Glossary 

• ab initio- from the beginning
• Aldehydes- Any of a class of highly reactive organic compounds obtained by oxidation of certain alcohols and containing the group CHO.  Aldehydes are used in manufacturing resins, dyes, and organic acids
• Aliphatic hydrocarbons- hydrocarbons that do not contain a benzene ring; known to be quite flammable and pose health risks from mild (i.e. dermatitis) to extreme due to neurotoxins
• Alveolar macrophages (AMs)- the most prevalent cells in the human airspace
• Ambient air- any unconfined portion of the atmosphere: open air, surrounding air
• Antigen- a substance that stimulates the production of an antibody when introduced into the body; includes toxins, bacteria, viruses, and other foreign substances
• APCD- Air Pollution Control District; a special district created by state law to enforce local, state, and federal air pollution regulations
• ARAR- Applicable or Relevant and Appropriate Standards, Limitations, Criteria, and Requirements
  • any state or federal statute or regulatory provision that pertains to protection of human life and the environment in addressing specific conditions at a particular cleanup at a Superfund site. CERCLA (the Federal SF statute) requires that remedial actions meet any federal standards, requirements, criteria, or limitations that are determined to be legally applicable or relevant and appropriate. CERCLA also requires state ARARs to be met if they are more stringent that federal requirements.
• Aromatic hydrocarbons- contain one or more benzene rings; have pungent odors
• BHCs- brominated hydrocarbons
• Bioavailability- the extent to which humans and ecological receptors are exposed to contaminants in the environment
• CAG: Community Advisory Groups
  • a Community Advisory Group (CAG) is made up of representatives of diverse community interests. Its purpose is to provide a public forum for community members to present and discuss their needs and concerns related to the Superfund decision-making process.
• Cardiac apoptosis- disintegration of cardiac cells into membrane-bound particles that are then eliminated by phagocytosis or by shedding; cardiac apoptosis diminishes the contractile mass, which leads to heart failure
• Cardiopulmonary disease- disorders that affect the normal functions of the heart and lungs that could disturb the complete physical, mental, and social well being of individuals
• CERCLA: Comprehensive Environmental Response, Compensation, and Liability Act
  • the CERCLA, commonly known as Superfund, was enacted by Congress on December 11, 1980. This law created tax on the chemical and petroleum industries and provided broad Federal authority to respond directly to releases or threatened releases of hazardous substances that may endanger public health or the environment.
• CERLIS: Comprehensive Environmental Response, Compensation, and Liability Information System
  • the CERLIS Information System is an EPA database of information about Superfund sites. This information is intended for use by EPA employees for management of the Superfund program.
• CFR: Code of Federal Regulations
  • Publication containing federal regulations. EPA regulations are in Title 40 (40 CFR). These can be found at law libraries and some public libraries.
• Chemisorptions- adsorption involving a chemical linkage between the adsorbent and the adsorbate
• Chiral pesticides/phytoestroens- chemical compounds which have two ways of connecting atoms in their three dimensional structure in which the two forms of the molecule are non-superimposible mirror images of each other
• Chlorinated Benzenes (CBz’s)- a group of 12 compounds which are resistant to chemical and biological degradation and tend to accumulate in lipid-containing tissues of animals and humans
• Chlorinated phenols (CP’s)- a group of 19 compounds which have widely been used in the production of pesticides, herbicides, and wood preservatives as well as being generated as byproducts in industrial operations
• Chronic Lung Disease (CLD)- a general term for long-term respiratory problems babies, especially premature babies; also known as bronchopulmonary dysplasia (BPD).
• Chronic Obstructive Pulmonary Disease (COPD)- a progressive (worsening over time) disease that makes it hard to breathe; cigarette smoking is the leading cause, but long-term exposure to other lung irritants, such as air pollution, chemical fumes, or dust, also may contribute to COPD
• CLP: Contact Laboratory Program
  • the Environmental Protection Agency (EPA)'s Contact Laboratory Program (CLP) is a national network of EPA personnel, commercial laboratories, and support contractors whose fundamental mission is to provide data of known and documented quality.The CPA supports the EPA's Superfund effort originally under the 1980Comprehensive Environmental Response, Compensation, and Lability Act (CERCLA) and under the 1986 Superfund Amendments and Reauthorization Act (SARA).
• Construction Completion- This designation identifies completion of physical cleanup construction of a Superfund site, although it does not necessarily indicate whether final cleanup levels have been achieved. 
• CWA: Clean Water Act
  • The Superfund law incorporates those substances listed as hazardous water pollutants under section311 (b)(4) of the Clean Water Act (CWA) as CERCLA hazardous substances. Section 311 of the CWA also addresses pollution from oil and hazardous substance releases, providing EPA and the U.S. Coast Guard with the authority to establish a program for preventing, preparing for, and responding to oil spills and hazardous substance releases that occur in navigable waters of the United States. 
• Dendritic Cells (DCs)- an antigen-presenting leukocyte that is found in the skin, mucosa, and lymphoid tissues and that initiates a primary immune response by activating lymphocytes and secreting cytokines; a cell that has branching processes
• Density Functional Theory (DFT)- an extremely successful approach for the description of ground state properties of metals, semiconductors, and insulators; the success of density functional theory not only encompasses standard bulk materials but also complex materials such as proteins and carbon nanotubes
• Diesel exhaust particulate (DEP)- emitted during the combustion of diesel fuel are a major contributor to airborne particulate matter (PM) mass in urban areas; consists of a carbonaceous particle core onto which thousands of organic compounds can be adsorbed; a key arbiter of the adverse cardiovascular effects of air pollution.
• Dose- the amount of a substance to which a person is exposed over some time period; measurement of exposure often expressed as milligram (amount) per kilogram (a measure of body weight) per day (a measure of time) when people eat or drink contaminated water, food, or, soil
• DQO: Data Quality Objectives
  • Quantitative and qualitative statements specified to ensure that data of appropriate quantity and quality is collected during field activities to support site specific decisions.
• EJ: Environmental Justice
  • Environmental Justice (EJ) is the fair treatment and meaningful involvement of all people regardless of race, color, national origin, or income with respect to the development, implementation, and enforcement of environmental laws, regulations, and policies. 
• EPA: Environmental Protection Agency
  • EPA was established as an independent agency on December 2, 1970. The mission of the U.S. Environmental Protection Agency is to protect human health and the safeguard the natural environment air, water, and land upon which life depends. 
• Epithelial- membranous tissue composed of one or more layers of cells separated by very little intercellular substance and forming the covering of most internal and external surfaces of the body and its organs.
• ERT: Environmental Response Team
  • In 1978, the Environmental Response Team (ERT) was established under Section 311 of the Clean Water Act to provide on-site national experts as required by the National Contingency Plan (NCP) section on Special Forces.
• Electron paramagnetic resonance (EPR)- to the process of resonant absorption of microwave radiation by paramagnetic ions or molecules, with at least one unpaired electron spin, and in the presence of a static magnetic field; used to probe the "static" structure of solid and liquid systems, and is also very useful in investigating dynamic processes; also known as electron spin resonance (ESR) and electron magnetic resonance (EMR)
• E-waste- consumer and business electronic equipment that is near or at the end of its useful life; wastes which pose a threat to the environment because of certain components which some electronic products contain that render them hazardous, depending on their condition and density
• Exposure pathway- the route a substance takes from its source to its end point, and how people can come into contact with (or get exposed to) it; consists of 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), only when all five parts are present, the exposure pathway is termed a completed exposure pathway.
• FFRRO: Federal Facilities Restoration and Reuse Office
  • EPA's Federal Facilities Restoration and Reuse Office's (FFRRO) overall mission is to facilitate faster, more effective, and less costly cleanup and reuse of Federal facilities. By focusing on teamwork, innovation, and public improvement, FFRA and its Regional counterparts improve environmental cleanup, while protecting and strengthening the conditions of human health, the environment, and local economies. 
• Fine Particles (FP)- particles found in the air, including dust, dirt, soot, smoke, and liquid droplets; 2.5 micrometers in diameter and smaller and are also referred to as PM_2.5; unhealthy to breathe and have been associated with premature mortality and other serious health effects
• Free radicals- highly reactive atoms or groups of atoms with an odd (unpaired) number of electrons and can be formed when oxygen interacts with certain molecules; key danger comes from the damage they can do when they react with important cellular components such as DNA, or the cell membrane causing cells to function poorly or die
• GC-MS- Gas chromatography ("GC") and mass spectrometry ("MS"); as two combined techniques form a single method of analyzing mixtures of chemicals: GC separates the components of a mixture and MS characterizes each of the components individually which allows an analytical chemist to both qualitatively and quantitatively evaluate a solution containing a number of chemicals
• Genotoxicity- the degree to which something causes damage to or mutation of DNA
• HA: Health Advisory
  • a non-regulatory health-based reference level of chemical traces (usually in ppm) in drinking water at which there are no adverse health risks when ingested over various periods of time. Such levels are established for one day, 10 days, long-term and life-time exposure periods. They contain a wide margin of safety
• Halogenated hydrocarbons- are derivatives of hydrocarbons which include some halogen atoms (commonly Fl, Cl) within their chemical structure; some occur naturally, being synthesized by halogenation reactions occurring during combustion of biomass containing the constituent atoms but most species of halogenated hydrocarbons are synthetic, and are manufactured by humans as industrially useful materials, or are incidentally produced as a by-product during industrial chemical reactions, or during the incineration of municipal waste
• HRS: Hazard Ranking System
  • the HRS is the principal mechanism EPA uses to place waste sites on the NPL. It is numerically based screening system that uses information from initial, limited investigations - the preliminary assessment and the site inspection - to assess the relative potential of sites to pose a threat to human health or the environment.
• HSRC: Hazardous Substance Research Centers
  • Hazardous Substance Research Centers are a set of national organizations that carry out an active program of basic and applied research, technology transfer, and training involving practical problems relating to hazardous substance management.
• Hydrocarbons- precursor to ground-level ozone; emissions result from incomplete fuel combustion and from fuel evaporation
• IEUBK: Integrated Exposure Uptake Biokinetic Model
  • Integrated Exposure Uptake Biokinetic Model for Lead in Children (IEUBK) and the Technical Review Workgroup for Lead (TRW) is an interoffice workgroup convened by EPA's Office of Emergency and Remedial Response (OERR). Its goal is to support and promote consistent application of the best science in the field of lead (Pb) rick assessment at contaminated sites nationwide. This goal encompasses work to further develop and continue to refine risk assessment tools for Pb, to promote the best use of available scientific data for site assessments, and to serve as an advisor to OERR management on Pb risk assessment concerns.
• INFOTERRA- INFOTERRA is an international environmental referral and research network made up of about 175 countries coordinated by the United Nations Environmental Programme (UNEP) in Nairobi, Kenya. The U.S. National Focal Point INFOTERRA is located at the EPA HEadquarters Library and managed by the Office of Information Resources Management. 
• In vitro- made to occur in a laboratory vessel or other controlled experimental environment rather than within a living organism or natural setting
• In vivo- occurring or made to occur within a living organism or natural setting
• Ischemic heart disease- term that doctors use to describe patients who have congestive heart failure due to coronary artery disease
• Macrophages- a type of white blood that ingests foreign material; key players in the immune response to foreign invaders such as infectious microorganisms
• MCL: Maximum Containment Level
  • MCLs are standards that are set by the United States Environmental Protection Agency for drinking water quality. A Maximum Containment Level is the legal threshold limit on the amount of a hazardous substance that is allowed in drinking water under the Safe Drinking Water Act. The limit is usually expressed as a concentration in milligrams or micrograms per liter of water.
• MCLG: Maximum Contaminant Level Goal
  • The MCGL is the level of a contaminant in drinking water below which there is no known or expected risk to health. MCLG's allow for a margin of safety. MCGL's are non enforceable health goals. 
• Mean aerodynamic diameter- the average diameter of a spherical particle having a density of 1 gm/cm³ that has the same inertial properties (i.e. settling velocity) in the gas as the particle of interest
• Multiple-path particle dosimetry (MPPD)- a useful state-of-the-art tool for predicting particle dosimetry in the human lung for risk assessments by incorporating more realistic asymmetries in the lung branching structure and calculating deposition at the individual airway level; enables risk assessors to calculate doses deposited, cleared, and retained in specific parts of the human lung for a specified exposure scenario and PM concentration
• National Ambient Air Quality Standard (NAAQS)- standards for six principal pollutants considered harmful to public health and the environment which are set by the Environmental Protection Agency under The Clean Air Act; two types of national air quality standards: Primary standards set limits to protect public health, including the health of "sensitive" populations such as asthmatics, children, and the elderly, and Secondary standards set limits to protect public welfare, including protection against decreased visibility, damage to animals, crops, vegetation, and buildings
• NCP: National Contingency Plan
  • the National Oil and Hazardous Substances Pollution Contingency Plan, more commonly called the National Contingency Plan (NCP), is the federal government's blueprint for responding to both oil spills and hazardous substance releases. The National Contingency Plan is the result of our company's efforts to develop a national response capability and promote coordination among hierarchy of responders and contingency plans.
• Neutrophils- type of white blood cell that is characterized histologically by its ability to be stained by neutral dyes and functionally by its role in mediating immune responses against infectious microorganisms; accounts for about 50-80% of all the white bloods cells occurring in the human body
• NMR- paramagnetic quenching
• Non-thermal treatment- a way to treat wastes that do not involve heat processes including bio-treatment, capping, recycling, and dig and haul
• NPL:National Priorities List
  • Sites are listed in the National Priorities List (NPL) upon completion of Hazard Ranking System (HRS) screening, public solicitation of comments about the proposed site, and final placement of the site on the NPL after al comments have been addressed. The NPL primarily serves as an information and management tool. It is a part of the Superfund cleanup process and is updated periodically.
• NRD: Natural Resources Damage
  • Natural Resources Damages (NRD) are defined as injury to, destruction of, or loss of natural resources, including land, fish, wildlife, biota, air, water, ground water, drinking water supplies, that are managed by the government. The measure of damages under CERCLA and OPA is th cost of restoring injured resources to their baseline condition, and the reasonable costs of a damage assessment.
• O&M: Operations and Maintenance
  • Operations and Maintenance activities protect the integrity of the selected cleanup plan for a Superfund site, O&M measures are initiated by a State after cleanup objectives have been reached, and the site is determined to be operational and functional based on the State and Federal agreement. 
• OECA: Office of Enforcement and Compliance Assurance
  • the OECA is responsible for ensuring the compliance of the regulated community with Federal environmental statutes. To achieve that goal, OECA employs an array of approaches including regulatory enforcement, compliance assistance, and compliance incentives.
• OSRTI: Office of Superfund Remediation and Technology Innovation
  • OSRTI manages the Superfund program. The Superfund program was created to protect citizens from the dangers posed by abandoned or uncontrolled hazardous waste sites. Congress established Superfund in 1980 by passing the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA).
• OSWER: Office of Solid Waste and Emergency Response
  • the Office of the Assistant Administrator for Solid Waste and Emergency Response provides Agency-wide policy, guidance and direction for the Agency's solid waste and emergency response programs. 
• Oxidative Stress (OS)- caused by an imbalance between the production of reactive oxygen and a biological system's ability to readily detoxify the reactive intermediates or easily repair the resulting damage
• Oxidize- To combine with oxygen; make into an oxide; to increase the positive charge or valence of (an element) by removing electrons.
• PA/SI: Preliminary Assessment/Site Inspection
  • The Preliminary Assessment (PA) and Site Inspection (SI) are used by EPA to evaluate the potential for a release of hazardous substances from a site. 
• P450 enzymes- a large family of oxidative enzymes that are widespread in nature
• Particulate Matter (PM)- solid or liquid particles found in the air; some are large or dark enough to be seen as soot or smoke, but fine particulate matter is tiny and is generally not visible to the naked eye; mobile source particulate emissions consist mainly of these very tiny particles, also known as PM2.5, because they are less than 2.5 microns in diameter
• PBCDD/Fs- polybrominated/chlorinated dibenzo-p-dioxins/furans ; tend to bind to organic matter in sediments and soils, accumulate in fatty tissues, and they can be transported over long distances from the source of emission; in the environment, they can be quickly transported great distances through evaporation and condensation cycles.
• PCDD/Fs- polychlorodibenzo-p-dioxins and dibenzofurans; in the dioxin family of toxic substances; most dioxins unintentionally produced as byproducts of chemicals and other products; enter the body through breathing contaminated air and drinking contaminated water though eating contaminated food accounts for About 90% of dioxin exposure because of its ability to accumulate in fatty tissue
• PCP- pentachlorophenol; a man made colorless crystal; formerly used as a biocide to kill small organisms, but is now used as a wood preservative to protect wood from decay and insect attack; can enter the system by inhalation, eating or drinking contaminated food or water, or through skin contact; exposure may cause damage to liver, kidneys, blood, lungs, nervous system, immune system and gastrointestinal tract; direct contact may irritate skin, eyes, and mouth
• Persistent Free Radicals (PFRs)- a type of free radical that persist in the air for days or longer
• Persistence- environmental persistence refers to the length of time a substance resides in environmental media and is usually defined in terms of half-life or residence time
• Post Construction Completion- Ensures that Superfund response actions provide for the long-term protection of human health and the environment. Included here are Long-Term Response Actions (LTRA), Operations and Maintenance, Institutional Controls, Five-Year Reviews, Remedy Optimization.
• PRP: Potentially Responsible Parties
  • The Superfund law (CERCLA) allows EPA to respond to releases or threatened releases of hazardous substances into the environment. Under CERCLA, potentially responsible parties are expected to conduct or pay for the cleanup. The Superfund enforcement program identifies PRPs at the site; negotiates with PRPs to do the cleanup; and recovers from PRPs the costs spent by EPA at Superfund cleanups.
• Physisorption- (or physical adsorption) is adsorption in which the forces involved are intermolecular forces of the same kind as those responsible for the imperfection of real gases and the condensation of vapors, and which do not involve a significant change in the electronic orbital patterns of the species involved
• Polyaromatic hydrocarbon (PAH)-  found in materials that do not combust completely; some can cause cancer
• Polyhalogenated substances- general term for a group of compounds which has many toxic and carcinogenic industrial chemicals as members; compounds with multiple substitutions of halogens; generally highly reactive and also bioaccumulate in humans
• Principal Organic Hazardous Constituents (POHCs)- hazardous compounds monitored during an incinerator's trial burn, selected for high concentration in the waste feed and difficulty of combustion
• Products of Incomplete Combustions (PICs)- organic compounds formed by combustion; usually generated in small amounts and sometimes toxic, PICs are heat-altered versions of the original material fed into the incinerator (e.g. charcoal is a P.I.C. from burning wood)
• PXDD/Fs- chlorinate/brominated dibenzo-p-dioxins and dibenzofurans
• RAGS: Risk Assessment Guidance for Superfund
  • The multi-volume series of guidance documents developed by EPA that provide the foundation for the various aspects of risk assessment conducted at Superfund sites.
• RCRA: Resource Conservation and Recovery Act
  • The primary goals of the Resource Conservation and Recovery Act are to protect human health and the environment from the potential hazards of waste disposal, to conserve energy and natural resources, to reduce the amount of waste generated, and to ensure that wastes are manages in an environmentally sound manner.
• RD/RA: Remedial Design/Remedial Action 
  • Remedial Design is the phase in Superfund site cleanup where the technical specification for cleanup remedies and technologies are designed. Remedial Action (RA) follows the remedial design phase and involves the actual construction or implementation phase of Superfund site cleanup. The RD/RA is based on the specifications described in the record of decision (ROD).
• Reactive Nitrogen Species (RNS)- are a family of antimicrobial molecules derived from nitric oxide and primarily expressed in macrophages after induction by cytokines and microbial products, notably interferon-gamma (IFN-γ) and lipopolysaccharide (LPS); formed naturally and anthropogenicly
• Reactive Oxygen Species (ROS)- phrase used to describe a number of reactive molecules and free radicals derived from molecular oxygen; have a role in cell signaling, including; apoptosis; gene expression; and the activation of cell signaling cascades
• Redox-cycling- A wide variety of aromatic compounds are enzymatically reduced to form free radicals that contain one more electron than their parent compounds. In general, the electron donor is any of a wide variety of flavoenzymes and their coenzymes. Once formed, these anion free radicals reduce molecular oxygen to superoxide, and regenerate the unchanged parent compound. The net reaction is the oxidation of the flavoenzyme's coenzymes and the reduction of molecular oxygen to form superoxide. This catalytic behavior has been described as futile cycle or redox cycling.
• Residual oil fly-ash (ROFA)- a transition metal-rich emission source
• Resource Conservation and Recovery Act (RCRA)- The primary goals are to protect human health and the environment from the potential hazards of waste disposal; to conserve energy and natural resources; to reduce the amount of waste generated; and to ensure that wastes are managed in an environmentally sound manner
• RI/FS: Remedial Investigation/ Feasibility Study
  • Adter a site is listed on the NPL, a remedial investigation/feasibility study is performed at the site. The RI serves as the mechanism for collecting data, while the FS is the mechanism for the development, screening, and detailed evaluation of alternative remedial actions. The RI and FS are conducted concurrently. Date collected in the RI influence the development of remedial alternatives in the FS, which in turn affect the data needs and scope of treatability studies and additional field investigations.
• Reuse Site Reuse/Redevelopment
  • information on how the Superfund program is working with communities and other partners to return hazardous waste sites to safe and productive use without adversely affecting the remedy.
• ROD: Record of Decision
  • the Record of Decision is a public document that explains which cleanup alternatives will be used to clean up a Superfund site. The ROD for sites listed on the NPL is created form information generated during the RI/FS.
• SARA: Superfund Amendments and Reauthorization Act
  • SARA amended the CERCLA on October 17, 1986. SARA reflected EPA's experience in administering the complex Superfund program during its first six years and made several important changes and additions to the program.
• SCDM: Superfund Chemical Data Matrix
  • The SCDM is a source for factor values and benchmark values applied when evaluating National Priorities List sites using Hazardous Ranking System. 
• SuperJTI: Superfund Job Training Initiative
  • The mission of SuperJTI is to provide or support job training opportunities for economically disadvantaged citizens living in communities affected by Superfund sites, and encourages their employment in site cleanup activities. 
• Superfund- Another name for the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA).
• TAB: Technical Assistance to Brownsfield Communities
  • TAB helps communities to clean and redevelop properties that have been damaged or undervalued by environmental contamination. The purpose of these efforts is to create bettor jobs, increase the local tax base, improve neighborhood environments,and enhance the overall quality of life. 
• TAG: Technical Assistance Grants
  • a TAG provides money for activities that help communities participate in decision-making at eligible Superfund sites. An initial grant up to $50000 is available for any Superfund site that is on the National Priorities List (NPL) or proposed for listing on the NPL and a response action has begun.
• TRW: Technical Review Workgroup for Lead
  • TRW and the Integrated Exposure Uptake Biokinetic Model for Lead in Children is an interoffice workgroup convened by the U.S. EPA Office of Solid Waste and Emergency Response/Office of Emergency and Remedial Response. Its goal is to support and promote consistent application of the best science in the field of lead risk assessment at contaminated sites nationwide. 
• TUNEL staining- used for detection and quantification of apoptosis (programmed cell death) at single cell level, based on labeling of DNA strand breaks
• Ultrafine Particulate Matter (UFP)- <0.2 um in diameter
• UST: Underground Storage Tank
  • An underground storage tank system is a tank and any underground piping connected to the tank that has at least 10 % of its combined volume underground. Under RCRA, EPA has established regulatory programs to prevent, detect, and clean up releases from USTs containing petroleum or hazardous substances.
• Western blot analysis- a technique that quantifies the amount of a protein in a cell extract by first separating the cell proteins using gel electrophoresis and then “blotting” the resultant spots onto a thin nitrocellulose or nylon membrane 

 

American Chemistry . American Chemistry Council, Inc. , 2009 . Web. 16 Nov.

     2009. <http://www.americanchemistry.com>.

CBS News. N.p., 2009 . Web. 16 Nov. 2009. <http://www.CBSnews.com >.

Dictionary.com, An Ask.Com Service . N.p., 2009 . Web. 16 Nov. 2009.

     <http://dictionary.reference.com/>.

Encyclopedia Britannica, Inc. . N.p., 2009 . Web. 16 Nov. 2009.

     <http://www.britannica.com/ >.

George Mason University . George Mason University , 2009 . Web. 16 Nov. 2009.

     <http://gmu.edu/>.

New Hampshire Department of Environmental Services . State of New Hampshire,

     2008 . Web. 16 Nov. 2009. <http://des.nh.gov/ >.

Richards, Ira S. "Principles and Practice of Toxicology in Public Health ."

     Science Direct . Jones and Bartlett, 2008. Web. 16 Nov. 2009.

     <http://www.sciencedirect.com>.

U.S. Environmental Protection Agency. N.p., 2009. Web. 16 Nov. 2009.

     <http://www.epa.gov/>.