Fenvalerate-induced alterations in circulatory thyroid hormones and calcium stores in rat brain.

Intraperitoneal administration of fenvalerate, a synthetic pyrethroid, in male rats for 45 days in doses of 100 and 200 mg/kg body weight/day induced hyperexcitability, tremors and paralysis. Tremors were observed after 7 days and gradually reached maxima on 45th day. The symptoms were more marked in rats treated with 200 mg/kg body weight/day. Fenvalerate provoked significant elevation of circulatory thyroid hormones, namely tri-iodothyronine (T3) and thyroxine (T4). A significant increase in total calcium as well as protein-bound calcium in whole brain and hypothalamus were recorded. The elevation of circulatory thyroid hormones as well as the active calcium pool could be together responsible for impairment of motor activity by altering various neuronal processes.

The role of reactive oxygen species in the degradation of lindane and DDT.

We have studied the photodegradation reactions of lindane and DDT under sunlight (72 hr) or a solar simulator (2 hr) either directly or in presence of selected photodynamic sensitizers. Direct photolysis did not cause noticeable degradation of the pesticides (below 1% in both the cases). However, addition of benzophenone or rose bengal to the irradiation solution of lindane resulted in 88% and 47% degradation, respectively, under sunlight. Similar experiments carried out with DDT resulted in 89%, 50% and 32% degradation with benzophenone, rose bengal and methylene blue, respectively. All the photosensitizers used for the study have been shown to induce photooxidation reactions by generation of reactive oxygen species. These studies suggest that by employing certain naturally occurring photosensitizers with reactive oxygen generation potential under sunlight, an effective method for safe removal of pesticides and other environmentally persistent agents from the surface of earth can be developed.

Organochlorine pesticide residues in different Indian cereals, pulses, spices, vegetables, fruits, milk, butter, Deshi ghee, and edible oils.

A total of 244 samples of cereals (wheat flour, rice, and maize), pulses (arhar, moong, gram, lentil, and black gram), spices (turmeric, chili, coriander, and black pepper), vegetables (potato, onion, spinach, cabbage, brinjal, and tomato), fruits (mango, guava, apple, and grape), milk, butter, Deshi ghee, and edible oils (vegetable, mustard, groundnut, and sesame) collected from different cities of Northern Province (Utter Pradesh) were analyzed by gas liquid chromatography for the presence of organochlorine pesticide residues. Residues of hexachlorocyclohexane (HCH) and 2,2-bis(p-chlorophenyl)-1,1,1-trichloroethane (DDT) were detected in about 85% of the total samples of cereals, spices, milk, butter, Deshi ghee, and edible oils analyzed in the present study. However, the residue levels were either very small (less than 0.06 ppm) or not detected at all in pulses, vegetables, and fruits as compared with very high concentrations in wheat flour (4.42 and 0.12 ppm), butter (1.19 and 4.85 ppm), mustard oil (1.26 and 2.42 ppm), Deshi ghee (1.10 and 3.84 ppm), vegetable oil (1.02 and 0.59 ppm), groundnut oil (0.51 and 1.49 ppm), and chili (0.48 and 1.92 ppm). The levels of HCH and DDT residues detected in rice, maize, turmeric, corlander, black pepper, and all the vegetables and fruits were also lower than those found in wheat flour, oil, and fat samples analyzed in the present study. These findings suggest that a restricted and controlled use of such persistent pesticides may be useful for decreasing their contamination levels in different food items.

Organochlorine pesticide residues in mother's milk: a source of toxic chemicals in suckling infants.

A total of 24 samples of mother's milk collected during the first week of lactation from four major cities in India (Karnal, Bangalore, Calcutta and Bombay) were analysed for the estimation of organochlorine pesticides (OCPs). alpha-HCH, p,p'-DDE, and p,p'-DDT were generally the main contaminants. The average total 1,1,1-trichloro-2,2-bis (p-chlorophenyl) ethane (DDT) levels stand at 0.05, 0.11, 0.19 and 0.22 p.p.m. (whole-milk basis) in the samples from Bangalore, Calcutta, Karnal and Bombay respectively. In the same order total hexachlorocyclohexane (HCH) levels were around 0.01, 0.03, 0.03 and 0.05 p.p.m. Wide variations among OCP levels observed in the present study have no relation with the fat content of the various samples. The samples from Calcutta and Bombay showed significantly high levels of OCPs. The daily intake of total HCH and DDT residues calculated for the suckling infant was significantly higher in the present study when compared with the WHO recommended value.

DDT and BHC residues in some body tissues of goats, buffalo, and chickens, Lucknow, India.

Muscle, liver, brain, and abdominal body fat samples of goats, buffalo, and chickens, all common meat sources in India, were analyzed by gas-liquid chromatography (GLC) for residues of DDT and benzene hexachloride (BHC). A few samples of goat and buffalo bone marrow were also included. Relatively high residue levels were found in body fat and bone marrow compared with other tissues. DDT and BHC residue levels were highest in chicken body fat, averaging 4.157 ppm sigma DDT and 3.879 ppm BHC. DDT content was much higher in goat and buffalo bone marrow than in the corresponding body fat. DDT levels in brain samples were highest (0.138 ppm) in buffalo. p,p'-TDE levels were higher than p,p'-DDE levels in buffalo; overall DDT levels were lowest in goats. BHC residues were generally low in buffalo; alpha-BHC accounted for most BHC residues in brain tissues. Greater accumulations of DDT and BHC were found in leg muscles than in breast muscles of chickens.

Organochlorine pesticide residues in some Indian wild birds.

Residues of BHC and DDT were estimated by gas-liquid chromatographic analysis of the internal body organs, depot fat, and blood plasma of a few species of Indian wild birds, captured in and around the urban area of Lucknow. Total BHC and gamma-BHC (lindane) levels were high in breast muscle, liver, heart, and lung tissues of pigeon, crow, and vulture, compared with the respective tissues of chicken, cattle egret, and kite. More lindane and total BHC was found in tissues of vulture compared with other species. The major part of BHC isomers in the brain of birds examined was accounted for by alpha-BHC. Total BHC detected in depot fat of crows was 29.7 ppm; lesser amounts were found in vulture, kite, and cattle egret, respectively. Total DDT levels were comparable in the blood plasma of chicken, pigeon, crow, and cattle egret, although residues generally showed the following order in the tissues examined: chicken less than pigeon less than cattle egret less than crow less than kite less than vulture. High levels of DDT were detected in depot fat of crow, kite, and vulture (50.8, 67.0 and 95.3 ppm, respectively). Avian species thus reflect biological magnification of BHC and DDT residues, presumably due to their food habits.

Effect of lead and zinc administration on liver, kidney and brain levels of copper, lead, manganese and zinc and on erythrocyte ALA-D activity in rats.

Albino male rats were given lead (Pb) and zinc (Zn) orally, singly or in combination, for 14 consecutive days. Liver Pb was increased and liver manganese (Mn) was decreased in animals receiving Pb. The combination of Pb and Zn led to increased Pb and decreased copper (Cu) and Mn. Kidney Zn was increased in rats given Zn or the combination of Pb and Zn. There were no changes in kidney Cu or Mn in any group. Brain Pb levels were significantly increased in animals given Pb and Zn levels in those given Zn. Erythrocytic amino levulinic acid dehydratase (ALA-D) activity was significantly decreased by Pb but not by Pb + Zn.

Organochlorine pesticides in specimens from women undergoing spontaneous abortion, premature of full-term delivery.

Organochlorine insecticides (BHC, aldrin, p,p'-DDE, p,p'-DDD, p,p'-DDT) were measured in the blood, placenta and fetus of women experiencing spontaneous abortions, preterm labor or full-term labor using an electron-capture gas chromatographic method. The following trend was found for insecticide concentrations in each of the specimens tested: spontaneous abortions greater than preterm greater than full-term. One conclusion of this work is that the organochlorine insecticides act as antagonists to pregnancy. A plausible explanation for the facilitory role of organochlorine insecticides in the initiation of preterm labor/abortion is hypothesized.

Role of chlorinated hydrocarbon pesticides in abortions and premature labour.

Premature labour and abortion possibly due to the high concentration of organochlorine pesticides have been investigated. Considerably higher amounts of organochlorine pesticide residues have been detected by gas liquid chromatography in the circulating blood and placental tissue of the women undergoing abortion or premature labour as compared with pregnant women in full term labour. The differences are highly significant for all pesticides estimated.