Background Level 01
Background Level 01 : (a) (1) Anthropogenic: concentrations of chemicals that are present in the environment due to human-made, non-site sources; (2) Naturally Occurring: ambient concentrations of chemicals that are present in the environmental and have not been influenced by humans. [AIHA, 2000: Risk Assessment Principles for the Industrial Hygienist, attributed to the Risk Assessment Guidance for Superfund, USEPA 1989]; (b) A typical or average level of a chemical in the environment. Background often refers to naturally occurring or uncontaminated levels. [ATSDR, 1999: Online Glossary] [New York Department of Health, 1999: Glossary of Environmental Health Terms]; (c) Two types of background levels may exist for chemical substances: . (1) Naturally occurring levels: Ambient concentrations of substances present in the environment, without human influence; (2) Anthropogenic levels: Concentrations of substances present in the environment due to human_made, non_site sources (e.g., automobiles, industries). [IRIS, 1999: Glossary of IRIS Terms]; (d) (1) In air pollution, the level of pollutants present in ambient air from natural sources. (2) More generally, the level of pollution present in any environmental medium attributable to natural or ubiquitous sources. [SRA, 1999: Glossary of Risk Analysis Terms, attributed to Stephen L. Brown] [USDOE, 2000: RAIS Glossary]; (e) The concentration of substance in a defined control area during a fixed period of time before, during, or after a data-gathering operation. [USEPA, 1992: GL for Exposure Assessment]; (f) (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.. [USEPA, 1997a: EPA Terms of Environment]
No records Found