Description of the Protocol
65
Se/g in measured concentrations could cause the hazard rating for an
environmental component to fall in the wrong category. Propogation
of this error throughout the 5 environmental components used in the
Protocol could result in an inappropriate final hazard characterization.
Acceptably sensitive analytical methods include neutron activation,
hydride-generation atomic absorption spectrophotometry, and cathodic
stripping voltammetry (McKown and Morris 1978; Jarzabek and Kublik
1982; Brooks et al. 1983). Tissue and sediment preparation techniques
appropriate for use with these methods are available (eg, Grant 1981;
May 1982; Krynitsky 1987; Fio and Fujii 1988; Brumbaugh and Walther
1989). Inductively coupled argon plasma spectroscopy (ICAP) should
be avoided if possible. Although ICAP scans are good for reconnaissance-level monitoring to identify field sites of concern, the detection
limits are generally too high and the precision too low for determining
concentrations to be used in the hazard assessment. Establishing a contract for selenium measurements with a reputable environmentallaboratory is a desirable cost-effective alternative to developing in-house
analytical chemistry capabilities.
Description of the Protocol
Selenium concentrations measured in samples collected from a study site,
preferably across a Hydrological Unit (see Chapter 6). are compared to
hazard profiles (Figs. 4.1-4.5). These profiles are based on the results of
extensive field and laboratory studies that investigated selenium
bioaccumulation and toxic thresholds across a wide range of habitat types
and environmental conditions. Waterborne concentrations are compared
to the profile for water, sediment concentrations are compared to the
profile for sediment. and so forth. A hazard rating is determined for each
of the 5 ecosystem components based on where the highest concentrations of selenium in the samples fall on the hazard scale (high, moderate,
low, minimal. none). Individual hazard ratings are then given a numerical score: high hazard = 5, moderate hazard = 4, low hazard = 3, minimal
hazard = 2, and no identifiable hazard = 1. A final hazard characterization is determined by adding together the 5 individual scores and comparing the total to the following evaluation criteria:
No hazard =5
Minimal hazard =6-8
Low hazard =9-11
Moderate hazard =12-15
High hazard = 16-25
65
Se/g in measured concentrations could cause the hazard rating for an
environmental component to fall in the wrong category. Propogation
of this error throughout the 5 environmental components used in the
Protocol could result in an inappropriate final hazard characterization.
Acceptably sensitive analytical methods include neutron activation,
hydride-generation atomic absorption spectrophotometry, and cathodic
stripping voltammetry (McKown and Morris 1978; Jarzabek and Kublik
1982; Brooks et al. 1983). Tissue and sediment preparation techniques
appropriate for use with these methods are available (eg, Grant 1981;
May 1982; Krynitsky 1987; Fio and Fujii 1988; Brumbaugh and Walther
1989). Inductively coupled argon plasma spectroscopy (ICAP) should
be avoided if possible. Although ICAP scans are good for reconnaissance-level monitoring to identify field sites of concern, the detection
limits are generally too high and the precision too low for determining
concentrations to be used in the hazard assessment. Establishing a contract for selenium measurements with a reputable environmentallaboratory is a desirable cost-effective alternative to developing in-house
analytical chemistry capabilities.
Description of the Protocol
Selenium concentrations measured in samples collected from a study site,
preferably across a Hydrological Unit (see Chapter 6). are compared to
hazard profiles (Figs. 4.1-4.5). These profiles are based on the results of
extensive field and laboratory studies that investigated selenium
bioaccumulation and toxic thresholds across a wide range of habitat types
and environmental conditions. Waterborne concentrations are compared
to the profile for water, sediment concentrations are compared to the
profile for sediment. and so forth. A hazard rating is determined for each
of the 5 ecosystem components based on where the highest concentrations of selenium in the samples fall on the hazard scale (high, moderate,
low, minimal. none). Individual hazard ratings are then given a numerical score: high hazard = 5, moderate hazard = 4, low hazard = 3, minimal
hazard = 2, and no identifiable hazard = 1. A final hazard characterization is determined by adding together the 5 individual scores and comparing the total to the following evaluation criteria:
No hazard =5
Minimal hazard =6-8
Low hazard =9-11
Moderate hazard =12-15
High hazard = 16-25