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Water: Microbial

Thesaurus of Terms Used in Microbial Risk Assessment: 5.14 EPA Terms

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  1. Nutrient-rich organic materials resulting from the treatment of domestic sewage in a treatment facility. When treated and processed, these residuals can be recycled and applied as fertilizer to improve and maintain productive soils and stimulate plant growth. Biosolids are treated sewage sludge. Biosolids are carefully treated and monitored and must be used in accordance with regulatory requirements. (EPA 2006)
  2. The organic product that results from sewage treatment processes (otherwise referred to as sewage sludge) (NSWEPA 2004)
  3. Biosolids products: organics containing any component of biosolids, including pure biosolids in the form of liquid or cake, or derived organics such as compost, lime sludges or pellets (NSWEPA 2004)
    RELATED TERMS: sludge
cancer slope factor          (ACRONYM: CSF)

An upper bound (approximating a 95% confidence limit) on the increased cancer risk from a lifetime exposure to an agent. This estimate, usually expressed in units of proportion (of a population) affected per mg/kg/day, is generally reserved for use in the low-dose region of the dose-response relationship; that is, for exposures corresponding to risks less than 1 in 100. This term is usually used to refer to oral slope factors (i.e., slope factors used for assessing ingestion exposure). (EPA 2004)

critical concentration

An ambient chemical concentration expressed in units of g/m3 and used in the operational derivation of the inhalation RfC. This concentration will be the NOAEL Human Equivalent Concentration (HEC) adjusted from principal study data. (EPA 2003)

critical study

The study that contributes most significantly to the qualitative and quantitative assessment of risk. Also called Principal Study. (EPA 2003)

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  1. Waste material being discharged into the environment, either treated or untreated. Effluent generally is used to describe water discharges to the environment, although it can refer to stack emissions or other material flowing into the environment. (EPA 1992)
  2. Wastewater—treated or untreated—that flows out of a treatment plant, sewer, or industrial outfall. Generally refers to wastes discharged into surface waters. (EPA 2005b)
  3. Wastewater discharged from a point source, such as a pipe. (EPA 2005e)
  4. Treated or untreated liquid waste material that is discharged into the environment from a point source, such as a wastewater treatment plant or an industrial facility. (NCSU 1997)
  5. Waste material discharged into the environment, treated or untreated. Generally refers to water pollution. (SRA 2004)
health assessment

An evaluation of available data on existing or potential risks to human health posed by a Superfund site. The Agency for Toxic Substances and Disease Registry (ATSDR) of the Department of Health and Human Services (DHHS) is required to perform such an assessment at every site on the National Priorities List. (EPA 2005b)

health consultation

In a public health assessment, 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. (EPA 2004)

limited evidence

A term used in evaluating study data for the classification of a carcinogen by the 1986 U.S. EPA guidelines for carcinogen risk assessment. This classification indicates that a causal interpretation is credible but that alternative explanations such as chance, bias, and confounding variables could not be completely excluded. (EPA 2003)

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lines of evidence

Information derived from different sources or by different techniques that can be used to describe and interpret risk estimates. Unlike the term “weight of evidence,” it does not necessarily assign quantitative weights to information. (EPA 1998a)

maximum individual risk          (ACRONYM: MIR)

An MIR represents the highest estimated risk to an exposed individual in areas that people are believed to occupy. (EPA 2004)
RELATED TERMS: worst case

nonpoint source
  1. A diffuse pollution source (i.e., without a single point of origin or not introduced into a receiving stream from a specific outlet). The pollutants are generally carried off the land by storm water. Common non-point sources are agriculture, forestry, urban, mining, construction, dams, channels, land disposal, saltwater intrusion, and city streets. (EPA 2005b)
  2. A contributing factor to water pollution that cannot be traced to a specific spot; like agricultural fertilizer runoff, sediment from construction. (SRA 2004)

Any substances in water, soil, or air that degrade the natural quality of the environment, offend the senses of sight, taste, or smell, or cause a health hazard. The usefulness of the natural resource is usually impaired by the presence of pollutants and contaminants. (EPA 2005e)

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residual risk

The extent of health risk from air pollutants remaining after application of the Maximum Achievable Control Technology (MACT). (EPA 2004)


A semi-solid residue from any of a number of air or water treatment processes; can be a hazardous waste. (EPA 2005b)

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