The present study includes an initial investigation of 
various models for the distribution of the chemicals discharged 
from the Tenneco site. Various options are considered between 
the two extremes—that the organics are fully trapped at the 
Tenneco site, or that all the organics are distributed uniformly 
into the Chester River sediment beds. 
The chemical analysis of sediment and oyster tissue for alkyl 
phthalates is prone to a myriad of error sources due to ubiqui¬ 
tous presence of these plasticizer compounds in the laboratory. 
As a result, there is a need to develop new technology that would 
scrupulously suppress the opportunity for contamination. The 
development succeeded because it relies on a well-established 
statistical maxim--that any risk if repeated often enough must 
lead to disaster. Since chemical methodology consists of a 
series of steps, each with an assigned risk, the approach was to 
develop a procedure that was designed to approach zero reliance 
on chemical manipulations. 
Quality assurance was not a part of the original work plan. 
However, independent laboratory tests of split samples showed 
that the developed chemical methodology was indeed adequate for 
the purposes at hand. 
The underlying goals, then, were to develop and test the new 
methodology, to explore the possible causal link of industrially 
discharged alkyl phthalates to the past oyster mortality, and to 
determine whether the present discharge constitutes an ecological 
threat. 
MICROBIAL TRANSFORMATION OF TIN 
Organotin compounds were first synthesized about 1850 (Van 
der Kerk 1976) , and they were first used as agents to control 
biological activity around 1930, when they were used as moth¬ 
proofing agents (Luijten 1972) . Shortly thereafter, organotins 
were used as stabilizers for vinyl resins, which continues to be 
a major application (Subramanian 1978). In the last 10 years, 
use of tin by industrial societies has more than doubled. Or¬ 
ganotin compounds are used widely to control a variety of plants, 
animals, and microorganisms (Deschiens and Floch 1962, Daum 1965, 
Holden 1972, Luijten 1972, van der Kerk 1976). All such organo¬ 
tin compounds are toxic, but the effect varies with the organic 
group(s) present (Thayer 1974). In general, triorganotin com¬ 
pounds are more toxic than di- or tetraorgano compounds. Dior- 
ganotins behave like organomercurials, reacting with sulfhydryl 
groups to inactivate enzymes. Trialklyl tin compounds interfere 
with oxidative phosphorylation and with photosynthetic phos¬ 
phorylation (Thayer 1974). Methyl tin compounds are poisonous 
to the central nervous systems of higher organisms (Ridley, 
Dizikes, and Wood 1977). Effects can be species-specific. For 
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