厦门海域贝类养殖环境中有机氯农药的积累和降解

利用气相色谱法(GC-ECD)对厦门海域贝类养殖环境(海水、底质和养殖贝类)中有机氯农药六六六(HCH)和滴滴涕(DDT)的含量进行了调查分析,初步探讨了贝类养殖环境中HCH和DDT的积累和降解规律.结果表明:厦门海域不同种贝类养殖环境中HCH和DDT的积累和降解存在明显差异,主要与各种贝类的栖息环境和生理生活习性有关.贝类养殖环境中处于积累状态(Rx＞1)的主要为p-HCH、δ-HCH和γ-HCH;处于降解状态(Rx＜1)的主要为α-HCH.α-HCH/γ-HCH的比值≤1.0,贝类养殖环境中的HCH来源于工业品HCH和林丹,大部分HCH为长时间残留,但尚有少量林丹输入.贝类养殖区海水中DDT主要为好氧降解,底质中主要为厌氧降解.海水中的降解产物主要为DDE,(DDD+ DDE )/DDTs(p,p-DDE+p,p-DDD+o,p-DDT+p,p-DDT)的比值＜0.5;底质和养殖贝类体中的降解产物主要为DDD,(DDD+DDE)/DDTs的比值＞0.5,贝类养殖区底质和养殖贝类体中的DDT大部分已降解为DDD和DDE,海水中尚有少量新的DDT输入.贝类养殖环境中HCH异构体降解率的高低顺序存在一定差异,其在贝类养殖生态系中的迁移、转化过程发生了构象变化.     

Determination of organochlorine pesticides in agricultural soil with special reference to gamma-HCH degradation by Pseudomonas strains

Soil samples were taken from different agricultural fields and analyzed for organochlorine pesticide residues by gas chromatography. The analysis indicated that the soil samples contained some common organochlorine pesticides DDT, DDD, DDE, HCH and Aldrin. gamma-HCH was detected as 47.35 ppb whereas the concentrations of alpha-HCH, beta-HCH, p('),p(')-DDE, o('),p(')-DDT were 38.81, 1.79, 7.10 and 13.30 ppb, respectively, in the same soil. Two Pseudomonas strains isolated from agricultural soil were found to possess gamma-hexachlorocyclohexane degrading ability when the isolates were grown in a mineral salt medium containing gamma-HCH as the sole source of carbon and a number of metabolites were produced and detected by the gas chromatography. These bacterial isolates were further tested for carbohydrate and amino acid utilization as well as for their susceptibility against 10 commonly used antibiotics namely amoxycillin, chloramphenicol, cloxacillin, doxycycline, methicillin, nalidixic acid, neomycin, nitrofurantoin, streptomycin and tetracycline. Both the isolates were also screened for plasmid DNA and found to harbour a single plasmid.     

Chemical-toxicological characteristic property of organochlorine pesticide transformation products formed under the effect of intensive fluxes of gamma-irradiation

The results of formation of stable products of organochlorinated pesticides (OCP) under gamma-irradiation (dose 10 kGy, dose rate 0.026, 0.14 kGy/min) are discussed in the article. The model solutions of alpha-,gamma-hexachlorocyclohexane (alpha-,gamma-HCH), p,p-dichlorodiphenyl-trichloroethane (p,p-DDT) and p,p-dichlorophenyl-dichloroethylene (DDE), with initial concentrations of 1.0-0.1 ppm, were exposed to gamma-radiation. Among the products of OCP radiolysis such compounds as DDE, 2,2-di(chlorophenyl)-1-chloroethylene, dichlorophenyl-dichloroethane and various isomers of HCH were found. It was shown that taking in account the whole data on the formed metabolites the toxicological characteristics of pesticide solutions cannot be improved by exposure to gamma-radiation.     

Elevated Concentrations of Pesticides and PCBs in Soils at the Southern Caspian Sea (Iran) are Related to Land Use

Soil contamination by organochlorine pesticides or PCBs is almost undocumented for Iran. Here we report a soil survey in Mazandaran and Guilan provinces that hold >30% of the agricultural areas of Iran where pesticide use is widespread. Concentration of DDTs, HCHs, cyclodienes, and PCBs were measured in 45 soil samples from different agricultural land uses and forest land. The average concentrations of ∑DDT (37 μg kg^?1) and ∑HCH (21 μg kg^?1) in agricultural soils are among the largest ever reported and exceed international soil screening standards. All residues were larger in agricultural than in forest soil. Within agricultural land, ∑DDT were largest for tea gardens, lindane was largest in rice fields, and cyclodiens largest in citrus orchards. The ratio of (DDD + DDE)/DDT is an index of the extent of DDT degradation in soil and was lower in tea gardens than in other soils (0.7 versus 2–5), indicating either ongoing DDT input or lower degradation rate in the tea gardens that are more acid than the other soils (pH 4.5 versus 6.5–7.0). The o,p′–DDT/p,p′–DDT ratio was about 3 in forest soils, suggesting that DDT is derived from dicofol application and not from technical DDT as in agricultural soils. The PCB 28, 180, and 138 showed the highest mean concentration compared with other PCB congeners in all land uses. This survey is the first of this kind for Iran and illustrates that concentrations of organochlorine pesticide in soil are relatively large.     

Bioremediation of DDT in soil by genetically improved strains of soil fungus Fusarium solani

Bioremediation of DDT in soil by genetically improved recombinants of the soil fungus Fusarium solani was studied. The parent strains were isolated from soil enriched with DDD or DDE (immediate anaerobic and aerobic degradation products of DDT), as further degradation of these products are slow processes compared to the parent compound. These naturally occurring strains isolated from soil, however, are poor degraders of DDT and differed in their capability to degrade its metabolites such as DDD, DDE, DDOH and DBP and other organochlorine pesticides viz. kelthane and lindane. Synergistic effect was shown by some of these strains, when grown together in the medium containing DDD and kelthane under mixed culture condition. No synergism in DDE degradation was observed with the strains isolated from enriched soil. DDD-induced proteins extracted from individual culture filtrate (exo-enzyme) when subjected to SDS-Polyacrylamide Gel Electrophoresis (SDS-PAGE) showed complementary polypeptide bands in these strains i.e., each strain produced distinct DDD degrading polypeptide bands and the recombinant or hybrid strains produced all of the bands of the two parents and degraded DDD better than the parental strains. Recombinant hybrid strains with improved dehalogenase activity were raised by parasexual hybridisation of two such complementary isolates viz. isolate 1(P-1) and 4(P-2) showing highest complementation and are compatible for hyphal fusion inducing heterokaryosis. These strains are genetically characterised as Kel⁺Ben^RDBP^-Lin^- and Kel^-Ben^rDBP⁺Lin⁺ respectively.Recombinants with mixed genotype, i.e., Kel⁺Ben^RDBP⁺Lin⁺ showing superior degradation quality for DDT were selected for bioremediation study. Recombination was confirmed by polypeptide band analysis of DDD induced exo-proteins from culture filtrate usingSDS-Polyacrylamide Gel Electrophoresis (PAGE) and RAPD (Random Amplified Polymorphic DNA) of genomic DNA using PCR (Polymerase Chain Reaction) technique. SDS-PAGE showed combination of DDD induced polypeptide bands characteristic of both the parents in the recombinants or the hybrids. PCR study showed the parent specific bands in the recombinant strains confirming gene transformation.     

Biochar in Co-Contaminated Soil Manipulates Arsenic Solubility and Microbiological Community Structure,and Promotes Organochlorine Degradation

We examined the effect of biochar on the water-soluble arsenic (As) concentration and the extent of organochlorine degradation in a co-contaminated historic sheep-dip soil during a 180-d glasshouse incubation experiment. Soil microbial activity, bacterial community and structure diversity were also investigated. Biochar made from willow feedstock (Salix sp) was pyrolysed at 350 or 550°C and added to soil at rates of 10 g kg^-1 and 20 g kg^-1 (representing 30 t ha^-1 and 60 t ha^-1). The isomers of hexachlorocyclohexane (HCH) alpha-HCH and gamma-HCH (lindane), underwent 10-fold and 4-fold reductions in concentration as a function of biochar treatment. Biochar also resulted in a significant reduction in soil DDT levels (P < 0.01), and increased the DDE:DDT ratio. Soil microbial activity was significantly increased (P < 0.01) under all biochar treatments after 60 days of treatment compared to the control. 16S amplicon sequencing revealed that biochar-amended soil contained more members of the Chryseobacterium, Flavobacterium, Dyadobacter and Pseudomonadaceae which are known bioremediators of hydrocarbons. We hypothesise that a recorded short-term reduction in the soluble As concentration due to biochar amendment allowed native soil microbial communities to overcome As-related stress. We propose that increased microbiological activity (dehydrogenase activity) due to biochar amendment was responsible for enhanced degradation of organochlorines in the soil. Biochar therefore partially overcame the co-contaminant effect of As, allowing for enhanced natural attenuation of organochlorines in soil.     

Assessment of the Genotoxic Potential of Sediments Contaminated with POPs and Agricultural Soils Using Vicia faba Micronucleus Assay

The aim of this study was to assess the levels of some persistent organic pollutants in the surface sediments from the Zahuapan and Atoyac rivers (Tlaxcala, Mexico), as well as to determine the genotoxic potential, by the micronucleus test in Vicia faba, of the sediments and agricultural soils irrigated with water from these rivers. This document is the first study on the presence of POPs in surface sediments of the above-mentioned rivers; among the compounds analyzed are the HCH isomers, DDT and its metabolite DDE, HCB, mirex, aldrin, and 41 PCB congeners. The concentrations of HCB, ΣDDTs, ΣHCHs, and ΣPCBs ranged from 138–510, 45–450, 3–27, and 59–1876 μg kg^?1 dry weight, respectively. The highest levels of HCB, HCH isomers, and PCB congeners were found in the Atoyac River, and these compounds have the potential for causing an environmental impact. On the other hand, biological testing shows that both sediments and agricultural soils possess a genotoxic potential, given that the micronuclei frequency in V. faba is increased.     

太湖湿地生态系统有机氯污染的夜鹭生物指示

1999年春季,在对无锡鼋头渚鹭鸟种群野外生态调查的基础上,对夜鹭幼鸟反吐物,觅食地底泥和水体进行了采样,并在实验室用气相色谱测定了样品中的α-HCH、β-HCH、γ-HCH、艾氏剂、狄氏剂、异狄氏剂、七氯、环氧七氯、p,p'-DDE、p,p'-DDD、o,p'-DDT和p,p'-DDT等有机氯农药的残留状况,结果表明,在有机氯农药禁用近20年后,六六六的异构体和滴滴涕及其衍生物均能在环境中和夜鹭食物中有不明,在有机氯农药禁用近20年后,六六六的异构体和滴滴涕及其衍生物均能在环境中和夜鹭食物中有不明,在有机氯农药禁用近20年后,六六六的异构体和滴滴涕及其衍生物均能在环境中和夜鹭食物中有不检出,有机氯污染物沿夜鹭食物链产生逐级富集,太湖湿地生态系统中夜鹭卵富集了滴滴涕万倍以上,富集了六六六数千倍,从而使有机氯污染物易被检测,因此夜鹭锘放可作为湿地生态系统有机氯污染的生物指示物。     

Diversity, distribution and divergence of lin genes in hexachlorocyclohexane-degrading sphingomonads

Two forms of hexachlorocyclohexane (HCH), gamma-HCH (lindane) and technical HCH (incorporating alpha-, beta-, gamma- and delta- isomers), have been used against agricultural pests and in health programs since the 1940s. Although all the isomers are present in the milieu, delta- and beta-HCH isomers are the most problematic and present a serious environmental problem. Bacteria that degrade HCH isomers have been isolated from HCH contaminated soils from different geographical locations around the world (from the family Sphingomonadaceae). Interestingly, all these bacteria contain nearly identical lin genes (responsible for HCH degradation), which are diverging to perform several catabolic functions. The organization and diversity of lin genes have been studied among several sphingomonads, and they have been found to be associated with plasmids and IS6100, both of which appear to have a significant role in their horizontal transfer. The knowledge of the molecular genetics, diversity and distribution of lin genes, and the potential of sphingomonads to degrade HCH isomers, can now be used for developing bioremediation techniques for the decontamination of HCH contaminated sites.     

松辽流域河流表层沉积物中有机氯农药的分布特征

利用气相色谱-电子捕获检测器(gas chromatography-electron capture detector,GC-ECD)对松辽流域重点污染河流22个表层沉积物样品的13种有机氯农药进行了分析.结果表明,大辽河流域有机氯农药含量为3.06～23.24 ng·g^-1,松花江流域为4.26～18.45 ng·g^-1.松辽流域沉积物中主要有机氯农药为六六六(HCH),松花江流域和大辽河流域表现出了不同的污染趋势.松花江沉积物中也有较高的滴滴涕(DDT)残留量.整个松辽流域都有较高含量的丙体六六六(γ-HCH),超过了其初始效应浓度,可能对该地区水生生物产生毒性效应.     

Effects of lindane on steroidogenesis and steroidogenic acute regulatory protein expression

Lindane, the gamma isomer of hexachlorocyclohexane (HCH), is one of the oldest synthetic pesticides still in use worldwide. Numerous reports have shown that this pesticide adversely affects reproductive function in animals. Although the pathogenesis of reproductive dysfunction is not yet fully understood, recent reports indicate that lindane can directly inhibit adrenal and gonadal steroidogenesis. Because Leydig cells play a pivotal role in male reproductive function through the production of testosterone, the mouse MA-10 Leydig tumor cell line was used to assess the potential effects of gamma-HCH and its isomers, alpha-HCH and delta-HCH, on steroid production, steroidogenic enzyme expression and activity, and steroidogenic acute regulatory (StAR) protein expression. StAR mediates the rate-limiting and acutely regulated step in hormone-stimulated steroidogenesis, the intramitochondrial transfer of cholesterol to the P450(scc) enzyme. Our studies demonstrate that alpha-, delta-, and gamma-HCH inhibited dibutyryl ([Bu](2)) cAMP-stimulated progesterone production in MA-10 cells in a dosage-dependent manner without affecting general protein synthesis; and protein kinase A or steroidogenic enzyme expression, activity, or both. In contrast, each of these isomers dramatically reduced (Bu)(2)cAMP-stimulated StAR protein levels. Therefore, our results are consistent with the hypothesis that alpha-, delta-, and gamma-HCH inhibited steroidogenesis by reducing StAR protein expression, an action that may contribute to the pathogenesis of lindane-induced reproductive dysfunction.     

c-fos Expression as a Model for Studying the Action of Hexachlorocyclohexane Isomers in the CNS

The induction of protooncogene c-fos in the CNS after administration of several convulsants has been studied. The organochlorine insecticide gamma-hexachlorocyclohexane (gamma-HCH, lindane) has been shown to induce c-fos expression in different brain areas. Pentylenetetrazole and picrotoxin, a known gamma-aminobutyric acid-receptor antagonist, have also been considered. The administration of two nonconvulsant isomers of gamma-HCH, alpha-HCH, and delta-HCH, before the mentioned toxicants, affects the protooncogene expression in different ways. The differential pattern of expression displayed by c-fos after these treatments suggests the presence of diverse mechanisms of action for the compounds studied.     

Differential presynaptic effects of hexachlorocyclohexane isomers on noradrenaline release in cerebral cortex.

To investigate presynaptic effects of hexachlorocyclohexane (HCH) isomers, the release of noradrenaline (NA) in brain tissue was analyzed using rat cerebral cortical slices preloaded with [3H]-NA. gamma-HCH (lindane) 50 microM significantly enhanced the [3H]-NA release evoked by 15-25 mM K+. alpha- and beta-HCH (50 microM) did not produce any significant effect on K(+)-evoked [3H]-NA release. delta-HCH (50 microM) induced a significant decrease of the 25 mM K(+)-evoked release of [3H]-NA. The effect of the gamma- and delta-HCH isomers on the presynaptic action of the alpha 2-agonist clonidine and the alpha 2-antagonist yohimbine was also studied. The presynaptic inhibitory effect of clonidine and the stimulatory effect of yohimbine on [3H]-NA release was attenuated by lindane and delta-HCH, respectively. These results are consistent with a presynaptic action of the HCH isomers on noradrenergic release processes.     

Organochlorine pesticides in Cyprinus carpio from Sidi Salem Dam,north-western Tunisia

Cyprinus carpio (Linnaeus, 1758) caught in Sidi Salem Dam in 2011 were analysed for the levels of organochlorine pesticides (OCPs), including hexachlorobenzene (HCB), aldrin, heptachlor, lindane, dieldrin, endrin, and pp′-DDT and its two main metabolites pp′-DDD and pp′-DDE, in order to evaluate the extent of contamination of the dam. Fish were sampled monthly within the dam during 2011. Muscle, liver and gill tissues were analysed by gas chromatography for the determination of OCPs. Samples had variable concentrations of OCPs, ranging from 2.26 to 17.93 ng g?1, 0.59 to 42.67 ng g?1 and 3.30 to 84.27 ng g?1, which were isolated from gills, muscle and liver, respectively. The organochlorine pesticide levels found posed no threat to human health. The highest OCP levels were found in the liver tissues. The pp′-DDE concentrations and their ratios to ΣDDTs indicate aged DDT pollution and suggests that there has been no recent input of technical DDT from the agricultural areas into Sidi Salem Dam.     

白鹭作为无锡太湖地区环境污染指示生物的研究

2000年4—6月对分布在无锡太湖地区的4种要鸟中的白鹭(Egretta garzetta)行为生态学及其生境污染状况进行了调查研究．调查地白鹭主要栖息树种包括马尾松(Pnus masson±ana)、香樟树(C±nnamomum hupehanum)、麻砾树(Quercus acut±ssema)、榆树(Ulmus prm±la)和杨梅树（Myr±ca rubra)．栖息地总面积为7hm^2,白鹭总巢数为4200个,每棵树平均0．38个．白鹭的孵化期为19—21d,卵重23．9±4．0g(n=41),平均卵大小(44．5±4．1)mm×(32．6±4．9)mm(n＝41),平均窝卵数5．02(2—8)枚,平均窝雏数3．86(2—7)只,孵化成功率为84．25％．对白鹭雏鸟左右跗Zhe的测量分析表明不对称性不显著(P>0．05)．白鹭雏鸟食物较小,繁殖期间主要以小型鱼类和虾类为食．污染物分析结果表明,白鹭卵中除例外,六氯苯、六六六、环二烯类、DDTs、DDE、PCBs、Cr、Hg和Pb均检测到．食物链(底泥-食物-白鹭雏鸟)中,有机杀虫剂和重金属都逐级富集．通过与相对无污染的鄱阳湖地区比较,太湖地区和鄱阳湖地区卵样品中的DDs(包括DDT、DDE和DDD)浓度最高(超过2μg·g^1),其它污染物浓度均较小．太湖地区白鹭卵中的DDTs、Cd和Cr浓度低于鄱阳湖地区,其它污染物浓度鄱阳湖地区均低于太湖地区．经比较分析,两地样品中有机氯杀虫剂、PCBs和各种重金属浓度都未达到影响白鹭繁殖成功率的阈值．     

Pseudomonas sp. to Sphingobium indicum: a journey of microbial degradation and bioremediation of Hexachlorocyclohexane

The unusual process of production of hexachlorocyclohexane (HCH) and extensive use of technical HCH and lindane has created a very serious problem of HCH contamination. While the use of technical HCH and lindane has been banned all over the world, India still continues producing lindane. Bacteria, especially Sphingomonads have been isolated that can degrade HCH isomers. Among all the bacterial strains isolated so far, Sphingobium indicum B90A that was isolated from HCH treated rhizosphere soil appears to have a better potential for HCH degradation. This conclusion is based on studies on the organization of lin genes and degradation ability of B90A. This strain perhaps can be used for HCH decontamination through bioaugmentation.     

Differential Effect of DDT,DDE, and DDD on COX‐2 Expression in the Human Trophoblast Derived HTR‐8/SVneo Cells

The purpose of this study was to investigate the effect of 1,1,1‐trichloro‐2,2‐bis‐(chlorophenyl)ethane (DDT), 1,1‐bis‐(chlorophenyl)‐2,2‐dichloroethene (DDE), and 1,1‐dichloro‐2,2‐bis(chlorophenyl)ethane (DDD) isomers on COX‐2 expression in a human trophoblast‐derived cell line. Cultured HTR‐8/SVneo trophoblast cells were exposed to DDT isomers and its metabolites for 24 h, and COX‐2 mRNA and protein expression were assessed by RT‐PCR, Western blotting, and ELISA. Prostaglandin E₂ production was also measured by ELISA. Both COX‐2 mRNA and protein were detected under control (unexposed) conditions in the HTR‐8/SVneo cell line. COX‐2 protein expression and prostaglandin E₂ production but not COX‐2 mRNA levels increased only after DDE and DDD isomers exposure. It is concluded that DDE and DDD exposure induce the expression of COX‐2 protein, leading to increased prostaglandin E2 production. Interestingly, the regulation of COX‐2 by these organochlorines pesticides appears to be at the translational level. © 2012 Wiley Periodicals, Inc. J Biochem Mol Toxicol 26:454‐460, 2012; View this article online at wileyonlinelibrary.com . DOI 10:1002/jbt.21444     

A Comparison of Ultrasonication and Soxhlet Methods for DDT Extraction from Soil

The goal of this study was to determine the efficacy of ultrasonication extraction of 1,1,1-trichloro-2,2-bis[p-chlorophenyl]ethane (DDT), 1,1-dichloro-2,2-bis[p-chlorophenyl]ethane (DDD), and 2,2-bis[p-chlorophenyl]1,1-dichloro-ethylene (DDE) residues in soil for the purposes of saving time, minimizing generation of hazardous solvent wastes, and reducing costs associated with monitoring contaminant concentrations at remediation sites. An ultrasonic extraction method was developed for DDT, DDD, and DDE residues in soil, and the efficiency of extraction using an ultrasonic cavitator was compared to the traditional soxhlet method by GC-MS. Un-contaminated soil was spiked with analytes DDT, DDD, and DDE at 0.1,1.0,10.0, and 100.0?mg/ kg. Experiments were performed in triplicate, and recoveries of analytes were determined and statistically compared. Results indicate that ultrasonic extraction is a suitable preparatory method for analysis of DDT, DDD, and DDE residues in soil. For spike concentrations of 1?mg/kg to 100?mg/kg, ultrasonication extraction resulted in recoveries in excess of 80% in all but one case. Most recoveries obtained by ultrasonication extraction were statistically indistinguishable from or slightly lower than recoveries obtained by soxhlet extraction. In addition, the lower temperatures employed in ultrasonication extraction may have reduced the amount of thermal degradation of DDT to DDE, a phenomenon that could occur during soxhlet extraction.     

Microcosm studies on the degradation of <Emphasis Type="Italic">o,p</Emphasis>′- and <Emphasis Type="Italic">p,p</Emphasis>′-DDT,DDE, and DDD in a muck soil

The muck soils of the north shore of Lake Apopka, near Orlando, Florida, USA are high in organic matter, inorganic nutrients, and water content. Ideally suited for agriculture, these soils have been exposed to a wide variety of agrochemicals. Some of the more recalcitrant organochlorine pesticides, such as DDT and its degradation products DDD and DDE, have persisted in the soil for over 30 years. Using the extracellular enzymes from wood rot fungi, it was demonstrated that it is possible to substantially reduce the amount of the o,p′ and p,p′ isomers of DDT, DDD, and DDE in this soil by more than 60% in 3 weeks. A fungal species with 99% DNA homology to Nectria mariannaeae was isolated from this muck soil and identified by nucleotide sequencing. When grown under nitrogen-limited conditions, this Nectria sp. has been shown to be comparable to Phanerochaete chrysosporium (ATCC 24725) in producing extracellular factors (or agents) that are capable of degrading these recalcitrant chlorinated chemicals.