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Frequent Questions
- What kind of results does RSEI provide?
- Why examine risk-related results?
- How does RSEI differ from a formal risk assessment?
- Has RSEI been peer reviewed?
- What kinds of analyses has RSEI been used for?
- Who is using RSEI?
- What is new in RSEI Version 2.2.0?
- What chemicals are included in the model?
- What data sources were used for the toxicity values in the RSEI model?
- What are the strengths and limitations of the RSEI model?
- Where can I find out more about the model?
- Has the Risk-Screening Environmental Indicators model ever been known by another name?
What kind of results does RSEI provide?
RSEI provides a full risk-related perspective for air and water
releases, and hazard-based and pounds-based perspectives releases
to air, water, and land. The full risk-related perspective covers
over 400 chemicals and chemical categories, and over 50,000
reporting facilities (over all 19 years). RSEI also contains important
information databases (chemical, facility, census, etc.) that are
fully accessible within and outside the model. RSEI has multi-faceted
outputs including geographic information system (GIS) mapping, graphs, sorted lists, and tables,
etc. These outputs are exportable to other software applications
for additional customizing.
Why examine risk-related results?
Reducing risk is a goal of the US Environmental Protection Agency,
states, communities, and the general public. Risk-related assessments
aid in allocating resources for maximizing risk reduction. Pounds-based,
hazard-based and risk-related perspectives give very different results.
Using pounds of releases as a risk surrogate incorrectly assumes
that all chemicals are equally toxic and that every person is equally
exposed.
How does RSEI differ from a formal
risk assessment?
Formal risk assessments are complicated and time consuming to perform,
and often require detailed data which are not always available.
They are often limited in scope and geographic area. The risk-related
estimates produced by RSEI do consider the important factors of
risk assessment, but do not address every potential factor. RSEI results are meaningful only in comparison to other RSEI results, and do not describe a specific level of risk.
Has RSEI been peer-reviewed?
The original model was reviewed by outside risk assessment experts
in 1991, and submitted for Agency review and public comment in 1992.
RSEI has undergone three reviews by EPA's Science Advisory Board:
the overall methodology was reviewed in 1997, and the toxicity weighting
system was reviewed separately twice. In addition, states reviewed
the model and submitted comments in 1999, and model versions underwent
beta testing in 1999, 2001, and 2002.
What kinds of analyses has RSEI been
used for?
Risk, compliance, and EJ analysis of Federal facilities reporting
to TRI (June 1997). Industry sector- and facility-based targeting
and strategic planning by several EPA offices. Outside analysts
have investigated:
- impact of regulations on cross-media risk transfers;
- national environmental justice (EJ) issues;
- community-based environmental protection;
- toxicity weights used for priority ranking at local level;
- assess disproportionate impacts on local population.
Examples of data analysis charts by Region 4 using RSEI are available.
- Office of Water - effluent guidelines development;
- Office of Enforcement and Compliance Assurance - risk-related targeting;
- EPA Regions - environmental justice; risk-related targeting; Regional reports; etc.;
- Department of Defense - geographic health correlations;
- States - P2 technical assistance; risk ranking; risk reduction efforts;
- Environmental Defense Scorecard
; - Companies, facilities - performance tracking.
What is New in RSEI Version 2.2.0?
- Installation CD includes 1996-2006;
- Updated air modeling program (AERMOD);
- Additional information on drinking water intakes;
- Updated toxicity weights and a new toxicity source (EPA's PPRTV system).
What chemicals are included in the
model?
The installation package for Version 2.2.0 of the model incorporates TRI chemicals for the years
1996 through 2006. Data for years 1988-1995 are available upon request. There are 611 discrete chemicals and chemical
categories. The model includes toxicity data for 430 of these chemicals.
What data sources were used for the
toxicity values in the RSEI model?
The following data sources were used, in order of preference:
- EPA's Integrated Risk Information System (IRIS);
- EPA Office of Pesticide Programs' Toxicity Tracking Reports (OPP);
- Agency for Toxic Substances and Disease Registry final, published chronic MRLs (ATSDR);
- California Environmental Protection Agency's Office of
Environmental Health Hazard Assessment final, published toxicity
values (Cal/EPA);
- EPA’s Provisional Peer Reviewed Toxicity Values (PPRTVs), which include toxicity values that have been developed by EPA’s Office of Research and Development/National Center for Environmental Assessment/Superfund Health Risk Technical Support Center (STSC);
- EPA's Health Effects Assessment Summary Tables (HEAST);
- Final Derived/Interim Derived Toxicity Weights (Derived) estimated by EPA's Office of Pollution Prevention and Toxics.
What are the strengths and limitations of the RSEI
model?
RSEI provides a sophisticated approach to incorporating a risk-related perspective when analyzing the impacts of chemical releases; however, as a screening-level tool, RSEI should be supplemented with additional analyses. For more information, see Strengths and Limitations of the RSEI Model.
Where can I find out more about the
model?
The methodology underlying the Risk-Screening Environmental Indicators
is described in detail in the Methodology
Document (PDF) (85 pp,
328K, About PDF). The User's
Manual (PDF) (184
pp, 1.7 MB, About PDF) describes the model more generally and provides instruction on using the model interface.
Has the Risk-Screening Environmental
Indicators model ever been known by another name?
Yes, the original project name was 'TRI Relative Risk-Based Environmental
Indicators'.