Abatement – The reduction in degree or intensity of pollution.
Absorbed Dose – The amount of a substance absorbed into the body, usually, per unit of time. The most common unit of dose is mg per kg body weight per day (mg/kg-day).
Absorption – The penetration of one substance into or through another: specifically, the penetration of a substance into the body from the skin, lungs, or digestive tract.
Acceptable Daily Intake – An estimate of the daily exposure dose that is likely to be without deleterious effect even if continued exposure occurs over a lifetime.
Air Acidification – Sulphur dioxide, nitrous oxides other acidic emissions to air cause an increase in the acidity of rainwater, which in turn acidifies lakes and soil. These acids can make the land and water toxic for plants and aquatic life. Acid rain can also slowly dissolve manmade building materials such as concrete. This impact is typically measured in units of either kg sulphur dioxide equivalent (S02e), or moles H+ equivalent.
Acute – Diseases or responses with short and generally severe course (often due to high pollutant concentrations).
Acute Exposure – A single exposure to a toxic substance which results in severe biological harm or death. Acute exposures are usually characterized as lasting no longer than a day, as compared to longer, continuing exposure over a period of time.
Added Risk – The difference between the cancer incidence under the exposure conditions compared with incidence under background conditions.
Aerobic – Life or processes that require, or are not destroyed by, the presence of oxygen.
Air Emissions – The release or discharge of a pollutant (from a stationary source) into the ambient air. For anthropogenic sources this may involve release (1) by means of a stack or (2) as a fugitive dust, mist or vapour as a result inherent to the manufacturing or formulating process. Pollutants may also be discharged from mobile sources, from area sources such as roads and fields, and from non-manufacturing, stationary sources.
ALARA(ref ALARP): Acronym for “As Low As 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 – US term).
Anaerobic: A life or process that occurs in, or is not destroyed by, the absence of oxygen.
Anthropogenic: Of human origin.
Attributable Risk: The rate of a disease in exposed individuals that can be attributed to the exposure. This measure is derived by subtracting the rate (usually incidence or mortality) of the disease among non-exposed persons from the corresponding rate among exposed individuals.
Benign: Not malignant; remaining localized.
Bias: Any difference between the true value and that actually obtained due to all causes other than sampling variability.
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.
Carbon Footprint – Carbon-dioxide and other gasses which result from the burning of fossil fuels accumulate in the atmosphere which in turn increases the earth’s average temperature. Carbon footprint acts as a proxy for the larger impact factor referred to as Global Warming
Potential (GWP). Global warming is blamed for problems like loss of glaciers, extinction of species, and more extreme weather, among others.
Carcinogen: A substance or agent that produces or incites cancerous growth.
Carcinogenic Potency: The gradient of the dose-response curve for a carcinogen.
Chronic: Having a persistent, recurring or long-term nature (opposite to acute).
Collective Dose: The sum of the individual doses received on a given period of time by a specified population from exposure to a specified source.
Cost-benefit Analysis: A formal quantitative procedure comparing costs and benefits of a proposed project or act under a set of pre-established rules. To determine a rank ordering of projects to maximize rate of return when available funds are unlimited, the quotient of benefits divided by costs is the appropriate form; to maximize absolute return given limited resources, benefits-costs is the appropriate form.
Cradle-to-Grave or Manifest System: A procedure in which hazardous materials are identified and followed as they are produced, treated, transported, and disposed of by a series of permanent, linkable, descriptive documents (e.g., manifests).
De Minimis Risk: From the legal maxim “de minimis non curat lex” or “the law is not concerned with trifles.”
Deterministic Effect: The health effects, the severity of which varies with the dose and for which a threshold is believedto exist. Radiation-induced cataract formation is an example of a deterministic effect (also called a nonstochastic effect).
Dose-response: A correlation between a quantified exposure (dose) and the proportion of a population that demonstrates a specific effect (response).
Environment: Water, air, land, and all plants and man and other animals living therein, and the interrelationships which exist among them.
Environmental Pathway: All routes of transport by which a toxicant can travel from its release site to human populations including air, food chain, and water. The connected set of environmental media through which a potentially harmful substance travels from source to receptor.
Epidemiology: The study of the distribution and dynamics of diseases and injuries in human populations. Specifically, the investigation of the possible causes of a disease and its transmission.
Externalities: Benefits or costs, generated as a by-product of an economic activity, that do not accrue to the parties involved in the activity.
Greenhouse Effect: The warming of the Earth’s atmosphere attributed to a build-up of carbon dioxide or other gases; some scientists think that this build-up allows the sun’s rays to heat the Earth, while infra-red radiation makes the atmosphere opaque to a counterbalancing loss of heat.
Hazard: A condition or physical situation with a potential for an undesirable consequence, such as harm to life or limb.
Hazard Assessment: An analysis and evaluation of the physical, chemical and biological properties of the hazard.
HI (hazard index): Potential non-carcinogenic (systemic) effects are characterized by comparing projected intakes of
chemicals to toxicity values (i.e., reference doses). The numerical risk or hazard quotient estimates that results is
a ratio. The ratio of the intake over the reference dose (hazard index) is compared to unity (1.0).
Hormesis: The notion that small doses of radiation can be healthful.
Individual Risk: The risk to an individual rather than to a population.
In Vitro: Outside the living organism. Literally, in glass.
In Vivo: Within the living organism.
Latency Period: The period of time from exposure to an agent to the onset of a health effect.
Leachate: Liquid that has percolated through solid waste and has extracted dissolved or suspended materials from it.
Leaching: The process by which nutrient chemicals or contaminants are dissolved and carried away by water, or are moved into a lower layer of soil.
Lifecycle Analysis: Studying the environmental impacts of a product/service from “cradle to grave.”
Lifetime Exposure: Total amount of exposure to a substance that a human would receive in a lifetime (usually assumed to be 70 years).
Logit Model: A dose-response model which, like the probit model, leads to an S-shaped dose-response curve, symmetrical about the 50% response point. The logit model leads to lower “very safe doses” than the probit model even when both models are equally descriptive of the data in the observable range.
Log-probit Model: A dose-response model which assumes that each animal has its own threshold dose, below which no response occurs and above which a tumour [or other effect] is produced by exposure to a chemical.
Lowest-Observed-Adverse-Effect-Level (LOAEL): The lowest dose in an experiment which produced an observable adverse effect.
Malignant: Tending to become progressively worse and to result in death if not treated; having the properties of anaplasia, invasiveness, and metastasis.
Morbidity: A departure from a state of physical or mental well-being, resulting from disease or injury. Frequently used only if the affected individual is aware of the condition. Awareness itself connotes a degree of measurable impact. Frequently, but not always, there is a further restriction that some action has been taken such as restriction of activity, loss of work, seeking of medical advice, etc.
Mortality: Death; the death rate; ratio of number of deaths to a given population.
Mortality Rate: The number of deaths that occur in a given population during a given time interval; usually deaths per 103 or 105 people per year. Can be age, sex, race, and cause specific.
No Observable Adverse Effect Level (NOAEL): From long-term toxicological studies of agriculture chemical active ingredients, levels at which indicate a safe, lifetime exposure level for a given chemical. Used to establish tolerance for human diets. Also written, NOEL.
One-hit Model: The basic dose-response model based on the concept that a tumour can be induced by a single receptor that has been exposed to a single quantum or effective dose unit of a chemical.
Ozone: Three-atom oxygen compound (03) found in two layers of the Earth’s atmosphere. One layer of beneficial ozone occurs at 7 to 18 miles above the surface and shields the Earth from ultraviolet light. Several holes in this protective layer have been documented by scientists. Ozone also concentrates at the surface as a result of reactions between by-products of fossil fuel combustion and sunlight, having harmful health effects.
Particulates: Visible air pollutants consisting of particles appearing in smoke or mist.
Person-year: The sum of the number of years each person in the study population is at risk; a metric used to aggregate the total population at risk assuming that 10 people at risk for one year is equivalent to 1 person at risk for 10 years.
Population at Risk: A limited population that may be unique for a specific dose-effect relationship; the uniqueness may be with respect to susceptibility to the effect or with respect to the dose or exposure itself.
Primary Energy: The energy that is embodied in resources as they exist in nature (e.g., coal, crude oil, natural gas, or sunlight). For the most part, primary energy is transformed into electricity or fuels such as gasoline or charcoal. These, in turn, are referred to as secondary or site energy.
Probit Analysis: A statistical transformation which will make the cumulative normal distribution linear. In analysis of dose-response, when the data on response rate as a function of dose are given as probits, the linear regression line of these data yields the best estimate of the dose-response curve. The probit unit is y = 5 + Z(p) , where p = the prevalence of response at each dose level and Z(p) = the corresponding value of the standard cumulative normal distribution.
Quadrillion Btu (Quad): Equivalent to 10 to the 15th power Btu (1 quad = 1.055 x 10e18 joules).
Reference Concentration (RfC): An estimate (with uncertainty spanning perhaps an order of magnitude) of a continuous inhalation exposure to the human population (including sensitive subgroups) that is likely to be without an appreciable risk of deleterious non-cancer effects during a lifetime.
Risk: The product of: impact of severity (consequence) and impact of likelihood (probability). Specifically for carcinogenic effects, risk is estimated as the incremental probability of an individual developing cancer over a lifetime as a result of exposure to a potential carcinogen. Specifically for non-carcinogenic (systemic) effects, risk is not expressed as a probability but rather is evaluated by comparing an exposure level over a period of time to a reference dose derived for a similar exposure period.
Source: A place where pollutants are emitted, for example a chimney stack.
Systemic Effects: Systemic effects are those that require absorption and distribution of the toxicant to a site distant from its entry point, at which point effects are produced. Most chemicals that produce systemic toxicity do not cause a similar degree of toxicity in all organs, but usually demonstrate major toxicity to one or two organs. These are referred to as the target organs of toxicity for that chemical. Systemic effects do not include cancer.
Threshold Limit Value (TLV): Refers to airborne concentrations of substances and represents conditions under which it is believed that nearly all workers are protected while repeatedly exposed for an 8-hr day, 5 days a week (expressed as parts per million (ppm) for gases and vapors and as milligrams per cubic meter (mg/m3) for fumes, mists, and dusts).
Water Eutrophication – When an over abundance of nutrients are added to a water ecosystem, eutrophication occurs. Nitrogen and phosphorous from waste water and agricultural fertilizers causes an overabundance of algae to bloom which then depletes the water of oxygen and results in the death of both plant and animal life. This impact is typically measured in either kg phosphate equivalent (P04e) or kg nitrogen (N) equivalent.