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APPENDICES

Appendix A

Contaminants of Concern

This list of Contaminants of Concern was compiled in part through ATSDR's literature review: Chemical Specific Consultation: Hazardous Substance Exposures and Autism. These chemicals were selected from studies and articles in the literature review, because they were suspected of causing or contributing to adverse health effects (i.e. autism or PDD) in children or during prenatal development. No one chemical or class of chemicals could be identified directly as a contributor to autism spectrum disorders, because very little is known about how biological and environmental factors contribute to autism and related disorders. This list was developed as a screening tool for looking at possible environmental exposures.

Contaminant

Concentration

Unit

Source

Acetone

1,000

ppb

CV

Anthracene

3,000

ppb

CV

Arsenic

3

ppb

CV

Benzene

1

ppb

CV

Benzo(b)flouranthene (PAH)

0.2

ppb

MCL

Benzo(a)pyrene (PAH)

0.005

ppb

CV

Benz(a)anthracene (PAH)

2,800

ppb

MCL

Bis(2-ethyl-hexyl)phthalate

6,000,000

ppb

MCL

Bromoform

4

ppb

CV

*Butyl benzyl phthalate

2,000

ppb

CV

Cadmium

5

ppb

CV

Carbon tetrachloride

0.3

ppb

CV

Chlordane

0.6

ppb

CV

Chlorobenzenes

100

ppb

CV

Chloroform

6

ppb

CV

Chromium

100

ppb

CV

Copper

100

ppb

CV

DDT

5

ppb

CV

Di-n-butyl phthalate

1,000

ppb

CV

Dibenzo(a,h)anthracene (PAH)

0.3

ppb

MCL

*1,2-Dichlorobenzene

600

ppb

CV

1,4-Dichlorobenzene

75

ppb

CV

Dichloroethanes

0

ppb

MCLG

1,1-Dichloroethene

0.06

ppb

CV

*Diethylstilbestrol

 

 

 

Dioxin (2,3,7,8 TCDD)

.00001

ppb

CV

Endosulfan

20

ppb

CV

Ethyl benzene

700

ppb

CV

Flouranthene (PAH)

400

ppb

CV

Heptachlor

0.008

ppb

CV

Heptachlor epoxide

0.004

ppb

CV

Hexachlorocyclohexane

0.02

ppb

CV

" alpha

0.006

ppb

CV

" beta

0.02

ppb

CV

" gamma

0.4

ppb

CV

Lead

0

ppb

MCLG

Mercury

2

ppb

MCL

Methylene chloride

5

ppb

CV

Naphthalene

20

ppb

CV

Nickel

100

ppb

CV

PCB's

0.02

ppb

CV

Pyrene (PAH)

300

ppb

CV

Silver

50

ppb

CV

Tetrachloroethylene (PCE)

0.7

ppb

CV

Toluene

200

ppb

CV

1,1,1-Trichloroethane

200

ppb

CV

1,1,2-Trichloroethane

0.6

ppb

CV

Trichloroethylene

20

ppb

CV

Vinyl Chloride

0.2

ppb

CV

Xylene

2,000

ppb

CV

Zinc

3,000

ppb

CV


* No Toxicological Profile
CV-Comparison Value
MCL-Maximum Contaminant Level
MCLG-Maximum Contaminant Level Goal
ppb-parts per billion

Appendix B

Comparison Values

To determine which chemicals might have some relationship to fetal birth effects, autism, and PDD ATSDR performed a literature search and developed a list of Contaminants of Concern (Appendix A). ATSDR evaluated all available environmental data from 1987 through 1995 to look for the Contaminants of Concern. To select chemicals for further evaluation, comparison values were used. Comparison values are chemical concentrations that are found in specific media (air, soil, and water). They are designed to be conservative and non-site specific. Therefore, they are protective for all probable exposures. Comparison values are intended to be used only to screen out chemicals that do not need further evaluation. They are not intended to be used as clean-up levels or to indicators of public health effects. Comparison Values are derived from toxicological information, using assumptions regarding body weights, ingestion rates, and exposure frequency and duration. Generally, the assumptions used are very conservative (i.e., worst case). For example, soil comparison values are developed for children who exhibit pica behavior. Soil ingestion in children with pica (5 to 10 grams per day) greatly exceeds the soil ingestion rate for the normal population (0.05 grams per day).

There are two different types of comparison values, those based on carcinogenic (cancer-causing) effects, and those based on noncarcinogenic effects. Cancer-based comparison values are calculated from the EPA's oral cancer slope factor or inhalation unit risk. They are calculated for a lifetime exposure a (70 years) with an unacceptable excess lifetime cancer risk of one case per million exposed people. Noncancer comparison values are calculated from ATSDR's minimal risk levels, or EPA's reference doses or reference concentrations. These values are calculated for adults, children, and small children who may eat large amounts of soil or drink large amounts of water (2 liters per day).

Appendix A contains the list of chemicals evaluated and the comparison values used to select the appropriate chemicals for more in-depth analysis (bolded items). A chemical is selected for further evaluation (bolded items in Appendix A) if the chemical was found in a valid environmental sample and exceeds comparison values. The presence of a chemical in the Appendix A table does not mean that either exposure to the chemical or adverse health effects has occurred or will occur. Just because a chemical has been bolded in the tables only indicates that the potential for human exposures to the selected chemical and the potential for adverse human health effects as a result of any exposures to the selected chemical and the potential for adverse human health effects as a result of any exposures to the selected chemical will be discussed in more detail in the health consultation.

The comparison values used in this health consultation are listed and described below:

Cancer Risk Evaluation Guides (CREGs) are estimated concentrations that would be expected to cause no more than one excess cancer in a million persons exposed over a lifetime. CREGs are calculated from EPA's cancer slope factors.

Environmental Media Evaluation Guides (EMEGs) are based on ATSDR's minimal Risk Levels (MRLs) and factor in body weight and ingestion or inhalation rates.

Minimal Risk Levels (MRLs) are an estimate of daily human exposure to a chemical (in milligrams of the chemical per kilogram of body weight per day [mg/kg/day]) that is likely to be without an appreciable risk of deleterious effects (noncarcinogenic) over a specified duration of exposure. MRLs are based on human and animal studies. They are reported in the ATSDR Toxicological Profiles for acute ( <14 days), intermediate (15-365 days), and chronic ( >365 days) exposures. Proposed MRLs are peer reviewed and available for public comment when the ATSDR Toxicological Profile for that chemical is out for public comment.

Reference Dose Media Evaluation Guides (RMEGs) are similar to EMEGs, except that they are based on EPA's reference doses (RfDs).

Reference Doses (RfDs) are developed by EPA. They are an estimate of the daily exposure to a chemical that is unlikely to cause adverse health effects even if the exposure occurs over a lifetime (70 years). RfDs do not consider carcinogenic effects. EPA has any proposed RfD peer reviewed before publishing them.

Appendix C
Table 1
Contaminants Detected in Brick Township Municipal Drinking Water, Above Environmental Screening Values
Source: BTMUA and NJDEP Data

Chemical

Observed
Concentration
Range (ppb)

Frequency of Detection

Comparison Value
(ppb)

EPA Cancer Slope Factor in (mg/kg/day) -1

Bromoform

0.6 - 5.0

14

4 (CREG)
2000 (EMEG)

0.0079

Chloroform

0.6 - 240

356

6 (CREG)
100 (EMEG)

0.0061

Tetrachloroethylene (PCE)

0.13 - 6.0

12

0.7 (CREG)
100 (RMEG)

0.052

Total Trihalomethanes

1.0 - 251

356

100 (MCL)

NA

Appendix C
Table 2
Contaminants Detected in Groundwater, Above Environmental Screening Values

Samples taken from Off-Site Monitoring Wells, Brick Township Landfill
Source: Remedial Investigation Data, January 1999

Chemical

Observed
Concentration
Range (ppb)

Comparison Value
(ppb)

EPA Cancer Slope Factor in (mg/kg/day) -1

Arsenic

8.5 - 269

.02 (CREG)
3 (EMEG)

1.5

Benzene

1.9 - 57

1 (CREG)

.029

Cadmium

5.4 - 228

2 (EMEG)

NA

Chlorobenzene

68 - 130

100 (MCL)

NA

Chromium

102 - 6,100

100 (MCL)

NA

Copper

1,250 - 2,020

100 (MCLG)

.04

Lead

10.9 - 2,230

0 (MCLG)

NA

Mercury

2.0 - 26.8

2 (MCL)

NA

Nickel

107 - 1,020

100 (MCL)

NA

Vinyl Chloride

12 - 71

.02 (CREG)
.2 (EMEG)

1.9

Zinc

5,890 - 12,800

3000 (EMEG)

NA

Appendix D
Theoretical Cancer Risk Associated with Exposure to Chemical Contaminants in the Brick Township Municipal Drinking Water Supply, Completed Exposure Pathway

Adults

Chemical

Maximum Concentration Detected (ppb)

Dose

EPA Cancer Slope Factor
(ug/kg/day)-1

Length of Exposure
(70 years)

Theoretical Cancer Risk

Bromoform

5

3.0x10-5

0.0079

10/70

2.4x10-7

Chloroform

240

1.4x10-3

0.0061

10/70

8.8x10-6

Tetrachloroehtylene (PCE)

6

3.6x10-5

0.052

10/70

1.9x10-6

Maximum Theoretical Cancer Risk for Adults from Exposure to Chemicals in Drinking Water

1.1x10-5

Appendix D

Bromoform

Persons who ingested water between 1987 and 1995 may have been exposed to bromoform at a maximum concentration of 5ppb or 0.005 milligrams per liter (mg/l). The EPA has set a Maximum Contaminant Level of 80 ppb or 0.080 mg/l for the combination of bromoform and other trihalomethanes in drinking water. The estimated exposure dose was below EPA's reference dose (RfD) of 0.020 milligrams per kilogram per day (mg/kg/day) and below the no-observed-adverse-effect-level (NOAEL) of approximately 10 mg/kg/day. ATSDR does not believe that adverse non-cancer health effects would occur due to these exposures. The Department of Health and Human Services and EPA have determined that bromoform is reasonably anticipated to be a carcinogen. The EPA has calculated a cancer risk factor, which can be used to estimate the probability of excess cancer risk for a lifetime of exposure to bromoform. Cancer risk for exposure was estimated based on the maximum concentration of bromoform in the contaminated medium. There appears to be no significant increased risk of cancer based upon these conservative estimations.

Chloroform

Persons who ingested water between 1987 and 1995 could have been exposed to chloroform at a maximum concentration of 240 ppb or 0.240 milligrams per liter (mg/l). The EPA has set a Maximum Contaminant Level of 80 ppb or 0.080 mg/l for the combination of chloroform and other trihalomethanes in drinking water. The estimated exposure dose was below EPA's reference dose (RfD) of 0.010 milligrams per kilogram per day (mg/kg/day) and below the no-observed-adverse-effect-level (NOAEL) of approximately 6 mg/kg/day. ATSDR does not believe that adverse non-cancer health effects would occur due to these exposures. The Department of Health and Human Services and EPA have determined that chloroform is reasonably anticipated to be a carcinogen. The EPA has calculated a cancer risk factor, which can be used to estimate the probability of excess cancer risk for a lifetime of exposure to chloroform. Cancer risk for exposure was estimated based on the maximum concentration of chloroform in the contaminated medium. There appears to be no significant increased risk of cancer based upon these conservative estimations.

Tetrachloroethylene (PCE)

The MCL for PCE is currently at 5 ppb. This MCL is based on a cancer risk estimate. Persons who ingested water between 1987 and 1994 could have been exposed to PCE at a maximum concentration 6 ppb or 0.006 milligrams per liter (mg/l). The actual level of exposure is most likely much less than 6 ppb since the water from the wells contaminated with PCE was diluted with water from the rest of the Brick system before it reached Brick residents. The estimated exposure dose was below EPA's reference dose (RfD) of 0.010 milligrams per kilogram per day (mg/kg/day) and below the no-observed-adverse-effect-level (NOAEL) of approximately 20 mg/kg/day. ATSDR does not believe that adverse non-cancer health effects would occur due to these exposures. The Department of Health and Human Services and EPA have determined that PCE is reasonably anticipated to be a carcinogen. The EPA has calculated a cancer risk factor, which can be used to estimate the probability of excess cancer risk for a lifetime of exposure to PCE. Cancer risk for exposure was estimated based on the maximum concentration of PCE in the contaminated medium. There appears to be no significant increased risk of cancer based upon these conservative estimations.

Exposure Scenario for Bromoform, Chloroform and Tetrachloroethylene

Exact information regarding possible exposures to bromoform, chloroform, and PCE were not available. To evaluate possible exposures certain assumptions were made by ATSDR. The following assumptions were made:

  • persons exposed were adults;
  • exposures occurred at the maximum concentration detected;
  • the maximum period of time people would have been exposed was 9 months (270 days) per year for 10 years;
  • the main routes of exposure were most likely ingestion, dermal contact, and inhalation from showering and other hot water uses.

Discussion of Theoretical Cancer Risk

ATSDR evaluated the theoretical cancer risk for exposure to bromoform, chloroform, and PCE in municipal drinking water in the tables above. The calculations presented in this Appendix over estimate the risk of cancer by several orders of magnitude (the real risk is 100s to 1,000s times lower). In addition cancer risk calculations generally assume a lifetime of exposure (70 years), where the maximum exposure period for Brick Township residents would be 10 years or less.

Even if the theoretical cancer risk calculations are correct, the predicted cancer occurrence for exposure to bromoform, chloroform, and PCE combined would be 1 per 100,000 in adults. In Brick Township the theoretical cancer risk calculations would predict less than 0.74 extra cancers in the adult population.

Calculation of rates:

These calculations were based on population figures from 1990 U.S. Census data indicating a total population for Brick Township of 66,414 and a child population (3-10 years old) of 7,117.

The number of children aged 3 to 10 years in Brick Township in 1998 was estimated by CDC using a 25% inflation factor. The 25% inflation factor was equivalent to the increase observed in the Brick Township student population for grades K through 5 in the school years, 1989-90 and 1998-99, which were provided by the Brick Township Public Schools. Using this inflation factor, the estimated number of children aged 3 to 10 years in Brick Township in 1998 was 8,896.

For consistency, the same inflation factor (25%) was then used by ATSDR to estimate the adult population in 1998. Using this inflation factor the estimated adult population in Brick Township in 1998 was 74,121.

Appendix E

FIGURES

Figure 1


Place of Birth
for children who participated in the clinical exams and were diagnosed with ASD,
(n=41)

Figure 2


Demographic Map

Figure 3

Brick Township Municipal Water System Map

Figure 4

Brick Township Study Participants

Figure 5

Locations of Total Trihalomethane Levels with at Least One Sample Above 80 Parts Per Billion

Figure 6

Locations of Total Trihalomethane Levels with at Least One Sample Above 80 Parts Per Billion with Residence at Birth/Conception for Study Participants

Figure 7

Brick Township Landfill and Residence at Birth/Conception

Appendix F

ATSDR Plain Language Glossary of Environmental Health Terms
Revised - 15 Dec 99

Absorption: How a chemical enters a person's blood after the chemical has been swallowed, has come into contact with the skin, or has been breathed in.

Acute Exposure: Contact with a chemical that happens once or only for a limited period of time. ATSDR defines acute exposures as those that might last up to 14 days.

Additive Effect: A response to a chemical mixture, or combination of substances, that might be expected if the known effects of individual chemicals, seen at specific doses, were added together.

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

Antagonistic Effect: A response to a mixture of chemicals or combination of substances that is less than might be expected if the known effects of individual chemicals, seen at specific doses, were added together.

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 B including animals, fish and plants.

CAP: See Community Assistance Panel.

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.

Community Assistance Panel (CAP): A group of people from the community and health and environmental agencies who work together on issues and problems at hazardous waste sites.

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.

Concern: A belief or worry that chemicals in the environment might cause harm to people.

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

Contaminant: See Environmental Contaminant.

Delayed Health Effect: A disease or injury that happens as a result of exposures that may have occurred far in the past.

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 chemicals 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.

Malignancy: See Cancer.

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.

Plume: A line or column of air or water containing chemicals moving from the source to areas further away. A plume can be a column or clouds of smoke from a chimney or contaminated underground water sources or contaminated surface water (such as lakes, ponds and streams).

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.

PRP: Potentially Responsible Party. A company, government or person that is responsible for causing the pollution at a hazardous waste site. PRP's are expected to help pay for the clean up of a site.

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.

SARA: The Superfund Amendments and Reauthorization Act in 1986 amended CERCLA and expanded the health-related responsibilities of ATSDR. CERCLA and SARA direct ATSDR to look into the health effects from chemical exposures at hazardous waste sites.

Sample Size: The number of people that are needed for a health study.

Sample: A small number of people chosen from a larger population (See Population).

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.

Special Populations: People who may be more sensitive to chemical exposures because of certain factors such as age, a disease they already have, occupation, sex, or certain behaviors (like cigarette smoking). Children, pregnant women, and older people are often considered special populations.

Statistics: A branch of the math process of collecting, looking at, and summarizing data or information.

Superfund Site: See NPL.

Survey: A way to collect information or data from a group of people (population). Surveys can be done by phone, mail, or in person. ATSDR cannot do surveys of more than nine people without approval from the U.S. Department of Health and Human Services.

Synergistic effect: A health effect from an exposure to more than one chemical, where one of the chemicals worsens the effect of another chemical. The combined effect of the chemicals acting together are greater than the effects of the chemicals acting by themselves.

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.

Tumor: Abnormal growth of tissue or cells that have formed a lump or mass.

Uncertainty Factor: See Safety Factor.

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.

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