PUBLIC HEALTH ASSESSMENT
ASARCO INCORPORATED (GLOBE PLANT)
DENVER, DENVER COUNTY, COLORADO
Appendix A -- Figures
Appendix B -- Air Data
Appendix C -- Soil Data
Appendix D -- Exposure Pathways
Appendix E -- Estimated Exposure Doses
Appendix F -- Public Comments
FIGURES 1-4
Figure 1. Site Location
The following figure was not available in electronic format for conversin to HTML at the time of preparation of this document. To obtain a hard copy of the document, please contact:
Agency for Toxic Substances and Disease Registry
Division of Health Assessment and Consultation
Attn: Chief, Program Evaluation, Records, and Information Services
Branch, E-56
1600 Clifton Road NE, Atlanta, Georgia 30333
Figure 3.
Figure 4. Priority Sample Population
AIR DATA
SOIL DATA
| August & June 1985, August 1986/ July 1987 | |||||
|---|---|---|---|---|---|
| METAL | CONC.RANGE (total) | YEAR SAMPLED | COMPARISONVALUE (CV)FORINGESTION -CHILD**** | FREQ>CV | |
| ppm | ppm | Source | |||
| Antimony* | 15 - 442 | 1985 | 20 | RMEG | 28/34 |
| Arsenic | 1.2 - 113 | 1986/87 | 0.4 20 | CREG EMEG | 136/136 42/136 |
| <1** - 168** | 1985 | 0.4 20 | CREG EMEG | 39/39 29/39 | |
| Cadmium | 0.48 - 175 | 1986/87 | 40 | EMEG | 18/136 |
| 5 - 398 | 1985 | 40 | EMEG | 21/39*** | |
| Lead | 20 - 1150 | 1986/87 | None | --- | 19/136 >bkgrd of413 ppm |
| 58 - 1500 | 1985 | None | --- | 11/39***>bkgrd of 413 ppm | |
| Manganese | 210 - 860 | 1985 | 300 | RMEG | 22/39 |
| Selenium | 1 - 153 | 1985 | 100 | IEMEG | 4/38*** |
| Zinc | 65 - 1535 | 1987/87 | 20,000 | RMEG | 0/136 |
| 69 - 720 | 1985 | 20,000 | RMEG | 0/39 | |
| *Analyses by Globe lab only, not a Quality Assurance Project Plan (QAPP) lab ** Widely varying results between labs at this sample location *** When two or more labs analyzed a sample and the results varied on eitherside of the C.V. (Comparison Value), an average was taken to determine if theconc. > C.V. The Industrial Drainage Ditch (IDD) samples were considered to be on-site. **** All or nearly all of the samples for Sb, As, Cd, Mn, and Se exceed theC.V.'s for pica children. The exception is Zn where only 19/175 samples >C.V. On-site maximums that exceed those found at 0-2" include: Arsenic at 235 ppm, 2-6" depth, due north of site Cadmium at 1000 ppm, 2-6" depth, east of site in non-residential area Lead at 19,630 ppm, former smelter Manganese at 900 ppm, 2-6" depth, east of site in non-residential area Selenium at 182 ppm, 0.5-1' depth, immediately north of site | |||||
APPENDIX D -- EXPOSURE PATHWAYS TABLES
| PATHWAY | SOURCE | ENVIRONMENTALMEDIA | POINT OFEXPOSURE | ROUTE OFEXPOSURE | EXPOSEDPOPULATION* | TIME |
|---|---|---|---|---|---|---|
| Air | Plantemissionsandre-entraineddust | air | ASARCO plantsite andresidentialareas | Inhalation andingestion | Workers on-site(200) and off-siteresidents in thearea (4878) | past future (dust) |
| Off-site surfacesoil | Directdepositsfromindustrialstackemissionsandwind-blowndust | surface soil andwind-blown dust | ResidentialareasparticularlyNorth/North-east andsouth/south-west of site | Inhalation andincidentalingestion | Residentialpopulationnorth/north-eastandsouth/south-east ofthe site (1563),emphasis onchildren under sixyears of age (578) | past, presentand future(until soilremediation) |
| On-site surfacesoil | Plantemissionsandwind-blowndust | surface soil andwind-blown dust | workers on-site | inhalation andincidentalingestion | on-site workers(unknown) | past present future |
| On-site indoorair | Industrialmetalprocesses | air | Indoor duringactive on-siteindustrial metalprocesses | Incidentalinhalation andingestion whenprotectiveequipment notcorrectly used | On-site workers(18) | past |
| Gardenvegetables | Air-bornedeposits andirrigation | surface soil and water | Home gardens | ingestion | Individual eatinghome-grownvegetables (100) | past |
1.* Estimated total potentially affected receptor population: 4360; Total children 5 years oryounger: 693; Total adults 60 years or older: 461;Total females aged 15-44: 897; Number of Blacks: 399; Number Whites: 1891; Number ofAmerican Indians: 61; Number of Asians: 54; Number of Hispanics: 2824; Other: 1646.
2.* Estimated total receptor population for current and past completed pathways: (a). Current -1055; (b). past - 3305.
| PATHWAY | SOURCE | ENVIRONMENTALMEDIA | POINT OFEXPOSURE | ROUTE OFEXPOSURE | EXPOSEDPOPULATION | TIME |
|---|---|---|---|---|---|---|
| groundwater | neutralizationpond, plantfacilities, andhistoric depositson land | groundwater | private wells fordrinking orirrigation(currently noneknown to existthat are in use incontaminatedwater plume) | ingestion | no knownresidential orindustrial use atpresent (populationunknown) | past present future |
| surface water/ sediment | contaminatedwater andsediment in theIndustrialDrainage Ditchand the Farmersand GardenersDitch | surface water/sediments | open ditch areas | dermalabsorption ofwater andincidentalingestion | children playing inditch area(populationunknown) | past |
APPENDIX E -- ESTIMATED EXPOSURE DOSES
1 Cancer Risk Evaluation Guide for 1 x 10-6 excess cancer risk.
2 Chronic Minimal Risk Level (MRL).
3 Exceeds MRL for overall maximum air value; however, the maximum may only be a 24 hour maximum from 180-361 samples taken in a year.
PUBLIC COMMENTS
APPENDIX F -- RESPONSE TO PUBLIC COMMENTS
The ASARCO, Inc. (Globe Plant) Public Health Assessment was available for public review andcomment from approximately November 18, 1994 to January 6, 1995. The comment period wasannounced in local newspapers. Copies were made available at the public library, and copieswere sent to several individuals and organizations. No comments were received from residents. A summary of comments received from the potentially responsible party (PRP) and ourresponses are presented in this section. We wish to acknowledge that comments received fromthe Colorado Department of Health and Environment (CDPHE), and the City and County ofDenver were useful and have been used to revise the body of the document where appropriate.
| Comment 1 | In general, the Globe ambient environmental issues should be viewed asbeing addressed through process change that began in 1983, and continuingprogram of emission control leading ultimately to cessation entirely of thecadmium production in 1993. In addition, a July 1993 consent order with thestate requires the clean up of residential soils as well as soils, sediments andwater on site which address potential off site migration. It appears that therisks the Agency for Toxic Substances and Disease Registry (ATSDR) hascharacterized are based on data generated prior to the change in plantoperations and before the consent order. We are concerned that the ATSDRdocument will cause concern on the part of the public that the remedy agreedto by the state, and with oversight by the Environmental Protection Agency(EPA) is not sufficiently rigorous. We believe that ATSDR should havetaken this opportunity to support what is being done. |
| Response. | The PHA acknowledges the past and continuing efforts of the PRP to addressthe environmental issues at the site. Past actions taken by the PRP and othersare clearly documented on pages three through seven, in the Summary,Conclusions, and in other sections of the document. Since the purpose of thePHA process is to address the entire exposure issues (accounting for humanexposures to contaminants in the past, present, and the future), it is imperativeto examine the entire available data. In addition, the document acknowledgespast actions by the PRP and others, which have succeeded in reducing orpreventing human exposures (as stated several times in the Summary,Environmental Contamination, and Conclusions sections of the document). ATSDR is supportive of all positive actions taken by the PRP to reduce andprevent exposure at the site. ATSDR has given its concurrence for themedical monitoring program, and has prepared a health consultation to assistthe state in establishing standards for soil cleanup. ATSDR has not receivedany comments from residents that might be described as alarming as a resultof information contained the PHA. |
| Comment 2 | The Colorado Department of Public Health and Environment's (CDPHE)treatment of the data generated through the 1990 ATSDR sponsoredGlobeville Childhood Metals Exposure study presents an interesting contrastto the draft public health assessment. The CDPHE May 1994 SuperfundBulletin for Health Professionals states that no elevated cadmium and arseniclevels were found (in the metals study) and 14 of the children (11.3%) testedhad blood lead levels equal to or greater than 10 µg/dl, the CDC level ofconcern. In addition, the average lead levels of Globeville children weresimilar to the comparison neighborhoods. |
| Response | The PHA states that 37 (about eight percent) of the young children testedfrom four neighborhoods in Globeville and control areas have blood leadlevels equal to or greater than 10 µg/dl. In addition, the PHA states that aGlobeville child is more likely than other children to be in the 5-10 µg/dlrange for blood lead levels. The statements will be reworded to reflect thenumber of study areas, a control area, and to indicate that the source of thelead exposure is unknown. However, the information you quoted from theCDPHE bulletin refers only to one of the study areas and not all fourneighborhoods and a control area as discussed in the PHA. |
| Comment 3 | We firmly believe the use of the one excess cancer in a million risk criteria asdiscussed on page 13 is unrealistic because of the lack of a sound basis forusing this level, and because of misunderstandings about one in a million risk(see enclosed article that discuss the myth of 10-6). |
| Response | The Cancer Risk Evaluation Guides (CREGs) used on page 13 are forscreening purposes to determine which contaminants should be looked atmore closely in the PHA. The selection of a contaminant for furtherevaluation does not mean that either exposure to the contaminant or adversehealth effects has occurred or will occur. However, you are correct that thereis some uncertainty associated with using the risk level of 10-6 to describecommunity exposure at hazardous waste sites. Because of this uncertainty therisk of 10-6 should not be consistently applied in every exposure situation. Although ATSDR recognizes the utility of numerical risk estimates in riskanalyses, the Agency considers these estimates in the context of the variablesand assumptions involved in their derivation and in the broader context ofbiomedical opinion, host factors, and actual exposure conditions. Forexample, ATSDR considers cancer exposure levels (as determined inepidemiological studies), the type and magnitude of contaminant levels aswell as the route of exposure. These considerations influenced the cancerrisks described in the Public Health Implications section of the PHA. |
| Comment 4 | It should be clear that the exacerbation of childhood respiratory diseaseconcerns as discussed on page 45 are far more likely to be caused by theDenver area general air quality rather than the small amounts of cadmium,tellurium, and antimony as alleged on page 41 in answer to a questionregarding respiratory problems. Is it not also true that cadmium, tellurium,and antimony exposures that may have led to respiratory problems in humanswere in an occupational setting? |
| Response | The PHA acknowledges that the Total Suspended Particulate (TSP) problemsin the Denver area are due in part to other industries in the area and the mainfreeway systems. The TSP can exacerbate the respiratory conditions that arecommonly observed in the area. It is clearly stated in the Summary,Environmental Contamination, Community Health Concerns Evaluation, andConclusions sections, that the city-wide problem of TSP levels contributes tothe occurrence of respiratory conditions. |
| Comment 5 | If the document truly is a public health assessment, why are continuedreferences made to historical worker exposures and violations (examples arefound in paragraph two of the Summary, pages 17 and 18, and paragraph oneof the Conclusion). |
| Response | As stated in the response to your first comment, the purpose of the PHAprocess is to address indicated exposure scenarios, taking into considerationworkers as well as nearby residents. It is necessary to examine allinformation pertaining to exposure to contaminants at the site. |
| Comment 6 | On page 34, a reference is made to Globe workers eating Globeville grownvegetables. ASARCO knew of only one Globe plant employee that lives inGlobeville, and that employee does not have a garden. |
| Response | That reference in the PHA is made in regard to any past PRP workers whomay fall into that exposure category. The document will be changed to reflectthe new information. |
| Comment 7 | It should be noted that EPA has not listed Globe on the NPL (page 3). |
| Response | The statement on page three indicates that the site is proposed for listing onthe NPL. The document has not been changed. |
| Comment 8 | The results of the 1982 FIT and EPA NEIC investigations did notdemonstrate either air quality or groundwater problems. |
| Response | The document has been reworded to indicate that the study focused on thosecontaminants listed on page 4 in the PHA. |
| Comment 9 | On page 6, state year of site visit; and 2nd last line - Globe does not producethallium. |
| Response | The document has been corrected. |
| Comment 10 | While ATSDR may have heard some concerns (last two lines on page 8), theenclosed news article from LA VOZ suggests community support for theclean up process. |
| Response | An exposure study by the Colorado Department of Health indicates that thereis concern among some residents about potential health threats posed by theASARCO plant. However, you are correct that the cleanup process is aimedat addressing this potential threat. |
| Comment 11 | On page 24 paragraph D - reference is made to buildings no longer being usedbecoming a safety and chemical hazard for the public. However, it should benoted that the site is completely fenced and public access strictly limited. |
| Response | The PHA acknowledges on pages 7 and 24 that the site is fenced. However,we have altered the last sentence of paragraph D, page 24, to clarify that theunused buildings could only become public hazards if access to the site doesnot continue to be strictly limited. |
| Comment 12 | On page 26, it should be noted that the PRP consent order requires annualwater use surveys to preclude future use of shallow groundwater. |
| Response | The document will be changed to reflect this comment. |
| Comment 13 | On page 32, the PRP is concerned about unnecessary speculation with regardto arsenic exposure and skin pigmentation. |
| Response | Epidemiological studies in humans suggest that residents exposed to levelssimilar to those reported in the PHA experienced hyperkeratosis. The PHAonly suggested that children exposed to the levels of arsenic reported in thisdocument might experience similar health effects. |
| Comment 14 | On page 41, the PRP is concerned that ATSDR has not stated that soils belowthe surface rapidly fall in metal concentration. |
| Response | The PHA states that contaminant concentrations do decrease with depth. However, the document will be revised to reflect that soils below the surfacerapidly fall in metal concentration. |
