Application of Biodegradable Pesticides in India
285
the food chain, perish in the process, thus adversely affecting the secondary and
tertiary productivity of freshwater ecosystems. Aerial spraying of pesticides
reaches the streams through runoff and causes heavy mortality of nontarget
aquatic insect predators, which in turn increases the vector and pest populations.
The tragic incidence of Handigodu syndrome in Karnatka State (India) was
probably due to the consumption of pesticide-poisoned crabs and fish by the
local population (Report of National Institute of Nutrition, 1977; Koundinya,
1978). According to a rough estimate, 25% of the pesticides used on land may
ultimately find their sink in the sea, and their cumulative effect on coastal water
can be expected to be considerable. India, a major subcontinent, is a major
producer of inland estuarine and marine fish. The impact of pesticides on the
fish population has therefore attracted some attention (Joshi and Rege, 1980;
Ahmed et al., 1978).
In vitro studies by O'Brien (1967) have revealed that fish are highly susceptible to organochlorine compounds in general and to endrin in particular.
This is in accordance with the indication that fish lack the mixed-function oxidases
responsible for drug oxidation (O'Brien, 1967; Brodie and Maicke, 1962). Presumably, fish dispose of foreign lipid-soluble compounds directly by diffusion
through gills or skin into the surrounding water without prior conversion to more
polar derivatives (Brodie and Maike, 1962). However, Potter and O'Brien (1964)
showed that trout liver slices converted parathion into paraoxon, and since then
several trout microsomal enzymes affecting drug oxidation, all requiring NAOPH
and oxygen, have been described (Creaven etal., 1965, 1967; Chan etal., 1967;
Lotlikar et al., 1967; Buhler and Rasmusson, 1968). The oxidizing system was
different in one or more components of the electron transport chain as compared
to the mammalian liver, and possibly the level of aldrin epoxidase was also low.
A lethal dose of fenitrothion had an inhibitory effect on the cholinesterase activity
in nervous and other tissues of fish, with a concomitant increase of acetylcholine
content and decreased SOH and increased LOH activities. These observations
indicated that anaerobic metabolism is favored in fenitrothion-treated fish (Koundinya, 1978; Koundinya and Ramamurthi, 1978a,b, 1979a).
Toxicity studies in fish reported from India have revealed significant accumulation of organochlorines in tissues (Verma and Gupta, 1976). Among
various chlorinated insecticides examined for their toxicity (namely, DDT, lindane, dieldrin, aldrin, endrin, endosulfan, and chlordane) endrin was extremely
toxic to fish and endosulfan was least toxic (Santha Ram et al., 1976; Basak
and Konar, 1976, 1977; Joshi et al., 1975; Rao, 1975; Saxena and Agarwal,
1970; Amminikutty and Rege, 1977; Reddy and Gomathy, 1977; Sastry and
Sharma, 1978; Banerjee, 1970; Verma et al., 1975). In catfish, endrin was
reported to be 70,000 times more toxic than carbaryl (Saxena and Agarwal,
1970). Biochemical studies carried out with endrin in fish revealed that a-amylase
activity was inhibited by more than 50%; this could be regained in the presence
285
the food chain, perish in the process, thus adversely affecting the secondary and
tertiary productivity of freshwater ecosystems. Aerial spraying of pesticides
reaches the streams through runoff and causes heavy mortality of nontarget
aquatic insect predators, which in turn increases the vector and pest populations.
The tragic incidence of Handigodu syndrome in Karnatka State (India) was
probably due to the consumption of pesticide-poisoned crabs and fish by the
local population (Report of National Institute of Nutrition, 1977; Koundinya,
1978). According to a rough estimate, 25% of the pesticides used on land may
ultimately find their sink in the sea, and their cumulative effect on coastal water
can be expected to be considerable. India, a major subcontinent, is a major
producer of inland estuarine and marine fish. The impact of pesticides on the
fish population has therefore attracted some attention (Joshi and Rege, 1980;
Ahmed et al., 1978).
In vitro studies by O'Brien (1967) have revealed that fish are highly susceptible to organochlorine compounds in general and to endrin in particular.
This is in accordance with the indication that fish lack the mixed-function oxidases
responsible for drug oxidation (O'Brien, 1967; Brodie and Maicke, 1962). Presumably, fish dispose of foreign lipid-soluble compounds directly by diffusion
through gills or skin into the surrounding water without prior conversion to more
polar derivatives (Brodie and Maike, 1962). However, Potter and O'Brien (1964)
showed that trout liver slices converted parathion into paraoxon, and since then
several trout microsomal enzymes affecting drug oxidation, all requiring NAOPH
and oxygen, have been described (Creaven etal., 1965, 1967; Chan etal., 1967;
Lotlikar et al., 1967; Buhler and Rasmusson, 1968). The oxidizing system was
different in one or more components of the electron transport chain as compared
to the mammalian liver, and possibly the level of aldrin epoxidase was also low.
A lethal dose of fenitrothion had an inhibitory effect on the cholinesterase activity
in nervous and other tissues of fish, with a concomitant increase of acetylcholine
content and decreased SOH and increased LOH activities. These observations
indicated that anaerobic metabolism is favored in fenitrothion-treated fish (Koundinya, 1978; Koundinya and Ramamurthi, 1978a,b, 1979a).
Toxicity studies in fish reported from India have revealed significant accumulation of organochlorines in tissues (Verma and Gupta, 1976). Among
various chlorinated insecticides examined for their toxicity (namely, DDT, lindane, dieldrin, aldrin, endrin, endosulfan, and chlordane) endrin was extremely
toxic to fish and endosulfan was least toxic (Santha Ram et al., 1976; Basak
and Konar, 1976, 1977; Joshi et al., 1975; Rao, 1975; Saxena and Agarwal,
1970; Amminikutty and Rege, 1977; Reddy and Gomathy, 1977; Sastry and
Sharma, 1978; Banerjee, 1970; Verma et al., 1975). In catfish, endrin was
reported to be 70,000 times more toxic than carbaryl (Saxena and Agarwal,
1970). Biochemical studies carried out with endrin in fish revealed that a-amylase
activity was inhibited by more than 50%; this could be regained in the presence