PUBLIC HEALTH ASSESSMENT
DALLAS, DALLAS COUNTY, TEXAS
The RSR Corporation National Priority List (NPL) site, also known as West Dallas Lead,includes the facility formerly associated with the RSR Corporation Lead Smelter and thesurrounding 13.6 square miles of residential, commercial, and industrial property of West Dallas,Dallas County, Texas that were contaminated with lead from RSR. This contamination resultedfrom historical air emissions from the RSR lead smelter, the use of battery chips and slag asresidential fill, and the disposal of battery chips and slag in landfills and dumps.
The U.S. Environmental Protection Agency (EPA) is removing environmental contaminationassociated with the RSR smelter in five separate operable units, the first of which (Operable Unit1) addresses the single-family residential properties that were contaminated by materials from thesmelter. This report focuses on the current public health significance of Operable Unit 1. Thisarea of the site formerly constituted a public health hazard since residents were exposed tosignificant levels of site contaminants in the past. More recent environmental sampling data andblood lead data indicate that residents currently are not being exposed to contaminants from thesite at levels that would be expected to cause adverse health effects; therefore, the single-familyresidential area of the site currently constitutes no apparent public health hazard. As informationabout the remaining operable units -- the area with multi-family housing units, dumpsites/slagdisposal areas, and the smelter facility site -- becomes available, the remaining public healthimplications of site contamination will be evaluated.
Air sampling data collected at the fenceline of RSR and in the residential areas near the smelterindicate that inhalation of contaminated air was a significant route of exposure in the past. Persons who were exposed to lead from the site in the past include residents and workers whoinhaled contaminated air when the smelter was active and who ingested contaminated soil anddust prior to remedial activities. Exposures to lead-contaminated air were probably greatest priorto 1968 when air emissions from the smelter were largely uncontrolled. Due to the limitedavailability of ambient air data collected in the residential area when the smelter was active, wewere unable to quantify past inhalation exposures. Air emissions from the smelter were reducedin the early 1980s and were eliminated as a source of contamination in 1984 when the smelterclosed.
Environmental sampling data indicate that soil was contaminated with arsenic and cadmium inaddition to lead. We were unable to determine from available data whether arsenic and cadmiumwere associated with battery chips, stack emissions, or both. If arsenic and cadmium wereassociated with stack emissions, past exposures to these contaminants could have occurredthrough inhalation as well as ingestion of contaminated soil and dust. Due to limited data, wewere unable to quantitatively evaluate past or present exposure to these contaminants.
Pre-remedial soil lead data were unavailable in a format suitable for exposure quantification;however, in 1982 the average blood lead level of 227 randomly-selected children living near theRSR Smelter was 20.1 µg/dL, indicating that significant exposure to lead was occurring. The likelihood of human exposure to site contaminants was decreased through remedial efforts in1984 and 1985 that included removal of soil with lead levels above 1,000 ppm. The potential forhuman exposure was further reduced by clean-up activities initiated in 1991 to identify andremove soil in residential areas with lead concentrations greater than 500 ppm, arsenicconcentrations greater than 20 ppm, and cadmium concentrations greater than 30 ppm.
In 1993, when this clean-up effort was nearing completion, the City of Dallas and the Agency forToxic Substances and Disease Registry (ATSDR) conducted a lead exposure study in which theblood lead levels of randomly-selected West Dallas children were determined. The averageblood lead level of all 305 children tested was 5.5 µg/dL. The average blood lead of the 53children who lived nearest the smelter was 7.0 µg/dL. These data suggest that exposure to leadin West Dallas has decreased significantly since 1982. The study identified 26 West Dallaschildren (8.5% of the 305 children tested) with elevated blood lead levels ( 10 µg/dL). Ten ofthe children with elevated blood lead levels lived in the area closest to the smelter (18.9% of the53 children from this area who were tested). The study, however, did not find a relationshipbetween blood lead concentrations and lead in residential soil and home dust.
Some areas within the site boundaries still have not been fully characterized; these areas includethe unoccupied Dallas Housing Authority (DHA) property, slag piles/disposal areas, the smelterfacility, and other RSR/Murmur property. Although trespassers could be exposed tocontaminants, current human exposure in these areas is unlikely since public access is minimal. We were unable to evaluate the public health significance of these unremediated areas and theresidential properties where owners refused access to EPA for remediation activities becauseenvironmental sampling data were not available.
Residents of West Dallas have raised several questions about the potential for adverse healtheffects among individuals who were exposed to high levels of lead as children, the health effectsof exposure to lead on adults, and the safety of lead cleanup levels for soil. Detailed answers to these questions are contained in the Public Health Implications section of this document.
The Texas Department of Health (TDH) has recommended continuing measures initiated by theEPA and the City of Dallas to protect public health in West Dallas, including limiting publicaccess to areas of the site which have not yet been remediated, further evaluating the sources ofexposure among the 10 children identified in Area 1 with elevated blood lead levels, andproviding ongoing blood lead testing for residents of West Dallas. TDH also has recommendedevaluating the potential public health implications of the site as additional sampling data become available for review.
This report has been reviewed by ATSDR's Health Activities Review Panel (HARP) fordetermination of appropriate follow-up health activities. HARP recommended that TDH andATSDR work with the City of Dallas Department of Health and Human Services to providecommunity education with specific attention to answering the community's health concerns. Although exposure to lead has occurred in the past, HARP did not recommend additionalfollow-up activities at this time because contaminants from the RSR site do not now pose asignificant threat to health.
While the health assessment process deals with scientifically verifiable findings, all phases of the process involve a degree of uncertainty. The degree of uncertainty depends upon thecompleteness of site data, the accuracy of assumptions that simplify and approximate siteconditions and site exposures, the completeness of toxicity data for the contaminants of concern,and the professional judgement used in developing and evaluating various parameters. Data gapsare bridged by using a variety of health protective assumptions. All assumptions that we used indeveloping this document weigh heavily toward the protection of public health.
In cooperation with the Agency for Toxic Substances and Disease Registry (ATSDR), the TexasDepartment of Health (TDH) has evaluated the public health significance of this site. Morespecifically, ATSDR and TDH have determined whether adverse health effects can result fromexposures to contaminants at this site and recommended actions to reduce or prevent possiblehealth effects. ATSDR, a federal agency within the Department of Health and Human Services,is authorized by the Comprehensive Environmental Response, Compensation, and Liability Actof 1980 (CERCLA) to conduct health assessments at hazardous waste sites.
The RSR NPL site, also known as West Dallas Lead, includes the former RSR (West Dallas)Lead Smelter and approximately 13.6 square miles of surrounding commercial, industrial, andresidential property in West Dallas, Dallas County, Texas. The RSR site (also referred to as thestudy area) is bounded to the north by the Trinity River, to the east by Fort Worth Avenue, to the south by Davis Street, and to the west by Texas local highway Loop 12 (Walton WalkerBoulevard). See Figure 1.
RSR was a secondary smelter and lead recovery facility that operated at the intersection ofSingleton Boulevard and Westmoreland Road from 1936 until 1984. The facility was originallylocated just outside the Dallas city limits until 1952 when the city of Dallas annexed the area. Inthe subsequent 15 years, residences, schools, a Boys Club, and a major Dallas Housing Authorityproject were constructed nearby . In 1971, RSR acquired Murph Metals, Inc., the previousowner of the smelter, and established it as an operating subsidiary. Murph Metals and itspredecessors had operated the smelter continuously from 1936 until 1971 under the namesSouthern Lead and Southern Smelter .
Contamination at the RSR NPL site has resulted from historical air emissions from the RSRLead Smelter, the use of battery chips (pieces of automotive battery casings generated fromrecycling operations at the smelter) and slag as residential fill, and the disposal of battery chipsand slag in landfills and dumps. Contaminants associated with the site include lead, arsenic, and cadmium . Lead has been identified in the soil on residential properties north and northeast of the smelter in a pattern suggesting that it was deposited through air emissions from the RSR smelter. Contaminants on residential properties throughout the community have been associated with battery chips and other materials from the smelter. According to residents, people used battery chips from the smelter as fill and paving material at a time when people had little awareness of the potential dangers that might be associated with these materials. These practices took place over a period of approximately 30 years, ending in the 1970s. The RSR properties and three landfills where RSR disposed of battery chips, slag, and smelter waste have not yet been fully characterized, but also contain site contaminants (Figure 2).
Principal activities associated with air pollution from the smelter included the preparation of scrap lead batteries for smelting, reverberatory and cupola smelting processes, hard and soft lead refining processes, alloying, and fabrication. According to available records, emissions from the smelter were uncontrolled prior to 1968 when a lead control ordinance was enacted by the City of Dallas. After RSR acquired the smelter in 1971, violations of the city ordinance began to occur almost immediately .
Numerous enforcement actions and compliance efforts were initiated in the early 1970s. In1975, RSR upgraded the capture efficiency of emissions control devices under a State Courtorder. The smelter operated inconsistently throughout the late 1970s under the constraints of thecontrol strategy imposed by the court. In 1979 and 1980, RSR completely revamped the smeltercontrol system in preparation for enforcement of the United States Environmental ProtectionAgency's (EPA's) new national lead standard. In the early 1980s, however, the Texas AirControl Board [TACB, which is now a part of the Texas Natural Resource ConservationCommission (TNRCC)] found that the smelter was in violation of the national ambient airstandard despite the recent implementation of controls. In the same period, blood screening ofchildren indicated that excessive exposure to lead was occurring .
In May 1983, the City of Dallas and the State of Texas filed suit against RSR and Murph Metals,Inc. under the Texas Clean Air Act and city ordinances alleging damage from air emissions oflead. The 95th District Court ordered RSR to remove and replace contaminated soil onapproximately forty acres of land within one-fourth mile of the smelter, to sod or plant grass onbare spots within one-half mile of the smelter, and to implement a comprehensive remedial plan. The order also required continued blood lead screening of children in the area and installation of adequate air pollution control equipment on the smelter stack .
In the same period, the EPA pursued an administrative order under the ComprehensiveEnvironmental Response, Compensation and Liability Act (CERCLA or Superfund) and theFederal Trade Commission ordered that RSR divest itself of the Dallas smelter. In February1984, RSR sold the facility to the Murmur Corporation and the court subsequently held Murmurliable for air pollution control costs .
Murmur assumed occupancy, began to install necessary controls, and ultimately received TACBapproval to begin operations. In September 1984, however, the Dallas Board of Adjustmentdenied Murmur's application for an operating permit on the basis that the smelter was anon-conforming use of the land and that cessation of operations in February had terminated its"grandfathered" status. After legal appeals, Murmur was permanently enjoined from operatingthe smelter in February 1985. There have been no lead emissions from the RSR stack sinceFebruary 24, 1984 when RSR ceased operation of the smelter .
Remedial work was initiated in 1984 under the direction of a court-appointed Special Master. A private contractor removed soil with lead levels of more than 1,000 parts per million (ppm) (alevel considered protective of public health at that time) from residential areas, public play areas, day care centers, and private gardens within a one-half mile radius of the smelter. Most soil removed from the area was taken to a dedicated landfill in southeast Dallas county, near Wilmer, Texas. The small amount of soil that exceeded the extraction procedure toxicity (EPT) standard was manifested to a commercial hazardous waste disposal site near Robstown, Texas. Soil was replaced with clean fill [1,6].
Areas in which contaminated soil was not removed, such as the former smelter facility site anduninhabited Dallas Housing Authority (DHA) buildings, were fenced to restrict public access. Groundcovers were planted and water credits were provided to residents to support sod wateringand growth. Unpaved driveways and alleys were paved to reduce dust emissions. Remedialwork was completed in 1985 [5,6].
A medical monitoring and public health program was initiated in 1984 by the City of Dallas. The program offered free blood lead screenings at six-month intervals for children and pregnantwomen living within one-half mile of the smelter . The City continues to offer free-of-chargeblood lead screening to all Dallas residents.
Problems reemerged at the site in July 1991 when the Texas Water Commission (TWC) [whichis now part of the Texas Natural Resource Conservation Commission (TNRCC)] began receivingcomplaints from residents around the RSR Smelter. TWC soil samples showed elevatedconcentrations of lead, arsenic, and cadmium .
TWC requested that the EPA become involved at the site to review the activities of the 1980s. As of December 1991, most soil samples contained less than 250 ppm lead, but approximately 16percent of samples contained levels between 500 and 1,000 ppm. The highest contaminantconcentrations were found in areas of West Dallas where contaminated soil, slag, and batterychips had been improperly disposed or used as residential fill [7,8].
EPA began a second removal effort in West Dallas in 1991, which involved the cleanup ofcontaminated residential areas. EPA proposed the RSR Corporation site to the National Priorities List (NPL) of Superfund sites May 10, 1993. EPA has prioritized the West Dallas cleanup into five operable units which are being addressed separately (Figure 2) [2,9]. OperableUnit 1 consists of all single-family residential properties that were contaminated by materialsfrom the RSR smelter facility. Contamination in this area resulted from air deposition from thesmelter smoke stacks and the use of battery chips and slag as yard and driveway fill material. Removal efforts for Operable Unit 1 were divided into two phases.
During Phase 1, EPA excavated soil from 206 residential lots that were subject to air deposition. Work began in October 1991, but due to legal challenges regarding soil disposal arrangements,full-scale removal activities were delayed until June of 1992. Phase 1 work was completed inJune of 1994. Phase 2 removal activities have focused on 194 residential properties wherebattery chips or slag have been identified or where soil lead levels are over 500 ppm, arsenicconcentrations are over 20 ppm, or cadmium concentrations are over 30 ppm. Phase 2 removalwas completed in June of 1994. Soils deemed non-hazardous under federal law were trucked tothe Republic Waste Industries facility in Avalon, Texas, while materials deemed hazardous weretrucked to a hazardous waste disposal facility in Peoria, Illinois [8,9].
Operable Unit 2 includes the multi-family housing units owned by the Dallas Housing Authority. Most of the buildings in this area have been unoccupied in recent years, with the exception ofbuildings on the eastern portion of DHA property that were renovated in 1988 and 1989. Properties with the highest levels of contamination were fenced to restrict access. Contaminationof this area is associated primarily with air deposition of lead emissions from the smelter. EPAand DHA formalized an agreement for DHA to conduct studies for this site and conduct acleanup comparable to EPA's Phase 1 removal action. Contamination removal activities beganin early 1995. Final remedial action decisions are currently being issued for both Operable Units1 and 2.
Operable Unit 3 includes three properties/dump sites where slag and/or battery chips may havebeen disposed. The properties are in three locations on the southern and western perimeters ofthe site. EPA describes the properties as Sites 1, 2, and 3: Site 1 is in the 1000 block of North Westmoreland Avenue; Site 3, also referred to as the Walton Walker Property is near Loop 12(Walton Walker Boulevard) and Singleton Boulevard; and Site 4 is at the end of ClaibourneStreet. Two of these properties were formerly City landfills. EPA began field activities and aninvestigation of these areas in October 1994 [2,8,9].
Operable Unit 4 refers to the secondary lead smelter facility at 2820 North WestmorelandAvenue. Operable Unit 5 refers to other properties south of Singleton Boulevard and west ofWestmoreland Avenue that are associated with the smelter, including a disassembled batterywrecking facility, a closed solid waste surface impoundment, and other potential slag/batterychip disposal areas. In November 1993, the potentially responsible parties declined theopportunity to conduct site studies at these locations. EPA recently conducted field activities and Remedial Investigation/Feasibility Studies (RI/FSs) in Operable Units 4 and 5. The RI/FSreports were released for public review in the Spring of 1995.
A Biologic Indicators of Exposure Study was initiated in Fall 1993 by ATSDR and the City ofDallas, along with assistance from EPA, to determine the public health significance of the RSRCorporation Smelter facility. This study includes a random sampling of more than 500 homes inthe West Dallas area and a northern Oak Cliff neighborhood, which serves as a baselinecomparison area. EPA conducted a home sampling study in October and November 1993. TheCity of Dallas Health Department workers took blood samples from 386 children six years of ageand under and administered questionnaires to identify other sources of exposure to lead . Results of this lead exposure study indicate that few West Dallas children currently have elevated blood levels; 26 of 222 children tested in the study area, including 10 of 53 children in Area 1, had blood lead levels greater than or equal to 10 µg/dL. Additional information about this studyis provided in this report and detailed analyses of the results is presented in a separate report by the participating agencies.
EPA has used the results of the West Dallas Lead Study as part of its risk assessment process todetermine the necessary actions for making the residential areas of the RSR Corporation Site safefor long-term exposure.
TDH and ATSDR staff members visited the neighborhoods encompassed within the boundariesof the Superfund "site" numerous times. They attended community meetings and public availability sessions in the area on at least seven occasions. John Villanacci, Ph.D. and KathrynEvans, M.P.H. of the Texas Department of Health, and Jennifer Lyke of ATSDR conducted a"site visit" on September 21, 1993 to examine the physical characteristics and layout of the areain a comprehensive manner and to learn more about EPA's remedial efforts. The site visitincluded a drive through the smelter facility and most of the surrounding neighborhoods andcommercial areas, and a walk through one of the three slag disposal areas. The EPA ProjectManager guided the site visit and was available to answer questions. Approximately two andone-half hours were spent on this tour.
The RSR Smelter is at the intersection of Singleton Boulevard and Westmoreland Road in WestDallas. The smelter is bordered to the south by the Missouri Pacific Railroad tracks, north by theBoys and Girls Club, north and northwest by the Lake West Housing Project (which is partiallyoccupied), and further north and northwest by single-family residential housing.
The smelter was inaccessible to the general public. A brick fence topped with barbed wiresurrounds the facility and there was a 24-hour guard at the entrance on Westmoreland Road.Buildings formerly associated with the smelter were being used to stockpile contaminated soilbefore transporting it to disposal facilities. EPA field offices were located in a mobile office on the smelter site.
Dilapidated facilities on the site of the former smelter may present physical hazards, but the area is well-restricted from the public to prevent accidents and injury. Other areas of the RSRCorporation site which have not yet been fully characterized may present similar hazards. Wedid not observe any apparent potential causes of avoidable physical hazard.
The area defined as the RSR NPL site surrounds the smelter and is used for commercial,industrial, and residential purposes. At its widest points, the site is approximately six miles from east to west and approximately three miles from north to south. The site's boundaries are roughly defined by Canada Drive on the north and east, Interstate 30 and Fort Worth Avenue on thesouth, and Texas local highway Loop 12 (Walton Walker Boulevard), the West Fork TrinityRiver, and mud flats on the west (Figure 2).
Numerous businesses and industrial sites are east and west of the smelter along SingletonBoulevard, including automobile repair shops, tire repair and sales shops, and GAF, a buildingmaterials manufacturing plant. Residences and several schools also are on Singleton Boulevard. There is a mixture of commercial, light industrial, and residential use along the busier streetsthrough the area. More densely populated residential neighborhoods are immediately northwest,north, and northeast of the smelter across Singleton Boulevard as well as southwest of thesmelter off Singleton Boulevard and south of the smelter off Westmoreland Road.
The residences closest to the smelter are directly across Singleton Boulevard to the north. Many of the buildings in this area, which are part of the Lake West Housing Project, were unoccupiedand boarded up; the yards surrounding most of the vacant buildings were enclosed with a six-footchainlink fence. Apartment buildings north of Bickers Street were apparently occupied. Theseareas were included in the 1984/1985 remediation activities.
We drove through residential neighborhoods east of the smelter on both the north and south sidesof Singleton Boulevard. These areas include primarily low socio-economic, single familydwellings. Many of the residents in these neighborhoods are Hispanic and African American.
Within the residential areas, we saw a church parking lot and several yards and driveways thatwere being remediated or that had been recently remediated. Yards had been seeded with grassand driveways covered with new gravel. We also saw two driveways in which battery chips hadbeen used for fill or gravel that had not yet been remediated.
Acording to the EPA On-site Director, three "slag piles" where large quantities of slag materialmay have been dumped are located on the site: 1) at the end of Claibourne Road near aresidential neighborhood on the northwest side of the site; 2) in an inaccessible area between the railroad track and Walton Walker Boulevard on the southwestern edge of the site; and 3) in anindustrial area between Westmoreland Road and Cement Plant Road near the central southernedge of the site (Figure 2).
We walked around the slag pile at the end of Claibourne Road, off Singleton Boulevard. Thearea where slag had been dumped was fenced, but one side of the six-foot chainlink fence hadbeen crushed, making the area easily accessible. A sign stating "Warning - contamination area,by TWC" was on the ground by the opening in the fence.
There was a dirt road within the fence leading across the dumping area to the Trinity River. The EPA Project Manager said that people have knocked the fence down in the past with four-wheeldrive vehicles in order to gain access to the road through the site which leads to the Trinity River bottoms.
Pieces of slag were visible along the roadside, but most of the area within the fence was coveredwith tall grass. We saw several beer bottles and a few shotgun shells along the road within thefenced area, but no evidence that young children had been playing in the area. We saw noevidence of trespassing within the fenced area other than the trash near the road. This slag pilearea is approximately two blocks from Jaycee/Zaragoza Park, which has well maintainedplayground facilities for children.
We drove by the slag pile near Westmoreland Road, south of the smelter. The immediatesurrounding area was predominantly commercial and light industrial, and there was a mobilehome/recreational vehicle park just south of the slag pile. The fence on the perimeter of the slagarea along Westmoreland Road was approximately six feet tall and in good repair. The area wascovered with dense vegetation and was apparently difficult to access; however, we were able tosee only the perimeter of the slag pile area adjacent to Westmoreland Road. We did not see theslag pile area at the western edge of the site, south of Interstate 30. The project manager said thatthis area was less easily accessible than the other slag piles.
The EPA Project Manager explained that the site has been divided into five operable units so thatclean-up activities can take place in order of priority. Current clean-up efforts began in 1991 andare part of Operable Unit 1. Operable Units 1 and 2 include residential areas off SingletonBoulevard immediately north, northeast, and northwest of the smelter. Operable Unit 3 includesthe three slag piles near the southern and western perimeters of the site. Operable Units 4 and 5include the smelter and additional land owned by RSR and the Murmur corporation. Clean-upefforts will address the remaining operable units when EPA completes the clean-up of residentialand public use areas (Figure 2).
On September 22, 1993, Health Department staff met with EPA, ATSDR, the City of DallasDepartment of Health and Human Services, and private contractors involved with the 1993 WestDallas Blood and Environmental Lead Study. This study was designed to assess the extent andimpact of current lead contamination in West Dallas. Study participants would include childrenunder age six in approximately 500 randomly-selected households in West Dallas and acomparison area in northern Oak Cliff neighborhood. A pilot study testing the questionnaire,blood lead sampling techniques, and environmental sampling techniques that would be used inthe study had just been completed; results were discussed in the meeting. The group estimatedthat questionnaires would be administered and samples would be collected in Fall 1993 and thatanalyses would be completed in Winter and Spring 1994. (A report of this study was released bythe participating agencies in November 1994 and is entitled "Biologic Indicators of Exposure toLead, RSR Smelter Site, Dallas, Texas).
C. Demographics, Land Use, and Natural Resources Use
According to 1990 census data, the total population of the census tracts in which the site lies (43,101.01, 101.02, 102, 103, 104, 105, and 106) is 27,349 persons, living in 6,615 housing units. Some of the residences in census tract 43 may not be within the site's boundaries, but allthe other census tracts apparently match the site's boundaries exactly.
As of 1990, approximately 27 percent of the primary householders in West Dallas had lived inthe same house since 1969 or earlier; 43 percent had lived in the same house since 1979 orearlier. In 1990, 55 percent of the population over age five had lived in the same house for five or more years. Approximately ten percent of the total population are younger than five years of age and approximately eight percent are older than 65 years of age.
The 1990 census reports that approximately 43 percent of the people in this area are AfricanAmerican, 18 percent are white, 1 percent are Asian, and 38 percent are of "other races." Approximately 52 percent of the total census population are of Hispanic origin. Fifty percent ofpeople over age five reported speaking a language other than English at home; most of theseindividuals (97%) reported speaking Spanish at home. Twenty-five percent of the totalpopulation over five reported that they do not speak English "very well."
The unemployment rate for persons ages 16 years and older was 16.4%. The median familyincome ranged from $4,999 in census tract 103 to $19,886 in census tract 43. In West Dallas in1989, the income of approximately 46 percent of families with children under five years of agewas below the federally-defined poverty level. Approximately 29% of persons ages 25 and overgraduated from high school and just less than one percent graduated from college.
The RSR Corporation NPL site covers approximately 13.6 square miles of West Dallas. Thepredominant land uses within the boundaries of the site are residential, commercial, and lightindustrial. Most commercial and industrial activities occur along Singleton Boulevard,Westmoreland Road, and other major streets. Businesses include Lilly Industrial Coatings,Dallas Woodcraft, Inc., Blanks Engraving Company, Comet Steel Inc., GAF Building Materials,QDT Ltd. boiler plate manufacturers, a cement plant, and numerous tire repair and automotiverepair shops . The Boys and Girls Club is immediately north of the site. A church and a school lie east of the site. Two other schools, several churches, day care centers, and parks are located within the site's boundaries.
The most densely populated residential areas are in the central portion of the site north ofSingleton Boulevard and at both the western and eastern ends of the site on the north side of I-30. Most of the residences are low-income, single-family dwellings. A large part of the residentialarea in the northern central portion of the site is owned by the Dallas Housing Authority (DHA)and includes numerous multi-unit buildings that make up the Lake West Housing Project. Manyof these apartments, which are in the high lead deposition area have been unoccupied for severalyears and have been demolished recently as part of the operable Unit 2 removal actions.
The Missouri Pacific Railroad (Amtrak) crosses the site from east to west on the south side ofSingleton Boulevard. The Atchison, Topeka & Santa Fe Railway runs from south to norththrough the central portion of the site and has several short extensions connecting it with theMissouri Pacific.
Natural Resource Use
The Woodbine, Paluxy, and Travis Peak aquifers underlie the West Dallas area. TheVulnerability Assessment Program of TNRCC's Water Utilities Division maintains a databasewhich includes city wells, community-use wells and some residential wells throughout Texas. This database documents three public water supply wells screened in the aquifers underlying theRSR site . These wells, which belong to the City of Grand Prairie, the City of Irving, and theGifford Hill American Company, are located just west and northwest of the study area. Thewells range in depth from 2,001 to 2,163 feet. The TNRCC database does not include anyresidential wells in the West Dallas area, but lists approximately 25 additional wells within thestudy area that are owned by industries and the City of Dallas. These wells range in depth from443 to 2,689 feet .
Since the 1950s, West Dallas has used a municipal water supply that is collected from surfacewater bodies outside the area. Most of the water supplied to West Dallas is drawn from lakesGrapevine and Lewisville .
The boundary of the site is formed by the Trinity River on the east, north, and part of the westside of West Dallas. This river contains water intermittently throughout the year, depending onrainfall. We were unable to determine whether the river is used for fishing. The climate ofDallas County is moderate to hot with average temperatures ranging from 36 to 95 degrees. Theaverage monthly rainfall ranges from under two inches in July to almost five inches in May, witha yearly average rainfall of 35.9 inches .
The general surface water runoff flow pattern in the area is dominated by constructed featuressuch as ditches, culverts, and drainageways. Surface water generally flows toward the TrinityRiver and other small bodies of surface water . Fish Trap Lake is three-fourths of a milenortheast of the RSR Smelter facility and is the largest of approximately six small bodies ofsurface water contained within the site. The Trinity River eventually flows through LakeLivingston and into Galveston Bay.
We obtained blood lead data collected in the West Dallas area by numerous agencies over thepast twelve years. These data are from a variety of sources including the report of the 1982 WestDallas Area Lead Assessment Study, the City of Dallas Health Department Walk-in Clinicdatabase, the TDH Early Periodic Screening, Detection, and Treatment (EPSDT) Programdatabase, and the 1994 City of Dallas/ATSDR Biologic Indicators of Exposure to Lead Study. Although these data are best classified as exposure assessment information rather than healthoutcome data, the relationship between blood lead levels and potential adverse health outcomesis well documented. We are presenting these data here to provide a frame of reference forsubsequent discussions of health outcomes. A complete discussion of these data and theirrelevance to the site will be presented in the Health Outcome Data Evaluation section of thisreport.
Report of the 1982 Dallas Area Lead Assessment Study
The earliest blood lead data we were able to obtain were reported for the 1982 Dallas Area LeadAssessment Study . This study was conducted by the EPA, the CDC, and the City of Dallasto evaluate the extent and potential effect of lead contamination in West Dallas. The LeadAssessment Study provided blood lead testing of 496 randomly-selected preschool childrenliving within one mile of the RSR smelter. The results were evaluated based on CDC's definitionof blood lead toxicity at that time (blood lead level30 µg/dL and erythrocyte protoporphryn(EP)50 µg/dL); the number of children with blood lead levels greater than or equal to 10 µg/dLwas not available in this report. Table 1 presents blood lead test results as they were available in the 1983 report.
|Distancefrom RSRSmelter||Number ofChildrenTested||MeanBloodLeadLevel||ApproximatePercent ofChildren withBlood Lead Level30 µg/dL and EP50 µg/dL||Approximate Percent ofChildren with BloodLead Level30 µg/dL|
|<1/2 mile||269||20.1µg/dL||5 %||10 %|
|1/2 - 1 mile||227||15.8µg/dL||0 %||1 %|
EP = erythrocyte protoporphryn.
City of Dallas Walk-in Clinics
The City of Dallas Health Department established a medical monitoring program after the 1984and 1985 remedial efforts in West Dallas. Voluntary blood lead screening has been offered to allDallas county residents continuously since that time. Summary data were available for twoperiods of testing conducted between the years 1991 and 1993.
During the first period of testing (July through December of 1991), 110 West Dallas childrenunder the age of six were tested in City of Dallas walk-in clinics. Thirty-three (30%) hadelevated blood lead levels (10 µg/dL). During the same period, 52 children who lived in other areas of Dallas county were tested at walk-in clinics. Seven (13.5%) of these children hadelevated blood lead levels .
During the second period of testing (July 1992 through December 1993), 4,475 individuals fromdifferent age groups were tested at City of Dallas walk-in clinics (Table 2) . Among thosetested, 1,138 were children ages six and under from the West Dallas area. The mean blood leadlevel of these West Dallas children was 6.2 µg/dL. During the same period, 330 children wholived in other areas of Dallas county were tested. The mean blood lead level of these childrenwas 7.0 µg/dL. Among the West Dallas children, 158 (13.9%) had elevated blood lead levels (10 µg/dL) . Among the children from other areas of Dallas county, 59 (17.9%) had elevatedblood lead levels (Table 3).
Also during this period, 39 pregnant women were tested -- 19 from West Dallas and 20 fromother parts of Dallas county. The mean blood lead level of the West Dallas women was 3.5µg/dL (levels ranged from 1.0 µg/dL to 8.0 µg/dL). The mean blood lead level of pregnantwomen from other areas of Dallas county was 3.1 µg/dL (levels ranged from 1.0 µg/dL to 5.0µg/dL) 
|Age and Residence ofIndividuals Tested||Individuals||Mean|
|Ages 0 - 6|
|West Dallas Residents||1,138||6.2||0.5||28.0|
|Other Dallas Residents||330||7.0||0.0||32.0|
|Ages 7 - 12|
|West Dallas Residents||444||4.9||0.5||29.0|
|Other Dallas Residents||178||4.6||1.0||14.0|
|Ages 13 and Above|
|West Dallas Residents||965||4.4||0.0||37.0|
|Other Dallas Residents||1,367||4.6||0.0||26.0|
|*Total - All Ages|
|West Dallas Residents||2,969||5.2||0.0||29.0|
|Other Dallas Residents||1,506||5.0||0.0||37.0|
|Location of Residence||ElevatedTests||Range of Blood Lead Levels||# Tests|
|(10)µ/dL||10-14µ/dL||15-19 µ/dL||>20 µ/dL||Total|
|Dallas, Excluding RSR Area||59||17.88||37||11.21||12||3.64||10||3.03||330|
Early Periodic Screening, Detection, and Treatment Program, January to June 1993
The Texas Department of Health maintains a database of blood lead testing data from the EarlyPeriodic Screening, Detection, and Treatment (EPSDT) Program. The EPSDT Program enrollsMedicaid-eligible children for routine medical testing which includes periodic blood leadscreening. Table 4 summarizes blood lead levels detected among Dallas children tested in theprogram between January and June of 1993 . A small number of tests may have beenduplicated for some children since children with elevated finger stick tests were referred for arepeat venous puncture sample. The results therefore are presented as the number of tests andnot the number of children tested. Of the 1,126 tests run on children from the West Dallas area,125 (11.1%) were elevated (10 µg/dL). Of the 5,361 tests run on children from other areas of Dallas, 486 (9.1%) were elevated.
|Residence of Child byZip Code||Number of Tests1||Number ofBlood LeadLevels10 µg/dL||Percent ofBlood LeadLevels10 µg/dL|
|West Dallas Total||1,126||125||11.10%|
|Dallas, Excluding WestDallas||5,361||486||9.07%|
1Some of these tests are finger stick tests, rather than venous punctures, which may falsely
register elevated blood leads due to contaminated samples.
2Majority of neighborhoods nearest RSR lie within this zip code.
The 1993 ATSDR/City of Dallas Biologic Indicators of Exposure to Lead Study
In 1993, ATSDR and the City of Dallas, with assistance from EPA, conducted a lead exposurestudy to determine the impact of lead from the RSR smelter facility on public health . InAugust and September of 1993, the City of Dallas Health Department collected blood samplesfrom 305 randomly-selected children in West Dallas and 81 children in the northern Oak Cliffneighborhood, which serves as a baseline comparison area for the study. The West Dallas studyarea was divided into subareas according to source and level of lead contamination in the area: Area 1 includes all homes in the area previously designated by the EPA as the high dispersionarea; Areas 2 and 3 include the homes in the areas designated as the eastern and western lowdispersion areas, respectively (Figure 3); and Area 4 includes homes located throughout WestDallas where battery chips or slag were found during the 1993 Texas Water Commission (nowTNRCC) survey. The average blood lead level of all 305 children in the study area was 5.5µg/dL; the average blood lead level of the 53 children who lived nearest the smelter was 7.0µg/dL. The study identified a total of 26 West Dallas children (8.5% of the 305 children tested)with elevated blood lead levels (10 µg/dL). Ten of the children with elevated blood lead levelslived Area 1, representing 18.9% of the 53 children from this area who were tested (Table 5).
|Area ofResidence||Households||Individuals||Blood Lead Level(µg/dL)||Elevated Blood Lead Levels(10µg/dL)|
|Mean||Min||Max||10 to <15 µg/dL||15 µg/dL||Total10µg/dL|
Area 1 - Includes all homes designated by the EPA as the high air dispersion area
Area 2 - Includes all homes in low air dispersion area east of Area 1.
Area 3 - Includes all homes in low air dispersion area west of Area 1.
Area 4 - Includes all homes in West Dallas where battery chips and/or slag were found duringTWC survey.
Comparison area - The North Oak Cliff area, consisting of all homes in census tracts 48.0 and54.0.
COMMUNITY HEALTH CONCERNS
We contacted the Community Outreach Officer (a contractor hired by EPA to serve as acommunity liaison), the EPA Community Relations Coordinator, and the City of Dallas HealthDepartment, and talked with individual residents to determine current community healthconcerns. We also attended two EPA-sponsored public availability sessions at the West DallasMulti-Purpose Center, reviewed the October 1993 Resolution by members of the TNRCC's WestDallas Citizen's Advisory Committee, and reviewed newspaper coverage about the site. Thefollowing health-related concerns were identified:
- Why is so much attention still focused on children?
- Should we be concerned about the residents who grew up in West Dallas and were exposed tolead all of their lives? Are they likely to develop illnesses resulting from their exposure to lead?
- Should individuals with high blood lead levels be tracked for follow-up treatment?
- Can residents be provided with free medical help for pollution-related illnesses?
- Could exposure to lead in the environment during pregnancy cause learning disabilities andhearing problems for the unborn child?
- Is EPA's 500 ppm clean-up level adequate to protect public health?