from occurring currently and in the future, because clean soils have replaced contaminated soils, the fence prohibits trespassers andvegetation covers the site.
It is unlikely that any present exposure is occurring on-site to anyone who may trespass. During remediation, arsenic was detected in air when soils were excavated from the site. Sincearsenic levels were only slightly elevated during excavation for a short period of time and theconcentrations would decreased further away from the site, it is very unlikely that thesurrounding community would experience adverse health effects from breathing any contaminated air that may have migrated off-site. Conditions during site operation are not known, so exposure to arsenic at that time cannot be determined.
Children and Other Populations that are Unusually Susceptible
The estimated exposure to on-site contaminants for an older child exposed to arsenic on-site and a young child exposed to arsenic in off-site residential areas are above arsenic's Minimal Risk Level (MRL). However, the exposure is below the exposures which are known to produce non-cancer health effects. Therefore, we not expect any adverse health effects to children fromexposure to arsenic from this site.
Chromium is a naturally occurring element found in soil. It is also used in industrial processessuch as steel and oil production. At the Lincoln Creosote site it was used in a chemical woodpreservative. There are three different forms of chromium which differ in their potential to causehealth effects. In calculating health risks, SEET and ATSDR assumed that all chromium is in themost adverse form, even though this rarely is the case.
Chromium was detected in the soils both on and off the Lincoln Creosote site and in air on-siteduring remediation. Exposure to chromium through soil ingestion may have occurred in the pastto adults who worked at the site and to children or teens who may have played on the site. Exposure may have also occurred in the past to young children that played in residential yardsnear the site.
The on-site worker exposure doses estimated from the maximum chromium concentration insurface soils slightly exceeds the chronic oral reference dose (RfD) for chromium (VI), but arebelow levels that caused health effects in humans. Currently, health effects are unlikely to occurfrom exposure to chromium in the shallow soils on-site since the site is remediated and fenced. Off-site soil concentrations were much lower (and similar to background levels), so that adversehealth effects are not expected.
The maximum concentration of chromium in air occurred during the excavation of contaminatedsoils during on-site remediation. Chromium was not detected in air before excavation. Consequently, exposure to chromium was very minimal for the community. It is unlikely thatany adverse health effects from chromium would result from breathing the air near the site.
Children and Other Populations That Are Unusually Susceptible
No human studies have been done that would indicate developmental effects caused bychromium. However, developmental effects were present when female mice were exposed tohigh levels of chromium, in extreme excess of the levels present in off-site surface soils.
The levels of chromium on-site, where contaminant levels would be expected to be highest, wereonly slightly elevated above comparison values. Off-site levels were much lower. There is littlerisk to children residing near the site even with their higher exposure to the soils.
Polycyclic Aromatic Hydrocarbons
Polycyclic aromatic hydrocarbons (PAHs) are a class of structurally related compounds. As agroup, these compounds have similar characteristics. As pure chemical compounds, PAHs generally exist as colorless, white, or pale yellow-green solids. There are more than 100 differentPAH compounds. They can have a faint, pleasant odor. Most PAHs do not occur alone in theenvironment and are usually found as a complex mixture of chemicals. They are found insubstances as crude oil, coal, coal tar pitch, creosote, and road or roofing tar.
Exposure to PAHs through incidental ingestion and dermal contact with contaminated soils andsediments may have occurred on the site in workers, trespassers and children. Off-site sedimentsand soils are also a source of exposure to PAHs for residents.
Adverse skin effects have been noted in animals with acute and sub-chronic dermal exposureswhen exposed to PAHs. Those effects include destruction of sebaceous glands (glands in theskin which secrete fatty substances), skin ulcerations, hyperplasia (abnormal increase in numberof skin cells), and overgrowth of the outer layer of the skin. Dermal exposure to certain PAHs,such as anthracene and phenanthrene, followed by exposure to sunlight may result in phototoxiceffects such as erythema (redness of the skin), urticaria (elevated patches of skin), and burningand itching. Persons with pre-existing skin conditions may be more sensitive to the adversedermal effects of PAHs. This is a factor of concern for workers on the site, who came into direct contact with the PAH-containing material.
Certain PAHs are not known to cause cancer. These include the following: acenaphthene,acenphthylene, anthracene, fluoranthene, fluorene, methylated naphthalene, naphthalene,phenanthrene, pyrene. Sufficient evidence exists to accept the following PAHs as carcinogenic:benzo(a)anthracene, benzo(a)pyrene, benzo(b)flouranthene, benzo(g,h,i)perylene,benzo(k)fluoranthene, chrysene, dibenzo(a,h)anthracene, indeno(1,2,3,c,d)pyrene.
Epidemiologic studies of workers occupationally exposed to PAHs have provided limitedevidence that PAH exposure may contribute to increased incidence of cancer. The most likelyexposure routes in the occupational settings were through inhalation and skin contact with thosecompounds. To determine cancer risk from exposure to PAHs, the relative potency of carcinogenic PAHs are added together as benzo(a)pyrene equivalents. Using the maximum concentrations in on-site surface soil, we estimate there may be a moderate increased risk ofdeveloping cancer for adults who worked on the site.
There is a low off-site cancer risk for adult residents, as levels of PAHs off-site weresignificantly lower than those levels on the site.
Children and Other Populations that are Unusually Susceptible
Developmentally, PAHs have detrimental effects in studies performed using mice. Low birthweights and sterility in future generations were observed. However, in regard to the site, usingthe highest total B(a)P equivalents detected in on-site surface soil before remediation, theingestion exposure for children does not exceed ATSDR's acute MRL for benzo(a)pyrene fornon-carcinogenic effects. Using the highest total B(a)P equivalents concentration detected in off-site soil, the ingestion exposure for younger children who have pica, which is a tendency toconsume dirt, habits does not exceed the acute oral MRL. ATSDR does not have MRLs for skinor inhalation exposure to PAHs. For that reason, it is difficult to determine the health effectsfrom dermal or inhalation exposure. Since remediation on and off-site has occurred, no healthhazard exists for children because of the presence of PAHs.
Exposure to pentachlorophenol (PCP) has probably occurred to trespassers and workers viaingestion and dermal contact with PCP-contaminated on-site soil. Using the highest levels ofPCP in surface soil on-site, the exposure for adult and children were estimated. The ingestionexposures to on-site soil for children and adults did not exceed ATSDR's intermediate MRL.
ATSDR could not locate any adequate studies that described significant levels of skin exposureto PCP. Occupational exposures to PCP have been associated with severe skin eruptions. Non-occupational exposures to wood treated with PCP have been associated with pemphigus vulgaris(a serious skin disease characterized by blisters and loss of skin) and chronic urticaria (a disorder of the skin characterized by itchy pink or white wheals). Skin effects discussed above may have resulted from impurities present in PCP from the manufacture of this chemical. The toxic dermal effects of PCP appear to be most serious following high-dose, acute exposure.
Sufficient evidence exists from animal studies to suggest that PCP might cause cancer inhumans. No convincing evidence has been obtained from human epidemiological studies thatindicate that PCP causes cancer in humans. Case reports suggest a possible association betweencancer (Hodgkin's disease, soft tissue sarcoma, and acute leukemia) and occupational exposure totechnical PCP that may have had other contaminants.
PCP is classified as a probable human carcinogen (Group B2) by EPA. Using the same highestPCP concentration in on-site soil, we estimate there is no increased risk of developing cancer for adults who worked on-site. There is also no increased risk to residents and children fromexposure to contaminated soil on site nor was there an increased risk for those off-site ascontaminant levels were lower off-site.
Children and Other Populations that are Unusually Susceptible
Laboratory animal and epidemiological studies for reproductive effects of PCP in humans doesnot exist; however animals studies showed no developmental effects. In a high dosage,exceeding the levels found on-site, PCP may be phototoxic. Studies have shown that childrenare more susceptible to the effects of PCP and infants more than children.
Based on the highest on-site concentration of PCP, no health effects resulting from exposure toPCP are expected for children living near this site. Since remediation on and off-site hasoccurred, no health hazard currently exists for children due to the presence of PCP.
It is always important to specifically address issues concerning unusually susceptiblepopulations. Children, specifically those in fetal stages, are most at risk to toxic effects ofchemicals if they cross the placental barrier. Because of the importance of correct developmentof the organs in young children, and the need for uninhibited development of health organsystems that will last a lifetime, we must pay particular attention to the effects thesecontaminants of concern will have on children, especially those in the fetal stages, as this is time injury will have the greatest and most lasting effect. At this time no exposure pathways exist at this site that are unique to children.
The Louisiana Tumor Registry (LTR) was used for the ascertainment of cancer incidence cases. The Tumor Registry, operated by Louisiana State University Medical Center, is a population-based cancer registry covering the entire state of Louisiana. The registry has been in operation inthe New Orleans metropolitan area since 1974, in South Louisiana since 1983 and in the rest ofthe state since 1988. By law, every health care provider is required to report newly diagnosedcancers.
The period of time selected for evaluation of the cancer incidence data was 1988-1995, which isthe most recent health data available for this part of the state at the time of analysis. The smallest geographic area for which we can calculate rates of disease is the census block groups. Cancer incidence was chosen for this review because cancer death rates are affected by how advanced the cancer was at the time of diagnosis, access to health care and other factors not related to exposure. A case was defined as an individual residing in one of the selected census block groups who was diagnosed with a new primary malignant cancer during the evaluation period. The variables used to analyze the cancer data included: address at time of diagnosis, parish of residence, primary cancer site or histology type, date of diagnosis, age at diagnosis, race, sex and census tract and block group. Information on other risk factors such as occupational exposures or personal lifestyle habits are not available in the abstracted information medical data used in this review.
In order to compare the cancer incidence rates around the Lincoln Creosote site with parish orregional rates, it is necessary to have specific population data. Population data, categorized byage, and health outcome data are both available at the Census Block Group level. Census BlockGroups are subdivisions of census tract and parishes. They usually have between 250 and 550households and are designed to be relatively homogeneous or similar with respect to populationcharacteristics, economic status, and living conditions.
The Lincoln Creosote site lies within Census Block Groups 10500-02, 10500-03, and 10602-04of Bossier Parish (see Figure 3). The total population for the combined block groups is 3,711persons, according to the 1990 census data.
For the Census Block Groups discussed, analysis was completed for all cancer types combinedand for selected cancer types. The following specific cancer types were able to be analyzedbecause there were at least five observed cases in the three Census Block Groups: colon, rectum,lung, female breast, prostate, bladder and leukemia.
Skin cancers (including melanomas) were not separately analyzed because there were less thanfive observed cases. Basal cell and squamous cell carcinomas of the skin are not recorded intumor registries unless they occur on the vermilion border of the lip or on the genital regions. Lymphomas of the skin would be grouped with Non-Hodgkin's lymphomas which are a separatecategory from skin cancers.
Analysis of cancer incidence was conducted using standardized incidence ratios (SIRs). The SIRis calculated by dividing the observed number of cases by the expected number of cases. Theexpected number was derived by multiplying a comparison population's age-sex-specificincidence rates and the Census Block Groups' age-sex-specific population data. SIRs werecalculated when 5 or more cases were observed in the combined census block groups. SIRs werecalculated for all races combined and for whites. A separate analysis for blacks was not donebecause of small numbers. The Northwest Louisiana (Region VII) average annual incidencerates (1988-1992) were used to derive the expected number of cases. The Region VII includesBienville, Bossier, Caddo, Claiborne, DeSoto, Natchitoches, Red River, Sabine and Websterparishes.
Evaluation of the observed and expected numbers is accomplished by interpreting the ratio ofthese numbers. If the observed number of cases equals the expected number of cases, the SIRwill equal one (1.0). When the SIR is less than one, fewer cases were observed than expected. For SIRs greater than one, more cases were observed than expected.
Caution should be exercised, however, when interpreting the SIR. The interpretation must takeinto account the actual number of cases observed and expected, not just the ratio. Two SIRs canhave the same number, but represent very different scenarios. For example, a SIR of 1.5 couldmean 3 cases were observed and 2 were expected (3/2 = 1.5). Or it could mean 300 cases wereobserved and 200 were expected (300/200 = 1.5). In the first instance, only 1 excess canceroccurred, which could easily have been due to chance. But, in the second instance, 100 excesscancers occurred and it would be less likely that this would occur by chance alone.
To help interpret the SIR, the statistical significance of the difference can be calculated. In other words, the number of observed cases can be determined to be significantly different from the expected number of cases or the difference can be due to chance alone. "Statistical significance" for this review means that there is less than 5 percent chance (p-value <0.05) that the observed difference is merely the result of random fluctuation in the number of observed cancer cases. If the SIR is found to be statistically significant, then the difference between the expected and observed cases is probably due to some set of factors that influences the rate of that disease.
Because cancer is, unfortunately, so common (more than 1 in 3 of us will develop cancer in ourlifetime), every community will experience a certain number of cancers. Through the years, youwould expect some fluctuation in the numbers. One year, there may be a few more cases ofcancer A and the next year a few less. This occurs by chance. There is no specific cause. Justlike flipping a coin, although you expect that you will get heads half the time and tails half thetime, it doesn't always come up even. Out of 10 coin tosses, you may get 7 heads and 3 tails or 4heads and 6 tails. The more tosses you make, the closer you will probably come to getting a 50-50 mix. This is why, in order to determine if cancer rates are elevated, the statistical significance must be considered.
Result of Cancer Incidence Analysis
Standardized incidence ratios were computed for all cancers combined and for specific cancersites when more than five cases were observed in the Block Groups. Appendix C contains tablessummarizing the results. Table C-1 shows the number of cancer cases detected in the 3 BlockGroups near Lincoln Creosote during 1988-1995. Table C-2 shows the results of the SIRanalysis for the combined Block Groups for all races combined by primary cancer type usingRegion VII cancer rates as the comparison. In general, there were fewer cases observed thanexpected, but the difference is not statistically significant. For females, the number of lungcancer cases observed was significantly higher than the expected cases as calculated withregional rates (SIR=1.7; p=0.0457). None of the cancer ratios for males were significantlydifferent than expected.
Table C-3 presents the results of the SIR analysis for the combined census block groups forwhites by primary cancer type using Region VII cancer rates as the comparison. For white males,all cancers combined were significantly lower than regional rates (SIR=0.7; p=0.0374). None ofthe cancer ratios for white females were significantly different than expected.
No cause or reason for the differences in cancer rates can be determined by this type of review. The influence of established risk factors for each type of cancer was not evaluated. This screening helps to identify unusual patterns of adverse health effects and direct future public health actions.
We have addressed each of the community concerns about health as follows:
- Is the water-filled ditch that runs between the site and the residential areas of North Park and Cloverdale Apartments safe for children to play in?
2. Are the crawfish from the ditches surrounding the site safe to eat?
While on a site visit before remediation, SEET staff observed run-off water from the sitedischarging directly into the ditch. This ditch running between the site and the residentialareas and is approximately two feet wide. Staff observed toys and children playing in theditch. This prompted SEET to have signs that read "KEEP OUT OF DITCH" to beposted on the fence near the ditch in May 1993. The signs contain the telephone numbersto both the Bossier Parish Health Unit and the Office of Public Health for anyone wishingadditional information. Due to the nature of the site it is difficult to determine if, in spiteof remedial efforts, the ditches are clean enough to accommodate all segments of thepopulation. Due to this fact and the hazards inherent in playing in urban ditches, SEETrecommends that children stay out of the ditches.
3. What is creosote and its potential health effects?
The ditches that surround the site drain an urban area and in cases of rain may be filledwith water that is possibly contaminated with bacteria and heavy metals as you may findin other urban ditches. No samples of crawfish from the ditch were collected. Thereforethe safety of eating crawfish from the ditches cannot be assessed at this time.
4. Is exposure to site chemicals causing rashes and other skin effects in the area?
Creosote is a complex mixture of many chemical compounds. Creosote containspolycyclic aromatic hydrocarbons (PAHs). Some of these substances are known to becarcinogens and others are known to cause conjunctivitis (an infection of the eye) as wellas skin effects such as rashes, burns, and phototoxic (a reaction when in the sun) effects.
5. Do the site contaminants cause or instigate asthma?
Some of the chemicals detected in soil on-site were at levels that could cause healtheffects in the past. Direct, unprotected contact with contaminants that may have migratedoff-site could have resulted in rashes and other skin effects. However, rashes have manycauses and should be evaluated by your physician. Elevated levels of metals and PAHs insome residential yards have been detected in the past. These areas have since beencleaned up by EPA. Current exposures are not likely to produce health effects, includingskin rashes. If residents near Lincoln Creosote are currently experiencing rashes, pleasecontact the state health department toll-free at 1-888-293-7020. If residents notice creosote material in their yards, they should contact Louisiana Department of Environmental Quality or theU.S. Environmental Protection Agency.
6. Is food grown in local gardens safe to eat?
Asthma episodes and respiratory problems may be triggered by fumes, odors, andparticulate matter in air. Creosote compounds that were on-site in the past may havecontributed to odors and dusts emanating from the site. Past odors from the site werediscussed by several people during the recent public meetings. Asthma may have beenaggravated by dust and particulate matter in air when the site was not vegetated. Inaddition, asthma may be an allergic reaction to substances such as pollens in air. Individual health questions should be discussed with a personal physician.
7. Is the local air contaminated?
Because of the remediation that has occurred at this site, the contaminated soil has beenreplaced. Food grown in local gardens is safe to eat.
8. Is the public drinking water safe?
The latest air samples indicate that the local air is not contaminated with site compounds.During October 1992, ambient air monitoring was conducted on-site in order tocharacterize the off-site migration of selected contaminants during the removal action. Air samples were collected at ten site locations each day that affected soils wereexcavated, loaded into trucks, or moved in any way. At least one upwind and threedownwind locations were analyzed for each day of monitoring depending on theprevailing wind speed and direction that day. Air analyses included PAHs includingnaphthalene, PCP, and metals. Only arsenic, chromium and copper were detected insome samples taken during the removal action, and these, based on levels obtained fromsampling are no health threat.
9. Houses adjacent to the site have flooded eight times over the past 20 years. Are these houses contaminated?
The Bossier City Water System supplies residents with water from the Red River for useat their homes. The water from the system is routinely monitored to ensure that it meetsbacteriological and chemical health standards. When we checked, the system met allfederal requirements of the Safe Drinking Water Act. The August 1994, bacteriologicaltesting met all Safe Drinking Water Act requirements. The September 1993 chemicalsampling and analysis met all federal requirements for safe drinking water as well. The chemical sampling includes metals, pesticides, herbicides, volatile organic compounds,trihalomethanes, radiological material, and sanitary chemicals (iron, sodium and otheraesthetic secondary requirements).
10. Where should residents report health concerns they believe to be related to exposures from the site?
Regular house cleanings after floods and over the years are likely to have removed anycontaminants that may have been brought into the houses with the flood waters. However,past sampling of residential yards did show soil contamination which has since beenremedied.
11. Is exposure to site chemicals causing cancer cases in the area?
Residents should report any problems to their local Bossier Parish Health Unit at 318-741-7413. Also, the Section of Environmental Epidemiology and Toxicology (SEET) can answer questions regarding exposure to site contaminants. The telephone number for SEET is 888-293-7020 (toll-free) or 504-568-8537.
12. What are the possible health effects from exposure to site contaminants in the past?
The Louisiana Tumor Registry has data on the cancer incidence (the number of cancercases diagnosed) for the area. This information is analyzed in the Health OutcomeSection. In general, cancer incidence rates for the census block groups surrounding theLincoln Creosote Site were lower than cancer incidence for the Northwest Region.
13. What is the timetable for remediation?
PAHs can cause skin irritation and rashes in humans and tumors in laboratory animals. They have been associated with lung and skin cancer in humans. Creosote may cause eyeburns, and reddening, blistering and peeling skin irritation. Creosote can cause tumors inlaboratory animals. Pentachlorophenol, or PCP, may damage the liver, kidney, lung, and central nervous system. It can also cause eye and nose irritation. Arsenic can cause gastrointestinal distress, skin, eye and throat irritation, and damage the liver, kidney, and blood vessels. Arsenic has been shown to cause lung, liver, kidney, and bladder cancer.
14. Was the entire site remediated?
LDEQ began remediation of the site in February 1992 and completed their work inNovember 1993. LDEQ removed 100,884 tons of contaminated soil from the site duringremediation. EPA has been conducting an off-site investigation since 1992 to determinethe concentrations of site contaminants in residential yards, off-site ditches, and on theNorth Park Apartment Complex grounds. Only PAH compounds were found at elevatedlevels. Off-site soils 0-2 feet where the total B(a)P equivalents exceeded 3 ppm wereexcavated starting in June of 1996 and was completed in Spring 1997.
15. Does the ditch behind the North Park apartment complex contain site chemicals and if so can my children get
Yes, not only the entire site but also the off-site areas where elevated levels of sitecontaminants were found. Confirmatory soil sampling was conducted to determine if thesite remediation was complete. Low levels of PAHs and lead were detected but at levelswhich would not affect health. Off-site areas including residential yards, ditches and theNorth Park Apartment complex grounds, were also sampled.
Soil with concentrations of B(a)P equivalents greater than 3 ppm were remediated. Consequently parts of the apartment complex grounds and several residential yards alongBardot Lane and Northside Drive were excavated.
sick from it?
The ditch behind the apartments contained creosote material. It did receive somedrainage from the site in the past but it was not a main drainage pathway. None of the 3samples taken from the ditch lately, showed levels of contaminants that would causehealth concern. However, clumps of creosote material have been found in the ditch. TheCity cleaned the ditch in June of 1996 by excavating the top several inches of soil fromthe ditch. It was then inspected by EPA for any visual signs of creosote contamination. A small amount of creosote material still remained in the ditch after the scrapping. Thisarea was excavated and the soil removed.
Past sampling does not indicate that contaminants were present in the ditch at levels thatwould cause people to get sick. However, ditches in any urban area may contain anumber of contaminants just from the surrounding area, including metals and bacteria. For this reason, we recommend that children do not play in the ditches.