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PUBLIC HEALTH ASSESSMENT

PORT WASHINGTON LANDFILL
NORTH HEMPSTEAD, NASSAU COUNTY, NEW YORK


APPENDIX A

Figures


Figure 1. Location of Port Washington Landfill


Figure 2. Port Washington Landfill Average
Hydrogen Sulfide Values from January 6, 1993
to March 7, 1993.

APPENDIX B

Tables


Table 1.

Port Washington Landfill On-Site Soil Vapor Sampling Data
from Remedial Investigation and Comparison Values.
(All values in parts per billion v/v)


Compound Range of
Detection
Typical
Background
Range
Comparison Value
Cancer** Basis*** Noncancer** Basis***

*vinyl chloride
*methylene chloride
*acetone
*1,1-dichloroethene
*1,1-dichloroethane
*1,2-dichloroethane
*trans-1,2-dichloro-
ethene
*chloroform
*2-butanone
*1,1,2,2-tetra-
chloroethane
*1,1,1-trichloro-
ethane
* 1,2-dichloro
propane
*trichloroethene
*tetrachloroethene
*chlorobenzene
ethylbenzene
*toluene
*benzene
*xylenes (total)
4-20,500 fbox
2-5,770 fbox
15-3,160 fbox
1-355 fbox
5-1,470 fbox
5-283 fbox
2-15,000 fbox

2-3 fbox
2,550 fbox
3-133 fbox

2-833 fbox

140 fbox

2-4,840 fbox
1-8,780 fbox
5-110 fbox
13-38 fbox
3-4,440 fbox
2-293 fbox
29-725 fbox
NA
NA
NA
NA
NA
NA
NA

NA
NA
NA

NA

NA

NA
NA
NA
NA
NA
NA
NA
0.005
0.56
--
0.005
--
0.01
--

0.01
--
0.003

--

--

0.11
0.26
--
--
--
0.03
--
EPA CPF
ATSDR CREG
--
ATSDR CREG
--
ATSDR CREG
--

ATSDR CREG
--
ATSDR CREG

--

--

ATSDR CREG
ATSDR CREG
--
--
--
ATSDR CREG
--
--
0.006
148
8
125
6.5
18

8.1
102
--

180

0.8

4.8
15
4.3
230
105
0.78
69
--
NYS RfG
EPA RfD
EPA RfD
EPA HEAST
NYS RfG
EPA RfD

EPA RfD
EPA RfC
--

EPA HEAST

EPA HEAST

NYS RfG
NYS RfG
EPA HEAST
EPA HEAST
EPA RfC
NYS RfG
EPA RfC

v/v = concentration as volume per volume of air
fbox = flux box data indicating contaminant release from landfill surface
NA - not available

*Contaminant selected for further evaluation.
**Comparison value determined for a 70 kilogram adult who breathes 20 cubic meters of air per day.
***ATSDR CREG = ATSDR Cancer Risk Evaluation Guide

EPA CPF = EPA Cancer Potency Factor
EPA RfC = EPA Reference Concentration
EPA RfD = EPA Reference Dose
EPA HEAST = EPA Health Effects Summary Tables
NYS RfG = NYS Risk Reference Guideline

Table 2.

Port Washington Landfill On-Site Leachate Sampling Data
from Remedial Investigation*
(All values in micrograms per liter)


Compound Range of Detection

vinyl chloride 6-12
1,1-dichloroethane 6-12
trans-1,2-dichloroethene 8.5-14
chloroethane 22
1,1,1-trichloroethane 4
tetrachloroethene 8
chlorobenzene 18-19
ethylbenzene 26-60
toluene 48-71
benzene 8-13
xylenes (total) 160-210

*Leachate has been eliminated as an exposure pathway; sampling results are provided for completeness, but toxicological evaluation is unnecessary because there is no direct contact.

Table 3.

Port Washington Landfill On-Site Groundwater
Sampling Data from Remedial Investigation and Standards/Guidelines and Comparison Values
(All values in micrograms per liter)


Compound Concentration
Range+

Comparison Values

Standards/Guidelines
New York State US EPA
Ground
Water
Drinking
Water
Drinking
Water
Cancer** Basis*** Noncancer** Basis***

*vinyl chloride
*methylene chloride
*1,1-dichloroethene
*1,1-dichloroethane
*1,2-dichloroethane
*trans-1,2-dichloro-
ethene
chloroform
*chloroethane
*1,1,2, 2-tetrachloro-
ethane
*1,1,1-trichloroethane
1,1,2-trichloroethane
*trichloroethene
*tetrachloroethene
*carbon tetrachloride
*chlorobenzene
toluene
*benzene
xylenes (total)

Metals
arsenic
*cadmium
*chromium
*copper
*iron
*lead
*manganese
19-41
1.7-117
0.6-12
0.8-130
2.1
2-260

0.1-0.6
3-33
0-4

0.2-109
0.5
8-28
1-69
4
1.3-10
0.1-0.9
2-6
0.1-0.8


ND(46)-50
ND(56)-11.5
ND(56)-1,020
ND(96)- 2,000
ND(306)-99,500
ND(16)-138
ND(56)-8,220
2
5
5
5
5
5

7
5
5

5
5
5
5
5
5
5
0.7
5n


25
10
50
200
300
25
300
2
5
5
5
5
5

100d
5
5

5
5
5
5
5
5
5
5
5n


50
5
100
1,300****
300
15*****
300
2
5
7
--
5
100

100d
--
--

200
5
5
5
5
100
1,000;40ps
5
10,000;20ps


50
5
100
1,300****
300s
15*****
50s
0.02
5
0.06
--
0.4
--

6
--
0.2

--
0.6
3
0.7
0.3
--
--
1.2
--


0.02
--
--
--
--
--
--
EPA CPF
EPA CPF
EPA CPF
--
EPA CPF
--

EPA CPF
--
EPA CPF

--
EPA CPF
EPA CPF
EPA CPF
EPA CPF
--
--
EPA CPF
--


EPA CPF
--
--
--
--
--
--
0.7
420
7
700
52
100

70
--
--

200
3
52
70
5
140
1,000
5
10,000


11
5
100
--
--
--
175
ATSDR MRL
EPA RfD
EPA LTHA
EPA RfD
EPA RfD
EPA LTHA

EPA RfD
--
--

EPA LTHA
EPA LTHA
EPA RfD
EPA RfD
EPA RfD
EPA RfD
EPA LTHA
EPA RfD
EPA LTHA


EPA RfD
EPA LTHA
EPA LTHA
--
--
--
EPA RfD

FOOTNOTES FOR TABLE 3.

+Range excludes samples in which none of the compound was detected

*Contaminant selected for further evaluation.

**Comparison value determined for a 70 kilogram adult who drinks 2 liters of water per day.

***ATSDR MRL = ATSDR Minimal Risk Level

EPA CPF = EPA Cancer Potency Factor
EPA RfD = EPA Reference Dose
EPA LTHA = EPA Lifetime Health Advisory

****Action level of 1,300 mcg/L at the tap.

*****The maximum contaminant level goal (MCLG) for lead is zero and the action level is 15 mcg/L at the tap.

d = drinking water standard for total trihalomethanes produced as a result of disinfection with chlorine. This standard is inappropriate for evaluating environmental contamination not associated with disinfection practices.

n = applies to each isomer separately unless isomers are analytically indistinguishable.

ps = proposed secondary MCL

s = secondary MCL

ND = not detected at instrument's detection limit

From Reference #42.

Table 4.

Port Washington Landfill Off-Site Ambient Air Sampling Data from US EPA
Data Presented in the Remedial Investigation Report and Comparison Values.
(All values in parts per billion v/v)




Compound

Range of
Detection
Typical
Background
Range**
Comparison Value
Cancer*** Basis**** Noncancer*** Basis****

*vinyl chloride
toluene
benzene
*hydrogen sulfide
2-3+
6-9+
2-4+
ND-3,100++
ND
0.7-37
0.2-2
0.7
0.005
--
0.03
--
EPA CPF
--
ATSDR CREG
--
--
105
0.78
0.6
--
EPA RfC
NYS RfG
EPA RfC

ND - not detected

*Contaminant selected for further evaluation

**ATSDR (1991a); Singh et al. (1981); Wallace et al. (1984); US EPA (1990)

***Comparison value determined for a 70 kilogram adult who breathes 20 cubic meters of air per day.

****EPA CPF = EPA Cancer Potency Factor

EPA RfC = EPA Reference Concentration
ATSDR CREG = ATSDR Cancer Risk Evaluation Guide
NYS RfG = NYS Risk Reference Guideline

+Reference 42, Results from US EPA TAGA (trace atmospheric gas analyzer), not verified and may be artificially high due to instrument interference, 1988.

++Data from L5 section of Port Washington Landfill 1990-1991 from consultants for the Town of Hempstead.


Table 5.

Port Washington Landfill Off-Site Soil Vapor Sampling Data from
US EPA Data Presented in the Remedial Investigation Report and Comparison Values.
(All values in parts per billion v/v)




Compound

Range of
Detection
Typical
Background
Range
Comparison Value
Cancer** Basis*** Noncancer** Basis***

*1,1-dichloroethene
*1,1-dichloroethane
*trans-1,2-dichloro-
ethene
*chloroform
*1,1,2,2-tetra-
chloroethane
*1,1,1-trichloroethane
*1,2-dichloroethane
*1,2-dichloropropane
*trichloroethene
*tetrachloroethene
*benzene
*carbon tetrachloride
1-19
1-385
4-68

3-8
4-29

12-692
30
10
5-119
8-614
2
1
NA
NA
NA

NA
NA

NA
NA
NA
NA
NA
NA
NA
0.005
--
--

0.01
0.003

--
0.01
--
0.11
0.26
0.03
0.01
ATSDR CREG
--
--

ATSDR CREG
ATSDR CREG

--
ATSDR CREG
--
ATSDR CREG
ATSDR CREG
ATSDR CREG
ATSDR CREG
8
125
18

8.1
--

180
6.5
0.8
4.8
15
0.78
0.37
EPA RfD
EPA HEAST
EPA RfD

EPA RfD
--

EPA HEAST
NYS RfG
EPA HEAST
NYS RfG
NYS RfG
NYS RfG
EPA RfD

NA - not available

*Contaminant selected for further evaluation

**Comparison value determined for a 70 kilogram adult who breathes 20 cubic meters of air per day.

***ATSDR CREG = ATSDR Cancer Risk Evaluation Guide

EPA RfD = EPA Reference Dose
EPA HEAST = EPA Health Effects Summary Tables
NYS RfG = NYS Risk Reference Guideline



Table 6.

Port Washington Landfill Off-Site Groundwater
Sampling Data from Remedial Investigation and Standards/Guidelines and Comparison Values
(All values in micrograms per liter)


Compound Concentration
Range+
Comparison Values
Standards/Guidelines
New York State US EPA
Ground
Water
Drinking
Water
Drinking
Water
Cancer** Basis*** Noncancer** Basis***

*vinyl chloride
*methylene chloride
*1,1-dichloroethene
*1,1-dichloroethane
*trans-1,2-dichloro-
ethene
*chloroethane
*chloroform
*1,1,2,2-tetrachloro-
ethane
*1,1,1-trichloroethane
*1,1,2-trichloroethane
*1,2-dichloroethane
*trichloroethene
*tetrachloroethene
chlorobenzene
*ethylbenzene
*xylenes (total)
*toluene
*benzene
1-16
0.8-32
1-10
2-76
1-80

2-7
0.5-8
0.2-1.1

2-130
0.4-1.3
1-2
6-18
0.4-43
0.1-4
0.2-8
0.1-21
0.6-6.8
0.1-4
2
5
5
5
5

5
7
5

5
5
5
5
5
5
5
5n
5
0.7
2
5
5
5
5

5
100d
5

5
5
5
5
5
5
5
5n
5
5
2
5
7
--
100

--
100d
--

200
5
5
5
5
100
700;30ps
10,000;20ps
1,000;40ps
5
0.02
5
0.06
--
--

--
6
0.2

--
0.6
0.4
3
0.7
--
--
--
--
1.2
EPA CPF
EPA CPF
EPA CPF
--
--

--
EPA CPF
EPA CPF

--
EPA CPF
EPA CPF
EPA CPF
EPA CPF
--
--
--
--
EPA CPF
0.7
420
7
700
100

--
70
--

200
3
52
52
70
140
700
10,000
1,000
5
ATSDR MRL
EPA RfD
EPA LTHA
EPA RfD
EPA LTHA

--
EPA RfD
--

EPA LTHA
EPA LTHA
EPA RfD
EPA RfD
EPA RfD
EPA RfD
EPA LTHA
EPA LTHA
EPA LTHA
EPA RfD

d = drinking water standard for total trihalomethanes produced as a result of disinfection with chlorine. This standard is inappropriate for evaluating environmental contamination not associated with disinfection practices.
n = applies to each isomer separately unless isomers are analytically indistinguishable
ps = proposed secondary MCL
ND = not detected at instrument's minimum detection limit
+ - range excludes samples in which none of the compound was detected
*Contaminant selected for further evaluation
**Comparison value determined for a 70 kilogram adult who drinks 2 liters of water per day.
***ATSDR MRL = ATSDR Minimal Risk Level
EPA CPF = EPA Cancer Potency Factor
EPA LTHA = EPA Lifetime Health Advisory
EPA RfD = EPA Reference Dose

Table 7.

Port Washington Landfill Off-Site Indoor Air Sampling Data
and Comparison Values.
(All values in parts per billion v/v)


Compound Range of
Detection**

Typical
Background
Range***

Comparison Value

Cancer**** Basis***** Noncancer**** Basis*****

*vinyl chloride 0-240 NA 0.005 EPA CPF -- --
*1,1,1-trichloroethane 0-48 0.3-4.4 -- -- 180 EPA HEAST
toluene 0-4 8.3 -- -- 105 EPA RfC
*1,1,2-trichloroethane 2 NA 0.01 ATSDR CREG 2.3 EPA RfD
*benzene 0-30 2.2-4.7 0.03 ATSDR CREG 0.78 NYS RfG
*methane 0-50,000,000 NA NA NA

NA - not available

*Contaminant selected for further evaluation.

**From Nassau County Health Department, March 1981.

***ATSDR (1989i, 1990e, 1991a)

****Comparison value determined for a 70 kilogram adult who breathes 20 cubic meters of air per day.

*****ATSDR CREG = ATSDR Cancer Risk Evaluation Guide

EPA CPF = EPA Cancer Potency Factor
EPA RfC = EPA Reference Concentration
EPA RfD = EPA Reference Dose
EPA HEAST = EPA Health Effects Summary Table
NYS RfG = NYS Reference Dose

Table 8.

Frequency of Health Conditions Reported to the Nassau County Department
of Health from Residents Living Near the Port Washington Landfill


Health Symptom

Percent of Households with Symptoms*

81 Households
11/26/90-2/6/91

22 Households**
2/6 - 3/5/91

Total 103 Households
through 3/5/91


Nausea/Sick to
Stomach

43.2

27.3

39.8

Headache

28.4

31.8

29.1

Eye Irritation/
Burning/Itching

19.8

18.2

19.5

Breathing Problems

14.8

22.7

16.5

Vomiting

12.4

13.6

12.6

Sick/Ill

8.6

4.6

7.8

Throat Irritation/
Scratchy/Sore

6.2

13.6

7.8

Cough

6.2

4.6

5.8

Dizziness/Light-
headedness

4.9

0.0

3.9

Asthma Attack

2.5

13.6

4.9

Nasal Congestion/
Drip

2.5

13.6

4.9

Other Symptoms

12.3

9.1

11.6


*Note that many households reported more than one symptoms, so the sum of the percentages is greater than 100.

**In the one month period 2/6 - 3/5/91, the percentages of households reporting upper respiratory tract symptoms (throat irritation, nasal congestion) and breathing problems and asthma increased markedly. In this same time period, there was a reported increase in the incidence of influenza B and other upper respiratory tract infections.


APPENDIX C

PROCEDURES FOR EVALUATING POTENTIAL HEALTH RISKS
FOR CONTAMINANTS OF CONCERN

To evaluate the potential health risks from contaminants of concern associated with the Port Washington Landfill site, the New York State Department of Health assessed the risks for cancer and noncancer health effects.

Increased cancer risks were estimated by using site-specific information on exposure levels for the contaminant of concern and interpreting them using cancer potency estimates derived for that contaminant by the US EPA or, in some cases, by the NYS DOH. The following qualitative ranking of cancer risk estimates, developed by the NYS DOH, was then used to rank the risk from very low to very high. For example, if the qualitative descriptor was "low", then the excess lifetime cancer risk from that exposure is in the range of greater than one per million to less than one per ten thousand. Other qualitative descriptors are listed below:

                                               Excess Lifetime Cancer Risk

Risk Ratio

Qualitative Descriptor

equal to or less than one per million very low
greater than one per million to less
than one per ten thousand
low
one per ten thousand to less than one
per thousand
moderate
one per thousand to less than one per ten high
equal to or greater than one per ten very high

An estimated increased excess lifetime cancer risk is not a specific estimate of expected cancers. Rather, it is a plausible upper bound estimate of the probability that a person may develop cancer sometime in his or her lifetime following exposure to that contaminant.

There is insufficient knowledge of cancer mechanisms to decide if there exists a level of exposure to a cancer-causing agent below which there is no risk of getting cancer, namely, a threshold level. Therefore, every exposure, no matter how low, to a cancer-causing compound is assumed to be associated with some increased risk. As the dose of a carcinogen decreases, the chance of developing cancer decreases, but each exposure is accompanied by some increased risk.

There is no general consensus within the scientific or regulatory communities on what level of estimated excess cancer risk is acceptable. Some have recommended the use of the relatively conservative excess lifetime cancer risk level of one in one million because of the uncertainties in our scientific knowledge about the mechanism of cancer. Others feel that risks that are lower or higher may be acceptable, depending on scientific, economic and social factors. An increased lifetime cancer risk of one in one million or less is generally considered an insignificant increase in cancer risk.

For noncarcinogenic health risks, the contaminant intake was estimated using exposure assumptions for the site conditions. This dose was then compared to a risk reference dose (estimated daily intake of a chemical that is likely to be without an appreciable risk of health effects) developed by the US EPA, ATSDR and/or NYS DOH. The resulting ratio was then compared to the following qualitative scale of health risk:

                                                Qualitative Descriptions for
                                                Noncarcinogenic Health Risks

Ratio of Estimated Contaminant
Intake to Risk Reference Dose
Qualitative
Descriptor
equal to or less than the risk
reference dose
minimal
greater than one to five times
the risk reference dose
low
greater than five to ten times
the risk reference dose
moderate
greater than ten times the
risk reference dose
high

Noncarcinogenic effects unlike carcinogenic effects are believed to have a threshold, that is, a dose below which adverse effects will not occur. As a result, the current practice is to identify, usually from animal toxicology experiments, a no-observed-effect-level (NOEL). This is the experimental exposure level in animals at which no adverse toxic effect is observed. The NOEL is then divided by an uncertainty factor to yield the risk reference dose. The uncertainty factor is a number which reflects the degree of uncertainty that exists when experimental animal data are extrapolated to the general human population. The magnitude of the uncertainty factor takes into consideration various factors such as sensitive subpopulations (for example, children or the elderly), extrapolation from animals to humans, and the incompleteness of available data. Thus, the risk reference dose is not expected to cause health effects because it is selected to be much lower than dosages that do not cause adverse health effects in laboratory animals.

The measure used to describe the potential for noncancer health effects to occur in an individual is expressed as a ratio of estimated contaminant intake to the risk reference dose. If exposure to the contaminant exceeds the risk reference dose, there may be concern for potential noncancer health effects because the margin of protection is less than that afforded by the reference dose. As a rule, the greater the ratio of the estimated contaminant intake to the risk reference dose, the greater the level of concern. A ratio equal to or less than one is generally considered an insignificant (minimal) increase in risk.

APPENDIX D

Response to Public Comments


Port Washington
Response to Comments

This responsiveness summary was prepared to answer the public's comments on the Port Washington draft Public Health Assessment. The public was invited to comment during the public comment period which ran from May 2, 1994 to June 9, 1994. Some comments were consolidated or grouped together to incorporate similar concerns raised by more than one person. If you have any questions, contact the Health Liaison Program at the toll-free number 1-800-458-1158, extension 402.

Comment #1

The purpose of a public health assessment and how this document fits into the overall Superfund Remedial Program needs to be explained. The role and responsibilities of the Department of Health, as well as that of the Agency for Toxic Substances and Disease Registry (ATSDR), in the remedial process should also be clearly explained.

Response #1

A note of explanation has been added to the final public health assessment document to explain ATSDR's role in the Superfund process. The New York State Department of Health (NYS DOH) has a cooperative agreement with the ATSDR and prepares those health assessments for the sites listed on the United States Environmental Protection Agency's (US EPA) National Priorities List in New York State.

Comment #2

Additional explanation is needed regarding what is meant by comparison values for cancer and noncancer on Tables 1, 3, 4, 5, 6 and 7.

Response #2

A public health assessment comparison value is a contaminant level in water, soil or air that is not likely to cause health effects given the potential for exposure. Comparison values are used to determine which site-associated contaminants found in water, soil or air need to be further evaluated for cancer and noncancer health risks. Public health assessment comparison values for carcinogenic effects were estimated for an increased lifetime cancer risk of one in a million from exposures to contaminants in air (Tables 1, 4, 5 and 7) and groundwater (Tables 3 and 6). Noncancer health risk comparison values for contaminants in air and groundwater were calculated from contaminant levels corresponding to a reference dose for noncancer health effects (see Response to Comment nos. 24 and 26).

Comment #3

A clear definition of what constitutes a health hazard is needed. The distinctions between public health hazards, threats and potential health threats should be clearly explained.

Response #3

The Port Washington site was identified as a "public health hazard" because the site fulfills the definition of a public health hazard given in the Health Assessment Guidance Manual prepared by the Agency for Toxic Substances and Disease Registry (ATSDR), U.S. Department of Health and Human Services. The criteria (also see Appendix E) are:

    "Evidence exists that exposures have occurred, are occurring, or are likely to occur in the future." And:

    "The estimated exposures are to a substance or substances at concentrations in the environment that, upon long-term exposures (greater than 1 year), can cause adverse health effects to any segment of the receptor population. The adverse health effect can be the result of either carcinogenic or noncarcinogenic toxicity from a chemical exposure." And/or:

    "Community-specific health outcome data indicate that the site has had an adverse health effect on human health that requires intervention."

The exposure pathways that fulfill the ATSDR criteria for a public health hazard are past exposures to contaminated soil gas documented in residential areas west of the landfill and past exposures to contaminants in the ambient air.

Please refer to the Pathways Analyses section for an explanation of what constitutes a completed or potential exposure pathway. The term "threat" may occasionally be interchanged with the term "potential hazard" but both terms have similar meanings.

Comment #4

Groundwater should be included with ambient air and off-site soil gas as the basis for classifying the landfill as a public health hazard.

The Port Washington Water District (PWWD) states that the groundwater contamination in a public supply well off-site is from the Port Washington Landfill. This conclusion was based on historical pumping data that show the cone of depression for the Southport well extending under the landfill, as well as other factors such as extensive well usage during summer months at the North Hempstead Country Club (NHCC) that may influence or reverse groundwater flow. Also, PWWD states that the vinyl chloride samples of 33 mcg/L and 47 mcg/L that were retracted because of improper instrumentation must be considered real results because follow-up results were not taken under similar pumping conditions.

Ingestion of contaminated groundwater was identified as a "potential" exposure pathway, despite the presence of volatile organic contaminants in the Southport municipal supply well in 1980. Some level of exposure definitely was present. This issue requires clarification.

Response #4

All of these comments have been considered and changes have been made to the public health assessment accordingly (refer to Off-Site Contamination section). The final public health assessment now identifies contamination in the Southport Public Supply well as originating from the Port Washington Landfill based on this information. Therefore, the groundwater exposure pathway is a past completed exposure pathway due to past exposures to contaminated groundwater.

Comment #5

Many comments identified the groundwater contamination threat to the public and environment as a "community concern". Another community concern is contamination of Hempstead Harbor.

Response #5

These additional concerns have been added to the "Community Concerns" section of the public health assessment.

Comment #6

What type of additional health studies and follow-up activities are recommended as stated in #3 of the "Recommendations" section? A chronology of actions required by the Department of Health in the remedial process should be included. The reference in the "Actions Implemented During the Public Health Assessment Process" subsection of the Background section is inadequate. Regarding the public health actions taken or planned, what is the role of the Department of Health in review/approval of remedial actions (closure, groundwater treatment, operation, maintenance, monitoring) to insure public health will be protected? What is the nature of the education planned for health professionals (HARP recommendations)?

Response #6

The additional health studies and other follow-up activities are listed in the "Public Health Actions" section of the public health assessment. The "Actions Implemented During the Public Health Assessment Process" section has been expanded to include all actions implemented prior to the public release version of this document.

The NYS DOH reviews all remedial investigative and closure workplans for the Port Washington Landfill inactive hazardous waste site and makes recommendations based on those workplans to ensure that the surrounding community's health is protected. In addition, NYS DOH regulates drinking water supplies. All public water supplies are required to monitor drinking water on a routine basis to determine if the water meets state drinking water standards. These data are reviewed by the Nassau County Health Department and NYS DOH.

The education planned for health professionals will be provided as people call with site-related health concerns. At the caller's request, a NYS DOH staff physician will contact the concerned individual's physician to discuss and relay appropriate health information relating to the Port Washington Landfill site.

Comment #7

The analysis of the public health implications from exposure to various landfill contaminants through a variety of pathways is quite complicated. A public meeting should be scheduled to explain this analysis and answer questions as well as explain the role of the Department of Health and ATSDR at this site. As indicated in the study, existing data is not always adequate to quantify certain health risks. A public meeting would also provide an opportunity to describe the scope and methods of additional health studies.

Response #7

At this time, a public meeting to discuss the public health assessment will not be held due to the few number of requests we received; however, if interest increases, a public meeting may be scheduled. In the meantime, individuals with questions about the public health assessment can contact NYS DOH staff at 1-800-458-1158, extension 402. Individuals that requested a public meeting during the public comment period will be contacted by NYS DOH staff to discuss individual concerns. Any other requests to hold a public meeting to discuss the public health assessment may be made by calling Nina Knapp at the toll free telephone number listed above.

Comment #8

Conclusions, number 4 - The plan will be made, but will it be implemented, and who will enhance it?

Response #8

The long-term monitoring plan is required for any New York State permitted landfill closure plan and the long-term monitoring plan for Port Washington Landfill will be developed and carried out by the Town of North Hempstead with oversight by the US EPA. Final approval of this plan is needed from the town, the NYS DEC and the NYS DOH.

Comment #9

On-Site Contamination, paragraph 3 - The contaminated sub-surface soil pathway cannot be eliminated and may be a major source of groundwater contamination.

Off-Site Contamination, paragraph 4 - It is probable that rainfall percolating through the unsaturated soil will dissolve the soil gas contaminants and take them to the groundwater. This represents a soil gas pathway to groundwater contamination.

Page 39, Table 2 - Leachate must be considered as a potential exposure pathway for groundwater contamination.

Response #9

The contaminated sub-surface soil pathway has been eliminated as a human exposure pathway because contaminated soils are found 20 to 100 feet below ground surface; therefore, human contact with contaminants in these soils is not expected (see On-Site Contamination section, paragraph 3).

Soil gas has been identified as a completed human exposure pathway because landfill soil gas containing methane and VOCs migrated to off-site homes west of the landfill (see Completed Exposure Pathways section, Soil Gas pathway subsection).

Although leachate has been eliminated as a human exposure pathway because human contact with the landfill leachate is not expected (see Eliminated Exposure Pathways section, Soil and Leachate pathway subsection), leachate is contributing to the contamination of the groundwater (see Potential Exposure Pathways section, Groundwater Pathway subsection).

Comment #10

There is the potential for contaminated groundwater to discharge into Hempstead Harbor, noted in Off-Site Contamination subsection. This possibility needs to be addressed, and if it can not confidently be ruled out, the potential impacts of such discharge need to be evaluated.

The study has identified a data gap regarding surface water, sediment and biota samples in Hempstead Harbor. A recommendation should be added to collect and analyze the necessary data. Drainage swales directing rainfall into the recharge basin, run along the south and north boundaries of the L-4 and L-5 landfills. This runoff is a potential contamination pathway to Hempstead Harbor. Biota sampling is a must.

Response #10

The potential that on-site contaminated groundwater is discharging to Hempstead Harbor was evaluated by reviewing on-going groundwater monitoring well data from downgradient wells closest to Hempstead Harbor. This PHA has been updated since the public comment period to include the well data review and the conclusion that the contaminant levels or types of contamination in the downgradient groundwater would not have a measurable effect on the water quality of Hempstead Harbor (see Off-Site Contamination subsection). Monitoring well data will be reviewed in the future to determine whether contaminated groundwater at levels of concern is approaching Hempstead Harbor.

While rainfall may occasionally runoff onto the landfill surface, the rainfall runoff with discharge to Hempstead Harbor is not expected to transport a significant amount of contaminants because surface soils (0-6 inches) are not a significant source of contamination (see On-Site Contamination subsection).

Comment #11

In the Site Description and History section, paragraph 9, the reference to explosions in basements of homes west of the landfill is not accurate. These homes do not have basements. They are constructed on slabs with an opening where the heating system is located.

In Site Description and History section, paragraph 9, it describes soil gas samplings which show methane migrating off-site along L4 boundary and into the North Hempstead County Club. There was also extensive migration into the neighborhood. This information should be included with specific reference to the distance and extent of the migration. Reference should also be made in this section of gas migration into the Seaview Industrial Park (referenced later on page 16).

Would the increased risk be even greater in light of the particular designs of the homes involved (slab - no basement, exposure to main living areas)?

Response #11

The public health assessment has been reworded to reflect that furnace explosions occurred, but not in basements. Also, changes have been made to indicate the approximate distance of methane migration into residential areas west of the landfill and to note that the Seaview Industrial Park was affected by off-site methane migration (see Site Description and History section).

A house with a basement may have a greater chance of intercepting subsurface soil gas than a house built on a slab because basements have greater surface area for soil gas to enter. However, control measures are now in place to eliminate or reduce the chance that landfill soil gas containing methane or VOCs will migrate to any off-site residence or building.

Comment #12

It was suggested years ago that the soil gas withdrawal system be put into operation with strict monitoring to see that gas did not migrate into people's homes. What is taking so long?

Has the indoor air been tested at the South Salem School in the wintertime and summertime?

Response #12

After 1981 when landfill gases were migrating into residences west of the landfill, the town installed a gas collection system to prevent the uncontrolled migration of subsurface gases to the west of the landfill. The existing soil gas venting system will be improved and a comprehensive monitoring plan for the gas venting system will be implemented as specified in the US EPA issued Record of Decision for this site.

Indoor air was sampled for methane and volatile organic compounds (VOCs) in several residences and the South Salem School by the Nassau County Health Department in March of 1981, June of 1982, and September of 1982. Indoor air samples were also collected from "control" homes to determine what levels of VOCs may be present in homes unaffected by the landfill. VOCs were detected in the school at levels comparable to the control homes. Methane and vinyl chloride were not detected in any of the air samples collected in the school.

Comment #13

Further study of cancer effects as well as the noncarcinogenic effects must be evaluated. Further explanation is needed as to why data is not sufficient (Toxicological Evaluation A.3 paragraph 5 & 6) to assess risks of exposure.

Response #13

The "Public Health Implications" section of the public health assessment assesses the risks for cancer and noncancer health effects to the contaminants of concern if the toxicological data are sufficient for these contaminants.

To evaluate if adverse noncancer health effects from exposure to a chemical may occur, there must be adequate toxicological data to determine the amount of a chemical a person may be exposed to without risk of any health effects--this is called the reference dose, described in Appendix C, Procedures for Evaluating Potential Health Risks for Contaminants of Concern. For noncancer health effects from past inhalation exposure to vinyl chloride, the toxicological data are not available. The word "toxicological" was added to the paragraph mentioned above for clarification.

Comment #14

Further explanation is needed as to why the ambient air data is questionable. More information is needed on how samplings were conducted (in accordance with EPA protocols, frequency) especially since other ambient air testing results have been questioned. Testing procedures and frequency of ambient air quality (p. 25) should be evaluated to see if they are sufficient to assess health impacts and protect the public.

Response #14

The data are limited because the potential exposures to contaminants in ambient air may have been occurring for up to 15 years; however, ambient air sampling was done for a brief period between 1988-1989. Please refer to the "Toxicological Evaluation" section under number 1 for further explanation.

Comment #15

Have the employees been informed that they have been exposed to VOCs for an extended period of time?

Response #15

Employees at the Port Washington Landfill have not been contacted. However, the public health assessment evaluates potential worker exposures to landfill contaminants and the public health assessment has been made available to all nearby residents and businesses. The NYS DOH will assist employees or their physicians with any health concerns regarding possible workplace exposures at the Port Washington Landfill. Concerned employees should call Nina Knapp (Health Liaison Program) of the NYS DOH at the toll-free number, 1-800-458-1158, extension 402.

Comment #16

Public Health Actions, #3 - Are all residents told that there is an investigation of the health effects of landfill gas migration going on? When will the DOH study on cancer incidence and landfills be completed?

Response #16

Residents were not directly notified, but may have learned through the media that the NYS DOH is studying cancer incidence around 42 landfills that have evidence of migration of methane and other gases into the surrounding community. The study is expected to be completed in 1995.

Comment #17

How long will it take for the NYS DOH VOC Registry to start generating data, does it have adequate funding?

Response #17

NYS DOH is currently reviewing drinking water sampling results from around the state to select households which will be included in the registry. Once the households are selected, telephone interviews will be conducted. The telephone interviews are scheduled to start toward the end of 1995. The NYS DOH is investigating whether sources of outside funding are available which could augment this effort.

Comment #18

How can the DOH determine if there's a relationship between the landfill and increased cancer incidence?

Response #18

When cancer incidence is found to be elevated in an area around a landfill or in any geographic area, it is difficult to attribute the increase to one particular factor or exposure. Cancer takes many years to develop during which time people move in and out of the area. Historical data on exposures from the landfill are also incomplete. In addition, there are many factors which can contribute to the development of cancer including occupational exposure to chemicals, smoking, diet, other medical conditions and family history of cancer. When an increase in cancer is found through a cancer incidence study, interviews are sometimes conducted to obtain information on length of residence near the landfill and on other factors such as those mentioned above that may be related to the development of cancer. Interviews can provide information that may be related to the cancer excess, such as occupational exposure to carcinogenic chemicals or existence of medical conditions that have been linked with development of cancer. In the cancer incidence study around Port Washington Landfill, an excess of brain cancer in males was found for the period 1978-1984. Interviews did not reveal occupational exposures that may be relevant, and only one of the seven cases had a medical condition known to increase the risk for brain cancer. To further investigate the relationship between residence near landfills and development of cancer, NYS DOH is in the process of conducting a study of cancer occurrence around 42 landfills (including Port Washington) that have shown evidence of migration of methane and other gases into the surrounding community. The results of this study are expected in 1995.

Comment #19

I lived within one mile of the Port Washington Landfill from June 1984 through June 1986 and within two miles from mid-1986 to the present. In 1990, I was diagnosed as having leukemia (CML). Questions concerning exposures to benzene were asked of me at that time. I noticed there was some benzene at the landfill. What is the connection between being a Port Washington resident and my leukemia?

Response #19

This individual's concerns have been referred to the NYS DOH's Bureau of Environmental and Occupational Epidemiology for a follow-up via telephone. Individuals that have similar health concerns may discuss them confidentially with NYS DOH personnel by contacting Nina Knapp (Health Liaison Program) of the NYS DOH at the toll free number, 1-800-458-1158, extension 402.

Comment #20

The surrounding community has been exposed to ambient vinyl chloride all this time. Is there also a high rate of breast cancer of post menopausal women in the surrounding community?

Response #20

The NYS DOH study of cancer incidence in Port Washington census tracts 3010 and 3014 for the years 1978-1984 did not find an increased incidence of breast cancer. Fourteen cases of breast cancer in females were observed, and 19 cases were expected.

Comment #21

It should be assumed that if contaminant levels are above zero, there will be detrimental health effects, since most of the vinyl chloride has been dissipated previously, it has already done its damage, before the gas collection system was installed.

Response #21

The potential health risks associated with vinyl chloride exposures in ambient and indoor air are discussed in the Public Health Implications section.

Comment #22

What are the results of the cancer incidence study of 1973-1984?

Response #22

Please refer to the "Health Outcome Data Evaluation" section of the public health assessment for a summary of the Port Washington cancer incidence study. If anyone wants a complete copy of the study, they should contact Nina Knapp (Health Liaison Program) of the NYS DOH at the toll free number, 1-800-458-1158, extension 402.

Comment #23

The exposure and risk calculations need to be presented more explicitly in the document. The assumed duration of exposures is not given, and the basis of the dermal exposures is unclear.

Response #23

Although quantitative risk calculations were completed to estimate health risks, the public health assessment is not intended to be a risk assessment document and detailed calculations are not provided. Instead, as discussed in Appendix C, calculated excess lifetime cancer risks and noncarcinogenic health risks were qualitatively ranked in the main part of the assessment. If the qualitative description was "moderate", then the excess lifetime cancer risk from that exposure fell in the range of one per ten thousand to less than one per thousand.

The exposure scenarios are given in the footnote section of Tables 1, 3, 4, 5 and 6. We also tried to provide sufficient data so that those who were interested could understand the assumptions that were made. For example, in regard to past inhalation exposure to volatile organic compounds in indoor air, we specify that the total duration of exposure was for about three to four months per year over a period of three years.

Dermal exposure to volatile organic contaminants in drinking water supplies can occur during showering, bathing or other household uses. A discussion of this point has been added to the revised public health assessment (Toxicological Evaluation, subsection A4). To account for these different sources of dermal exposure, the NYS DOH, in carrying out risk calculations, doubles the exposure compared to that which an individual receives from only drinking the water.

Comment #24

The exposure and risk calculations appear to be based on healthy adults. Health risks to sensitive subpopulations, such as children and the elderly appear to be overlooked. Dose and toxic effect calculations need to be modified for these groups.

Response #24

Estimation of a chemical's cancer potency to determine human cancer risk to that chemical is usually based on animal studies. Generally, the most sensitive animal species is used. However, this may not ensure that the human cancer risk will not be underestimated if humans, particularly sensitive subpopulations, are more susceptible to the effects of the chemical agent. Other steps that are taken which may avoid underestimating human cancer risk include, determining a chemical's cancer potency at very low doses and assuming that every exposure, no matter how small, to a cancer-causing compound is associated with some increased risk.

To estimate noncarcinogenic health risks, the intake of each contaminant (estimated by using exposure assumptions for conditions at the Port Washington Landfill site) was compared to a risk reference dose. A risk reference dose is an estimate (with an uncertainty spanning perhaps an order of magnitude or greater) of a daily exposure level for the human population that is likely to be without any appreciable risk of adverse health effects. The risk reference dose is calculated, taking into consideration sensitive subpopulations (for example, children or the elderly). Thus, exposure to the risk reference dose is not expected to cause health effects in these sensitive subpopulations.

Comment #25

The exposure analyses fail to address multipathway exposures (e.g., ingestion, dermal absorption and inhalation).

Response #25

Although we consider all possible exposure pathways, we don't combine risks associated with the different pathways, since some people may not be exposed to all of them. For example, some people may have been exposed to contaminated air, but not to contaminated drinking water.

Comment #26

The qualitative descriptions that label various risks as "high", "medium", and "low" are inappropriate because there is no scientific consensus on these descriptors. Furthermore, many, if not most toxicologists would find the definition of "low" risk (five times the reference dose) used in the PHA completely unacceptable.

Response #26

To estimate the risks of noncarcinogenic effects from potential exposures, the intake of each contaminant was compared to a risk reference dose (see response #24) and we assigned qualitative terms to describe these risks. In addition, the document defines these terms although we recognize other qualifiers are possible. We assigned the qualitative descriptor "low" to designate a level of risk that is greater than "minimal" but less than "moderate". A "minimal" risk is assigned when the ratio of the estimated contaminant intake to the risk reference dose is equal to or less than the risk reference dose. In turn, we assigned the qualitative descriptor "moderate" to a ratio of estimated contaminant to risk reference dose of greater than five to ten times the risk reference dose. If exposure to a contaminant exceeds the risk reference dose, there may be concern for potential noncarcinogenic effects because the margin of protection is less than that afforded by the reference dose. For example, when the estimated intake of a contaminant is five times the reference dose, the margin of protection is five times less than when the estimated contaminant intake is equal to the risk reference dose. As a rule, the greater the decrease in the margin of protection, the greater the level of concern.

A "low" risk posed by a site contaminant does not mean that the site is not a public health hazard. In fact, according to the Agency for Toxic Substances and Disease Registry (ATSDR) Public Health Assessment Guidance Manual, a site should be categorized as a public health hazard if evidence exists that long-term exposures to hazardous substances can cause adverse health effects and these exposures exceed a risk reference dose or comparable value such as an ATSDR chronic minimal risk level. Consistent with these criteria, the NYS DOH in estimating health risks from past exposures to contaminants from the Port Washington Landfill, categorized this site as a public health hazard.

Comment #27

While the risk assessment appears to be consistent with standard practice, the presentation of conclusions regarding public health implications makes assertions that are not supported. A simple example is the error of describing cancer risks as a "plausible upper bound" estimate of the probability of developing cancer. While the slope factors used in these estimates are "upper bound" estimates, the exposure factors, and the resulting risk estimates, most certainly are not.

The assertion that there is only a five percent chance that the true risk is greater than the estimate is completely unsupported by data, and probably false. In reality, we know too little about the distributions of critical variables in exposure estimation, and their interdependence, to make any such claim.

Response #27

We have deleted the phrase "there is only a five percent chance that the risk of a response is greater than the estimated value" from our discussion of cancer risks (see Appendix C).

We recognize the limitations of risk assessment methodology. A major limitation is the lack of sufficient scientific data on the biological mechanisms of tumor induction by most cancer causing chemicals. In the absence of such data, estimation of human cancer risk from exposure to carcinogenic chemicals is based on conservative steps and assumptions (see Response #24). When upper bound estimates of cancer potency are combined with upper-end estimates of exposure, the resulting risk estimates are frequently characterized as bounding estimates or high-end estimates. This basic approach is used by federal and state agencies, including the NYS DOH, ATSDR and the US EPA, to evaluate human health risk associated with environmental contamination.


APPENDIX E

Public Health Hazard Categories

The following section was not available in electronic format for conversion 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



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