studies have concluded that specific level of OP-induced AChE redundance and lethality
in estuarine fish species. Sheep head minnows (Cyprinodon variegatus) were
exposed to selected OP insecticides at normal and high level of fatal rate(40–60% mortality) concentrations. The
blockage and barrier of brain AChE was always greater that caused mortality ith
great concentrations. The suppression of brain was much in number about 80% than
was expected in the fish that survived median lethal exposures. The authors
also concluded that diversity observed in AChE levels in control fish, the
mechanism must be lowered by 13% to indicate exposure to OP insecticides. These
results conclude that levels of brain suppression brain was 20 to 70% in live
fish could be diagnostic of OP insecticide exposure.
AChE used as
an indicator to detect any possible fluctuation of OP in marine invertebrates
but it is not well defined as expected to be in fish and mollusks. Because of the
lack of a well-defined organ system data (such as brains in fish), researchers depended
on a chain of multiple choices of techniques to estimate the results.
Various investigators have used hemolymph, nerve
ganglion, tissue of muscles, and whole body tissues of invertebrates to estimate
the results of OPs on AChE levels. Blue crabs, Callinectes sapidus, were
exposed to DEF(S, S, S,-tri-n-butyl phosphorotrithioate) at concentrations of
1.0 to 10.0 mg/L for 96 h and then assayed for AChE activity. In control crabs,
high activity was found in the ventral ganglion as well as the brain with
negligible activity in claw musculature. Exposed crabs showed a 90% reduction in
ventral ganglion AChE activity and a greater than 80% reduction in brain AChE
activity AChE activity levels were predominantly higher in the ganglion and
brain after this period.
Impact on Marine Mammals and Human Population
In recent decades the load of pollutants have
increased and reduced water quality of many rivers, lakes, and coastal oceans. Environmental
degradation of these important water re- sources can be estimated by the
evaluation of natural water system, species and its environmental components
and viability on the environment, and the amenities that they provide (U.S. EPA
1996, Postel and Carpenter 1997).
The indigenous population of Greenland and Northern
Canada can reduce their pollutant intake and risk of health problems by
decreasing their intake of improper food to maintain the health of internal organs,
adipose tissue, and preferential consumption of lower trophic species. The consumption
of young animals will result in decrease level of Cd and Hg and in some cases
OHC exposure. For OHCs adult females will be less polluted than that of adult
males. At the same time, these foods are main sources of nutrients and health
risk can be reduced by changing in diet pattern.
Marine mammal distribution is of major importance in
planning contaminant studies and for evaluation the pollution done by municipal
sewage because of their larger size, these are primarily and prominently be
seen and recorded. In some regions contaminant samples and samples for investigation
of effect parameters can only be obtained during tagging operations.