Relative cumulation of beta-BHC in ecological and biological system.

During 1971-1974 a study was undertaken to analyze 1234 samples of different elements of food chain from three regions of Slovakia in order to obtain information on ecological relations of the dynamics of residues of four isomers of BHC compared with p,p-DDT and DDE. In contrast to most literature data, a higher relative cumulation of beta-BHC in animal food products compared to the other isomers was noted. The observed relations between the individual BHC isomers were verified in a model feeding experiment on poultry. Dynamics of the transfer of the BHC isomers between fodder, meat, liver, and eggs were studied in broilers and laying hens. All results of the model feeding experiment confirmed the conclusions of the ecological studies concerning beta-, gamma-, and -delta -BHC. The persistence of the alpha-BHC was not confirmed in this manner.     

Toxicity of technical X-factor to weanling rats. II. A subacute oral study

Eighty male weanling rats were fed dietary levels of Technical X-factor (beta-isomer free BHC, a by-product obtained during the separation of lindane from Tech. BHC) at dosages of 10,50,250,750,1500 and 3000 ppm for 90 days. No overt signs of toxicity or mortality were observed at any of the dietary levels. However, a significant reduction in food consumption and growth was evident beyond 750 ppm. Pronounced hepatomegaly observed at 1500 and 3000 ppm was associated with histological alterations such as cellular hypertrophy, cytoplasmic vacuolisation and focal necrosis. Adrenals showed cortical hypertrophy and highly vacuolated cytoplasm. Though a significant increase in the levels of SGOT was noted at 3000 ppm dosage, no appreciable changes were observed in the levels of SGPT and SLDH. Technical X-factor appeared to possess low chronic toxicity compared to Tech. BHC as evidenced by the various parameters studied. The observed low chronic toxicity of X-factor is probably due to the absence if beta-isomer and altered composition of delta and alpha isomers.     

Pesticide-induced impairment of thyroid physiology in the freshwater catfish, Heteropneustes fossilis

Effects of BHC (8 mg litre(-1)) and malathion (10 mg litre(-1)) exposure for 96 h have been studied on T(3) and T(4) concentrations in plasma, and in pharyngeal thyroid tissue preparations. Thyroid peroxidase (TPO) activity in the pharyngeal thyroid tissue, along with the extra-thyroidal conversion of T(4) into T(3) were measured in a freshwater catfish, Heteropneustes fossilis. BHC stimulated TPO activity in this fish, during both in vitro and in vivo studies. In contrast, malathion was found to stimulate TPO activity during the in vitro experiments but to inhibit it in the in vivo study. Concentrations of T(3) and T(4) increased in the thyroid gland, as well as in the plasma, in response to BHC exposure. However, in both these tissues, malathion increased T(3) concentrations and reduced T(4) concentrations. The extrathyroidal conversion of T(4) into T(3) was stimulated by malathion and inhibited by BHC.     

Toxicity op technical X‐factor∗ to weanling rats. II. A subacute oral study

Abstract

Eighty male weanling rats were fed dietary levels o£ Technical X‐factor (β ‐isomer free BHC, a by‐product obtained during the separation of lindane from Tech. BHC) at dosages of 10, 50, 250, 750, 1500 and 3000 ppm for 90 days. No overt signs of toxicity or mortality were observed at any of the dietary levels. However, a significant reduction in food consumption and growth was evident beyond 750 ppm. Pronounced hepatomegaly observed at 1500 and 3000 ppra was associated with histolo‐gical alterations such as cellular hypertrophy, cyto‐plasmic vacuolisation and focal necrosis. Adrenals showed cortical hypertrophy and highly vacuolated cytoplasm. Though a significant increase in the levels of SGOT was noted at 3000 ppra dosage, no appreciable changes were observed in the levels of SGPT and SLDH. Technical X‐factor appeared to possess low chronic toxicity compared to Tech. BHC as evidenced by the various parameters studied. The observed low chronic toxicity of X‐factor is probably due to the absence of β ‐isomer and altered composition of delta and alpha isomers.     

水泥窑共处置污染土壤的污染排放研究

以被DDT和六六六污染的土壤为研究对象,开展了利用水泥窑进行共处置的工程试验研究,分析了共处置过程对尾气排放的影响。结果表明,水泥窑共处置对农药污染物的焚毁去除率很高,DDT达到99.99991%,六六六达到99.99964%,均高于我国危险废物焚烧炉规定99.99％的焚烧效率;与空白处理相比,尾气排放中有机污染物（包括二恶英/呋喃,简称PCDD/F、多氯联苯PCB、六氯苯HCB、挥发性有机物VOC）、酸性气体和重金属的排放在共处置过程中没有显著增加,且都低于相应的规定限值。试验结果表明,水泥窑共处置固体废物不会导致污染负荷的增加。     

Mammalian toxicity of Technical X-factor I. An acute oral study

Intragastric administration of acute doses of Technical X-factor (beta-isomer free BHC, a byproduct obtained during separation of Lindane from Tech. BHC) carried in peanut oil elicited typical signs of central nervous system depression in adult rats. The computed oral LD50 values of X-factor were 4174 and 5673 mg/kg. body weight for male and female rats respectively indicating that its acute toxicity was of relatively low order compared to Tech. BHC. It is suggested that the low acute mammalian toxicity of X-factor could possibly be due to a direct antagonism of the delta isomer (present in larger proportion in X-factor) with the gamma isomer.     

Two Sensitive Tests for Carcinogens in the Air

Presently, the carcinogenicity of polluted air is determined by repeated skin painting or subcutaneous injection of crude organic extracts of atmospheric particulates in adult mice. In general such techniques are not ideal, inasmuch as large amounts of extracts are required to produce significant yields of local tumors, and these may take one to two years to develop. A photodynamic bioassay for poly cyclic atmospheric pollutants, based on the previous demonstration of a positive and significant association between high photodynamic activity and carcinogenicity in a large series of polycxjclics, has been developed in an attempt to provide a simple and rapid, but presumptive, indirect index of carcinogenicity attributable to polycyclic compounds. Photodynamic activity, measured with Paramecium caudatum, was found to vary widely between organic extracts, and even more widely between 6 eluted fractions thereof, from over 100 different sources in the U.S.A. Additionally, the carcinogenicity of organic extracts of atmospheric pollutants has been directly measured with newborn mice, based on the well-known enhanced response cf neonates to a variety of defined chemical carcinogens. Mice were injected subcutaneously with extracts at doses of 55 mg or less, fractionally administered in the first 21 days of life. A high incidence of pulmonary adenomas, and hepatomas, and a lower incidence of lymphomas developed over a period from 12 to 50 weeks. Current correlative evaluation with chemical and other data indicates the practical utility of both assays for carcinogenic air pollutants.     

Behavior of the organophosphorus insecticide fenitrothion in stored faba beans and its biological effects towards experimental animals

Sound whole-seed faba beans were treated with (methyl-(14)C) fenitrothion [O, O-dimethyl-O-(3-methyl-4-nitrophenyl) phosphorothioate] at 5 and 10 mg insecticide/kg seeds, a dose normally used in practice. During the 30 weeks of storage period, the penetration and distribution of insecticide residues were studied. The amount of surface residues, internal residues and bound insecticide residues was estimated. Surface residues were found to decrease with the increase in time of storage, whereas internal residues showed a gradual increase with time apparently not dose dependent. Grain-bound residues increased with time and reached to its maximum (14-18%) after 24 weeks of storage. Chromatographic analysis of the internal extracts revealed the presence of the parent compound together with three main metabolites which were found in both free and conjugated form. Feeding mice for 90 days with a diet mixed with total internal fenitrothion residues in stored faba beans led to a reduction in body weight gain, and an appreciable decrease in cholinesterase activity of 32% for plasma and 15% for red blood cells (RBC(S)) after two months of experiment. Also, a significant decrease was showed in both total protein and albumin concentration at the end of feeding period (90 days). Liver and kidney function, as well as lipid profile of treated mice significantly increased at the end of feeding period. After a one-month recovery period, all the examined blood parameters returned to about the control values except blood urea and serum triglyceride.     

Behavior of the organophosphorus insecticide fenitrothion in stored faba beans and its biological effects towards experimental animals

Sound whole-seed faba beans were treated with (methyl-¹⁴C) fenitrothion [O, O-dimethyl-O-(3-methyl-4-nitrophenyl) phosphorothioate] at 5 and 10 mg insecticide/kg seeds, a dose normally used in practice. During the 30 weeks of storage period, the penetration and distribution of insecticide residues were studied. The amount of surface residues, internal residues and bound insecticide residues was estimated. Surface residues were found to decrease with the increase in time of storage, whereas internal residues showed a gradual increase with time apparently not dose dependent. Grain-bound residues increased with time and reached to its maximum (14–18%) after 24 weeks of storage. Chromatographic analysis of the internal extracts revealed the presence of the parent compound together with three main metabolites which were found in both free and conjugated form. Feeding mice for 90 days with a diet mixed with total internal fenitrothion residues in stored faba beans led to a reduction in body weight gain, and an appreciable decrease in cholinesterase activity of 32% for plasma and 15% for red blood cells (RBC_S) after two months of experiment. Also, a significant decrease was showed in both total protein and albumin concentration at the end of feeding period (90 days). Liver and kidney function, as well as lipid profile of treated mice significantly increased at the end of feeding period. After a one-month recovery period, all the examined blood parameters returned to about the control values except blood urea and serum triglyceride.     

Acrylamide-induced alterations in lungs of mice in relation to oxidative stress indicators

The aim of the experiment was to study the influence of acrylamide (ACR) on major antioxidants in the lungs of Swiss mice. The experiment was conducted on male mice that were 8 weeks old. The mice were exposed to ACR at a single dose of 26 µg per animal, which was administered orally. Mice were anesthetized 3, 24, and 48 h after the ACR gavage. Next, histopathological and biochemical analyses of GSH concentration and the activities of SOD, GPx, and CAT were performed in the lungs. Animals exposed to ACR showed demonstrated symptoms of inflammation in lungs, hypertrophy of bronchiolar epithelium, and hyperplasia of alveolar epithelium. GSH concentration was significantly decreased 3 h after ACR gavage, which was followed by a significant increase 48 h after ACR gavage. Similarly, SOD and GPx demonstrated decreased activities 3 h after exposure to ACR, followed by increased activities 48 h after exposure to ACR. CAT activity was significantly increased 24 and 48 h after exposure to ACR. We conclude that oral exposure of mice to ACR results in alterations of lung microstructure, accompanied by the symptoms of redox imbalance.     

盐城滩涂土壤中六六六和滴滴涕的残留量测定

采集了盐城滩涂响水-滨海段化工园区周边区域内9个表层土壤样品,通过索氏提取土壤中的六六六(BHC)和滴滴涕(DDT)。最后通过带电子捕获检测器的气相色谱仪,定量分析了土壤中六六六和滴滴涕各异构体的含量及其百分比,以及六六六、滴滴涕的总含量,以了解该区域土壤中有机氯的当前含量水平和评估其潜在的环境毒害能力。结果表明,所有样品的六六六、滴滴涕总含量均远低于国家规定的土壤环境质量一级标准(50μg/kg)。     

Promotive effect of diethylstilbestrol on urethan-induced mouse lung tumorigenesis

The effect of diethylstilbestrol (DES) on urethan-induced mouse lung tumorigenesis was assessed by a single intraperitoneal injecting of urethan (50 mg/kg) or/and multi intramuscular injecting of DES (5 or 50 mg/kg). All mice were sacrificed 18 weeks after administration, and the lung tumors were examined histopathologically. DES did not produce an elevated lung tumor response when administered alone, but it produced a statistically significant enhancement of incidence of tumors, average number of tumors, incidence of cancers and constituent ratio of malignant tumors when given in conjunction with urethan. The results indicated that DES may be a promoter in lung tumor formation.     

Bioaccumulation studies of organochlorinated pesticides in tissues of Cyprinus carpio

Freshwater fish Cyprinus carpio was selected for the study of bioaccumulation of organochlorinated pesticides in tissues like gills, muscle, intestine, kidney, and liver in a continuous fed system. The pesticides used were Aldrin, Dieldrin, BHC, and DDT. The bioaccumulation of Dieldrin was maximum of 85.0 microg g(-1) wet weight in liver tissue while minimum of 7.30 microg g(-1) wet weight for DDT at 30 days exposure time. Bioconcentration factor (BCF) has followed the same trend in liver tissue for Dieldrin and DDT. The rate of bioaccumulation was found to be maximum of 4.3879 microg g(-1) wet weight in liver tissue and minimum of 0.0021 microg g(-1) wet weight in gill tissue for 30 days exposure. As evidenced by the increasing values of BCF, pesticide uptake also showed increased trend with the increase in exposure time. A high correlation coefficient ranging between 0.7247 and 0.9616 between the pesticide concentration and exposure time was observed. Based on actual BCF values, log Kow were calculated and the values are well within the reported values of 6.5 indicating efficient relationship between BCF and log Kow because beyond the 6.5 the bioconcentration levels off.     

A ten-year study of chlorinated hydrocarbon insecticide residues in bovine milk in Illinois, 1972 - 1981

Milk supplies in Illinois were monitored for chlorinated hydrocarbon insecticide residues from 1972 through 1981. The percentage of milk samples that were contaminated with aldrin/dieldrin, DDT and its analogs, and BHC/lindane decreased during the 10-year sampling period. The percentage of samples contaminated with aldrin/dieldrin decreased from 98.7% in 1978 to 5.9% in 1981. The amount of aldrin/dieldrin residues found in contaminated samples also decreased from an average of 0.077 ppm (1972-79) to 0.001 ppm in 1980-81. The levels of chlordane and heptachlor/heptachlor epoxide residues in milk did not decrease, but residues of BHC and DDT decreased gradually over the 10-year period. The percentage of samples that had less than 0.1 ppm of all chlorinated hydrocarbon residues combined ranged from 10.6% to 25.7% during 1972 through 1978 and increased to 36.2% in 1979, 71.1% in 1980, and 61.4% in 1981.     

Effect of soil on microbial responses to metal contamination

An experiment was conducted to investigate microbial responses to metal inputs in five soils with varying clay and organic contents; one soil had also a higher pH. These soils were treated with a low metal, sewage sludge control or with this sludge contaminated to achieve Cu=112, Ni=58 and Zn=220 mg kg(-1) in medium and Cu=182, Ni=98 and Zn=325 mg kg(-1) in high metal soils. CO(2) evolution rates were measured at 1 week and at 4-5-day intervals thereafter until the end of the incubation (7 weeks). Extractable metals (CaCl(2) and water), biomass C, metabolic quotient, ergosterol, bacterial-fungal phospholipid fatty acid (PLFA-3 weeks only) ratio and mineral N were measured at 3 and 7 weeks. Metal inputs caused a marked increase in metal availability in the slightly acidic sandy loams, a smaller increase in slightly acidic clays and had little effect in the alkaline loam. After an initial increase in CO(2) evolution with metal inputs in all soils, the high metal treatment alone caused a significant decrease at later stages, mainly in sandy loams. Although biomass C and metabolic quotient decreased in all soils with higher metal inputs, the effect was more pronounced in the sandy loams. Metal inputs increased ergosterol and decreased bacterial-fungal PLFA ratios in most soils. Larger mineral N contents were found in all high metal soils at 3 weeks but, after 7 weeks, metals caused a significant decrease in sandy loams. CaCl(2) and water-extractable Cu, Ni and Zn contents were closely correlated with microbial indices in sandy loam but not in clay soils. Overall, the effect of treatments on microbial and extractable metal indices was greater in loams. Within a single series, higher organic soils showed less pronounced responses to metal inputs, although this trend was not always consistent.     

Cu accumulation in the earthworm Dendrobaena veneta in a heavy metal (Cu, Pb, Zn) contaminated site compared to Cu accumulation in laboratory experiments

Earthworms (Dendrobaena veneta) were exposed to heavy metal contaminated soil from a field site under both laboratory and field conditions. In the laboratory study, D. veneta were analysed for Cu after 2 weeks' exposure. The tissue Cu concentration (Cu(W)) increased proportionally with the total extractable soil Cu content (Cu(T)) in soils that contained less than 150 mg Cu kg(-1). In D. veneta exposed to soils containing more than Cu(T) = 150 mg kg(-1), however, we observed no further increase in Cu(W). In a 64-m(2) field plot at a contaminated site, 81 soil samples were taken and analysed for Cu, Pb, Zn and pH. In June 1994, 1000 D. veneta were homogeneously distributed in the plot and sampled after 1, 2 and 5 weeks to analyse for Cu. Additionally, 2000 D. veneta were introduced in September 1994 and sampled after 1, 2 and 4 weeks. At locations where earthworms were removed, the soil Cu content was estimated by disjunctive kriging. Cu concentration factors (ratio of Cu(W) to Cu(T)) in the field experiment were in excellent agreement with those of the laboratory experiment. This indicates that, with a sufficiently high sampling density, it may be feasible to predict earthworm Cu accumulation in the field using a concentration factor determined in the laboratory.     

Biochemical characterization of a multiple heavy metal, pesticides and phenol resistant Pseudomonas fluorescens strain

Pseudomonas fluorescens SM1 isolate was found to be resistant to some major water pollutants namely Cd2+, Cr6+, Cu2+, Ni2+, Pb2+, BHC, 2,4-D, mancozeb and phenols up to a concentration four times to the normal levels occurring in the highly pollulated regions. Curing experiment brought about the loss of one or more resistance markers indicating the plasmid born resistance. Plasmid profile of SM1 strain showed the presence of one DNA band of 43.6 kb. This Plasmid was isolated from SM1 strain and introduced into Escherichia coli DH5 alpha with a transformation frequency of 6.7 x 10(-4)transformants/recipient cell. The test SM1 strain was also capable of biotransforming Cr(VI) to Cr(III) which is less toxic compounds. Present studies further indicated that the test SM1 strain was not only resistant to 2,4-D, phenols and catechol but also capable of bioremediating these toxicants quite efficiently. Moreover, studies with inhibitors like sodium azide, 2,4-DNP and chloramphenicol suggested that the major mechanism for the bioremediation of the heavy metals other than Cr6+ would be the biosorption process.     

Effect of Chlorella pyrenoidosa on fecal excretion and liver accumulation of polychlorinated dibenzo-p-dioxin in mice

The effect of Chlorella pyrenoidosa on fecal excretion and liver accumulation of polychlorinated dibenzo-p-dioxin in C57BL/6N mice administered dioxin was examined. Mice were administered 2.2 microg of 1,2,3,4,7,8-hexachlorodibenzo-p-dioxin (H6CDD) dissolved in corn oil once after a period of acclimatization, after which they were fed either a basal diet, a 10% C. pyrenoidosa diet, or a 10% Spinach diet, for five weeks. Among mice fed the 10% C. pyrenoidosa diet, cumulative fecal excretion of H6CDD over the first week following administration was significantly greater (9.2-fold) than that observed among mice fed the basal diet. Moreover, excretion during the fifth week following administration of H6CDD was still significantly greater (3.1-fold) among mice fed the 10% C. pyrenoidosa diet than among mice fed the basal diet. Five weeks after administration of H6CDD, liver accumulation of H6CDD in mice fed the 10% C. pyrenoidosa diet was significantly less than that observed among mice fed either the basal diet and the Spinach diet (by 27.9% and 34.8%, respectively). These findings suggest that C. pyrenoidosa may be useful in inhibiting the absorption of dioxins via food and the reabsorption of dioxins stored already in the body in the intestinal tract, thus preventing accumulation of dioxins within the body.     

Biochemical toxicology of lindane and its analogs

The inhibitory potencies of BHC isomers against Na+-K+- ATPase, yeast growth and nerve conduction of the American cockroach were determined. The insecticidal and neuroexcitatory activities of a number of analogs with the same configuration as lindane in which some chlorine atoms had been replaced by other substituents were also examined against American cockroaches. The structure-activity relationships and the mode of action of lindane and its analogs were discussed. Their metabolic fate was studied extensively in vivo as well as in vitro. The critical step in the biodegradation of lindane is the cleavage of C-H bonds which we found by utilizing the isotope effect of hexadeuterated lindane.     

典型氯碱污染场地环境风险评价

以广东某氯碱化工污染场地为研究区域,采集了场地22个土壤及地下水样品,分析了25项污染物在不同区域的分布特征及其来源。监测结果表明,煤炭堆场与锅炉房区土壤受重金属铅、镍污染。六六六、四氯化碳、三氯甲烷、六氯苯、苯是场地的特征污染物,主要分布在危险品仓库、漂洗车间与四氯化碳车间。根据监测结果开展了不同暴露途径致癌风险值及非致癌危害商的计算。结果表明,部分样品表层土壤中上述有机污染物的基于人体健康致癌风险指数均超过10-6,最高达到1.65×10-2,表明风险水平高;非致癌危害在各暴露途径下也超过可接受值1,最高达5.59×104,表明风险水平高。说明对于存在高风险的区域必须进行采取合适的措施进行修复,减缓场地再利用后对人群健康的影响。