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Frequently Asked Questions and Answers

Community-Based Environmental Program

Q: What EPA information is available on community-based environmental work ?

A: The Office of Pollution Prevention and Toxics (OPPT) sponsors a variety of community-based programs which are designed to address environmental problems faced by communities by linking government with citizens and other stakeholders to achieve long-term environmental preservation and sustainable economic development.

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Environmental Fate

Q: Where can I find data for half-life and biodegradation rate of toxic substances in atmosphere, soil and surface water ?

A: While EPA does not endorse the use of any specific database, EPA believes the following basic information may be helpful in searching for data for these endpoints. You should always carefully evaluate the quality of the data and applicability of the data to your specific use. Many databases serve as a convenient source of extracted data but we recommend that users carefully evaluate and use primary sources to the extent possible.

Syracuse Research Corporation DatabasesExit Disclamer

The Environmental Fate Data Base (EFDB), developed and maintained by Syracuse Research Corporation (SRC), is a source of extracted data as well as pointers (references) to data on environmental chemistry, fate, and properties of chemicals. EFDB has been funded for many years by EPA/OPPT and others and is now available free to users via SRC's website.

PHYSPROP is a database that contains basic chemical property data on more than 40,000 chemicals. This has also been published in hard copy (book) form, authors PH Howard and WM Meylan: Handbook of Physical Properties of Organic Compounds (CRC Press: Boca Raton, FL)(1997). Further information may be found on the SRC website.

The Hazardous Substances Data Bank (HSDB)Exit Disclamer

The National Library of Medicine has developed a source of online information in the Hazardous Substances Data Bank. These records are often helpful because they contain evaluated and synthesized information.

Hard copy data sources

There are many hard copy sources of fate and chemical property data. SRC has published a series of handbooks, as have Prof. Donald Mackay and colleagues at Trent University, Peterborough, Ontario, Canada. The publisher is CRC Press in both cases. Publication details are available from SRC (for their handbooks) or directly from the publisher: CRC Press LLC, 2000 Corporate Blvd., NW, Boca Raton, FL 33431 (http://www.crcpress.com). The handbooks are also available on CD-ROM.

The Handbook of Environmental Degradation Rates, authors PH Howard, RS Boethling, WF Jarvis, WM Meylan, EM Michalenko (Lewis: Boca Raton, FL) (1991) is a data source containing abbreviated records for several hundred (mostly US Toxics Release Inventory) chemicals. The records have measured values from the literature and/or estimates of half-lives for the various environmental fate processes (biodegradation, photolysis, etc) as well as for key environmental compartments (soil, water, air). This enables the user to identify a half-life for the dominant fate process or processes for a given chemical, which may be needed for input to models.

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Exposure Assessment

Q: What other EPA information is available on exposure assessment ?

A: . The Human Exposure & Atmospheric Sciences Division conducts intramural and extramural research to characterize exposures, across the whole of the exposure assessment paradigm from the pollutant source to the exposed person or receptor.
     . US EPA held a workshop on the Relationship between Exposure Duration and Toxicity.
     . The Chemical Exposure Branch conducts research which is designed to reduce uncertainty in risk assessment by providing analytical methods to measure human exposure and provide data on human exposure.
     . The Wildlife Exposure Factors Handbook provides data, references, and guidance for conducting exposure assessments for wildlife species exposed to toxic chemicals in their environment.
     . The Exposure Factors Handbook provides a summary of the available statistical data on various factors used in assessing human exposure.
     . The Guidelines for Exposure Assessment describe the general concepts of exposure assessment including definitions and associated units, and by providing guidance on the planning and conducting of an exposure assessment.

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Health Effects of Chemicals

Q: Where can I find information on the health effects of chemicals in my work place ?

A: It's very important that you understand the possible hazards of the chemicals in your workplace, and that you take the necessary precautions to use those chemicals appropriately. Your employer may have information on the possible health effects of the chemicals you are working with, and how to protect yourself when using them. If you believe that the chemical is coming from a specific chemical product, a Material Safety Data Sheet (MSDS) may be available and your employer must make these available to employees. The MSDSs generally provide some useful information for discussing issues with physicians, government agencies, or the employer. You may want to ask for that information if you have not already done so. Exposure to chemicals at work are the primary responsibility of the Occupational Safety and Health Administration (OSHA) and the National Institute for Occupational Safety and Health (NIOSH). EPA's Office of Pollution Prevention and Toxics (OPPT) has responsibility for evaluating and managing risks to new chemicals prior to introduction in the marketplace.

  1. You may contact OSHA to obtain answers to safety and health related issues, to report accidents and unsafe working conditions, and for information on laws, policy, etc. Certain States are covered by OSHA State Plans. If you work in a State covered by one of these plans, you should contact the OSHA State Plan. If you are not covered by an OSHA State Plan, you should contact the nearest OSHA Area Office or Consultation Program. Here is a link to the OSHA website where you can find information to contact the appropriate OSHA office.

  Contact Occupational Safety & Health Administration (OSHA)Exit Disclamer

  OSHA also has a toll free phone number which may be helpful. The telephone number is 1-800-321-OSHA.

  2. NIOSH conducts field investigations of possible health hazards in the workplace in response to requests from employees, authorized representatives of employees, or employers to determine whether any substance found in the workplace has potentially toxic effects in such concentrations as used or found. These field investigations are called Health Hazard Evaluations. Here is a link to the NIOSH Health Hazard Evaluation website where you can find information on Health Hazard Evaluations and a variety of safety and health topics.

  National Institute for Occupational Safety and Health, (NIOSH)Exit Disclamer

  NIOSH also has an 800 number staffed by scientists who answer questions about workplace issues. You might find this to be helpful. The telephone number is 1-800-35-NIOSH.

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Q: What other EPA information is available on models ?

A: . A Dietary Exposure Potential Model has been developed to correlate extant food information in a format for dietary exposure modeling.
     . The EMSOFT: Exposure Model for Soil-Organic Fate and Transport User's Guide describes a computer screening model that may be used 1) to determine concentrations of contaminants remaining in the soil over a given time (when the initial soil concentration is known); 2) to quantify the mass flux (rate of transfer) of contaminants into the atmosphere over time; and 3) to subsequently calculate contaminant air concentrations by inputting mass flux values into atmospheric dispersion models.
     . The Support Center for Regulatory Air Models offered information on atmospheric dispersion (air quality) models that support regulatory programs required by the Clean Air Act. Documentation and guidance for these computerized models are a major feature of this website.

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Risk Assessment

Q: What other EPA information is available on risk assessment ?

A: . National Center For Environmental Assessment has developed some examples of risk assessments and risk tools.
      . The Radiation Protection Program provides methods and scientific basis for radiation exposure, dose and risk assessments.
     . The U.S. EPA has issued policy for use of probabilistic analysis in risk assessment
     . A report summarizes the current understanding of dose-duration relationships, the approaches that can be used in their modeling, the inclusion of these relationships in risk assessment, and future directions in this area.
     . NCEA's Ecological Assessment Program develops guidelines, assessments, and methods that quantify risks to ecosystems from multiple stressors at multiple scales and multiple endpoints.

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