有机氯农药六六六污染土壤的植物修复研究

我国20世纪六七十年代大量施用的有机氯农药,由于其性质极其稳定,在土壤至今仍有残留。植物修复有机农药污染土壤并不多见,但具有广阔的应用前景。此项研究对提高土壤环境质量、保证农产品的安全、实现农业可持续发展等有着重要的理论和现实意义。文章以多花黑麦草(Lolium multiforum Lan.)、紫花苜蓿(Medicago sativa L.)和籽粒苋(Amaranthus hypochondriacus L.)作为供试植物,在有机氯农药六六六(HCH)质量分数为1.09 mg.kg-1的污染土壤中种植3个月,研究了种植不同植物条件下土壤中HCH的消解情况。研究结果表明,与对照相比,种植植物大大提高了土壤中微生物数量和酶的活性,并且微生物的数量和酶的活性与土壤中HCH的消解密切相关。试验结束后,不同处理中HCH及其4种异构体的总含量降低幅度为43.87%~65.79%,其中种植紫花苜蓿和多花黑麦草的处理中HCH消解较快,对HCH污染土壤修复的效果较好。可见,植物修复技术是一种可行的环境友好的修复六六六污染土壤的技术。     

Effects of the level of dietary protein on the toxicity of hexachlorocyclohexane in rats

Male albino rats were fed for 28 days from weaning on diets containing 5% (group 1), 10% (group 2) and 21% (group 3, normal protein) protein as casein. At the end of dietary period, HCH was administered daily for 30 days to investigate the interaction between protein deficiency and pesticide toxicity. The results indicated that rats fed a lower protein diet and HCH had a higher mortality, lower rate of growth, increased liver weight and deposition of the pesticide in blood and tissues in larger amounts. Blood pressure (systolic and diastolic) was significantly increased and the heart rate showed tachycardia in low protein exposed animals. A significant increase of total lipids, cholesterol, triglycirides, free fatty acids in serum and tissues of animals exposed to low protein was observed. A close correlation existed between lipid accumulation and storage of HCH in tissues and dietary protein seemed to play an important role in detoxification.     

Occupational exposures,delivered doses and exposure limits for chromium and nickel†

The interaction of HCH (50 mg/kg) and dietary protein levels on microsomal drug metabolizing enzymes system and liver lipids were studied in the rats for 90 days. The results indicated that rats fed a lower protein diet and HCH has a higher rate of mortality, lower rate of growth and an increased liver weight. A significant induction in the hepatic microsomal aminopyrine‐N‐demethylase, p‐nitroanisole‐O‐dealkylase, benzo(a)pyrene hydroxylase and glutathione‐S‐transferase activity was observed in pesticide treated animals as compared to control animals. The pathological changes observed in liver of HCH treated animals consisted mainly of necrosis and fatty degeneration of hepatocytes. HCH also induced the significant accumulation of cholesterol, triglycerides, phospholipid and total lipid in liver in low protein diet animals. Protein accelerates the metabolism of HCH, resulting in a decrease of HCH concentration with the increase of dietary protein level. A close correlation existed between lipid accumulation, induction of drug metabolizing enzyme system and deposition of HCH in liver.     

Accumulation of organochlorine insecticides in the blood of the general population of Nigeria

Gas Chromatographic determination of blood levels of organochlorine pesticides in people of Southern Nigeria is described. Among the compounds detected and quantified were the HCH‐isomers, DDT and its metabolites and dieldrin, the major pollutants being DDT, DDE and the HCH‐isomers. Delta‐HCH, HCB and Endrin were also detected in a few samples. Total DDT (DDT + DDE + DDD) ranged from 0.04–7.24 ppm, total HCH (alpha + beta + gamma) 0.08–5.64 ppm, and dieldrin 0.03–0.28 ppm.     

Influence of cadmium on the storage and metabolism of HCH in rats

Male albino rats were administered Cd and HCH daily for six weeks to study the effect of Cd on storage and metabolism of HCH. The results indicated a marked inhibition of the metabolism of HCH in the group dosed with HCH + Cd. The metabolic rate of HCH in the group dosed with HCH + Cd was also significantly lower than that in the group dosed with HCH alone. The hepatic content of Cd and Zn was significantly increased whereas a marked depletion of Cu and Fe was observed in the groups exposed to Cd and HCH + Cd. A high level of free Cd and Zn or a low level of Fe and Cu in liver seemed to play an important role in the metabolic inhibition observed in this study.     

Factors affecting HCH and DDT in soils around watersheds of Beijing reservoirs,China

The factors that influence the dynamics of hexachlorocyclohexane (HCH) and dichlorodiphenyltrichloroethane (DDT) in soils around the watersheds of Beijing reservoirs were examined. Compared with other studies on HCH and DDT in soils and established reference values, the concentrations of HCH and DDT in soils around our study area were relatively low. The relationships between HCH and DDT concentrations and land use, soil texture, and soil properties were discussed. HCH and DDT concentrations were higher in arable soils than those in uncultivated fallow soils. Although land use was the most important factor affecting HCH and DDT residues, additional factors such as soil texture and soil total organic carbon were also involved in pesticide retention in soils. The results indicated that the historical agricultural applications of HCH and DDT were the major source of their residues. Atmospheric deposition, as well as long-distance transportation and inputs from surrounding weathered agricultural soils may also serve as important sources of HCH and DDT residues in the watersheds.     

The concentration and distribution of organochlorine pesticides in the air from the karst cave, South China

Organochlorine pesticides (OCPs) in the air of Dayan Cave in Guilin were analyzed, to investigate the source and contamination levels. Generally, air outside of the cave had much higher concentrations than inside air, and both outside and inside air showed much lower contamination levels than those observed in other regions in China and abroad. The ratios of α-/γ-HCHs and the percentages of β-(or δ-)HCH implied a residue of historical local technical HCH contamination. The DDT concentrations, o,p'-DDT/p,p'-DDT, and p,p'-DDE/p,p'-DDT suggested fresh DDT-containing products acted as the primary source of DDT for the air in Dayan Cave. An intermediate level concentration of α-endosulfan (156.00?pg/m(3)) was observed in the outside air, implying local source was dominant. Based on the similar sources of HCH and DDT and the relationships between outside and inside air, it appeared that outside air pollutants affected on inside HCH and DDT's distribution. For other OCPs, outside air might be major contributor to inside air contamination under conditions of high concentrations in outside air compared with low levels in inside air for semi-closed karstic caves.     

珠江八大入海口表层沉积物中DDTs和HCHs残留调查

于2010年8月-2011年5月4次采集珠江八大人海口表层沉积物,采用气相色谱-电子捕获（GC—ECD）法分析沉积物中DDTs（p,P’-DDE、P,P’-DDD、0,P’-DDT、P,P-DDT）和HCHs（α-HCH、β-HCH、γ-HCH、δ-HCH）的污染现状。结果显示,珠江8大人海口表层沉积物中DDTs总含量介于1．02—3．08μg·kg-1之间（以干质量计,下同）,平均值为1．91μg·kg-1;HCHs总含量介于0．21—0．41μg·kg-1之间,平均值为0．31μg·kg-1。DDTs平均含量大于HCHs,其中P,P。DDT对污染的贡献最大,含量范围为ND～7．66μg·kg-1,平均值为2．12μg·kg-1。大部分样点伽（α-HCH）／w（γ-HCH）比值小于3,说明研究区α-HCH大都被降解,或者林丹正取代工业HCHs成为珠江口水环境中HCHs输入的主要来源;甜（DDT）／w（DDD＋DDE）比值大于2,表明沉积物中除早期农药残留外,仍然有新的DDTs类农药输入。     

Distribution of organo-chlorine pesticides (DDT and HCH) between plant and soil system

This paper reports a study of the distribution of organo-chlorine pesticides (DDT and HCH) between rice plants and the soil system by spraying before the heading stage at four different dosage levels--control, normal dosage (15 kg ha(-1) of 6% HCH and 7.5 kg ha(-1) of 25% DDT), double dosage and four times dosage. Soil and plant samples were taken respectively at the 1st h, 3rd, 10th, 20th, and 40th day after spraying and at the harvest time. The results indicate that less than 5% of HCH and 15% of DDT were absorbed by the surface of rice leaves for normal dosage. Most of both pesticides moved into the soil in solution after spraying. Compared with DDT, HCH was degraded and run off more easily. HCH residues in the surface soil layer (1-3 cm) were already below 6.4 microg kg(-1) at the mature stage, lower than Chinese Environmental Quality Standard for Agricultural Soils: HCH < 0.05 mg kg(-1). However DDT residues in the surface soil layer remained 172 microg kg(-1), higher than the national standard: DDT < 0.05 mg kg(-1). According to the test f OCP residues in rice seeds, it can be concluded that the OCP sprayed onto the surface of rice leaves can move into rice plants and accumulate in the seeds at the mature stage. HCH residues in rice seeds of the double and four times dosage treatments, and DDT residues in all treatments, exceeded the Chinese National Food Standard (HCH < 0.10 mg kg(-1), DDT < 0.20 mg kg(-1)).     

Spatial variability and temporal trends of HCH and DDT in soils around Beijing Guanting Reservoir,China

Spatial variability and temporal trends in concentrations of the organochlorine pesticides (OCPs), hexachlorocyclohexane (HCH) and dichlorodiphenyltrichloroethane (DDT), in surface soils around Beijing Guanting Reservoir (GTR) were studied in 2003 and 2007. Concentrations of the two OCPs in soils around GTR were generally less than reference values set by the Chinese government for the protection of agricultural production and human health. Among the OCPs, β-HCH and p, p′-DDE were the two predominant compounds. This result indicates that the HCH and DDT residues in soils were primarily from historical use. Based on kriging, a spatial distribution of HCH and DDT around the GTR was observed. Spatial variability indicated how HCH and DDT had been applied and been distributed in the past. Between 2003 and 2007, concentrations of HCH and DDT decreased more rapidly in orchard soils than those in fallow soils.     

Effect of anti-juvenile hormone agent,KK-42 on the incorporation rate of radioactive glycine and biosynthesis of silk proteins of silkworm,Bombyx mori L.

The effects of anti-juvenile hormone agent, KK-42 on incorporation rate of radioactive glycine in cocoon crop production and biosynthesis of silk proteins of silkworm, Bombyx mori L. were studied in a popular bivoltine silkworm hybrid, Xinhang (Chinese) × Keming (Japanese). Administration of KK-42 on first day larvae of fourth instar induced 100% trimolters, and the total larval duration was shortened by four days, which has marked advantages in sericulture. The impact of KK-42 on enhanced incorporation rate of radioactive glycine, cocoon weight, RNA content, and fibroin content was significant compared to control, which leads to superior quality of silk. This has a significant economic importance in the reeling industry.     

Polychlorinated biphenyls and Organochlorine insecticides residues in fish and shellfish from lake Biwa

Results of surveys on Polychlorinated biphenyls (PCB) and organochlorine insecticides (HCH and DDT) in fish and shellfish from Lake Biwa were summarized from 1987 to 1996. In 1975, fish and shellfish in Lake Biwa were highly contaminated with PCB, HCH and DDT but recently in 1992–1996 the concentrations of these chemicals were very low and nearly constant. In the composition of HCH isomers, β‐HCH was dominant in all kinds of fish and shellfish. In the composition of DDT and DDT metabolites, pp'‐DDE was similarly dominant in all kinds of fish and shellfish. Further, the data in Lake Biwa were compared with those in Lake Michigan and Lake Baikal.     

HCH residues in point-source contaminated samples of the Teltow Canal in Berlin,Germany

Contaminated groundwater and a riverine sediment core heavily affected by the same industrial point source were analysed for hexachlorocyclohexanes (HCH) and its degradation products. A detailed quantification by GC/MS revealed contamination levels up to 730 μg/L and 396 ng/g in sum for the water and sediment samples, respectively. The isomer pattern differed significantly in both compartments. The ground water samples were depleted in γ-HCH, whereas a significant loss of α-HCH was evident in the sediments as compared to the technical composition. The data obtained revealed interesting insights into the transformation behaviour and fate of HCH mixtures in anaerobic environmental compartments. In the affected groundwater system an ongoing microbial degradation was pointed out by the identification of indicative anaerobic metabolites. On the contrary in the sedimentary system a high environmental stability or rather a hindered degradation was observed as indicated by unaltered concentration levels as compared to production rates as well as by the absence of metabolites. Interestingly, the environmental fate of HCH in subaquatic sediments as well as in anaerobic ground water differs highly in contrast to the behaviour in anaerobic soil or surface water systems. Further on, it has to be stated, that the knowledge about the long-term behaviour of HCH residues in sedimentary material under anaerobic conditions is rather limited so far.     

Organochlorine pesticides (HCHs and DDTs) in soils along the north coastal areas of the Bohai Sea,China

A systematic survey of organochlorine pesticides (OCPs) including hexachlorocyclohexane isomers (α-HCH, β-HCH, γ-HCH, δ-HCH and ΣHCH) and dichlorodiphenyltrichloroethane metabolites (p,p′-DDT, p,p′-DDE, o,p′-DDT, p,p′-DDD and ∑DDT) in soils along the north coastal areas of the Bohai Sea, China, has been lacking. In this study, 31 representative surface soil samples were collected along the north coastal and riverine areas of the Bohai Sea to characterise the potential for adverse effects of ∑HCH, ∑DDT and their individual isomers and transformation products. Concentrations of ΣHCH and ΣDDT in soils ranged from less than the limit of detection (1 ng · g^?1 dw (mean: 3.5 ng · g^?1 dw) and2 ng · g^?1 dw (mean: 1.7 × 10¹ ng · g^?1 dw), respectively. Compared with studies of OCPs in soils from other locations, concentrations of HCHs and DDTs observed in this study were moderate. Concentrations of OCPs observed in soils were generally less than proposed reference values. HCH residues were a mixture of historical technical HCH and current lindane sources. The pattern of DDTs was consistent with historical releases of technical DDTs. Selected soil physicochemical properties did not explain the sorption and/or partitioning of HCHs or DDTs.     

Residues of 14C‐γ‐HCH in paddy after dusting,and the fate of γ‐HCH during refining process of rice bran oil

Paddy (rice) plants were dusted with 10% HCH containing ¹⁴C‐Γ‐HCH, at the rate of 2.5 kg a.i./ha and ¹⁴C‐residues were determined in different fractions of rice. Rice bran (0.187 ppm) had more of ¹⁴C‐residues than grain (0.026 ppm) and husk (0.042 ppm). The rice bran oil contained 0.129 ppm HCH residues. While degumming, dewaxing, alkali refining and bleaching had no effect, deodorisation alone eliminated 99.5% of added ¹⁴C‐residues in rice bran the oil during refining process.     

Concentrations of Hchs and Ddts in the Tissues of River Dolphins,Platanista Gangetica,From the River Ganges,India

Abstract

Concentrations of HCH and DDT organochlorine insecticide residues were measured in blubber, muscle and oil samples from three specimens of river dolphins, Platanista gangetica, from the River Ganges, India. Concentrations of HCH and DDT ranged from 94 to 289 ng g^?1 and from 1324 to 9388 ng g^?1 on wet wt. basis respectively. Comparisons are made with other aquatic mammals and other studies on river dolphins. P. gangetica appears to exhibit similar patterns of accumulation with age and with ß-HCH and p-p′-DDE being accumulated to higher levels than other HCH isomers and parent DDT and its other metabolites, respectively. These organochlorines may pose a health risk to river dolphin populations that are already showing evidence of environmental stress. Further studies are recommended.     

Biodegradation of Hexachlorocyclohexane by two species of Bacillus isolated from contaminated soil

Biodegradation of α, β, γ and δ hexachlorocyclohexane (HCH) isomers was studied in broth medium and soil microcosm by Bacillus circulans and Bacillus brevis isolated from contaminated soil. Degradation of α and γ isomers by both the bacterial isolates was higher than thermodynamically stable β and δ isomers. However, B. circulans was found more effective than B. brevis for β and δ isomers. Maximum rate of degradation was recorded at 150 mg/L followed by 100 and 50 mg/L. Soil microcosm study revealed maximum degradation of HCH isomers in the treatment containing natural soil, pesticide and bacterial inocula than the treatment having sterilised soil, pesticide and bacterial isolates. Chloride release was positively co-related with HCH degradation in broth medium as well as in soil microcosm, suggesting that B. circulans and B. brevis hold promising potential by having efficient enzyme(s) required for dechlorination of HCH from contaminated sites.     

Distribution of Organo-Chlorine Pesticides (DDT and HCH) Between Plant and Soil System

This paper reports a study of the distribution of organo-chlorine pesticides (DDT and HCH) between rice plants and the soil system by spraying before the heading stage at four different dosage levels – control, normal dosage (15 kg ha^–1 of 6% HCH and 7.5 kg ha^–1 of 25% DDT), double dosage and four times dosage. Soil and plant samples were taken respectively at the 1st h, 3rd, 10th, 20th, and 40th day after spraying and at the harvest time. The results indicate that less than 5% of HCH and 15% of DDT were absorbed by the surface of rice leaves for normal dosage. Most of both pesticides moved into the soil in solution after spraying. Compared with DDT, HCH was degraded and run off more easily. HCH residues in the surface soil layer (1–3 cm) were already below 6.4 g kg^–1 at the mature stage, lower than Chinese Environmental Quality Standard for Agricultural Soils: HCH <0.05 mg kg^–1. However DDT residues in the surface soil layer remained 172 g kg^–1, higher than the national standard: DDT <0.05 mg kg^–1. According to the test f OCP residues in rice seeds, it can be concluded that the OCP sprayed onto the surface of rice leaves can move into rice plants and accumulate in the seeds at the mature stage. HCH residues in rice seeds of the double and four times dosage treatments, and DDT residues in all treatments, exceeded the Chinese National Food Standard (HCH <0.10 mg kg^–1, DDT <0.20 mg kg^–1).     

Acute toxicity evaluation of copper,arsenic and HCH to paddy field crab,Paratelphusa hydrodromus (Herb.)

Routine static tests were conducted for determining the median lethal tolerance limit of paddy field crab, Paratelphusa hydrodromus exposed to Copper, Arsenic and HCH at different time intervals of 24, 48, 72 and 96 hour. The LC50 values for Copper came to be 28.00, 22.00, 18.20 and 15.70 ppm; Arsenic 136.00, 128.00, 121.500 and 114.00 ppm and HCH 10.00, 8.80, 7.00 and 6.00 ppm, respectively. The safe concentration, application factor and safe application rate were also calculated. They were for, Copper: 5.56, 1.59 and 3.26 ppm, Arsenic: 38.53, 11.40 and 76.00 and HCH : 4.07, 0.06 and 1.28 ppm. Animals exposed to different concentrations of test chemicals (Copper, Arsenic and HCH) showed prominent behavioural/morphological alterations viz., coughing, redness on the ventral side, paralysis and disorientation in scaphognathite activity. Animals exposed to high concentrations showed an avoidance behaviour by keeping away from the direct contact with the toxic solution either by climbing on the wall of aquarium or by mounting over the weak individual and forming a type of pyramid.     

Contamination,spatial distribution,and source contribution of persistent organic pollutants in the soil of Guiyang city,China: a case study

Environmental Geochemistry and Health - The contamination of persistent organic pollutants (POPs), including dichlorodiphenyltrichloroethane (DDT), hexachlorocyclohexane (HCH), and polycyclic...