Bioaccumulation Aquatic biological indicators

The criteria listed in Section 4.3.1 were applied to the selection of biological indicators to ensure their relevance and utility for assessing trends in the bioaccumulation of MeHg associated with altered loadings of mercmy to aquatic systems. This evaluation, based largely on the discussion in Section 4.3.2, is summarized in Table 4.1. 

PROBABLE FATE photolysis, photodissociation in stratosphere may be important, not important in aquatic environment, photooxidation half-life in air >7.3->73 yrs photooxidation by U.V. in aqueous medium 90-95 C time for the formation of C02 (% theoretical) 25% 25.2 hr, 50% 93.7 hr, 75% 172.0 hr oxidation not an important process hydrolysis probably unimportant volatilization some volatilization occurs, importance as a fate mechanism is unknown, measured half-life for evaporation from 1 ppm aqueous solution 25 C, still air, and an average depth of 6.5 cm 40.7 min, should volatilize slowly from dry soil surfaces, if released to water, volatilization appears to be the most dominant removal mechanism (half-life 15 hrs from a model river) sorption no data available, moderate to slight adsorption to suspended solids and sediments may occur biological processes high Log Kow indicates possibility of bioaccumulation... 

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