Environmental Health Flashcards
1
Q
Absorption
A
Penetration of a substance into an organism and its cells by various processes, some specialized, some involving expenditure of energy (active transport), some involving a carrier system, and others involving passive movement down an electrochemical gradient.
Note: In mammals absorption is usually through the respiratory tract, gastrointestinal tract, or skin into the circulatory system and from the circulation into organs, tissues and cells.
2
Q
Acceptable Risk
A
The risk that has minimal detrimental effects or for which benefits outweigh the potential hazards. Note: Calculated risk of an increase of one case in a million people per year for cancer is usually considered to be negligible.
3
Q
Acid Deposition
A
Acidification occurs after the release of nitrogen oxide and sulfur dioxide from point or nonpoint sources into the atmosphere. Chemical processes may transform these chemicals into sulfuric and nitirc acids. These are returned to the earth in snowfall, rain, fog, and dust and may deposit at distances far from the original sources.
4
Q
Acute Exposure
A
Acidification occurs after the release of nitrogen oxide and sulfur dioxide from point or nonpoint sources into the atmosphere. Chemical processes may transform these chemicals into sulfuric and nitirc acids. These are returned to the earth in snowfall, rain, fog, and dust and may deposit at distances far from the original sources. Perry, James A. and Elizabeth Vanderklein. 1996. Water Quality: Management of a Natural Resource.
5
Q
Additive Effect
A
A biologic response to exposure to multiple substances that equals the sum of responses of all the individual substances added together [compare with antagonistic effect and synergistic effect ].
6
Q
Adverse Health Effect
A
A change in body function or cell structure that might lead to disease or health problems.
7
Q
Aerobic
A
Life or processes that require, or are not destroyed by, the presence of oxygen.
8
Q
Aerosol
A
Mixture of small droplets or particles (solid, liquid, or a mixed variety) and a carrier gas (usually air).
9
Q
Agency for Toxic Substances and Disease Registry (ATSDR)
A
The Agency for Toxic Substances and Disease Registry (ATSDR) , based in Atlanta, Georgia, is a federal public health agency of the U.S. Department of Health and Human Services . ATSDR serves the public by using the best science, taking responsive public health actions, and providing trusted health information to prevent harmful exposures and diseases related to toxic substances
10
Q
Air Toxics
A
Any air pollutant for which a national ambient air quality standard (NAAQS) does not exist (i.e. excluding ozone, carbon monoxide, PM-10, sulfur dioxide, nitrogen oxide) that may reasonably be anticipated to cause cancer; respiratory, cardiovascular, or developmental effects; reproductive dysfunctions, neurological disorders, heritable gene mutations, or other serious or irreversible chronic or acute health effects in humans
11
Q
Alpha Particle
A
A positively charged particle ejected spontaneously from the nuclei of some radioactive elements. It is identical to a helium nucleus that has a mass number of 4 and an electrostatic charge of +2. It has low penetrating power and a short range (a few centimeters in air). The most energetic alpha particle will generally fail to penetrate the dead layers of cells covering the skin and can be easily stopped by a sheet of paper. Alpha particles are hazardous when an alpha-emitting isotope is inside the body.
12
Q
Ambient Air
A
Any unconfined portion of the atmosphere: open air, surrounding air.
13
Q
American Conference of Governmental Industrial Hygienists
A
ACGIH ® is a member-based organization that advances occupational and environmental health. Examples of this include our annual editions of the TLVs ® and BEIs ® and work practice guides in ACGIH ® ‘s Signature Publications.
14
Q
Anaerobic
A
A life or process that occurs in, or is not destroyed by, the absence of oxygen.
15
Q
Analyte
A
A substance that is undergoing analysis or is being measured. For example, if the analyte is mercury, the laboratory test will determine the amount of mercury in the sample.
16
Q
Antagonism
A
Combined effect of two or more factors that is smaller than the solitary effect of any one of those factors.
17
Q
Anthropogenic
A
Caused by or influenced by human activities.
18
Q
Apoptosis
A
Programmed cell death, the body’s normal method of disposing of damaged, unwanted, or unneeded cells.
19
Q
Aqueous
A
of, relating to, or resembling water b. made from, with, or by water
20
Q
Aqueous Solubility
A
The maximum concentration of a chemical that will dissolve in pure water at a reference temperature.
21
Q
Aquifer
A
An underground geological formation, or group of formations, containing water. Are sources of groundwater for wells and springs.
22
Q
ALARA
A
Acronym for “as low as (is) reasonably achievable.” Means making every reasonable effort to maintain exposures to ionizing radiation as far below the dose limits as practical, consistent with the purpose for which the licensed activity is undertaken, taking into account the state of technology, the economics of improvements in relation to state of technology, the economics of improvements in relation to benefits to the public health and safety, and other societal and socioeconomic considerations, and in relation to utilization of nuclear energy and licensed materials in the public interest (see 10 CFR 20.1003 ).
23
Q
Assessment endpoint
A
An explicit expression of the environmental value that is to be protected, operationally defined by an ecological entity and its attributes. For example, salmon are valued ecological entities; reproduction and age class structure are some of their important attributes. Together “salmon reproduction and age class structure” form an assessment endpoint.
24
Q
Asthma
A
Chronic respiratory disease characterized by bronchoconstriction, excessive mucus secretion and oedema of the pulmonary alveoli, resulting in difficulty in breathing out, wheezing, and cough.
25
B lymphocyte
A type of lymphocyte (white blood cells), produced in the bone marrow, which synthesizes and secretes antibodies in response to the presence of a foreign substance or one identified by it as being foreign. Also called B-cell.
26
Background Level
1. The concentration of a substance in an environmental media (air, water, or soil) that occurs naturally or is not the result of human activities. 2. In exposure assessment the concentration of a substance in a defined control area, during a fixed period of time before, during, or after a data-gathering operation.
27
Bacteria
(Singular: bacterium) Microscopic living organisms. Bacteria in soil, water or air may be pathogenic and cause illnesses in humans, animals and plants. They can also be non-pathogenic and be beneficial in pollution control by metabolizing organic matter in sewage, oil spills or other pollutants.
28
Basal metabolic rate
The rate at which heat is given off by an organism at complete rest.
29
Bedrock
The solid rock underneath surface soils.
30
Bench-scale Tests
Laboratory testing of potential cleanup technologies
31
Beta particle
A charged particle emitted from a nucleus during radioactive decay, with a mass equal to 1/1837 that of a proton. A negatively charged beta particle is identical to an electron. A positively charged beta particle is called a positron. Large amounts of beta radiation may cause skin burns, and beta emitters are harmful if they enter the body. Beta particles may be stopped by thin sheets of metal or plastic.
32
Bioaccumulants
Substances that increase in concentration in various tissues of living organisms as they take in contaminated air, water, or food because the substances are very slowly metabolized or excreted
33
Biochemical Oxygen Demand (BOD)
A measure of the amount of oxygen consumed in the biological processes that break down organic matter in water. The greater the BOD, the greater the degree of pollution.
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Biocide
Substance intended to kill living organisms.
35
Biodegradable
Capable of decomposing under natural conditions.
36
Biohazard
An agent of biological origin that has the capacity to produce deleterious effects on humans, i.e. microorganisms, toxins, and allergens derived from those organisms; and allergens and toxins derived from higher plants and animals.
37
Biological Exposure Indices (BEI)
Biological Exposure Indices. A guidance value recommended by ACGIH ® for assessing biological monitoring results.
38
Biologic monitoring
The measuring of hazardous substances in biologic materials (such as blood, hair, urine, or breath) to determine whether exposure has occurred. A blood test for lead is an example of biologic monitoring.
39
Biologic uptake
The transfer of substances from the environment to plants, animals, and humans.
40
Biomarker
A cellular or molecular indicator of exposure, health effects, or susceptibility. Biomarkers can be used to measure internal dose, biologically effective dose, early biological response, altered structure or function, suceptability.
41
Biomedical testing
Testing of persons to find out whether a change in a body function might have occurred because of exposure to a hazardous substance.
42
Bioremediation
Use of living organisms to clean up oil spills or remove other pollutants from soil, water, or wastewater; use of organisms such as non-harmful insects to remove agricultural pests or counteract diseases of trees, plants, and garden soil.
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Biota
The animal and plant life of a given region.
44
Biotechnology
The broad definition of biotechnology is simply the industrial use of living organisms (or parts of living organisms) to produce foods, drugs, or other products.
45
Bioterrorism
Terrorism by intentional release or dissemination of biological agents ( bacteria , viruses or toxins ); these may be in a naturally-occurring or in a human-modified form.
46
BOD5
The amount of dissolved oxygen consumed in five days by biological processes breaking down organic matter.
47
Body burden
Total amount of a substance, organism, or noxious agent present in an organism at a given time.
48
Built Environment
It encompasses all buildings, spaces and products that are created, or modified, by people. It includes homes, schools, workplaces, parks/recreation areas, greenways, business areas and transportation systems. It extends overhead in the form of electric transmission lines, underground in the form of waste disposal sites and subway trains, and across the country in the form of highways. It includes land-use planning and policies that impact our communities in urban, rural and suburban areas.
49
Cancer
Any one of a group of diseases that occur when cells in the body become abnormal and grow or multiply out of control.
50
Cancer risk
A theoretical risk for getting cancer if exposed to a substance every day for 70 years (a lifetime exposure). The true risk might be lower.
51
Carcinogen
Any substance that can cause or aggravate cancer.
52
Case study
An uncontrolled (prospective or retrospective) observational study involving an intervention and outcome in a single patient. (Also known as a single case report or anecdote.)
53
CAS Registration Number
A number assigned by the Chemical Abstract Service to identify a chemical.
54
Centers for Disease Control and Prevention (CDC)
Collaborates to create the expertise, information, and tools that people and communities need to protect their health – through health promotion, prevention of disease, injury and disability, and preparedness for new threats. CDC seeks to accomplish its mission by working with partners throughout the nation and the world to
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monitor health,
detect and investigate health problems,
conduct research to enhance prevention,
develop and advocate sound public health policies,
implement prevention strategies,
promote healthy behaviors,
foster safe and healthful environments,
provide leadership and training.
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55
Central nervous system
The part of the nervous system that consists of the brain and the spinal cord.
56
Certified Output Protection Protocol
A device driver technology used to enable high-bandwidth Digital Content Protection ( HDCP ) during the transmission of digital video between applications and high-definition displays. COPP is a Microsoft security technology for video systems that require a logo certification. For security drivers are authenticated and protected from tampering to prevent unauthorized high-quality recording from the video outputs. COPP control signals are also encrypted .
57
Chemical, Biological, Radioactive Nuclear, Explosive (CBRNE) Incidents
CBRN incidents are deliberate, malicious acts with the intention to kill or sicken and disrupt society. CBRN may be used in warfare or terrorism.
58
Chemical Oxygen Demand (COD)
A measure of the oxygen required to oxidize all compounds, both organic and inorganic, in water.
59
Chronic Effect
1. An adverse effect on a human or animal resulting from long term exposure to a substance. 2. A persistent (month, years or permanent) adverse health effect resulting from a short term (acute) exposure
60
Chronic Exposure
Multiple exposures occurring over an extended period of time or over a significant fraction of an animal's or human's lifetime (Usually seven years to a lifetime.)
61
Chronic Obstructive Pulmonary Disease
Chronic obstructive pulmonary disease (COPD) is a lung disease characterized by chronic obstruction of lung airflow that interferes with normal breathing and is not fully reversible. The more familiar terms 'chronic bronchitis' and 'emphysema' are no longer used, but are now included within the COPD diagnosis. COPD is not simply a "smoker's cough" but an under-diagnosed, life-threatening lung disease.
62
Cluster investigation
A review of an unusual number, real or perceived, of health events (for example, reports of cancer) grouped together in time and location. Cluster investigations are designed to confirm case reports; determine whether they represent an unusual disease occurrence; and, if possible, explore possible causes and contributing environmental factors.
63
Cohort study
An epidemiological method of identifying two groups (cohorts) of individuals, one which has received the exposure of interest and one which has not, and following both groups forward for the outcome of interest.
64
Command and control (C&C)
Standards are usually tailor-made to regulate how a specific activity or class of activities need to be carried out. Compliance monitoring and eventual sanctioning of trespasses are usually indispensable features of effective C&C. The primary disadvantages of the C&C approach are that it is overly constraining, leaves little room for flexibility, is not adaptable on a case-by-case basis and tends to retard technological change. Moreover, regulations underlying the C&C approach offer no incentive for producers to attain standards higher than those imposed by the law. While C&C is often criticized for these reasons, it is widely used by government agencies and even sometimes requested by the industry. Producing regulations is done within the logic of public administration, often regardless of their enforceability. In terms of political relations, “something has been done”, and since the same norm or standard applies to everybody, it provides a sense of fairness. The frequent weakness of results monitoring and accountability, in the political arena, however, often leaves implementation in the shadow.
65
Community Assistance Panel (CAP)
A group of people from a community and from health and environmental agencies who work with ATSDR to resolve issues and problems related to hazardous substances in the community. CAP members work with ATSDR to gather and review community health concerns, provide information on how people might have been or might now be exposed to hazardous substances, and inform ATSDR on ways to involve the community in its activities.
66
Comparison value (CV)
Calculated concentration of a substance in air, water, food, or soil that is unlikely to cause harmful (adverse) health effects in exposed people. The CV is used as a screening level during the public health assessment process. Substances found in amounts greater than their CVs might be selected for further evaluation in the public health assessment process.
67
Composite Sample
1. Composite sampling is a technique whereby multiple temporally or spatially discrete, media or tissue samples are combined, thoroughly homogenized, and treated as a single sample. An example would be a series of water samples taken over a given period of time and weighted by flow rate.
68
Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA)
CERCLA, also known as Superfund, is the federal law that concerns the removal or cleanup of hazardous substances in the environment and at hazardous waste sites. ATSDR, which was created by CERCLA, is responsible for assessing health issues and supporting public health activities related to hazardous waste sites or other environmental releases of hazardous substances. This law was later amended by the Superfund Amendments and Reauthorization Act (SARA)
69
Concentration
The relative amount of a substance within another substance. An example is five ppm of carbon monoxide in air or 1 mg/l of iron in water.
70
Consumer Product Safety Commission (CPSC)
The U.S. Consumer Product Safety Commission is charged with protecting the public from unreasonable risks of serious injury or death from more than 15,000 types of consumer products. Deaths, injuries and property damage from consumer product incidents cost the nation more than $800 billion annually. The CPSC is committed to protecting consumers and families from products that pose a fire, electrical, chemical, or mechanical hazard or can injure children. The CPSC's work to ensure the safety of consumer products - such as toys, cribs, power tools, cigarette lighters, and household chemicals - contributed significantly to the 30 percent decline in the rate of deaths and injuries associated with consumer products over the past 30 years.
71
Contaminant
Any physical, chemical, biological, or radiological substance or matter that has an adverse effect on air, water, or soil.
72
Criteria Pollutants
The 1970 amendments to the Clean Air Act required EPA to set National Ambient Air Quality Standards for certain pollutants known to be hazardous to human health. EPA has identified and set standards to protect human health and welfare for six pollutants: ozone, carbon monoxide, total suspended particulates, sulfur dioxide, lead, and nitrogen oxide. The term, "criteria pollutants" derives from the requirement that EPA must describe the characteristics and potential health and welfare effects of these pollutants. It is on the basis of these criteria that standards are set or revised.
73
Cryptosporidium
A protozoan microbe associated with the disease cryptosporidiosis in man. The disease can be transmitted through ingestion of drinking water, person-to-person contact, or other pathways, and can cause acute diarrhea, abdominal pain, vomiting, fever, and can be fatal as it was in the 1993 Milwaukee episode.
74
Curie (Ci)
The basic unit used to describe the intensity of radioactivity in a sample of material.
75
Cytokine
Any of a group of soluble proteins that are released by a cell causing a change in function or development of the same cell (autocrine), an adjacent cell (paracrine), or a distant cell (endocrine); cytokines are involved in reproduction, growth and development, normal homeostatic regulation, response to injury and repair, blood clotting, and host resistance (immunity and tolerance).
76
Delayed health effect
A disease or an injury that happens as a result of exposures that might have occurred in the past.
77
Dermal Absorption/Penetration
Process by which a chemical penetrates the skin and enters the body as an internal dose.
78
Dermal Exposure
Contact between a chemical and the skin.
79
Dermal Toxicity
The ability of a pesticide or toxic chemical to poison people or animals by contact with the skin.
80
Descriptive epidemiology
Study of the occurrence of disease or other health -related characteristics in populations, including general observations concerning the relationship of disease to basic characteristics such as age, sex, race, occupation, and social class; it may also be concerned with geographic location. The major characteristics in descriptive epidemiology can be classified under the headings: individuals, time and place.
81
`Detection Limit
The lowest concentration of a chemical that can reliably be distinguished from a zero concentration.
82
Disease registry
A system of ongoing registration of all cases of a particular disease or health condition in a defined population.
83
Disease Vector
A phrase used in parasitology and entomology to describe a special type of intermediate host for parasites. A vector is not only required as part of the parasite's development, but it also delivers the parasite directly to subsequent hosts, avoiding free living stages such as those observed in Schistosoma which infects snails before having a brief free living stage that actively infects their next host.
84
Disinfectant
A chemical or physical process that kills or prevent the growth of bacteria and other micro- organisms in water, air, or on surfaces. Chlorine is often used to disinfect sewage treatment effluent, water supplies, wells, and swimming pools.
85
Disinfectant By-Product
A compound formed by the reaction of a disinfenctant such as chlorine with organic material in the water supply; a chemical byproduct of the disinfection process.
86
DNA Repair
As a major defense against environmental damage to cells DNA repair is present in all organisms examined including bacteria, yeast, drosophila, fish, amphibians, rodents and humans. DNA repair is involved in processes that minimize cell killling, mutations, replication errors, persistence of DNA damage and genomic instability. Abnormalities in these processes have been implicated in cancer and aging.
87
Dosage/Dose
1. The actual quantity of a chemical administered to an organism or to which it is exposed. 2. The amount of a substance that reaches a specific tissue (e.g. the liver). 3. The amount of a substance available for interaction with metabolic processes after crossing the outer boundary of an organism. (See: absorbed dose, administered dose, applied dose, potential dose.)
88
Dose-Response Relationship
The quantitative relationship between the amount of exposure to a substance and the extent of toxic injury or disease produced.
89
Ecological Risk Assessment
The application of a formal framework, analytical process, or model to estimate the effects of human actions(s) on a natural resource and to interpret the significance of those effects in light of the uncertainties identified in each component of the assessment process. Such analysis includes initial hazard identification, exposure and dose-response assessments, and risk characterization.
90
Economic Incentives`
Incentives are a different approach. The idea of incentives is not to strictly forbid/allow, but rather to provide signals on public objectives while leaving some room for individual and collective decision-making to respond to them. Incentives play indirectly through the determinants of individual/collective choices, such as the profit motive or normative values. Market or social forces can be very efficient vectors to force the global outcome of individual actions towards collectively set objectives. Different kinds of incentives can be developed in isolation or in combination:
improving the institutional framework (definition of rights and participatory processes);
developing collective values (education, information, training);
creating nonmarket economic incentives (taxes and subsidies); and
establishing market incentives (tradable property/access rights; eco-labelling).
91
ED50
The dose of a drug that is pharmacologically effective for 50% of the population exposed to the drug or a 50% response in a biological system that is exposed to the drug.
92
Emergency Planning and Community Right-to-Know Act (EPCRA)
Emergency Planning and Community Right-to-Know Act (EPCRA) establishes requirements for Federal, state and local governments, Indian Tribes, and industry regarding emergency planning and "Community Right-to-Know" reporting on hazardous and toxic chemicals. The Community Right-to-Know provisions help increase the public's knowledge and access to information on chemicals at individual facilities, their uses, and releases into the environment. States and communities, working with facilities, can use the information to improve chemical safety and protect public health and the environment. EPCRA was passed in response to concerns regarding the environmental and safety hazards posed by the storage and handling of toxic chemicals. These concerns were triggered by the disaster in Bhopal, India, in which more than 2,000 people suffered death or serious injury from the accidental release of methyl isocyanate. To reduce the likelihood of such a disaster in the United States, Congress imposed requirements on both states and regulated facilities.
93
Emission
Pollution discharged into the atmosphere from smokestacks, other vents, and surface areas of commercial or industrial facilities; from residential chimneys; and from motor vehicle, locomotive, or aircraft exhausts.
94
Endocrine disruptor
Exogenous chemical that alters function(s) of the endocrine system and consequently causes adverse health effects in an intact organism, its progeny or (sub) populations.
95
Environmental Equity/Justice
Equal protection from environmental hazards for individuals, groups, or communities regardless of race, ethnicity, or economic status. This applies to the development, implementation, and enforcement of environmental laws, regulations, and policies, and implies that no population of people should be forced to shoulder a disproportionate share of negative environmental impacts of pollution or environmental hazard due to a lack of political or economic strength levels.
96
Environmental media
Soil, water, air, biota (plants and animals), or any other parts of the environment that can contain contaminants.
97
Environmental media and transport mechanism
Environmental media include water, air, soil, and biota (plants and animals). Transport mechanisms move contaminants from the source to points where human exposure can occur. The environmental media and transport mechanism is the second part of an exposure pathway .
98
Epidemiology
Study of the distribution of disease, or other health-related states and events in human populations, as related to age, sex, occupation, ethnicity, and economic status in order to identify and alleviate health problems and promote better health.
99
Ergonomics
Ergonomics is the study of human characteristics for the appropriate design of the living and working environment. Ergonomic researchers strive to learn about human characteristics (capabilities, limitations, motivations, and desires) so that this knowledge can be used to adapt a human-made environment to the people involved. There are three levels of ergonomic knowledge utilization: tolerable, acceptable, and optimal.
100
Estrogen
Any of various natural steroids (as estradiol) that are formed from androgen precursors, that are secreted chiefly by the ovaries, placenta, adipose tissue, and testes, and that stimulate the development of female secondary sex characteristics and promote the growth and maintenance of the female reproductive system.
101
Eutrophication
The slow aging process during which a lake, estuary, or bay evolves into a bog or marsh and eventually disappears. During the later stages of eutrophication the water body is choked by abundant plant life due to higher levels of nutritive compounds such as nitrogen and phosphorus. Human activities can accelerate the process.
102
Exposure Assessment
Identifying the pathways by which toxicants may reach individuals, estimating how much of a chemical an individual is likely to be exposed to, and estimating the number likely to be exposed.
103
Exposure-dose reconstruction
A method of estimating the amount of people's past exposure to hazardous substances. Computer and approximation methods are used when past information is limited, not available, or missing.
104
Exposure investigation
The collection and analysis of site-specific information and biologic tests (when appropriate) to determine whether people have been exposed to hazardous substances.
105
Exposure pathway
The route a substance takes from its source (where it began) to its end point, and how people get exposed to it. An exposure pathway has five parts: a source of contamination (such as an abandoned business); an environmental media and transport mechanism (such as movement through groundwater); a point of exposure (such as a private well); a route of exposure (eating, drinking, breathing, or touching), and a receptor population (people potentially or actually exposed). When all five parts are present, the exposure pathway is termed a completed exposure pathway.
106
Feasibility Study
1. Analysis of the practicability of a proposal; e.g., a description and analysis of potential cleanup alternatives for a site such as one on the National Priorities List. The feasibility study usually recommends selection of a cost-effective alternative. It usually starts as soon as the remedial investigation is underway; together, they are commonly referred to as the "RI/FS". 2. A small-scale investigation of a problem to ascertain whether a proposed research approach is likely to provide useful data.
107
Exposure PoinT
A location of potential contact between an organism and a chemical or physical agent.
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Exposure registry
A system of ongoing follow-up of people who have had documented environmental exposures.
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Exposure-Response relationship
the connection between the amount of a chemical administered and a specific toxic effect in the organism, also called the dose-response relationship.
110
Gamma radiation
High-energy, short wavelength, electromagnetic radiation emitted from the nucleus. Gamma radiation frequently accompanies alpha and beta emissions and always accompanies fission. Gamma rays are very penetrating and are best stopped or shielded by dense materials, such as lead or depleted uranium. Gamma rays are similar to x-rays.
111
Gas phase
The simplest chemical reactions are those that occur in the gas phase in a single step, such as the transfer of a chlorine atom from ClNO 2 to NO to form NO 2 and ClNO.
ClNO 2 ( g ) + NO( g) NO 2 ( g ) + ClNO( g )
This reaction can be understood by writing the Lewis structures for all four components of the reaction. Both NO and NO 2 contain an odd number of electrons. Both NO and NO 2 can therefore combine with a neutral chlorine atom to form a molecule in which all of the electrons are paired. This reaction therefore involves the transfer of a chlorine atom from one molecule to another, as shown in the figure below.
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Geographic Information System (GIS)
A computer system designed for storing, manipulating, analyzing, and displaying data in a geographic context.
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Gene
Structurally a basic unit of hereditary material; an ordered sequence of nucleotide bases that encodes one polypeptide chain (following transcription to mRNA).
114
Global Warming
An increase in the near surface temperature of the Earth. Global warming has occurred in the distant past as the result of natural influences, but the term is most often used to refer to the warming predicted to occur as a result of increased emissions of greenhouse gases. Scientists generally agree that the Earth's surface has warmed by about 1 degree Fahrenheit in the past 140 years. The Intergovernmental Panel on Climate Change (IPCC) recently concluded that increased concentrations of greenhouse gases are causing an increase in the Earth's surface temperature and that increased concentrations of sulfate aerosols have led to relative cooling in some regions, generally over and downwind of heavily industrialized areas.
115
Gradient
Change in the value of a quantity (as temperature, pressure, or concentration) with change in a given variable and especially per unit on a linear scale.
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Gray (Gy)
The international system (SI) unit of absorbed dose. One gray is equal to an absorbed dose of 1 Joule/kilogram (one gray equals 100 rads).
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Ground Water
The supply of fresh water found beneath the Earth's surface, usually in aquifers, which supply wells and springs. Because ground water is a major source of drinking water, there is growing concern over contamination from leaching agricultural or industrial pollutants or leaking underground storage tanks.
118
Hazard Analysis and Critical Control Points
HACCP is a production control system for the food industry. It is a process that identifies where potential contamination can occur (the critical control points or CCPs) and strictly manages and monitors these points as a way of ensuring the process is in control and that the safest product possible is being produced. HACCP is designed to prevent rather than catch potential hazards.
119
Half-Life
1. The time required for half the atoms in a sample to decay, or a pollutant to lose one-half of its original concentration, for example, the biochemical half-life of DDT in the environment is 15 years. 2. The time required for half of the atoms of a radioactive element to undergo self-transmutation or decay (half-life of radium is 1620 years). 3. The time required for the elimination of half a total dose from the body.
120
Hazard
1. Potential for radiation, a chemical or other pollutant to cause human illness or injury. 2. In the pesticide program, the inherent toxicity of a compound. Hazard identification of a given substances is an informed judgment based on verifiable toxicity data from animal models or human studies.
121
Hazardous Substance
1. Any material that poses a threat to human health and/or the environment. Typical hazardous substances are toxic, corrosive, ignitable, explosive, or chemically reactive. 2. Any substance designated by EPA to be reported if a designated quantity of the substance is spilled in the waters of the United States or is otherwise released into the environment.
122
Hazardous Substance Release and Health Effects Database (HazDat)
The scientific and administrative database system developed by ATSDR to manage data collection, retrieval, and analysis of site-specific information on hazardous substances, community health concerns, and public health activities.
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Hazardous Waste
By-products of society that can pose a substantial or potential hazard to human health or the environment when improperly managed. Possesses at least one of four characteristics (ignitability, corrosivity, reactivity, or toxicity), or appears on special EPA lists.
124
Health Assessment
Public health assessments challenge ATSDR to integrate environmental sampling data, health outcome data, and community concerns successfully in the evaluation of the health implications of hazardous substances released to the environment. Doing so enables ATSDR staff members to make the difficult decisions as to why, where, and for whom public health actions should be undertaken.
125
Health Consultation
A review of available information or collection of new data to respond to a specific health question or request for information about a potential environmental hazard. Health consultations are focused on a specific exposure issue. Health consultations are therefore more limited than a public health assessment, which reviews the exposure potential of each pathway and chemical [compare with public health assessment ].
126
Health effects stuides related to contaminants
a combination of procedures, methods and tools bywhich a policy, program or project may be judged as to its potential effects on thehealth of a population, and the distribution of those effects within the population.
127
Health investigation
The collection and evaluation of information about the health of community residents. This information is used to describe or count the occurrence of a disease, symptom, or clinical measure and to evaluate the possible association between the occurrence and exposure to hazardous substances.
128
Health Registry
The Agency for Toxic Substances and Disease Registry (ATSDR) , based in Atlanta, Georgia, is a federal public health agency of the U.S. Department of Health and Human Services . ATSDR serves the public by using the best science, taking responsive public health actions, and providing trusted health information to prevent harmful exposures and diseases related to toxic substances.
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Health Statistics Review
The analysis of existing health information (i.e., from death certificates, birth defects registries, and cancer registries) to determine if there is excess disease in a specific population, geographic area, and time period. A health statistics review is a descriptive epidemiologic study.)
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Heavy Metals
Metallic elements with high atomic weights; (e.g. mercury, chromium, cadmium, arsenic, and lead); can damage living things at low concentrations and tend to accumulate in the food chain.
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Helminths
A group of parasites commonly referred to as worms. The group includes
trematodes, cestodes, and nematodes. Schistosomes are trematodes; the species that most commonly infect humans are: Schistosoma haematobium , S. intercalatum , S. japonicum , S. mansoni , and S.mekongi . Cestodes include the beef and pork tapeworms, the largest of the helminths, and nematodes include the roundworm Ascaris lumbri-coides , the whipworm Trichuris trichiura , and the hookworms Necator americanus and Ancylostoma duodenale ; these nematodes are collectively referred to as .soil-transmitted helminths. (STH).
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Herbicide
Substance intended to kill plants
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HGPRT
Hypoxanthine-guanine phosphoribosyltransferase ( HGPRT ) is an enzyme in purine metabolism . The enzyme primarily functions to salvage purines from degraded DNA to renewed purine synthesis. In this role, it acts as a catalyst in the reaction between guanine and phosphoribosyl pyrophosphate (PRPP) to form GMP .
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Hydrophilic
Having a strong affinity for water.
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Hydrophobic
Having a strong aversion for water.
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Incidence
The number of new cases of disease in a defined population over a specific time period [contrast with prevalence]. Often confused with incidence rate.
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Incineration
A treatment technology involving destruction of waste by controlled burning at high temperatures; e.g., burning sludge to remove the water and reduce the remaining residues to a safe, non-burnable ash that can be disposed of safely on land, in some waters, or in underground locations.
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Indeterminate public health hazard
The category used in ATSDR's public health assessment documents when a professional judgment about the level of health hazard cannot be made because information critical to such a decision is lacking.
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Industrial Hygiene
Industrial hygiene is the science of anticipating, recognizing, evaluating, and controlling workplace conditions that may cause workers' injury or illness. Industrial hygienists use environmental monitoring and analytical methods to detect the extent of worker exposure and employ engineering, work practice controls, and other methods to control potential health hazards.
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Ingestion
The act of swallowing something through eating, drinking, or mouthing objects. A hazardous substance can enter the body this way [see route of exposure].
