New Database Software Aids Environmental Assessments During Spill Responses
Adriana Bejarano, Research Planning Inc., James Farr, Federal Government, Valerie Chu, Genwest Systems Inc.
Centralized database repositories of fate and effects data are important tools used to support environmental decisions, including those involving chemical spills. One of the sessions at the SETAC Portland meeting in 2010 provided an opportunity to demonstrate the usefulness of databases in environmental toxicology, and it will be presented at the upcoming SETAC North America 36th Annual Meeting in Salt Lake City.
Figure 1—Type of data in CAFE that can help inform critical steps within the chemical response process.
Five years later, a new and free software, developed by the Emergency Response Division (ERD) of NOAA’s Office of Response and Restoration and Research Planning, Inc., is adding to the collection of spill response tools. This new tool, the Chemical Aquatic Fate and Effects (CAFE) Database, was developed in response to the growing needs of ERD, which since 2003 has responded to thousands of spill incidents in aquatic environments. CAFE is designed to provide time-sensitive information that helps spill responders make informed decisions in the event of a chemical incident (figure 1). CAFE provides easy access data that can help answer questions regarding environmental concerns, while providing estimates on the relative sensitivity of aquatic organisms to a chemical of interest.
CAFE allows for rapid and unrestricted access to fate and effects data. Data are integrated into two primary modules, the fate module and effects module.
The Aquatic Fate Module contains chemical specific information helpful in assessing the fate of chemicals in aquatic environments. Some of the data currently within this module include (figure 2):
- Structure and physical properties (e.g., boiling point, water solubility, molecular weight, molecular structure) of more than 30,000 chemicals
- Environmental fate properties (e.g., estimated KOC, biodegradation timeframes, volatilization, environmental partitioning) including explanations of individual properties
- Analytical methods used in the quantification of chemicals in different media as well as details on the intended use of specific chemicals
- Citations of the original data sources
Figure 2—Components of the Aquatic Fate Module include physical properties (pictured), environmental fate, analytic methods.
Environmental modelers can use the information available in the Aquatic Fate Module, combined with site-specific information, in their estimation of the concentrations of the spilled chemical in water, as well as its fate in the aquatic environment. This module also helps answer basic operational questions such as the media that needs to be sampled for spilled chemical.
The Aquatic Effects Module contains chemical, oil, dispersant and chemically dispersed oil toxicity information—helpful in assessing the potential effects of the spilled chemical on aquatic receptors. This module contains acute toxicity data, which can be queried through different windows allowing for on-the-fly data searches and data plotting in the form of Species Sensitivity Distributions (SSDs). SSDs are probabilistic models generated by ranking the relative sensitivity of individual species from the most sensitive to the least sensitive, and are used to estimate the proportion of species adversely affected at a given chemical concentration.
For each individual species, the geometric mean of all reported concentrations for a single chemical is calculated and used to derive SSDs. Using a logistic function, curves are developed for datasets with a minimum of five species. SSDs are plotted over a colored background, adopted from the USEPA Office of Pesticide Programs, representing a common scale of relative toxicity for aquatic organisms. In CAFE, two hazard concentrations (HC) (HC1 and HC5, equivalent to the concentrations at which 1% and 5%, respectively, of the species in the SSD may not be protected) are automatically estimated with each SSD. Features of the Aquatic Effects Module include (Figures 3 and 4):
- Acute toxicity (i.e., LC50, EC50, LOEC, NOEC) data for a variety of aquatic receptors under different exposure durations (i.e., 24, 48, 72, and 96 hours)
- A graphic display of toxicity data in the form of Species Sensitivity Distributions (SSD) based on exposure duration (24, 48, 72, and 96 hours)
- SSDs based on user-defined features (e.g., water type, exposure duration)
Figure 3—One of the five windows of the Aquatic Effects Module where selections can be made based on species, life stages, endpoints, water type and exposure duration. Only the top portion of the individual window is shown.
To date, the fate and effects modules of CAFE contain information for more than 30,000 and 4,000 chemicals, respectively. Toxicity data are also available for over 200 oils, dispersants and chemically dispersed oils. CAFE’s fate information comes from a variety of sources, including the Hazardous Substances Data Bank (HSDB), the SRC Inc. (formerly Syracuse Research Corporation) PHYSPROP database, USEPA’s EPI Suite™ model and others. CAFE’s toxicity records come primarily from the USEPA ECOTOX database.
In addition to these two large modules, CAFE also includes short exposure risk reports for a selected number of chemicals, following the methodology described in Bejarano and Farr (ET&C, 2013, 32:1918-1927). Candidates for these types of reports included those chemicals with sufficient acute toxicity data in CAFE that followed one or more of the following criteria:
- Involved in accidents by the Department of Transportation (DOT)
- Potentially toxic to humans and biological resources
- Reasonably water soluble
- Shipped in bulk and having a reasonable risk of being spilled in large quantities
There is also a user-added section that allows CAFE users to add their own data to CAFE’s SSDs plots and a detailed documentation in the form of a comprehensive manual.
Figure 4—CAFE’s graphic display of toxicity data in the form of SSDs.
CAFE serves as a one-stop, rapid response tool to aid spill responders in their assessment of the potential environmental impacts arising from spills, while supplements NOAA’s expertise in spill response by providing time-sensitive information.
For example, within minutes following an incident, spill responders could gain an understanding of the potential fate of the spilled chemical in the aquatic environment.
Using toxicity data in CAFE, a spill responder could quickly determine where aquatic toxicity data derived from relatively short exposures (e.g, 24 hours) fall within the relative scale of toxicity. From an SSD, estimated HC5 values could also be compared to modeled environmental concentrations of the spilled material in the aquatic environment. Data contained in CAFE may also serve other needs of the scientific community and will likely have a broader use extending beyond that of the spill response community.
CAFE (version 1.1) for Windows and Mac is available to the larger scientific community and the public, free of charge, through NOAA’s Office of Response and Restoration website.
Authors’ contact information: ABejarano@researchplanning.com, Jim.Farr@NOAA.gov and Valerie.Chu@NOAA.gov
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