Comparative excretion of DDT analogues into milk of indian buffalo,Bubalus bubalis L. following oral administration

Four groups of Indian buffaloes were fed daily with 25 mg of p,p′-DDT p,p′-TDE p,p′-DDE or o,p′-DDT for 100 days. Milk was analysed for organochlorine residues during this period and also for 100 days after pesticide administration had been discontinued. For the period showing ‘plateau level’ residues, 17.2% of p,p′-DDE, 17% of p,p′-TDE, 14% of p,p′-DDT as p,p′-DDT (3.5%); p,p′-TDE (10.5%); 3.2% of p,p′-DDT as o,p′-DDT (1.3%) and o,p'-TDE (1.9%) of their administered amounts were excreted in the milk. Since these compounds were excreted at different rates, the residue levels in the milk expected from a given feed would depend on their concentration and proportional distribution in the feed. The maximum tolerable content of DDT analogues in feed was derived to be 0.1 mg kg^?1 (dry weight basis) by using the maximum accumulation coefficient and incorporation of the necessary safety margin. It is concluded that Indian buffaloes fed with rations contaminated with a total of DDT analogues below this limit will yield milk of acceptable quality. Following the termination of feeding with contaminated rations, the elimination of p,p′-DDE in the milk took the longest time and that of o,p′-DDT the shortest. These results suggest that the time required for the initial high residue concentration to decline to less than the legal limit would be determined by the relative amounts of DDE, TDE and DDT in the milk, after elimination of the potent source of contamination.     

Inhibition of acetyl-coenzyme a carboxylase by coenzyme a conjugates of grass-selective herbicides

A total of 146 samples of different kinds of cheeses produced in Spain were analysed in order to ascertain the specific contamination pattern. The organochlorine compounds studied were those most commonly investigated in previous surveys: α-HCH, β-HCH, γ-HCH (lindane), γ-HCH, chlordane, aldrin, dieldrin, endrin, heptachlor, heptachlor epoxide, and the isomers and metabolites of DDT. α-HCH, β-HCH, γ-HCH, chlordane, p,p′, DDT, and p,p′-DDE were found in more than 76% of samples; p,p′-DDE and γ-HCH were the most frequently detected, with frequencies of 100 and 97.9% respectively. γ-HCH, aldrin, dieldrin, heptachlor, heptachlor epoxide, o,p′-DDT, p,p′-DDD and o,p′-DDD were observed at lower frequencies. No residues of endrin were detected in any sample. Insecticides exceeding the maximum residue limits (MRLs) were chlordane, β-HCH, α-HCH and γ-HCH, with 42, 20, eight and six samples respectively. Mean residues of organochlorines found were as follows (μ kg^?1 butterfat): α-HCH = 46.3; β-HCH = 46.5; γ-HCH = 54.2; δ-HCH = 16.9; aldrin = 16.7; dieldrin = 9.7; heptachlor = 15.9; heptachlor epoxide = 14.8; chlordane = 50.2; o,p′-DDT = 5.1; p,p′-DDT = 12.4; o,p′-DDT = 19.6; p,p′-DDD = 46.7; o,p′-DDE = 6.9; p,p′-DDE = 40.7 (.DDT = 55.0). Estimated dietary intakes (EDIs) from cheese consumption were compared to acceptable daily intakes (ADIs) for the pesticides where residues exceeded the MRL. EDIs calculated were in all cases below ADIs, and, therefore, based on the ADIs, there is no health risk involved in the consumption of cheese from Spain arising from organochlorine residues.     

Distribution and breakdown of DDT in orchard soil

Amounts of DDT and its breakdown products were determined in soil in an apple orchard in Herefordshire. Samples were taken for a number of years (1972–79) after use of the insecticide in the orchard had ceased in 1969. The results were compared with those obtained in an investigation of the same orchard in 1968. From 1968 to 1979, soil residues of pp′-DDT, p′--DDT and pp′--TDE decreased gradually whereas those of pp′--DDE increased, and there were linear relationships between log (concentration) and time. The calculated time for 50% decrease in concentration (Dt₅₀) was 11.7 years for pp′--DDT, 3.3 years for pp′--TDE and 7.1 years for op′--DDT; the time for doubling the concentration for pp′--DDE was 9.1 years. Regression analysis on the two major components (pp′--DDT+pp′--DDE) indicated that the total amount (2.7 mg kg^?1) was not decreasing with time. It was concluded that during a post-spray era, the breakdown of pp′--DDT to pp′--DDE was a significant feature of the persistence of DDT, and that, in contrast to the findings of other workers who sampled when DDT was being used, there were no losses by volatilisation. There was an exponential decrease in the amount of DDT residues with increasing soil depth and approximately 90% was found in the top 10 cm of the undisturbed soil profile.     

Accumulation and distribution of pp′-DDT and related compounds in an apple orchard. II. Residues in trees and herbage

DDT residues in or on the roots and leaves of the herbage and the roots, bark, leaves and fruit of the trees are given for an apple orchard sprayed annually (1953–1969). The distribution of DDT in both the grass and the grass roots was in circular areas of residues, with maximum values at each trunk and decreasing radially to each alley. Of the spray applied at the green cluster stage 80% was deposited on the grass sward and very little, if any, directly on the soil surface. The pp′-DDT content of the grass fell rapidly with successive mowings (from which the cuttings remained in situ) from 400 μg/g at spraying to 2 μg/g after nine months. 33 g/ha pp′-DDT was found in the herbage roots (0.87% of the total residues in the soil). The residues in the bark (87.5 g/ha) were much lower than expected after 13 years spray application. There were increased amounts of pp′-DDE, pp′-TDE and pp′-TDEE relative to pp′-DDT, indicating some breakdown on the bark, but the chief losses were attributed to volatilisation and to removal by wind and rain. The residue content of root bark varied from 3 μg/g near the emerging trunk to 0.05 μg/g at a depth of 90 cm. The pp′-DDT content of leaves at leaf fall rose from <1 ng/g after a single spring spray to 8.33 μg/g following an additional spray in late June. There was a large loss of DDT from the canopy between the June spray and leaf fall (440–480 g/ha down to 25 g/ha), attributed to volatilisation. The amount of pp′-DDT on the fruit, after a single spray, was 3 ng/g fresh weight (80.9 mg/ha out of a total of 1.0–1.5 kg/ha used).     

Residues of organochlorine pesticides in broilers from feed fortified with known levels of these compounds

p, p'-DDT, HEOD, endrin, heptachlor epoxide, hexachlorobenzene and lindane were fed in combination to day-old broiler chickens at levels of 0.05, 0.15 and 0.30 part/million in the feed, for a period of about 7 weeks. Birds were killed at regular intervals and samples of abdominal fat and other tissues examined for residues of the chlorinated pesticides by gas-liquid chromatography. The lipid content of each sample was determined and the residue levels calculated for the whole tissue and also for the fat contained in the sample. At the end of the 7 weeks (when in practice broilers are slaughtered) residues were highest for heptachlor epoxide, followed by hexachlorobenzene, HEOD, DDT (total), endrin, and lindane. Heptachlor epoxide residue levels in fat were 13 times the levels in the feed, for lindane the ratio was 3.3. Fat residues of each pesticide reached a plateau level relatively quickly, and these levels were proportional to the fortification rates in the feed. HEOD and p, p'-DDT alone were fed to separate groups of birds. No differences in residue build-up of these compounds were found between these groups and the groups that had received these compounds in combination with the other pesticides. The total amounts of each pesticide in the tissues were reduced when the meat was fried, probably by loss of fat during preparation and frying. For p, p'-DDT and heptachlor epoxide also smaller residue were observed in the remaining fat after frying.     

Studies on the induction of rat uterine ornithine decarboxylase by DDT analogs. I. Comparison with estradiol-17β activity

The effect of DDT analogs and estradiol-17β on uterine ornithine decarboxylase activity in the immature intact and ovariectomized rat was studied. Pretreatment with various doses of o,p′DDT [1-(o-chlorophenyl)-1-(p-chlorophenyl)-2,2,2-trichloroethane] or estradiol-17β caused a marked increase in the specific activity of ornithine decarboxylase in the 20,000g supernatant fraction of uterine homogenates but not in liver homogenates. Doses as low as 0.5 mg of o,p′DDT or 0.002 μg of estradiol-17β stimulated uterine ornithine decarboxylase activity in the ovariectomized rat. The peaks of activity after treatment with o,p′ DDT and estradiol-17β occurred at 6 and 5 hr, respectively. The level of ornithine decarboxylase activity in untreated groups was consistently lower in ovariectomized rats than in intact immature animals. Treatment with o,p′ DDT (10 mg/100 g body weight) of ovariectomized and intact immature rats demonstrated at 131-fold and an about 20-fold increase in uterine ornithine decarboxylase activity, respectively. Treatment of ovariectomized rats with cycloheximide or actinomycin D effectively blocked the increase in ornithine decarboxylase caused by o,p′ DDT. Similar results were obtained with cycloheximide in the intact immature rat. Animals subjected to both adrenalectomy and ovariectomy demonstrated an increase in ornithine decarboxylase activity when treated with either estradiol-17β or o,p′ DDT. Dose-response curves obtained for estradiol-17β and o,p′ DDT suggest a similar mechanism of action for the two compounds. Graphic analysis of the dose-response curves for estradiol-17β and o,p′ DDT demonstrated an ED₅₀ of 0.038 μg/100 g body weight and 1.8 mg/100 g body weight, respectively. The examination of various DDT analogs in intact and ovariectomized animals showed that o,p′ DDT was the most potent inducer of ornithine decarboxylase. The order of decreasing potency of DDT analogs was o,p′ DDT, o,p′ DDD. p,p′ DDT, p,p′ DDD, and p,p′ DDE.     

Endocrine modifications produced by o,p′-DDT in the male adult rat

The action of o,p′-DDT on plasma steroids and steroidogenesis in adrenal and brain tissues has been studied using 26 Sprague-Dawley adult male rats. The animals were divided into three groups: the first was injected with sesame oil, the second injected with 20 mg of o,p′-DDT in 0.5 ml of sesame oil and the third group was not treated. The animals were sacrificed 8 hr after the injection; blood, adrenal, and brain were removed and used for plasma steroid determinations. A decrease in testosterone and an increase in estradiol were found in plasma of treated animals. The injection of o,p′-DDT produced also a decrease in corticosterone formed from progesterone and in unchanged progesterone in the adrenal glands, an increase in dihydrotestosterone and a decrease in androstenediol formation from testosterone in the brain. These results indicate that the effect of o,p′-DDT administration implies: (i) a general decrease in androgen biosynthesis, which is evident also from the lower level of plasma testosterone; (ii) a decrease of plasma estradiol level, which could indicate a binding of o,p′-DDT to estradiol receptor sites; (iii) a decrease in 11β-hydroxylase activity, which is evident from the lower amount of corticosterone formed from progesterone in the adrenal tissue.     

The effect of some DDT and methoxychlor analogs on temperature selection and lethality in brook trout fingerlings

The effects of several DDT and methoxychlor analogs on trout fingerling temperature selection and lethality were investigated. The molecular requirements for lethality and alteration of temperature selection were different. Only p, p′-DDT, p, p′-DDD, and p, p′-methoxychlor were toxic in the range 10–50 ppb used. All the compounds tested, except DDE-type analogs, altered temperature selection. The effect of p, p′-methoxychlor on temperature selection progressively decreased until normal values were obtained 5 days after exposure. The effect of p, p′-DDT was still pronounced 9 days after exposure.     

The accumulation and distribution of pp′DDT and related compounds in an apple orchard .I. residues in the soil

Soils from an orchard sprayed annually (1953-1969) with technical DDT (77% pp′DDT and 22 % pp′DDT) were analysed for residues from 1964 until 1969. The amount of DDT found after 17 years was 21 %pp′DDTout of 27.1 kg/ha applied, and 7 % of pp′DDT out of 7.6 kg/ha. The vertical distribution of residues (pp′DDT, pp′DDE, pp′TDE and pp′DDT) showed a linear relationship between log amount and depth, with approximately 80% in the top 10 cm of soil. At depths from 50 to 210 cm, residue values were too small to be determined (i.e. < 1 ng/g dry wt). The surface distribution in the orchard showed a systematic pattern of circular areas of residues, with maximum values centred at each trunk (7.5 μg/g) and decreasing rapidly to each alley (1.9 ug/g). The levels of pp′DDT had reached a steady state (3-4 kg/ha) and the half-life time was calculated as 3.0 j′ears. pp′DDE (1.8 kg/ha) was the main metabolite of pp′DDT. Small amounts of pp′TDE were also found, pp′DDT was less persistent than pp′DDT, with a half-life time of 1.5 years.     

Organochlorine pesticide residue in Chinese herbal medicine

Over ten-year routine inspection results on organochlorine pesticide (OCP) residue were summarized, OCPs residues, including BHC isomers (α, β, γ, and δ-BHC), DDT analogs (p,p′-DDD, p,p′-DDE, o,p′-DDT, and p,p′-DDT), and pentachloronitrobenzene (PCNB) and its metabolites (pentachloroaniline and methyl pentachlorophenyl sulfide (MPCPS)), in 1,665 samples for 37 types of Chinese herbal medicine (CHM) using the QuEChERS method coupled with the GC-ECD. Based on the maximal residue levels for OCPs set by Asian pharmacopeias, PCNB contamination in Ginseng radix as well as the total DDT and PCNB contamination in Panacis quinquefolii radix are of concern. OCP residues in different parts of Panax ginseng were also compared. The total BHC residue in leaf and fibrous root, as well as the total DDT and PCNB residue in all parts, exceeded MRL of 0.1 mg/kg. Overall, this study provided meaningful results about OCP residue in CHM for pharmaceutical industries and consumers.     

The metabolism of p,p′-DDT by the feral pigeon (Columba livia)

Male feral pigeons were dosed with ring-labeled $\text{[}{}^{14}\text{C}\text{]p,p′-}\text{DDT}$ and the tissues and droppings analyzed for total ¹⁴C, extractable ¹⁴C, and metabolites. Only 16% of an intraperitoneal dose of 1.5–2.2 mg kg^?1 was voided in the droppings over 28 days; the rate of loss reached a maximum on the 14th day and then fell quickly away. The rate of removal of ¹⁴C in droppings was low in comparison to that found in the rat and the Japanese quail. When pigeons were dosed with 32–38 mg kg^?1 DDT per bird, and killed after 77 days, 5.4% of the dose was eliminated in droppings and 87% was recovered in the body. The tissues and droppings from this experiment were analyzed for DDT and its metabolites. Of the ¹⁴C remaining in tissues 88% was accounted for as the apolar compounds DDE, DDT, and DDD. Approximately half of the ¹⁴C in droppings was present as DDE, DDT, and DDD, whereas 27–35% was apparently in conjugated form, extractable from aqueous solutions by ethyl acetate after prolonged acid hydrolysis. Two polar metabolites were isolated from the acid-released material. One was p,p′-DDA; the other was extractable from aqueous solution at pH 8 and was tentatively identified as a monohydroxy derivative of p,p′-DDT. DDE accounted for 93% of the ¹⁴C present as metabolites in tissues and droppings, clearly indicating the importance of this intermediate in this study. The metabolism of DDT in the feral pigeon is discussed in relation to its metabolism by other species.     

Persistence and binding of DDT and gamma-HCH in a sandy loam soil under field conditions in Delhi,India

Persistence and binding capacity of [¹⁴C]p, p′-DDT and [¹⁴C]y-HCH were studied for one year in a sandy loam soil of Delhi, India, after surface treatment during monsoon, winter and summer seasons under field conditions. Both DDT and HCH dissipated more rapidly under the Indian subtropical climate than reported for temperate regions. In all three seasons, both insecticides dissipated most rapidly during the initial 60 days. However, in the final six months there was very little change in the residue levels. After one year, the final soil burden of DDT varied from 33 to 36% and of HCH from 14 to 15% of the initial concentrations in the different experiments. HCH bound more with the soil as, out of the total residues present after one year, more than 75% of HCH was in bound form compared with only 24% of DDT. The observed time for 50% initial dissipation of DDT ranged from 60 to 120 days, while in the case of HCH it varied from 30 to 45 days. However, the rate of loss of residues which persisted for more than 6 months was equivalent to a half-life of between 500 and 10000 days for DDT, and between 700 and 2000 days for HCH, thus illustrating the very long persistence of aged residues. Since degradation of both insecticides was apparently minimal, the data indicate that dissipation of DDT and HCH was largely due to volatilisation.     

Enhanced excretion of DDT and metabolites in rats treated with trans,trans-muconate

The interactions between trans,trans-muconate and p,p′-DDT were examined. Male Wistar rats were injected intraperitoneally with 6.67 mg kg^?1 [¹⁴C]p,p′-DDT. Two hours later the experimental animals received orally a solution of sodium muconate (75 mg kg^?1, 0.3 ml) in physiological saline, pH 7.2; control animals received an equal volume of physiological saline. Treatment was repeated every 12 hr for 10 days. Sodium muconate does not modify urinary excretion of labeled compounds, yet it reduces body burden by accelerating the excretion rate of these compounds in rat feces. This action was observed only during the first 24 hr after the animals were exposed to p,p′-DDT.     

Long-term effects of DDT on the behavior and central nervous system activity in Periplaneta americana

The effects of p,p′-DDT and four of its analogs on electrical activity in the central nervous system of the cockroach, Periplaneta americana (L.), were investigated. Cockroaches were injected intraabdominally with an organochlorine compound at LD₅₀ 96-hr doses (except for p,p′-DDE). Extracellular recordings were made from the central nervous system at 1 hr, 24 hr, or 3 weeks postinjection. p,p′-DDT, methoxychlor, and p,p′-DDD induced behavioral changes (tremors, jitters, hyperexcitability) and repetitive firing in the central nervous system prior to 1 hr postinjection. By 24 hr postinjection, most behavioral signs of poisoning had disappeared, though repetitive firing could still be readily elicited in the central nervous system. Cockroaches injected with o,p′-DDT, however, usually required about 48 hr before overt signs of poisoning became apparent. Cockroaches treated with p,p′-DDT or o,p′-DDT behaved normally at 3 weeks postinjection but still displayed a significant occurrence of repetitive firing in the central nervous system. A mechanism is proposed to explain how a cockroach might recover behaviorally from a sublethal dose of an organochlorine compound but still display repetitive firing in its central nervous system. A direct “cause and effect” relationship between repetitive firing in the central nervous system and mortality (and external signs of poisoning) is therefore questioned.     

Residues of DDT in cottonseed after spraying with DDT and torbidan

DDT at 1.12 and 2.24 kg/ha a.i. and Torbidan at 5 and 10 litre formulation/ha (1 and 2 kg DDT/ha) were sprayed five times on cotton over a period of 15 weeks. Seeds from the first pick of the crop were found to contain as residues pp′-DDT and pp′-DDE [1,1-dichloro-2,2-di- (4-chlorophenyl)ethylene]. The highest residue level (0.783 parts/10⁶) was found in seeds from Torbidan 10 litre/ha treatment.     

In-vivo and in-vitro studies on DDT uptake and metabolism in susceptible and resistant strains of the mosquito Aedes aegypti L.

Twelve strains of Aedes aegypti have been compared for resistance to pp′-DDT, uptake of pp′-DDT, and dehydrochlorination of pp′-DDT to pp′-DDE in vivo and in vitro both at the larval and adult stages. Resistant larvae were shown to contain significantly more pp′-DDE than susceptible larvae after a standard exposure to pp′-DDT but also substantially more pp′-DDT in an unmetabolised state. There was a small increase in the percentage dehydrochlorinated in vivo in the resistant strains compared with the susceptible strains, but this was not correlated with the level of resistance nor with dehydrochlorination in vitro. However, dehydrochlorination in vitro was correlated with resistance. Adult resistance was correlated positively with dehydrochlorination, both in vivo and in vitro, but the resistant adults did not contain increased levels of unmetabolised DDT. By comparing resistance levels at the two stages, it was found that there were two kinds of resistant strain: four strains of Asian origin and one from West Africa were highly resistant as larvae but showed almost no resistance as adults; five strains from Central and South America were highly resistant at both stages. The different mechanisms of resistance in adults and larvae are discussed in relation to genetic studies.     

Residues of some chlorinated hydrocarbon pesticides in milk and milk products after their addition to the feed of cows

Lactating cows fed 0.05 part/million aldrin, 0.2 part/million γ-BHC and 2.0 parts/million pp'-DDT in their concentrate ration gave detectable residues of dieldrin, γ-BHC, pp'-DDE, pp'-TDE and pp'-DDT in the milk and also aldrin in the butter and cheese. The levels found after 28 days of feeding were not significantly greater than those after 14 days. Subsequent increase of the pesticide content of the feed increased the residue content of the milk, butter and cheese. Only a small percentage of pesticide residue was found in the buttermilk, separated milk and the whey.     

Shell and operculum formation by immature roman snails Helix pomatia L. when treated with pp′-DDT

Roman snails (Helix pomatia) have been treated with pp′-DDT from 2 wk of age until hibernation. Taking snail size into account, relatively low doses of DDT significantly reduced shell and operculum weight whereas higher doses of DDT did not cause this response. After reemergence from hibernation, the incidence of operculum eating was significantly higher among snails hibernating late in the season, and as exposure to DDT increased so operculum eating became more prevalent.Shell thinning in snails due to pesticide is likely to have occurred in some heavily treated agricultural localities if the response of other species to DDT is similar to that of Helix pomatia.     

Dichlorodiphenyltrichloroethane determination in air by thermal desorption gas chromatography-mass spectrometry

BACKGROUND: Current quantitative methods for airborne dichlorodiphenyltrichloroethane (DDT) require collection and extraction times of ≥ 12 h. The aim of this study was to develop a method for quantifying airborne DDT with a short (<4 h) collection and analysis time. RESULTS: Precision [relative standard deviation (RSD)] for each calibration point (0.8–9.0), linearity (R² = 0.99) and apparent recovery (R′ = 96.5%) were determined from thermal desorption (TD) gas chromatography–mass spectrometry (GC-MS) analyses of Tenax-TA-packed sampling tubes spiked with 1–250 ng of DDT. Recovery of ¹³C-labeled 4,4′-DDT from tubes spiked before and after air sampling was 97.3 and 90.3% respectively. DDT was detected and quantified in 1–3 L samples of air collected during 10–180 min sampling events. A significant difference was observed in DDT air concentration between 28 and 33 °C during microchamber studies. CONCLUSIONS: The results demonstrate that the TD GC-MS method developed in this study is precise, reproducible and linear over the span of 1–250 ng of DDT spiked onto TD tubes. By avoiding dilution of the sample, the method described allows the measurement of DDT vapor concentrations during short sampling periods (10–180 min) relevant to mosquito behavior studies. Published 2012 by John Wiley & Sons, Ltd.     

Biota uptake of pesticides by selected plant species; the case study of Kilombero sugarcane plantations in Morogoro Region, Tanzania

This paper reports on biota uptake of pesticides by selected plant species from soil in which they are grown. The study was conducted at Kilombero sugarcane plantations and environs, Morogoro Region, Tanzania. Three species of the plant materials were collected namely sugarcane (Saccharum officinarum), guinea grass (Panicum maximum) and mango leaves (Mangifera indica). The sugarcane and guinea grass were used to reveal the plant uptake in the plantations whereas mango leaves were used to represent the environs. GPC cleaned sample extracts were analysed by GC-ECD and GC-NPD and the results confirmed using GC-MS. A total of 16 different pesticide residues were detected in soil samples and only 11 pesticide residues were detected in flora samples. o,p′-DDT had the highest concentration of all detected pesticides in soil samples with a mean concentration of 21.04 μg/kg d.w. whereas the highest concentrations of 17.16 μg/kg d.w. was recorded for p,p′-DDD in flora samples. The other DDT metabolites detected in soil samples were p,p′-DDT, p,p′-DDE, o,p′-DDE, p,p′-DDD and o,p′-DDD with concentration ranging from 2.00 to 18.30 μg/kg d.w. whereas the other pesticides detected in flora samples were p,p′-DDT α-endosulfan and γ-HCH with a mean concentration range of 3.21 to 13.54 μg/kg d.w. The paired sample t-test showed no significant difference between the concentrations of pesticides in flora and those found in soil.