多溴二苯醚毒理学研究进展及展望(Research Progress and Future Perspectives in Toxicology Study on Polybrominated Diphenyl Ethers)

多溴二苯醚(PBDEs)虽然已在一些国家禁止生产和使用,商品五溴和八溴二苯醚也在2009年被列入《关于持久性有机污染物(POPs)的斯德哥尔摩公约》受控范围内,但目前学术界对PBDEs的毒理学效应及其机制尤其是环境剂量效应的认识并不十分清楚. 论文从甲状腺干扰、神经毒性、生殖内分泌干扰3个方面介绍了近年来PBDEs毒理学研究的进展,分析了该领域研究中存在的几个问题,提出今后应大力开展环境相关剂量下PBDEs及代谢物的毒性研究,以推进对实际环境中PBDEs真实毒性的认识;同时探索能够反映PBDEs毒性的非创性生物标记物,为开展PBDEs人体健康影响的流行病学调查提供线索.     

Biodegradation of 1,1,1-trichloro-2,2-bis(4-chlorophenyl) ethane (DDT) by using Serratia marcescens NCIM 2919

A solvent tolerant bacterium Serratia marcescens NCIM 2919 has been evaluated for degradation of DDT (1,1,1-trichloro-2,2-bis (4-chlorophenyl) ethane). The bacterium was able to degrade up to 42% of initial 50 mg L^?1 of DDT within 10 days of incubation. The highlight of the work was the elucidation of DDT degradation pathway in S. marcescens. A total of four intermediates metabolites viz. 2,2-bis (chlorophenyl)-1,1-dichloroethane (DDD), 2,2-bis (chlorophenyl)-1,1-dichloroethylene (DDE), 2,2-bis (chlorophenyl)-1-chloroethylene (DDMU), and 4-chlorobenzoic acid (4-CBA) were identified by GC-Mass and FTIR. 4-CBA was found to be the stable product of DDT degradation. Metabolites preceding 4-CBA were not toxic to strain as reveled through luxuriant growth in presence of varying concentrations of exogenous DDD and DDE. However, 4-CBA was observed to inhibit the growth of bacterium. The DDT degrading efficiency of S. marcescens NCIM 2919 hence could be used in combination with 4-CBA utilizing strains either as binary culture or consortia for mineralization of DDT. Application of S. marcescens NCIM 2919 to DDT contaminated soil, showed 74.7% reduction of initial 12.0 mg kg^?1 of DDT after 18-days of treatment.     

4种磺胺类药物及乙酰化代谢物在污水处理厂的去除及机制

乙酰化代谢物是磺胺类药物的重要代谢产物.为研究4种常见磺胺类药物及其乙酰化代谢物在污水厂中的去除机制,根据污水停留时间采集厦门某A2/O型工艺污水厂不同处理单元的污水和污泥样品,采用固相萃取-高效液相色谱串联质谱法检测目标化合物.结果显示,8种目标物中有6种在水体中被检测出,污泥中有5种目标物被检测出.计算总去除率及各个处理单元间的去除率,结果表明,磺胺二甲基嘧啶在污水厂中总去除率几乎为0,而其他5种化合物都有不同程度的去除,但不同目标物在各处理单元的去除率不同.利用质量平衡,分析各物质可能的去除机制,磺胺二甲基嘧啶可能去除机制为污泥吸附,磺胺嘧啶、磺胺甲基嘧啶和磺胺甲唑可能的去除机制均为生物降解.     

Alterations of endogenous metabolites in urine of rats exposed to decabromodiphenyl ether using metabonomic approaches

There is large usage of polybrominated diphenyl ethers （PBDEs） especially for decabromodiphenyl ether （BDE-209, Deca-BDE） in controlling the risks of fire. The toxicological effects of PBDEs are worth being concerned about. Female SD rats were daily gavaged with BDE-209 ether at the dose of 100 mg/kg for 20 days. Histological observation was performed for the screening of the target organs for BDE-209 exposure. The distribution and metabolism of PBDEs in the exposed main organs were evidenced by HRGC-HRMS. Alterations of the endogenous metabolite concentrations in urine were investigated using metabonomic approaches based on IH NMR spectrum. Histopathological changes including serious edema in kidney, hepatocellular spotty necrosis and perivasculitis in liver indicated that BDE-209 caused potential influences on endogenous metabolism in the exposed liver and the kidney. BDE-209 was found to be highly accumulated in lipid, ovary, kidney and liver after 20 days＇ exposure. Occurrence of other lower brominated PBDEs in the rats demonstrated that reductive debromination process happened in vivo. Hydroxylated and methoxylated-BDEs, as metabolism products, were also detected in the rat tissues. A total of 12 different endogenous metabolites showed obvious alterations in urine from the exposed rats, indicating the disturbance of the corresponding internal biochemical processes induced by BDE-209 exposure. These findings in vivo suggested the potential health risk might be of concern due to the toxicological effects of BDE-209 as a ubiquitous compound in the environment.     

Review of advances in the thin layer chromatography of pesticides: 2012–2014

Publications reporting techniques and applications of thin layer chromatography (planar chromatography) for the separation, detection, qualitative, and quantitative determination, and preparative isolation of pesticides and their metabolites are reviewed for the period from November 1, 2012 to November 1, 2014. Analyses are described for a variety of sample types and pesticide classes. In addition to references on residue analysis, studies such as pesticide structure – retention relationships, identification and characterization of natural and synthesized pesticides, metabolism, bioactivity, degradation, soil mobility, and lipophilicity are covered.     

Biodegradation of mixed pesticides by mixed pesticide enriched cultures

This paper discusses the degradation kinetics of mixed (lindane, methyl parathion and carbofuran) pesticides by mixed pesticide enriched cultures (MEC) under various environmental conditions. The bacterial strains isolated from the mixed microbial consortium were identified as Pseudomonas aeruginosa (MTCC 9236), Bacillus sp. (MTCC 9235) and Chryseobacterium joostei (MTCC 9237). Batch studies were conducted to estimate the biokinetic parameters like the maximum specific growth rate (μ_max), Yield Coefficient (Y_T), half saturation concentration (K_s) and inhibition concentration (Ki) for individual and mixed pesticide enriched cultures. The cultures enriched in a particular pollutant always showed high growth rate and low inhibition in that particular pollutant compared to MEC. After seven weeks of incubation, mixed pesticide enriched cultures were able to degrade 72% lindane, 95% carbofuran and 100% of methyl parathion in facultative co-metabolic conditions. In aerobic systems, degradation efficiencies of lindane methyl parathion and carbofuran were increased by the addition of 2g L^{? 1} of dextrose. Though many metabolic compounds of mixed pesticides were observed at different time intervals, none of the metabolites were persistent. Based on the observed metabolites, a degradation pathway was postulated for different pesticides under various environmental conditions.     

Review of advances in the thin layer chromatography of pesticides: 2006–2008

Applications of thin layer chromatography and high performance thin layer chromatography for the separation, detection, qualitative and quantitative determination, and preparatire isolation of pesticides and their metabolites are reviewed for the period from July 1, 2006 to November 1, 2008. Analyses are described for a variety of sample types and pesticide classes. In addition to references on residue and formulation analysis, studies such as pesticide-structure relationships, identification and characterization of plant pesticides, metabolism, degradation, mobility, and lipophilicity are covered. Future prospects for pesticide thin layer chromatography are also considered.     

Dissipation of chlorpyrifos,oxon, and 3,5,6‐trichloro‐2‐pyridinol in litter and elm forest soil

Abstract

After chlorpyrifos was applied to the basal 1 meter of elm tree trunks for control of elm bark beetles at two different application times and sites, initial chlorpyrifos residues in forest floor litter ranged from 120 to 916 μg/g depending on the application time. Residues dissipated by approximately 99% after 791 d with the DT₅₀ from 3.9 to 59 d and DT₉₀ from 55 to 310 d. The initial residues of chlorpyrifos in elm forest soil varied from 0.8 to 28 μg/g and were 1 to 2 μg/g at 791 d after application. The dissipation half‐lives of chlorpyrifos in fortified soil placed in the field ranged from 116 to 121 d.     

Polycyclic aromatic hydrocarbons and their hydroxylated metabolites in fish bile and sediments from coastal waters of Colombia

Sediments and fish bile collected from the Atlantic coastal waters of Colombia were analyzed for 16 parent polycyclic aromatic hydrocarbons (PAHs), and 23 hydroxylated PAHs (OH-PAHs), respectively. Sediments contained overall mean SigmaPAH concentrations of 2090, 234 and 170 ng/g, dry wt, for Cartagena Bay, Caimanera Marsh, and Totumo Marsh, respectively. The mean concentration of the summed OH-PAHs in fish bile was 1250, 180 and 64.1 ng/g bile wt for Cartagena Bay, Caimanera Marsh, and Totumo Marsh, respectively. The results suggest that Cartagena Bay is heavily polluted by PAHs, and that exposure to high concentrations of PAHs together with other factors could contribute to the decreased health of fish living in this ecosystem. This is one of the first studies to describe the analysis of 23 individual OH-PAHs in fish bile, using authentic standards.     

The essential oil qualitative and quantitative composition in the needles of Pinus sylvestris L. growing along industrial transects

The aim of this study was to evaluate composition of the essential oils in the needles of Pinus sylvestris growing in the areas affected by a cement factory (CF), and an oil refinery (OR). Volatile components of the needles were analyzed by GC and GC/MS. The most heavily polluted CF stand had significantly higher concentration of gamma-Terpinene, Caryophyllene oxide in the current-year needles, while higher concentration of delta-3-Carene, alpha-Terpinene, gamma-Terpinene and Terpinolene was documented for 1-year-old needles. The most heavily polluted OR stand had a significantly higher concentration of Sabinene+beta-Pinene, 1-epi-Cubenol in the current-year needles and a significantly higher concentration of Camphene, Sabinene+beta-Pinene, Myrcene, alpha-Cadinene, 1-epi-Cubenol in the 1-year-old needles than the least polluted site. Along transects an increase in the amount of some diterpenes and a decrease in the components of the shorter chain essential oils was observed. These effects could be at least partially attributed to SO(2).