环境医学

X 18 9502092苯并(a)花对人血淋巴细胞的细胞遗传学损伤研究/杨业鹏…(北京医科大学卫生毒理学教研室)户环境与健康杂志z本刊编辑部(天津、一1994,11(6)一25()一252环信R一36 以不同浓度苯并(a)花(BaP)对人血淋巴细胞进行体外染毒·运用微核(MN)、染色体畸变(C八)和姊妹染色单体交换〔SCE)试验.综合评价了BoP对人血淋巴细胞的细胞遗传学损伤作用结果表明,经S9代谢活化,BaP可诱发细胞MN率,CA率和SCE率显著增高,并呈现明显浓度一反应关系。_上述三指标的变化相互间呈高级正相关。三项指标中与BaP染毒浓度的对数值呈高度正相关。三项…     

综合评定苯并（a）芘低浓度污染有毒危险性的研究

在细胞遗传损伤和免疫功能综合指标中,观察对苯并（a）芘（BaP）敏感并适用于人群检测的指标。结果显示外周血淋巴细胞姐妹染色单体交换（SCE）率与尿中BaP含量呈正相关;并在BP低于10μg/100M³的接触人群中观察到SCE率增高;血清IgG和补体C³与血中BaP含量呈负相关。以SCE率增高、IgG降低和尿中BaP负荷量增高综合评定BaP污染的有危毒险性有应用前景,饮用中华猕猴桃饮料,有助于SCE率增高的恢复和体内BaP的排出。     

姊妹染色单体交换在检测有害环境因素中的应用

用人外周血淋巴细胞和大麦根尖细胞做姊妹染色单体交换（SCE）实验,发现丝裂霉素C、放线菌酮D、异烟酰肼及糖精钠能显著提高SCE频率,而且诱发细胞的平均SCE值在两种材料中有极显著的一致性,表明植物细胞SCE在检出环境诱变剂中与人外周血淋巴细胞同样敏感有效。在高浓度介质中植物幼苗生长发育受到抑制,处理的早期可检测到幼苗根尖细胞SCE水平的明显升高。环境中的重金属铬和镉即使浓度较低也能通过大麦SCE实验检测到。结果表明,大麦根尖细胞SCE实验能有效地检测出环境中的有害因素。     

聚乙烯微塑料对大型溞的摄食抑制

该研究以32μm粒径聚乙烯颗粒模拟微塑料污染环境,探究其对典型淡水水体初级消费者大型溞摄食行为的影响。首先确认了其对大型溞存在急性毒性,24 h急性毒性LC₅₀当量浓度为309.6 mg/L,证明在自然水体中微塑料污染的峰值暴露可能对浮游动物产生较严重的影响。然后进行了大型溞摄食实验和摄食恢复实验,在实验观测的染毒范围内,大型溞表现出了明显的摄食抑制。3 d蚤龄的较10 d蚤龄更为敏感,3 d蚤龄的8 h摄食抑制的EC₅₀当量浓度为97.0 mg/L。恢复实验显示,微塑料染毒后,大型溞如脱离污染环境,其摄食抑制将逐渐减轻,2 h后即达到恢复稳定,但高浓度染毒组的大型溞无法恢复至正常水平。     

垃圾填埋场渗滤液诱发小鼠骨髓细胞微核效应

研究了垃圾填埋场渗滤液诱发小鼠骨髓嗜多染红细胞(PCE)微核(MN)效应.结果表明,渗滤液可诱发微核的形成,且呈明确的浓度(渗滤液COD_Cr)-效应关系.在亚急性染毒条件下,渗滤液COD_Cr为10mg/L时,可诱发微核率和微核细胞率显著高于阴性对照(n=16,P<0.001);在亚慢性染毒条件下,渗滤液COD_Cr为5mg/L时,即可诱发微核率和微核细胞率显著高于阴性对照(n=16,P<0.001).这一结果从整体水平上证明了垃圾填埋场渗滤液对哺乳动物具有遗传损伤效应,同时提示可以以小鼠骨髓嗜多染红细胞微核试验结果作为渗滤液生物监测指标.渗滤液处理时间越长,引起细胞遗传损伤所需的最低浓度越低,意味着长期接触环境低浓度渗滤液污染有引起体内细胞遗传物质损伤的潜在危险.     

苯作业工人外周血淋巴细胞的细胞遗传学分析

选用外周血淋巴细胞染色体畸变（CA）率和微核细胞（MN）率两项指标对两个厂苯作业工人进行了研究分析,结果表明,在3种平均浓度54,108和219mg/m³,苯接触组和对照组比较CA率和MN率均有显著性差异,且未发现二者间有线性相关,提示二者形成机制不完全相同,且较低浓度下苯的遗传毒性应引起重视。     

1株汞挥发真菌的分离及特性分析

近年来土壤汞污染日益严峻,严重危害环境和人类健康,已成为一个世界性的环境问题,因此选择合理有效的方法对其进行修复与控制刻不容缓。有些微生物对汞具有吸附和挥发的特性,可用于受汞污染环境的修复。实验从受重金属污染的土壤中分离纯化出1株高抗汞真菌（DC-F9）,其汞的最小抑菌浓度（MIC）达到160 mg/L;通过ITS序列比较,鉴别该菌属于曲霉属真菌;摇瓶培养发现,该真菌在Hg（Ⅱ）浓度为5 mg/L的培养基中对汞的挥发率、吸附率和总去除率分别为36.8%、58.4%、95.2%;而在Hg（Ⅱ）浓度为10 mg/L的培养基中,其值分别为45.4%、40.2%、85.6%;通过FTIR分析,发现该菌株为响应汞的胁迫表现出多种生理上变化。结果表明该菌株具有对汞污染环境修复的应用潜力。     

生物质炭对重金属污染红壤中蚯蚓活性的影响

生物质炭改良剂在钝化污染土壤中重金属的同时,显著改善土壤物理、化学和生物性质。该文通过添加2%400℃下制备的玉米、水稻、小麦、大豆、豌豆等秸秆生物质炭到Cd和Pb染毒红壤中,研究蚯蚓（赤子爱胜蚓）暴露30 d后的体重损失率、死亡率和体内抗氧化酶活性等指标的影响。结果表明,施加生物质炭显著降低Cd、Pb染毒土壤中可交换态重金属含量。另外,蚯蚓体重损失率分别从改良前的37.16%和38.81%降低至改良后的(31.92%±2.54%)和(28.02%±1.46%),同时死亡率从46.67%分别降低至(40.00%±2.98%)和(32.00%±6.29%),但都未达显著水平（P>0.05）。相比于染毒土壤,施加生物质炭处理土壤中蚯蚓体内过氧化氢酶（CAT）、过氧化物酶（POD）活性和丙二醛（MDA）含量在Cd污染土壤中分别显著降低15.19%～44.89%、12.09%～56.57%、32.52%～59.13%;在Pb污染土壤中分别显著降低1.54%～20.70%、18.44%～48.94%、44.65%～58.46%。相关性分析结果表明,Cd和Pb污染土壤中蚯蚓的CAT、POD活...     

北京冬季重污染过程黑碳气溶胶的飞机观测

利用空中国王飞机平台搭载单颗粒黑碳光度计（SP2）针对北京2016年12月冬季一次污染过程进行了连续观测,阐述了污染发生、发展和消散过程中的黑碳（BC）气溶胶质量浓度、粒径分布和混合状态的变化特征.结果表明,此次污染过程是以PM_2.5污染为主的霾污染过程,最大值为432μg/m³.NO₂、SO₂和CO等气态污染物浓度经过3次污染积累阶段,为PM_2.5最终爆发增长提供了物质基础.静稳的大气条件为PM_2.5爆发增长提供了动力条件.污染发展过程中BC气溶胶先在地面累积增加,然后向高空传输;清除过程则是高空先被移除,低层缓慢降低.污染发展过程中北京地区黑碳气溶胶在边界层（PBL）浓度变化为先升高后减小,平均浓度为3.45μg/m³,质量中值直径（MMD）范围在190~220nm.随着污染过程的发展,气溶胶迅速老化,PBL内的BC老化比例在一天内可从27%增加到了51%,老化过程使得PM_2.5质量浓度爆发增长.污染过程中BC在边界层的垂直演变导致大气加热率发生变化,有利于逆温的维持和发展,加剧了污染物过程.     

壬基酚和辛基酚联合暴露的血清代谢特征及生物标志物

运用代谢组学方法分析了壬基酚（NP）和辛基酚（OP）联合暴露后大鼠血清代谢成分变化,雄性SD大鼠随机分为对照组、壬基酚和辛基酚（联合染毒低剂量组（25mg/kg NP+25mg/kg OP）及高剂量组（75mg/kg NP+75mg/kg OP）.连续灌胃7d后处死.通过超高效液相色谱-飞行时间质谱（UPLC/QTOF-MS）技术获得大鼠血清的代谢指纹图谱,通过主成分分析观察了联合染毒的剂量-效应,通过t检验筛选潜在的生物标志物,并结合代谢物数据库检索对潜在的生物标志物进行鉴定.结果显示,对照组、高、低剂量组各组间代谢谱有明显差别,且随着染毒剂量的增加毒性增强,表现为剂量-效应关系.联合染毒后的血清代谢物中,含量升高的有牛黄胆酸及1-棕榈酰基磷脂酰胆碱,含量降低的有酪氨酸、5-尿苷一磷酸及硫脑苷酯,提示染毒可能对内分泌系统、心血管系统、神经系统以及核苷酸合成、糖代谢、磷脂代谢等产生不良影响.     

Toxic effects of acetochlor, methamidophos and their combination on nifH gene in soil

Toxic effects of two agrochemicals on nifH gene in agricultural black soil were investigated using denaturing gradient gel electrophoresis （DGGE） and sequencing approaches in a microcosm experiment. Changes of soil nifH gene diversity and composition were examined following the application of acetochlor, methamidophos and their combination. Acetochlor reduced the nifH gene diversity （both in gene richness and diversity index values） and caused changes in the nifH gene composition. The effects of acetochlor on nifH gene were strengthened as the concentration of acetochlor increased. Cluster analysis of DGGE banding patterns showed that nifH gene composition which had been affected by low concentration of acetochlor （50 mg/kg） recovered firstly. Methamidophos reduced nifH gene richness that except at 4 weeks. The medium concentration of methamidophos （150 mg/kg） caused the most apparent changes in nifH gene diversity at the first week while the high concentration of methamidophos （250 mg/kg） produced prominent effects on nifH gene diversity in the following weeks. Cluster analysis showed that minimal changes of nifH gene composition were found at 1 week and maximal changes at 4 weeks. Toxic effects of acetochlor and methamidophos combination on nifH gene were also apparent. Different nifH genes （bands） responded differently to the impact of agrochemicals： four individual bands were eliminated by the application of the agrochemicals, five bands became predominant by the stimulation of the agrochemicals, and four bands showed strong resistance to the influence of the agrochemicals. Fifteen prominent bands were partially sequenced, yielding 15 different nifH sequences, which were used for phylogenetic reconstructions. All sequences were affiliated with the alpha- and beta-proteobacteria, showing higher similarity to eight different diazotrophic genera.     

Arsenic uptake by arbuscular mycorrhizal maize （Zea mays L.） grown in an arsenic-contaminated soil with added phosphorus

The effects of arbuscular mycorrhizal (AM) fungus (Glomus mosseae) and phosphorus (P) addition (100 mg/kg soil) on arsenic (As) uptake by maize plants (Zea mays L.) from an As-contaminated soil were examined in a glasshouse experiment.Non-mycorrhizal and zero-P addition controls were included.Plant biomass and concentrations and uptake of As,P,and other nutrients,AM colonization,root lengths,and hyphal length densities were determined.The results indicated that addition of P significantly inhibited root colonization and development of extraradical mycelium.Root length and dry weight both increased markedly with mycorrhizal colonization under the zero-P treatments,but shoot and root biomass of AM plants was depressed by P application.AM fungal inoculation decreased shoot As concentrations when no P was added,and shoot and root As concentrations of AM plants increased 2.6 and 1.4 times with P addition,respectively.Shoot and root uptake of P,Mn,Cu,and Zn increased,but shoot Fe uptake decreased by 44.6%,with inoculation, when P was added.P addition reduced shoot P,Fe,Mn,Cu,and Zn uptake of AM plants,but increased root Fe and Mn uptake of the nonmycorrhizal ones.AM colonization therefore appeared to enhance plant tolerance to As in low P soil,and have some potential for the phytostabilization of As-contaminated soil,however,P application may introduce additional environmental risk by increasing soil As mobility.     

Degradation of metabolites accumulated of benzo[a]pyrene by coupling Penicillium Chrysogenum with KMnO4

Several main metabolites of benzo[a]pyrene （BaP） formed by Penicillium chrysogenum, Benzo[a]pyrene-1,6-quinone （BP 1,6- quinone）, trans-7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene （BP 7,8-diol）, 3-hydroxybenzo[a]pyrene （3-OHBP）, were identified by high-performance liquid chromatography （HPLC）. The three metabolites were liable to be accumulated and were hardly further metabolized because of their toxicity to microorganisms. However, their further degradation was essential for the complete degradation of BaP. To enhance their degradation, two methods, degradation by coupling Penicillium chrysogenum with KMnO4 and degradation only by Penicillium chrysogenum, were compared; Meanwhile, the parameters of degradation in the superior method were optimized. The results showed that （1） the method of coupling Penicillium chrysogenum with KMnO4 was better and was the first method to be used in the degradation of BaP and its metabolites; （2） the metabolite, BP 1,6-quinone was the most liable to be accumulated in pure cultures; （3） the effect of degradation was the best when the concentration of KMnO4 in the cultures was 0.01% （w/v）, concentration of the three compounds was 5 mg/L and pH was 6.2. Based on the experimental results, a novel concept with regard to the bioremediation of BaP-contaminated environment was discussed, considering the influence on environmental toxicity of the accumulated metabolites.     

Impact of atrazine and nitrogen fertilizers on the sorption of chlorotoluron in soil and model sorbents

Sorption of chlorotoluron in ammonium sulfate, urea and atrazine multi-solutes system was investigated by batch experiments. The results showed application of nitrogen fertilizers to the soil could affect the behavior of chlorotoluron. At the same concentration of N, sorption of chlorotoluron decreased as the concentration of atrazine increased on the day 0 and 6 in soil, respectively. The sorption of chlorotoluron increased from 0 to 6 d when soils were preincubated with deionized water, ammonium sulfate and urea solution for 6 d. That indicated incubation time was one of the most important factors for the sorption of chlorotoluron in nitrogen fertilizers treatments. The individual sorption isotherms of chlorotoluron in rubbery polymer and silica were strictly linear in single solute system, but there were competition sorption between pesticides or between pesticides and nitrogen fertilizers. That indicated the sorption taken place by concurrent solid-phase dissolution mechanism and sorption on the interface of water-organic matter or water-mineral matter.     

Potential of plant polyphenol oxidases in the decolorization and removal of textile and non-textile dyes

In this study an effort has been made to use plant polyphenol oxidases; potato （Solanum tuberosum） and brinjal （Solanum melongena）, for the treatment of various important dyes used in textile and other industries. The ammonium sulphate fractionated enzyme preparations were used to treat a number of dyes under various experimental conditions. Majority of the treated dyes were maximally decolorized at pH 3.0. Some of the dyes were quickly decolorized whereas others were marginally decolorized. The initial first hour was sufficient for the maximum decolorization of dyes. The rate of decolorization was quite slow on long treatment of dyes. Enhancement in the dye decolorization was noticed on increasing the concentration of enzymes. The complex mixtures of dyes were treated with both preparations of polyphenol oxidases in the buffers of varying pH values. Potato polyphenol oxidase was significantly more effective in decolorizing the dyes to higher extent as compared to the enzyme obtained from brinjal polyphenol oxidase. Decolorization of dyes and their mixtures, followed by the formation of an insoluble precipitate, which could be easily removed simply by centrifugation.     

Effects of two sludge application on fractionation and phytotoxicity of zinc and copper in the soil

The potential harm of heavy metals is a primary concern in application of sludge to the agricultural land. A pot experiment was conducted to evaluate the effect of two sludges on fractionation of Zn and Cu in soil and their phytotoxicity to pakchoi. The loamy soil was mixed with 0%, 20%, 40%, 60% and 80% (by weight) of digested sewage sludge (SS) and composted sludge (SC). The additions of both sludges caused a significant raise in all fractions, resulting in that exchangeable (EXCH) and organic bound (OM) became predominance of Zn and organic bound Cu occupied the largest portion. There was more available amount of Zn and Cu in SS treatments than SC treatments. During the pot experiment, the concentration of Zn in EXCH, carbonate (CAR) and OM and Cu in EXCH and OM fractions decreased in all treatments, so their bioavailability reduced. Germination rate and plant biomass decreased when the addition rate was high and the best yield appeared in 20% mixtures at the harvest of pakchoi. The two sludges increased tissue contents of Zn and Cu especially in the SS treatments. Zn in pakchoi was not only in relationship to ΔEXCH and ΔCAR forms but also in ΔOM forms in the sludge-soil mixtures. Tissue content of Cu in pakchoi grown on SC-soils could not be predicted by ΔEXCH. These correlation rates between Zn and Cu accumulation in pakchoi and variation of different fractions increased with time, which might indicate that sludges represented stronger impacts on the plant in long-term land application.     

Intraspecific differences in effects of co-contamination of cadmium and

A hydroponic experiment was carried out to study intraspecific differences in the effects of different concentrations of cadmium (Cd)(0-10 mg/L) and arsenate (As(V)) (0-8 mg/L) on the growth parameters and accumulation of Cd and As in six wheat varieties Jing-9428, Duokang-1, Jingdong-11, Jing-411, Jingdong-8 and Zhongmai-8. The endpoints of wheat seedlings, including seed germination,biomass, root length and shoot height, decreased with increasing the Cd and As concentrations. Significant differences in seed germination, biomass, root length, shoot height and the accumulation of Cd and As were observed between the treatments and among the varieties (p ＜ 0.05). The lethal dosage 50% were about 20, 80, 60, 60, 80 and 20 mg As/L for Jing-9428, Duokang-1, Jingdong-11,Jing-411, Jingdong-8 and Zhongmai-8, respectively, and the corresponding values for Cd were about 30, 80, 20, 40, 60 and 10 mg Cd/L, respectively. Among the six varieties, Duokang-1 was found to be the most resistant to Cd and As toxicity, and Zhongmai-8 was the most sensitive to Cd and As co-contamination. The resistance of the six varieties was found dependant on the seedling uptake of Cd and As. Duokang-1 was the most suitable for cultivation in Cd and As co-contaminated soils.     

Removal of heavy metals from sewage sludge by low costing chemical method and recycling in agriculture

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Isolation and preliminary characterization of a 3-chlorobenzoate degrading bacteria

A study was conducted to compare the diversity of 2-, 3-, and 4-chlorobenzoate degraders in two pristine soils and one contaminated sewage sludge. These samples contained strikingly different populations of mono-chlorobenzoate degraders. Although fewer cultures were isolated in the uncontaminated soils than contaminated one, the ability of microbial populations to mineralize chlorobenzoate was widespread. The 3- and 4-chlorobenzoate degraders were more diverse than the 2-chlorobenzoate degraders. One of the strains isolated from the sewage sludge was obtained. Based on its phenotype, chemotaxonomic properties and 16S rRNA gene, the organism S-7 was classified as Rhodococcus erythropolis. The strain can grow at temperature from 4 to 37℃. It can utilize several （halo）aromatic compounds. Moreover, strain S-7 can grow and use 3-chlorobenzoate as sole carbon source in a temperatures range of 10-30℃ with stoichiometric release of chloride ions. The psychrotolerant ability was significant for bioremediation in low temperature regions. Catechol and chlorocatechol 1,2-dioxygenase activities were present in cell free extracts of the strain, but no （chloro）catechol 2,3- dioxygenase activities was detected. Spectral conversion assays with extracts from R. erythropolis S-7 showed accumulation of a compound with a similar UV spectrum as chloro-cis,cis-muconate from 3-chlorobenzoate. On the basis of these results, we proposed that S-7 degraded 3-chlorobenzoate through the modified ortho-cleave pathway.     

Single and joint effects of pesticides and mercury on soil urease

The influence of two pesticides including chlorimuron-ethyl and furadan and mercury （Hg） on urease activity in 4 soils （meadow burozem and phaeozem） was investigated. The soils were exposed to various concentrations of the two pesticides and Hg individually and simultaneously. Results showed that there was a close relationship between urease activity and organic matter content in soil. Chlorimuron-ethyl and furadan could both activate urease in the 4 soils. The maximum increment of urease activity by chlorimuronethyl was up to 14%-18%. There was almost an equal increase （up to 13%-21%） in the urease activity by furadan. On the contrary, Hg markedly inhibited soil urease activity. A logarithmic equation was used to describe the relationship （P〈0.05） between the concentration of Hg and the activity of soil urease in the 4 tested soils. Semi-effect dose （ED50） values by the stress of Hg based on the inhibition of soil urease in the 4 soils were 88, 5.5, 24 and 20 mg/kg, respectively, according to the calculation of the corresponding equations. The interactive effect of chlorimuron-ethyl or furadan with metal Hg on soil urease was mainly synergic at the highest tested concentrations.