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PUBLIC HEALTH ASSESSMENT

ASARCO INCORPORATED (GLOBE PLANT)
DENVER, DENVER COUNTY, COLORADO


APPENDICES

Appendix A -- Figures
Appendix B -- Air Data
Appendix C -- Soil Data
Appendix D -- Exposure Pathways
Appendix E -- Estimated Exposure Doses
Appendix F -- Public Comments


APPENDIX A

FIGURES 1-4


Figure 1. Site Location

Figure 2. Globe Plant Plan

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



APPENDIX B

AIR DATA

Table 3.

ON-SITE AIR QUALITY (1987 - 1992)
Monitoring Stations
MetalYearBookstore
58 samples/yr
Old Office Site
58 samples/yr
Nutech
58 samples/yr


Concentration (µg/m3)
Max.Avg.Max.Avg.Max.Avg.
Cadmium1992
1991
1990
1989
1988
1987**
0.054
0.233
0.053
0.184
0.142*
0.165
0.019
NC
0.027
0.041
0.018*
NC
0.090
0.136
0.603
0.447
0.429
0.589
0.046
0.028
0.080
0.065
0.048
NC
0.195
0.093
0.879
0.589
0.440
0.745
0.032
NC
0.062
0.072
0.060
NC
Arsenic***1992
1991
1990
1989
1988
1987**
<0.022
0.018
0.021
0.022
0.032*
<0.010
0.009
NC
0.010
0.007
NC
NC
0.021
0.064
0.022
0.022
0.04
0.095
0.008
NC
0.009
0.009
0.012
NC
0.021
0.074
0.098
0.042
0.05
0.087
0.009
NC
0.007
0.007
0.012
NC
Lead1992
1991
1990
1989
1988
1987**
0.23
0.18
0.25
0.33
0.66*
0.64
0.11
NC
0.11
0.12
NC
NC
0.16
0.34
1.4
0.38
0.79
1.57
0.17
NC
0.18
0.15
0.21
NC
0.49
0.30
1.4
0.27
1.39
1.64
0.14
NC
0.14
0.13
0.23
NC
TSP1992
1991
1990
1989
1988
1987**
214.8
229.1
241.7
287.6
248.9*
738.5
113.80
108.34
92.19
111.00
122.80
NC
165.6
217.9
234.9
224.3
188.3
281.3
85.01
NC
75.78
86.27
NC
NC
211.3
228.2
236.1
166.8
228.5
308.5
100.55
NC
82.76
83.46
NC
NC
TSP = Total Suspended Particulates
NC = Not calculated
* March through May data gaps, only 38 samples compared to about 58 samples per year in 1989, stationrelocated to site second quarter 1988.
** Based on 6 months of data
*** Concentrations were usually below the detection limit so half of the minimal detectable activity wasused in averaging.
1993 data were not available.
The September 1982 NEIC sampling showed average results in µg/m3 of 0.022 - 0.095 cadmium, 0.003 -0.014 arsenic, 0.641 - 0.955 lead, and 0.113 - 0.243 zinc.


Table 4.

OFF-SITE AIR QUALITY (1987 - 1993)

Monitoring Stations
MetalYear Clinicare
180- 361samples/yr
Forklift City
59 samples/yr
Background,Adams City*
56 samples/yr


Concentration (µg/m3)
Max.Avg.Max.Avg.Max.Avg.
Cadmium1993
1992
1991
1990
1989
1988
1987
2.027*
3.900
0.713
0.750
ND
ND
ND
0.077*
0.054
0.035
0.073
ND
ND
ND
ND
0.487
2.161
0.433
1.136
0.577
1.555
ND
0.054
0.071
0.063
0.092
0.046
NC
0.024
0.100
0.009
0.016
ND
ND
ND
0.003
0.004
0.002
0.004
ND
ND
ND
Arsenic1993
1992
1991
1990
1989
1988
1987
0.070*
0.015
0.300
0.028
ND
ND
ND
0.002*
0.002
0.005
0.004
ND
ND
ND
ND
<0.022
0.016
0.022
0.011
0.011
0.010
ND
0.006
NC
0.006
0.006
0.006
0.006
0.003
0.011
0.004
0.015
ND
ND
ND
0.001
0.002
0.004
0.004
ND
ND
ND
Lead1993
1992
1991
1990
1989
1988
1987
1.00*
0.50
0.43
0.72
ND
ND
ND
0.10*
0.09
0.07
0.14
ND
ND
ND
ND
1.21
0.53
1.66
0.79
6.34
2.48
ND
0.24
NC
0.28
NC
0.50
NC
0.23
0.17
0.14
0.22
ND
ND
ND
0.03
0.03
0.03
0.05
ND
ND
ND
TSP1993
1992
1991
1990
1989
1988
1987
308*
368
359
246
ND
ND
ND
101*
106
105
97
ND
ND
ND
ND
311.6
239.5
190.5
241.8
187.2
293.1
ND
96.5
89.0
75.7
90.2
95.7
NC
261
319
211
228
ND
ND
ND
100
90
82
79
ND
ND
ND
TSP = Total Suspended Particulates
ND = No data
NC = Not calculated
Clinicare is about a half block North East of the North East corner of the ASARCOproperty.
The Forklift City site is north of the site.
The Adams City site is approx. 3 miles NE of ASARCO.
*1993 data for Clinicare represents 1/1/93 through 6/30/93 or 180 samples, the other years represent the entire year or from 278 to 361 samples.



APPENDIX C

SOIL DATA

Table 5.

ON-SITE SOIL (RI, App 9) SURFACE SOIL 0-2
August & June 1985, August 1986/ July 1987
METALCONC.RANGE
(total metals)
YEAR
SAMPLED
COMPARISONVALUE (CV)FOR INGESTION -CHILD****FREQ >CV

ppm
ppmSource
Antimony*9 - 104198520RMEG15/16
Arsenic19 - 67701986/870.4
20
CREG
EMEG
9/9
8/9
3** - 53519850.4
20
CREG
EMEG
17/17
17/17***
Cadmium21 - 99001986/8740EMEG7/9
21 - 272198540EMEG14/17
Lead120 - 11,5001986/87None---6/9 > bkgrdof 413 ppm
66 - 18751985None---11/17***>bkgrd of
413 ppm
Manganese93 - 10001985300RMEG12/17
Selenium0.5** - 1081985100IEMEG2/17
Zinc285 - 107,5001987/8720,000RMEG1/9
114 - 5200198520,000RMEG0/17
*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.
**** Arsenic and cadmium were the only metals exceeding comparison valuesfor an adult. The comparison values are 200 and 500 ppm, respectively with11/26 samples >C.V. for As and 4/26 samples >C.V. for Cd.
On-site maximums that exceed those found at 0-2" include:
Arsenic at 15,250 ppm, 16' depth, former neutralization pond
Antimony at 293 ppm, 0.5-1', IDD
Cadmium at 14,708 ppm, 0-6" depth, center of site-terrace escarpment
Lead at 16,000 ppm, 2-6" depth, lead slag pile
Manganese at 1525 ppm, 2-6", NW corner
Zinc at 117,500 ppm, 7'& 11' depths, former neutralization pond


Table 6.

OFF-SITE SOIL (RI, App 9) SURFACE SOIL 0-2

August & June 1985, August 1986/ July 1987
METALCONC.RANGE
(total)
YEAR
SAMPLED
COMPARISONVALUE (CV)FORINGESTION -CHILD****FREQ>CV

ppm
ppmSource
Antimony*15 - 442198520RMEG28/34
Arsenic1.2 - 1131986/870.4
20
CREG
EMEG
136/136
42/136
<1** - 168**19850.4
20
CREG
EMEG
39/39
29/39
Cadmium0.48 - 1751986/8740EMEG18/136
5 - 398198540EMEG21/39***
Lead20 - 11501986/87None---19/136 >bkgrd of413 ppm
58 - 15001985None---11/39***>bkgrd of
413 ppm
Manganese210 - 8601985300RMEG22/39
Selenium1 - 1531985100IEMEG4/38***
Zinc65 - 15351987/8720,000RMEG0/136
69 - 720198520,000RMEG0/39
*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

Table 7.

COMPLETED EXPOSURE PATHWAY

PATHWAYSOURCEENVIRONMENTALMEDIAPOINT OFEXPOSUREROUTE OFEXPOSUREEXPOSEDPOPULATION*TIME
AirPlantemissionsandre-entraineddust airASARCO plantsite andresidentialareasInhalation andingestionWorkers on-site(200) and off-siteresidents in thearea (4878) past

future (dust)

Off-site surfacesoilDirectdepositsfromindustrialstackemissionsandwind-blowndust surface soil andwind-blown dustResidentialareasparticularlyNorth/North-east andsouth/south-west of siteInhalation andincidentalingestionResidentialpopulationnorth/north-eastandsouth/south-east ofthe site (1563),emphasis onchildren under sixyears of age (578)past, presentand future(until soilremediation)
On-site surfacesoilPlantemissionsandwind-blowndust surface soil andwind-blown dustworkers on-site inhalation andincidentalingestion on-site workers(unknown)past
present
future
On-site indoorairIndustrialmetalprocessesairIndoor duringactive on-siteindustrial metalprocessesIncidentalinhalation andingestion whenprotectiveequipment notcorrectly usedOn-site workers(18) past
GardenvegetablesAir-bornedeposits andirrigationsurface soil and waterHome gardensingestionIndividual 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.

Table 8.

POTENTIAL EXPOSURE PATHWAY

PATHWAYSOURCEENVIRONMENTALMEDIAPOINT OFEXPOSUREROUTE OFEXPOSUREEXPOSEDPOPULATIONTIME
groundwater neutralizationpond, plantfacilities, andhistoric depositson landgroundwaterprivate wells fordrinking orirrigation(currently noneknown to existthat are in use incontaminatedwater plume) ingestionno knownresidential orindustrial use atpresent (populationunknown)past
present future
surface water/
sediment
contaminatedwater andsediment in theIndustrialDrainage Ditchand the Farmersand GardenersDitchsurface water/sedimentsopen ditch areasdermalabsorption ofwater andincidentalingestionchildren playing inditch area(populationunknown)past



APPENDIX E -- ESTIMATED EXPOSURE DOSES

Table 9.

COMPARISON OF EXPOSED DOSE TO HEALTH GUIDELINES FOR INHALATION
CONTAMINANTEXPOSURE PATHWAYHEALTH GUIDELINE IN
µg/m3
SOURCEEXCEEDS HEALTH GUIDELINES DOSE
ArsenicOn-site air0.0002CREG1Yes
Off-site air0.0002CREG1Yes
CadmiumOn-site air0.2Chronic MRL2No
Yes3
Off-site air0.2Chronic MRL2No
Yes3
LeadOn-site airNONENONEN/A
Off-site airNONENONEN/A

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.

Table 10.

COMPARISON OF ESTIMATED EXPOSED DOSE TO HEALTH GUIDELINES FOR INGESTION
ContaminantExposure PathwayHealth Guideline for Ingestion - mg/kg/day
ValueSourceExceeded by Estimated Exposure Dose
Antimonyon-site surface soil0.0004chronic oral RfDNo
off-site surface soil0.0004chronic oral RfDYes (pica child only)
Arsenicon-site surface soil0.0003 chronic oral MRLYes
off-site surface soil0.0003chronic oral MRLYes
Cadmiumon-site surface soil0.0007/0.0005 chronic oral MRL/RfDYes
off-site surface soil0.0007/0.0005chronic oral MRL/RfDYes
Lead on-site surface soil none none N/A
off-site surface soilnonenoneN/A
Manganeseon-site surface soil1chronic oral RfDNo
off-site surface soil1chronic oral RfDNo
Seleniumon-site surface soil0.003chronic oral MRLNo
off-site surface soil0.003chronic oral MRLNo
Zincon-site surface soil0.3chronic oral RfDNo
off-site surface soil0.3chronic oral RfDYes (Pica Child only)



APPENDIX F

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 1In 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 2The 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.

ResponseThe 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 3We 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).

ResponseThe 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 4It 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?

ResponseThe 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 5If 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).

ResponseAs 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 6On 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.

ResponseThat 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 7It should be noted that EPA has not listed Globe on the NPL (page 3).

ResponseThe statement on page three indicates that the site is proposed for listing onthe NPL. The document has not been changed.

Comment 8The results of the 1982 FIT and EPA NEIC investigations did notdemonstrate either air quality or groundwater problems.

ResponseThe document has been reworded to indicate that the study focused on thosecontaminants listed on page 4 in the PHA.

Comment 9On page 6, state year of site visit; and 2nd last line - Globe does not producethallium.

ResponseThe document has been corrected.

Comment 10While 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.

ResponseAn 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 11On 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.

ResponseThe 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 12On page 26, it should be noted that the PRP consent order requires annualwater use surveys to preclude future use of shallow groundwater.

ResponseThe document will be changed to reflect this comment.

Comment 13On page 32, the PRP is concerned about unnecessary speculation with regardto arsenic exposure and skin pigmentation.

ResponseEpidemiological 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 14On page 41, the PRP is concerned that ATSDR has not stated that soils belowthe surface rapidly fall in metal concentration.

ResponseThe 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.


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