Level III indicators

Indicator levels are determined based on the ease of measurement and its ability to respond to change. We describe three levels of indicators level I indicators are easily measurable, whereas level 11 and 111 indicators provide more scientihc rigor and are used to support the validity of easily measurable indicators. For routine monitoring of a wetland, only selected level I indicators are used to assess the level of impacts. As dehned, assessment endpoints are explicit expressions of an environmental value to be protected, whereas measurement endpoints are measurable responses of an assessment endpoint to a stressor (USEPA, 1992 Suter, 1990). Level I indicators are of low cost, are easily measurable but less sensitive to stress/impact, and show a weak spatial variability and have long response time. Level II indicators are moderately complex and sensitive, show moderate spatial variability, and have medium response time. Level III indicators are highly complex and sensitive, show high spatial variability, and have short response time (Figure 15.3). 

Level III indicators water column, detritus, and soils... 

Note Standard methods are available to determine level I indicators and some of the level II indicators. Research methods are available in the literature to determine level II and level III indicators. References to many of these methods are presented in various chapters of this book. Some of the key methods are described in the following books APHA (2002) Wetzel and Likens (1990) Methods of Soil Analysis, Book Series 5, Parts 1. ... 

Scenario II assumes that indicator variables are collocated, meaning they are sampled at the same sites X , that is, sample sites are shared (isotopic data) (Wackernagel, 2003). A special case arises if an indicator variable of interest (e.g., level III indicator that is difficult to measure, labor-intensive or costly to measure—phosphate sorption index) is known at a few sites and an auxiliary variable known at many sites (e.g., level I indicator that is easy and cheap to measure—total phosphorus). 

Use of tartrazine as indicator. Satisfactory results may be obtained by the use of tartrazine as indicator. Proceed as above, but add 4 drops of tartrazine (0.5 per cent aqueous solution) in lieu of the iron(III) indicator. The precipitate will appear pale yellow during the titration, but the supernatant liquid (best viewed by placing the eye at the level of the liquid and looking through it) is colourless. At the end point, the supernatant liquid assumes a bright lemon-yellow colour. The titration is sharp to one drop of 0.1 M thiocyanate solution. 

For each of the following, (i) give the systematic name of the compound and specify the oxidation state of the transition metal, (ii) draw a crystal field energy-level diagram and assign the d electrons to orbitals, (iii) indicate whether the complex is high-spin or low-spin (for dA-d7 complexes), and (iv) specify the number of unpaired electrons. 

A compilation of available lead retention data is given in Table III, indicating only the most important conditions of a given test, where the information was available. With the exception of the work with pelleted vanadia catalysts (14), all the data pertain to lead levels in the range of 0.01-0.5 g Pb/gal, which was the range of interest in the years from 1972 to 1975, when the limits for contaminant levels in gasoline compatible with catalyst operation were actively considered. The data in the table cover an extremely wide set of conditions and include laboratory simulation, dynamometer, and vehicle fleet tests. Nevertheless, with a few exceptions, the lead retention falls within a relatively narrow band between 13 and 30%. 

Mails and Muir (19) treated an experimental pond with fenitrothion and observed that fenitrothion levels in duckweed changed relatively little from 1 to 10 days after treatment. The averages of radioactivity (as fenitrothion) in the plants over that interval were 17480 and 18229 pg/kg in shaded and sunlit ponds respectively, on a dry weight basis. During the period after treatment water content of radioactivity declined continuously, but "average" values taken as the means of initial and 10-day samples were 43 and 37 pg/L for the same ponds. Calculated bioconcentration factors were therefore 406 and 492 fold for the shaded and sunlit ponds. The rate constant ratio (Table III) indicates a steady state prediction of 24 on a wet... 

One such difficulty is that, while it appears that [Sn2 ] levels may be as high as 400 /iM in some hypoxic environments, the precise number (n) of sulfur atoms in these polysulfide species, or even the range of n, is uncertain. Bouleague (16) discusses some of the thermodynamic equilibrium calculations which may be used to estimate the distribution of s[Sn2 ] among the various polysulfide species. Another difficulty with these data is that the structures of the thiols (RSH) detected are not well known. Mopper and Taylor (14) identified 13 different thiols in slurries of intertidal sediments from Biscayne Bay (FL), and found at least 20 more thiols whose structures could not be determined. Their observations (Table III) indicate that thiols encountered in natural waters will probably exhibit a broad variety of structures in any one location, but that a relatively small number of compounds may dominate the mixture. 

A reason that no aldicarb residues were detected at many positions could be that the well depths selected were above or below a narrow plume of aldicarb contamination. However, the results observed with the multilevel samplers, with the 45 cm depth intervals between sampling ports (Table III), indicate that this is not likely where contamination occurs, the plume is usually spread out over a depth of several sampling levels. Also, no significant aldicarb residues were encountered at all in some multilevel samplers (e.g. at locations 3 and 7 in Field 5 location 2 in Field 6). 

TCDD residual in soil was achieved for all three soils subjected to the highest temperature. There was some difference in treatability observed between the three soils at the lower temperatures. Also, longer treatment times were required for the MCBC soil because of the higher initial 2,3,7,8-TCDD level (500 ng/g vs. 100 ng/g). One set of treated test samples which contained less than 1 ng/g 2,3,7,8-TCDD was also analyzed for the other CDD and CDF congeners and 2,4-D/2,4,5-T. These results, shown in Table III, indicate greater than 99.999 percent removal of the initial... 

The data in Table III indicate that the presence of PAH in the environment is worldwide. Only two samples [one from a coarse, sandy, desert like environment (Nevada soil, Sample 30) and the other the freeze-dried remains of a still living algal layer from the lagoon of a South Pacific atoll (Hao 232, Sample 34)] were found to contain no PAH above blank levels. The concentrations of PAH in these global samples vary drastically, however. The total concentration of nonalkylated three-to-five-ring PAH ranges from less than 1 ppb (Samoan soils and an... 

Normal, elevated, or reduced serum levels of thyrotropin (TSH) have been reported in the geriatric population. The Whickham study showed a progressive increase in TSH concentrations in women, associated with a rise in the titers of thyroid autoantibodies (Tunbridge et al., 1977). Data from the US National Health and Nutrition Examination Survey (NHANES III) indicated that serum TSH values rose from a median value of 1.26 mU/1 in... 

Tables II and III indicate that the levels of both toxicants were highest in 1981. Perhaps these results account for variation in resistance to rot that is observed in carrots from year to year (6). The interaction of varieties with year was not significant, suggesting that varietal differences tended to remain the same from year to year.

Figure 10.10 Representation of the four major compartments of a fugacity model along with D values for intercompartment transfer in a level III model. Input, E, reaction, R, and advection. A, options are indicated. [Reprinted from D. Mackay, S. Paterson, and W. Y. Shiu, Generic models for evaluating the regional fate of chemicals , Chemosphere 24, 695. Copyright 1992, with permission from Elsevier.]...

FIGURE 15.7 Suggested sampling designs to sample level I, II, and III indicators. 

Level I indicators are easily measurable whereas level II and III indicators provide more scientific rigor and are used to support easily measurable indicators. 

Level II and III indicators may include more comprehensive measurements such as enzyme activity, denitrification, microbial and algal diversity, microbial biomass, primary production, and acid volatile sulfide and gaseous flux measurements to name a few. 

The median of column sums X coi o Table 16 is 5 which indicates that, on average, five out of nine evaluated measurements are implemented ( 55.6%). The median of row sums Xlrow O which is equivalent of safeguard level III. Tlii s level is mapped with an expected frequency of failures F within [6 5] which follows the FMEA frequency rating as mentioned above. 

The data in Table 4.1 indicate that ONCB has limited water solubility and volatility. ONCB does not appear to biodegrade readily. The Level III fugadty model within EpiSuite 4.11 predicts the environmental distribution and half-lives in various media shown in Figures 4.1 and 4.2. (As discussed in more detail in Chapter 2, these model results do not serve as an absolute predictor of the fate and transport of a substance, but rather indicate in general terms the tendency of a substance to partition between compartments and biodegrade.)... 

The substance is toxic to aquatic organisms. Fugacity Level III calculations indicate that if released into the environment, it will exist predominantly in the soil and/or the aquatic enviromnent depending on the environmental compartment that they first contact. The log Kow indicates low bioaccumulation potential. 

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