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1. ATSDR > Public Health Assessments & Consultations

PUBLIC HEALTH ASSESSMENT

TULSA FUEL AND MANUFACTURING
COLLINSVILLE, TULSA COUNTY, OKLAHOMA

APPENDICES

Appendix A - Figures

Figure 1. Location Map and Demographic Information

Figure 2. Site Sketch from Removal Assessment Report

Figure 3. Arsenic Levels in Surface Soil

Figure 4. Lead Levels in Surface Soil

Figure 5. Cadmium Levels in Surface Soil

Appendix B - Tables

Table B1. On-site Surface Soil Results, Tulsa Fuel & Manufacturing Site, Tulsa County, Oklahoma.

Contaminant	From Site Investigation, 9/94 1 n=7		From Removal Assess. Report, 5/99; XRF analysis 2 n=106		From Removal Assess. Report, 5/99 TAL lab analysis 3 n=2		Comparison Value 4
	Concentration Range (ppm)	Average (ppm)	Concentration Range (ppm)	Average (ppm)	Concentration Range (ppm)	Average (ppm)	Concentration (ppm)	Type
Arsenic	18.5 - 302	151	ND - 864	138	12.1 - 26.7	19.4	0.5 20	CREG EMEG-child
Cadmium	41.1 - 275	119	DNU	-	17.2 - 76.9	47.1	10	EMEG-child
Copper	126 - 1670	874	ND - 4023	659	87.3 - 122	105	2,000	estimated CV for child
Lead	1160 - 16,600	8539	138 - 36,565	4992	566 - 1560	1063	400	EPA SSL
Manganese	691 - 24,700J	10,610	ND - 45,655	5641	657 - 974	816	7,000	RMEG-child
Zinc	6770 -37,000J	20,714	694 - 104,232	27,842	3030 - 11,500	7265	20,000	EMEG-child

¹ Includes five 0-2 inch samples from waste piles and two 0-3 inch samples from on-site residential yard.
² Screening level analysis of 99 grid samples (0-6"), 5 road samples (0-2"), and 2 samples (0-6") from residential property.
³ Two surface soil samples sent to laboratory for confirmation purposes, one from residential property and one grid sample from northern portion of site.
⁴ The Comparison Values are defined on page 34.
n = number of samples
ppm = parts per million (or milligrams per kilogram)
ND = not detected
DNU = Data Not Usable because laboratory confirmation of this compound did not correlate well with XRF data.
J = estimated value


Table B2. On-site Subsurface Soil Results, from the Removal Assessment Report, 5/99. Tulsa Fuel & Manufacturing Site, Tulsa County, Oklahoma.

Contaminant	XRF analysis Slag samples from waste piles, 0-9 ft. n=37		XRF analysis Road samples, 2-24 inches n=6		TAL lab analysis 1 n=6		Comparison Value 2
	Concentration Range (ppm)	Average (ppm)	Concentration Range (ppm)	Average (ppm)	Concentration Range (ppm)	Average (ppm)	Concentration (ppm)	Type
Arsenic	ND - 1071	285	ND - 69	36	5.8 - 258	53.8	0.5	CREG
Cadmium	DNU	-	DNU	-	ND - 35.4	22.2	10	EMEG-child
Copper	ND - 2826	792	ND - 44	17	13 - 1130	225	2000	estimated CV for child
Lead	50 - 39,964	7604	3.4 - 986	350	14.4 - 91,800	15,722	400	EPA SSL
Manganese	323 - 56,320	18,382	216 - 1086	518	159 - 6540	1774	7000	RMEG-child
Zinc	396 - 79,511	30,841	139 - 7647	3465	42.7 - 25,200	5935	20,000	EMEG-child

¹ Five waste pile samples and 1 road sample were sent to the lab for confirmation purposes.
² The Comparison Values are defined on page 34.
n = number of samples
ppm = parts per million (or milligrams per kilogram)
ND = not detected
DNU = Data Not Usable because laboratory confirmation of this compound did not correlate well with XRF data.

Table B3. Off-site Surface Soil Results, Tulsa Fuel & Manufacturing Site, Tulsa County, Oklahoma.

Contaminant	From Site Investigation, 9/941 n=2		From Removal Assess. Report, 5/99; XRF analysis2 n=6		From Removal Assess. Report, 5/99 TAL lab analysis3 n=1	Comparison Value 4
	Concentration Range (ppm)	Average Concentration (ppm)	Concentration Range (ppm)	Average (ppm)	Concentration (ppm)	Concentration (ppm)	Type
Arsenic	10.4 - 13.7	12.1	ND - 48	33	5.56	0.5	CREG
Cadmium	4.2 - 6.2	5.2	DNU	-	0.85	0.4 10	EMEG-pica EMEG-child
Lead	226 - 362	294	ND - 700	166	14	400	EPA SSL
Manganese	521 - 548	535	205 - 893	490	323	300 7000	RMEG-pica RMEG-child
Zinc	892 - 786	839	360 - 3824	1094	311	600 20,000	EMEG-pica EMEG-child

¹ Two soil samples taken in residential yards, north of site on 136^th St.
² The soil samples were taken within 800 ft. of the site, 5 from north of the site and 1 outside the southwest corner. They were labeled as background samples in the Removal Assessment Report.
³ One sample taken approximately 800 ft. north of the site.
⁴ The Comparison Values are defined on page 34.
n = number of samples
ppm = parts per million (or milligrams per kilogram)
ND = not detected
DNU = Data Not Usable because laboratory confirmation of this compound did not correlate well with XRF data.

Table B4. On-site Sediment Sample Results, Tulsa Fuel & Manufacturing Site, Tulsa County, Oklahoma.

Contaminant	Site Investigation, 9/94 n=4		Removal Assess. Report, 5/99 TAL lab analysis, n=29		Comparison Value1
	Concentration Range (ppm)	Average Concentration (ppm)	Concentration Range (ppm)	Average Concentration (ppm)	Concentration (ppm)	Type
Antimony	ND - 50.9	18	ND - 20J	6.1	20	RMEG-child
Arsenic	7.8 - 514	157	ND - 110	14	0.5	CREG
Cadmium	13.9 - 1833	498	1.5 - 189	33	10	EMEG-child
Lead	160 - 25,400	8192	12 - 395J	129	400	EPA SSL
Manganese	741 - 6946	3894	35 - 2280J	856	7000	RMEG-child
Zinc	1590 - 22,900	12,780	101 - 4800	1300	20,000	EMEG-child

¹ The Comparison Values are defined on page 34.
n = number of samples
ppm = parts per million (or milligrams per kilogram)
ND = not detected
J = Estimated Value

Table B5. Surface Water Sample Results, Tulsa Fuel & Manufacturing Site, Tulsa County, Oklahoma.

Contaminant	Site Investigation, 9/94 n=4		Removal Assess. Report, 5/99 n=12		Surface Water Comparison Values 1
	Concentration Range (ppb)	Average Concentration (ppb)	Concentration Range (ppb)	Average Concentration (ppb)	Concentration (ppb)	Type
Arsenic	ND - 3.2 J	1.6	ND - 51	14	2.0 5000	CREG2 MCL2
Cadmium	5 - 58.3	36	ND - 30	9.3	200 500	EMEG-child2 MCL2
Lead	ND - 31.8	17	ND - 18	6.0	1500	EPA Action Level2
Manganese	ND - 300	107	45 - 289	210	5000	RMEG-child2

¹ Comparison Values are defined on page 34.
² Comparison Values for drinking water were multiplied by 100, because it was assumed that daily ingestion of surface water for a child was 10 ml rather than the 1000 ml used for drinking tap water.
n = number of samples
ppb = parts per billion (or micrograms per liter)
ND = not detected
J = Estimated Value

Table B6. Completed Exposure Pathways

Pathway Name/ Media:	Surface Soil (On-site)	Sediment (On-site)	Surface Water
Source:	TFM	TFM	TFM
Exposure Point:	on-site surface soil/ waste piles	northern ponds, southern impoundments, ditches	northern ponds, southern impoundments, ditches
Exposure Route:	ingestion	ingestion	ingestion
Likely Exposed Population:	on-site residents visitors/trespassers smelter workers (1914-25)	on-site residents visitors/trespassers/fishers smelter workers (1914-25)	on-site residents visitors/trespassers/fishers smelter workers (1914-25)
Exposure Period:	past current future	past current future	past current future
Contaminants potentially of public health interest	metals - arsenic, cadmium, copper, lead, manganese, zinc	metals - antimony, arsenic, cadmium, copper, lead, manganese, zinc	metals - arsenic, cadmium, lead, manganese
Comments	Residential area has lower concentrations than waste piles. No children currently live on site. As this site is somewhat isolated, trespassing would be limited, but has occurred.	Exposure to sediments is limited. Past levels are not known.	This water is not used for drinking water; exposure would be incidental during recreational activities such as fishing. Swimming in the past has been reported .
NOTE: THE PRESENCE OF AN EXPOSURE PATHWAY IN THIS TABLE DOES NOT IMPLY THAT AN EXPOSURE WOULD BE SUBSTANTIVE OR THAT AN ADVERSE HEALTH EFFECT WOULD OCCUR

Table B7. Other Pathways Considered

Pathway Name/ Media:	Soil (off-site)	Surface Water (off-site)	Groundwater	Air	Sediment (off-site)	Biota/Food chain
Source:	TFM	TFM & possible Collinsville smelter	TFM	TFM	TFM & possibly Collinsville smelter	TFM
Exposure Point:	1) near site 2) possibly residential driveways, or anywhere smelter waste was deposited	ditches off-site and intermittent streams	on-site residence tap water	on-site	ditches off-site and intermittent streams	Residences nearby Wherever fish or berries or goat milk are consumed
Exposure Route:	ingestion inhalation (dust)	ingestion	ingestion	inhalation	ingestion	ingestion
Likely Exposed Population:	nearby residents	nearby residents, children playing in stream	on-site resident	past & future workers on-site resident	nearby residents, children playing in stream	nearby residents who ingest berries & fish gathered from site or ingest milk from goat which roams site.
Exposure Period:	past current future	past current future	future	past future	past current future	past current future
Contaminants potentially of health interest	metals	metals	metals	metals sulfur dioxide (during operation of smelter)	metals	metals
Comments	The extent of off-site soil contamination is unclear. The possibility of off-site disposal of slag/waste in driveways, roads, tracks exists, but has not been investigated.	Limited sampling. The downstream ditches and streams are not used for drinking water.	Limited sampling. One on-site well did not show metal contamination. Currently, on-site resident does not drink the well water.	Recent sampling shows no significant contamination. In the past, smelter workers could have been exposed SO2, etc. Any future soil removal would have the potential to increase dust in air.	Limited sampling. Exposure would be limited.	Reports of fishing & berry-picking on-site have been made. Frequency is unknown. Low levels of a few metals were detected in catfish fillet. Berries have not been sampled. Goat has been seen on-site - no sampling data.
NOTE: THE PRESENCE OF AN EXPOSURE PATHWAY IN THIS TABLE DOES NOT IMPLY THAT AN EXPOSURE WOULD BE SUBSTANTIVE OR THAT AN ADVERSE HEALTH EFFECT WOULD OCCUR

Appendix C - Comparison Values

EMEG = Environmental Media Evaluation Guide.
An estimated comparison concentration for which exposure is unlikely to cause adverse health effects, determined by ATSDR from its toxicological profiles for a specific chemical.

RMEG = Reference Dose Media Evaluation guide
A comparison concentration that is based on EPA's estimate of the daily exposure to a contaminant that is unlikely to cause adverse health effects.

CREG = Cancer Risk Evaluation Guide
A comparison concentration that is based on an excess cancer rate of one in a million persons and is calculated using EPA's cancer slope factor.

MCL = Maximum Contaminant Level
MCLs represent contaminant concentrations in drinking water that EPA deems protective of public health (considering the availability and economics of water treatment technology).

EPA Action Level:
The estimated contaminant concentrations in water where additional evaluation is needed to determine if action is required to eliminate or reduce exposure. Action levels can be based on mathematical models.

EPA SSL = Environmental Protection Agency Soil Screening Level
A level of a contaminant in the soil that is used to identify areas needing further investigation at National Priority List (NPL) sites.

Appendix D - Evaluation Process

In evaluating these data, ATSDR used comparison values to determine which chemicals to examine more closely. Comparison values are health-based thresholds below which no known or anticipated adverse human health effects occur. Comparison values can be based on cancer or non-cancer health effects. Non-cancer levels are based on the lowest (i.e., most toxic) valid toxicological study for a chemical and the assumption that a small child (22 lbs.) is exposed every day. Cancer levels are the media concentrations where there would be a one in a million excess cancer risk for an adult eating contaminated soil everyday for 70 years. For chemicals for which both cancer and non-cancer numbers exist, the more toxic (i.e., lower) level is used. A description of the comparison values used in this evaluation can be found in Appendix C. Exceeding a comparison value does not mean that health effects will occur, just that more evaluation is needed.

Further evaluation focuses on identifying which chemicals and exposure situations are likely to be a health hazard. The first step is the calculation of child and adult exposure doses, as described in Appendix E. These are then compared to an appropriate health guideline for a chemical. An exposure dose is the amount of chemical ingested daily per unit of body weight. Health guidelines are the amount of chemical per unit of body weight where health effects very likely do not occur, based on investigations of human exposures to the chemical, or, if human data don't exist or are not valid, of animal experiments. Most health guidelines are based on animal data. The results of these calculations are presented in Tables E1 through E3 starting on page 37. Any exposure situation, where the exposure dose is lower than a health guideline, is eliminated from further evaluation.

The next step in the evaluation process is determining whether the worst case exposure situations used in earlier calculations need to be revised to better fit the actual situation.

The last evaluation step is the comparison of these revised exposure doses to known toxicological values for the chemical of concern. This would include the no observed and lowest observed adverse health effects levels (NOAEL & LOAEL) identified in ATSDR Toxicological Profiles. If the chemical of concern is a carcinogen, the cancer risk is recalculated using the revised exposure dose. These comparisons are the basis for stating whether the exposure might be a health hazard or not.

Calculation of Exposure Dose from Ingestion of Contaminated Soil or Sediment

The exposure doses for ingestion of contaminated soil or sediment were calculated in the following manner. The maximum or mean concentration for a chemical in soil or sediment were multiplied by the soil ingestion rate for adults, 0.0001 kg/day, or the rate for children, 0.0002 kg/day. This product was divided by the average weight for an adult, 70 kg (154 pounds), or for a small child, 10 kg (22 pounds). Those calculations assume that there is frequent daily exposure to soil or sediment contaminated at the specified level. The results of the actual calculations are recorded in Tables E1 through E2 which are on the following pages.

Calculation of Exposure Dose from Ingestion of Contaminated Surface Water

The exposure doses for ingestion of contaminated surface water were calculated in the following manner. The maximum or mean concentration for a chemical in surface water was multiplied by a surface water ingestion rate for adults, 0.02 liters/day, or a rate for children, 0.01 liters/day. This product was divided by the average weight for an adult, 70 kg (154 pounds), or for a small child, 10 kg (22 pounds). Those calculations assume that there is daily exposure to surface water contaminated at the specified level. The results of the actual calculations are recorded in Table E3 which follows.

Calculation of Risk of Carcinogenic Effects

Carcinogenic risks from the ingestion of soil, sediment, or surface water were calculated using the following procedure. The adult exposure doses for ingestion of soil, sediment, or surface water were calculated as described previously, then multiplied by the EPA's Cancer Slope Factor (CSF) for that chemical (16). The results of the calculation of carcinogenic risk from exposure can be found on Tables E1 through E3 which are on the following pages.

The actual risk of cancer is probably lower than the calculated number. The method used to calculate EPA's Cancer Slope Factor assumes that high dose animal data can be used to estimate the risk for low dose exposures in humans (17). The method also assumes that there is no safe level for exposure (18). There is little experimental evidence to confirm or refute those two assumptions. Lastly, the method computes the 95% upper bound for the risk, rather than the average risk, which results in there being a very good chance that the risk is actually lower, perhaps several orders of magnitude (19). One order of magnitude is 10 times greater or lower than the original number, while two orders of magnitude are 100 times, and three orders 1,000 times.

TABLE E1 - ESTIMATED EXPOSURE DOSES AND CANCER RISK FOR ON-SITE SOIL CONTAMINANTS COMPARED TO HEALTH GUIDELINES FOR INGESTION¹

Contaminant	Level in parts per million (ppm)	Estimated Adult Exposure Doses in mg/kg/day*	Estimated Child Exposure Doses in mg/kg/day*	Health Guideline in mg/kg/day*	Source of Guideline	Cancer Risk
Maximum Arsenic Level	864	0.001	0.02	0.0003	MRL2	2 in 1,0003
Mean Arsenic Level	138	0.0002	0.003	0.0003	MRL2	3 in 10,0004
Maximum Cadmium Level	275	0.0004	0.006	0.0002	MRL2	No CSF5
Mean Cadmium Level	119	0.0002	0.002	0.0002	MRL2	No CSF5
Maximum Copper Level	4,023	0.006	0.08	0.04	pRfD6	not carcinogen
Mean Copper Level	659	0.0009	0.01	0.04	pRfD6	not carcinogen
Maximum Lead Level	36,565	0.05	0.7	None available7	--	No CSF5
Mean Lead Level	4,992	0.007	0.1	None available7	--	No CSF5
Maximum Manganese Level	45,655	0.07	0.91	0.14	RfD8	not carcinogen
Mean Manganese Level	5,641	0.008	0.11	0.14	RfD8	not carcinogen
Maximum Zinc Level	104,232	0.15	2.08	0.3	MRL2	not carcinogen
Mean Zinc Level	27,842	0.04	0.56	0.3	MRL2	not carcinogen

* mg/kg/day = milligrams/kilogram/day
1 An explanation of how these exposure doses and cancer risk were calculated can be found in the preceding page.
2 MRL = ATSDR's minimal risk level
3 Maximum additional lifetime risk of cancer per 1,000 individuals
4 Maximum additional lifetime risk of cancer per 10,000 individuals.
5 CSF = EPA's cancer slope factor
6 pRfD = EPA's provisional reference dose.
7 No health guideline is available for lead.
8 RfD = EPA's reference dose.

TABLE E2 - ESTIMATED EXPOSURE DOSES AND CANCER RISK FOR ON-SITE SEDIMENT CONTAMINANTS COMPARED TO HEALTH GUIDELINES FOR INGESTION¹

Contaminant	Level in parts per million (ppm)	Estimated Adult Exposure Doses in mg/kg/day*	Estimated Child Exposure Doses in mg/kg/day*	Health Guideline in mg/kg/day*	Source of Guideline	Cancer Risk
Maximum Arsenic Level	110	0.0002	0.002	0.0003	MRL2	2 in 10,0003
Mean Arsenic Level	14	0.00002	0.0003	0.0003	MRL2	3 in 100,0004
Maximum Cadmium Level	189	0.0003	0.004	0.0002	MRL2	No CSF5
Mean Cadmium Level	33	0.00005	0.0007	0.0002	MRL2	No CSF5

* mg/kg/day = milligrams/kilogram/day
1 An explanation of how these exposure doses and cancer risk were calculated can be found at the start of this appendix.
2 MRL = ATSDR's minimal risk level
3 Maximum additional lifetime risk of cancer per 10,000 individuals
4 Maximum additional lifetime risk of cancer per 100,000 individuals.
5 CSF = EPA's cancer slope factor

TABLE E3 - ESTIMATED EXPOSURE DOSES AND CANCER RISK FOR SURFACE WATER CONTAMINANTS COMPARED TO HEALTH GUIDELINES FOR INGESTION¹

Contaminant	Level in parts per million (ppm)	Estimated Adult Exposure Doses in mg/kg/day*	Estimated Child Exposure Doses in mg/kg/day*	Health Guideline in mg/kg/day*	Source of Guideline	Cancer Risk
Maximum Arsenic Level	0.05	0.00001	0.00005	0.0003	MRL2	3 in 100,0003
Mean Arsenic Level	0.01	0.000003	0.00001	0.0003	MRL2	7 in 1,000,0004

* mg/kg/day = milligrams/kilogram/day
1 An explanation of how these exposure doses and cancer risk were calculated can be found at the start of this appendix.
2 MRL = ATSDR's minimal risk level
3 Maximum additional lifetime risk of cancer per 100,000 individuals
4 Maximum additional lifetime risk of cancer per 1,000,000 individuals.

Adverse Health Effect:

A change in body function or the structures of cells that can lead to disease or health problems.

ATSDR:

The Agency for Toxic Substances and Disease Registry. ATSDR is a federal health agency in Atlanta, Georgia that deals with hazardous substance and waste site issues. ATSDR gives people information about harmful chemicals in their environment and tells people how to protect themselves from coming into contact with chemicals.

Background Level:

An average or expected amount of a chemical in a specific environment. Or, amounts of chemicals that occur naturally in a specific environment.

Biota:

Used in public health, things that humans would eat - including animals, fish and plants.

Cancer:

A group of diseases which occur when cells in the body become abnormal and grow, or multiply, out of control

Carcinogen:

Any substance shown to cause tumors or cancer in experimental studies.

CERCLA:

See Comprehensive Environmental Response, Compensation, and Liability Act.

Chronic Exposure:

A contact with a substance or chemical that happens over a long period of time. ATSDR considers exposures of more than one year to be chronic.

Completed Exposure Pathway:

See Exposure Pathway.

Comparison Value (CVs):

Concentrations or the amount of substances in air, water, food, and soil that are unlikely, upon exposure, to cause adverse health effects. Comparison values are used by health assessors to select which substances and environmental media (air, water, food and soil) need additional evaluation while health concerns or effects are investigated.

Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA):

CERCLA was put into place in 1980. It is also known as Superfund. This act concerns releases of hazardous substances into the environment, and the cleanup of these substances and hazardous waste sites. ATSDR was created by this act and is responsible for looking into the health issues related to hazardous waste sites.

Concentration:

How much or the amount of a substance present in a certain amount of soil, water, air, or food.

Contaminant:

See Environmental Contaminant.

Dermal Contact:

A chemical getting onto your skin. (see Route of Exposure).

Dose:

The amount of a substance to which a person may be exposed, usually on a daily basis. Dose is often explained as "amount of substance(s) per body weight per day".

Dose / Response:

The relationship between the amount of exposure (dose) and the change in body function or health that result.

Duration:

The amount of time (days, months, years) that a person is exposed to a chemical.

Environmental Contaminant:

A substance (chemical) that gets into a system (person, animal, or the environment) in amounts higher than that found in Background Level, or what would be expected.

Environmental Media:

Usually refers to the air, water, and soil in which chemical of interest are found. Sometimes refers to the plants and animals that are eaten by humans. Environmental Media is the second part of an Exposure Pathway.

U.S. Environmental Protection Agency (EPA):

The federal agency that develops and enforces environmental laws to protect the environment and the public's health.

Epidemiology:

The study of the different factors that determine how often, in how many people, and in which people will disease occur.

Exposure:

Coming into contact with a chemical substance.(For the three ways people can come in contact with substances, see Route of Exposure.)

Exposure Assessment:

The process of finding the ways people come in contact with chemicals, how often and how long they come in contact with chemicals, and the amounts of chemicals with which they come in contact.

Exposure Pathway:

A description of the way that a chemical moves from its source (where it began) to where and how people can come into contact with (or get exposed to) the chemical.

ATSDR defines an exposure pathway as having 5 parts:

1. Source of Contamination,


2. Environmental Media and Transport Mechanism,


3. Point of Exposure,


4. Route of Exposure; and,


5. Receptor Population.
   
   

When all 5 parts of an exposure pathway are present, it is called a Completed Exposure Pathway. Each of these 5 terms is defined in this Glossary.

Frequency:

How often a person is exposed to a chemical over time; for example, every day, once a week, twice a month.

Hazardous Waste:

Substances that have been released or thrown away into the environment and, under certain conditions, could be harmful to people who come into contact with them.

Health Effect:

ATSDR deals only with Adverse Health Effects (see definition in this Glossary).

Indeterminate Public Health Hazard:

The category is used in Public Health Assessment documents for sites where important information is lacking (missing or has not yet been gathered) about site-related chemical exposures.

Ingestion:

Swallowing something, as in eating or drinking. It is a way a chemical can enter your body (See Route of Exposure).

Inhalation:

Breathing. It is a way a chemical can enter your body (See Route of Exposure).

LOAEL:

Lowest Observed Adverse Effect Level. The lowest dose of a chemical in a study, or group of studies, that has caused harmful health effects in people or animals.

MRL:

Minimal Risk Level. An estimate of daily human exposure - by a specified route and length of time -- to a dose of chemical that is likely to be without a measurable risk of adverse, noncancerous effects. An MRL should not be used as a predictor of adverse health effects.

NPL:

The National Priorities List. (Which is part of Superfund.) A list kept by the U.S. Environmental Protection Agency (EPA) of the most serious, uncontrolled or abandoned hazardous waste sites in the country. An NPL site needs to be cleaned up or is being looked at to see if people can be exposed to chemicals from the site.

NOAEL:

No Observed Adverse Effect Level. The highest dose of a chemical in a study, or group of studies, that did not cause harmful health effects in people or animals.

No Apparent Public Health Hazard:

The category is used in ATSDR's Public Health Assessment documents for sites where exposure to site-related chemicals may have occurred in the past or is still occurring but the exposures are not at levels expected to cause adverse health effects.

No Public Health Hazard:

The category is used in ATSDR's Public Health Assessment documents for sites where there is evidence of an absence of exposure to site-related chemicals.

PHA:

Public Health Assessment. A report or document that looks at chemicals at a hazardous waste site and tells if people could be harmed from coming into contact with those chemicals. The PHA also tells if possible further public health actions are needed.

Point of Exposure:

The place where someone can come into contact with a contaminated environmental medium (air, water, food or soil). For examples: the area of a playground that has contaminated dirt, a contaminated spring used for drinking water, the location where fruits or vegetables are grown in contaminated soil, or the backyard area where someone might breathe contaminated air.

Population:

A group of people living in a certain area; or the number of people in a certain area.

Public Health Assessment(s):

See PHA.

Public Health Hazard:

The category is used in PHAs for sites that have certain physical features or evidence of chronic, site-related chemical exposure that could result in adverse health effects.

Public Health Hazard Criteria:

PHA categories given to a site which tell whether people could be harmed by conditions present at the site. Each are defined in the Glossary. The categories are:
- Urgent Public Health Hazard
- Public Health Hazard
- Indeterminate Public Health Hazard
- No Apparent Public Health Hazard
- No Public Health Hazard

Receptor Population:

People who live or work in the path of one or more chemicals, and who could come into contact with them (See Exposure Pathway).

Reference Dose (RfD):

An estimate, with safety factors (see safety factor) built in, of the daily, life-time exposure of human populations to a possible hazard that is not likely to cause harm to the person.

Route of Exposure:

The way a chemical can get into a person's body. There are three exposure routes:
- breathing (also called inhalation),
- eating or drinking (also called ingestion), and
- or getting something on the skin (also called dermal contact).

Safety Factor:

Also called Uncertainty Factor. When scientists don't have enough information to decide if an exposure will cause harm to people, they use "safety factors" and formulas in place of the information that is not known. These factors and formulas can help determine the amount of a chemical that is not likely to cause harm to people.

Source (of Contamination):

The place where a chemical comes from, such as a landfill, pond, creek, incinerator, tank, or drum. Contaminant source is the first part of an Exposure Pathway.

Superfund Site:

See NPL.

Toxic:

Harmful. Any substance or chemical can be toxic at a certain dose (amount). The dose is what determines the potential harm of a chemical and whether it would cause someone to get sick.

Toxicology:

The study of the harmful effects of chemicals on humans or animals.

Urgent Public Health Hazard:

This category is used in ATSDR's Public Health Assessment documents for sites that have certain physical features or evidence of short-term (less than 1 year), site-related chemical exposure that could result in adverse health effects and require quick intervention to stop people from being exposed.

Table of Contents

Agency for Toxic Substances and Disease Registry, 1825 Century Blvd, Atlanta, GA 30345
Contact CDC: 800-232-4636 / TTY: 888-232-6348 

Department of Health and Human Services