汞、镉和苯并[α]芘、多氯联苯对栉孔扇贝幼贝单一与联合毒性的研究

研究了重金属Hg2+、Cd2+和苯并[α]芘(B[α]P)、多氯联苯(PCB1254)对栉孔扇贝(Chlamys farreri)幼贝的单一与联合毒性效应。实验结果表明,Hg2+、Cd2+对栉孔扇贝幼贝单一毒性实验24、48、72、96 hLC50分别为2.0、1.95、1.38、0.847mg/L和4.48、3.16、2.25、1.62 mg/L,因此2种重金属对幼贝的单一毒性Hg2+Cd2+;B[α]P、PCB1254对栉孔扇贝幼贝单一染毒的LC5010 mg/L。Hg2+、Cd2+分别与B[α]P、PCB1254联合毒性效应基本相当,但联合毒性Hg2++B[α]PCd2++B[α]P,Hg2++PCB1254Cd2++PCB1254。同时Hg2+与B[α]P、PCB1254对幼贝联合染毒96 h内均表现为拮抗作用;Cd2+与B[α]P、PCB1254对幼贝的联合毒性24 h时表现为拮抗作用,24～96 h表现为协同作用。由此可见,栉孔扇贝幼贝对Hg2+、Cd2+敏感,可作为较理想的重金属毒性试验受试生物,同时Hg2+、Cd2+分别与B[α]P、PCB1254对栉孔扇贝幼贝的联合毒性与污染物组成、浓度和作用时间等因素有关。     

苯并(a)芘和苯并(k)荧蒽混合物对栉孔扇贝毒理学指标的影响

检测了暴露于不同浓度多环芳烃中栉孔扇贝(Chlamys farreri)消化盲囊和鳃丝的几项毒理学指标变化.苯并(a)芘和苯并(k)荧蒽混合物的浓度梯度设置为0.5、1.0、10.0、50.0μg·L-1.结果表明,低浓度PAHs对消化盲囊EROD活力无显著影响,对GST有一定的诱导作用,而高浓度PAHs对消化盲囊EROD有明显的诱导作用,对GST先诱导后抑制;在PAHs作用下消化盲囊和鳃丝的3种抗氧化酶(SOD、CAT和GPx)活力呈现一定的峰值变化,且在高浓度PAHs下均被显著抑制,同时鳃丝的酶活力较消化盲囊抑制显著;消化盲囊和鳃丝的LPO水平在PAHs处理下随时间不断上升,并表现出明显的剂量和时间效应.暴露于PAHs中栉孔扇贝的EROD、GST和抗氧化酶活力的变化反映了机体的解毒代谢过程和能力,而LPO水平则直接反映了机体的氧化损伤程度,而且各毒理学指标在解毒过程中相互关联,具有很强的规律性.     

天津市环境空气中苯并[a]芘的变化趋势

分析了天津市环境空气中苯并[a]芘污染的程度及变化趋势,结果表明,天津市大气中苯并[a]芘污染成逐年下降趋势,同一年中苯并[a]芘浓度是非采暖期低于采暖期,月均值变化规律是夏季<春、秋季<冬季,天津市环境空气中苯并[a]芘污染总体来说处于较低的水平。     

微生物对芘和苯并[a]芘污染土壤的修复

将枯草芽孢杆菌、白腐真菌和分离筛选菌群分别用于芘和苯并[a]芘污染土壤的修复,比较其修复性能,并对表面活性物剂Tween80和葡萄糖对修复效果的影响规律做了初步探讨.结果表明,60 d时,枯草芽孢杆菌和分离筛选菌修复芘污染的土壤,芘的残留率分别为7.58%±0.59%和8.69%±61.35%,空白残留率为48.18%...     

苯并(a)芘对栉孔扇贝血细胞损伤与凋亡的研究

研究了苯并[α]芘(B[α]P对栉孔扇贝血细胞存活率、活性氧(ROS)含量、溶酶体膜和DNA损伤以及凋亡指数的影响。结果表明:B[α]P对栉孔扇贝血细胞存活率无明显影响,存活率在96.72%～97.71%,而B[α]P对血细胞ROS含量、溶酶体膜稳定性和DNA损伤以及凋亡指数影响显著(p<0.05),且对照组无明显变化。各处理组血细胞ROS含量在实验时间内均表现出明显的上升趋势,且与B[α]P的作用时间呈正相关,同时在12、24 h时,各B[α]P处理组血细胞ROS含量大小为:1 mg/L>4 mg/L>16 mg/L>0.25 mg/L。除0.25 mg/L处理组血细胞溶酶体膜稳定性、拖尾率和任意值在12 h和6 h内以及1 mg/L处理组血细胞溶酶体膜稳定性、拖尾率在6 h内与对照组无明显差异外,其余各处理组血细胞溶酶体膜稳定性以及拖尾率、任意值、凋亡指数在实验时间内分别呈现下降或上升趋势,同时各处理组血细胞溶酶体膜稳定性和DNA损伤程度、凋亡指数分别与B[α]P浓度和作用时间呈负、正相关性。因此,作者认为B[α]P对栉孔扇贝血细胞具有明显的免疫毒性损伤效应,且与B[α]P胁迫程度直接相关,同时B[α]P在血细胞内代谢产生的ROS及其代谢产物是造成血细胞损伤、凋亡的重要原因之一。     

大气飘尘中苯并[a]芘的激光诱导荧光法测定

以激光诱导荧光法测定大气飘尘中的苯并[a]芘。方法的检测限为0.01μg·l~(-1),降低了常规荧光法的检测限。综合溶剂提取、柱色层及纸色层分离技术,测定了上海市某些地区大气飘尘样品中苯并[a]芘的含量。     

南京市环境空气中苯并[a]芘的时空分布

通过在南京市大气国控点采集PM10样品,测量苯并[a]芘浓度。结果表明:南京市大气中苯并[a]芘月均值浓度呈双峰型变化,季节变化是夏季<春季<秋季<冬季,受工业污染的影响,呈现北高南低的局面。南京市苯并[a]芘浓度在国内外部分大城市中处于较低污染水平。     

苯并[a]芘对鲫鱼生物标志物的影响研究

研究了苯并[a]芘暴露对鲫鱼(Carassius auratus)的几种生物标志物的影响.在鲫鱼接受3个不同质量分数苯并[a]芘(BaP)的腹腔注射14 d后,分析了其肝脏7-乙氧基-3-异吩噁唑酮-脱乙基酶(EROD)活性,以及超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GPx)等抗氧化酶活性和红细胞核异常(NA)率变化.结果显示:w(BaP)为1 mg/kg处理组的EROD活性显著升高(P＜0.001).w(BaP)为0.1和1 mg/kg处理组SOD活性显著低于对照组(P＜0.001),在暴露结束时,w(BaP)为1 mg/h处理组CAT活性显著低于对照组(P＜0.01),而w(BaP)为0.1和1 mg/kg处理组GPx活性被显著抑制(P＜0.001).表明BaP对EROD活性有诱导作用,而对SOD,CAT和GPx等抗氧化酶活性的抑制作用明显.所有处理组NA率与对照组均无显著差异.因此,鲫鱼EROD,SOD,CAT和GPx等酶活性的改变适于作为生物标志物,可以用来显示暴露于多环芳烃有机污染物鱼类的生活状态.      

环境中苯并[a]芘的研究进展

苯并[a]芘(B[a]P)是国际公认的人类化学致癌物,在自然界中分布极广,卫生学中一般以它作为多环芳烃类致癌物的代表物.详细介绍了B[a]P的来源、理化性质、检测方法、毒性、致毒机理以及降解特性等方面最近的研究进展.展望了B[a]P今后重要的研究方向.     

苯并[a]芘对脊尾白虾(Exopalaemon carinicauda)肝脏生物标志物指标的影响

研究了脊尾白虾(Exopalaemon carinicauda)在对苯并[a]芘(benzo[a]pyrene,BaP)的富集(15 d)、释放(15 d)过程中肝脏的生物标志物(EROD、GST、SOD、CAT、GPx、MDA)的响应,结果显示:在富集阶段,第1 d低浓度实验组(0.05 g/L)和高浓度实验组(0.45 g/L)六种生物标志物即均显著受到诱导(P0.05),诱导程度与暴露浓度成正相关,而后不同种类生物标志物呈现差异性的变化趋势,EROD继续上升并在第10 d后达到稳定状态,GST继续上升并在第10 d后受到抑制下降,SOD、CAT、GPx均受到抑制逐渐下降,且均在15 d时低于对照组水平,MDA呈现持续上升的趋势,直接反映了肝脏的氧化损伤程度。在释放阶段,低浓度实验组各生物标志物的恢复速度较高浓度实验组要快,且均能恢复到接近对照组水平(P0.05),高浓度实验组各生物标志物则均未能恢复到对照组水平(P0.05)。实验结果表明,脊尾白虾肝脏具有一定恢复能力,各生物标志物对BaP暴露的敏感性具有一定差异,BaP暴露的浓度及时间是影响各生物标志物响应变化的主要因素。     

一株苯并[a]芘降解菌-紫茉莉联合修复污染土壤的研究

从长期受多环芳烃(PAHs)污染的土壤中获得1株高效降解菌BB-1,经鉴定为巨大芽孢杆菌Bacillus megaterium.为了考察菌株的降解特性,将10和20 mg·L~(-1)的苯并[a]芘(B[a]P)加入到培养液中并在30℃下振荡培养8 d.结果表明,BB-1对不同浓度的B[a]P的降解率分别为52.1%和23.5%,B[a]P浓度为10 mg·L~(-1)时降解效果更优.将不同重金属外加到培养液中,Cu2+(50 mg·L~(-1))和Cd2+(100 mg·L~(-1))能在一定程度上影响BB-1对B[a]P的生物降解作用,但菌株仍有很强的耐受性;Zn2+(200 mg·L~(-1))和Pb2+(300 mg·L~(-1))会显著影响降解效果.为了研究菌BB-1与植物的联合降解修复作用,通过对比研究将该菌株加入到种植紫茉莉的B[a]P污染土壤中,在未加入BB-1的污染土壤中,紫茉莉在开花期和成熟期对B[a]P的降解率分别为27.42%±1.99%和51.31%±3.06%,在加入BB-1的污染土壤中降解率分别为68.22%±1.21%和77.16%±0.62%,可见加入菌株BB-1后能显著提高紫茉莉对土壤中B[a]P的降解效率.为确定降解作用的菌株来源,分别对比了非根际和根际土壤中的B[a]P含量,发现在开花期和成熟期任何一种处理的根际土中B[a]P残留浓度都小于非根际土,说明土壤中B[a]P的去除主要是源于根际的作用.在植物修复的基础上,添加能耐受一定重金属浓度的高效B[a]P降解菌,能提高B[a]P降解率,有望为日后大规模田间应用提供可靠的技术参数.     

Metabolism of benzo[a]pyrene in peroxynitrite/Fe(III) porphyrin system

The peroxynitrite/porphyrin biomimetic system was established to investigate the effects of peroxynitrite on benzo[a]pyrene (B[a]P) metabolism. Three model systems consisting of different iron porphyrins were compared, and the results showed that the peroxynitrite/T(p-Cl)PPFeCl system was the highest catalytic efficiency in the metabolism of B[a]P. We analyzed the B[a]P metabolites produced from this system by RP-HPLC method and firstly identified the formation of nitrobenzo[a]pyrenes which are the special metabolites of B[a]P induced by peroxynitrite.     

Metabolism of benzo[a]pyrene in peroxynitrite/Fe（Ⅲ） porphyrin system

The peroxynitrite/porphyrin biomimetic system was established to investigate the effects of peroxynitrite on benzo[a]pyrene （B[a]P） metabolism. Three model systems consisting of different iron porphyrins were compared, and the results showed that the peroxynitdte/T（p-Cl）PPFeCl system was the highest catalytic efficiency in the metabolism of B [a]P. We analyzed the B [a]P metabolites produced from this system by RP-HPLC method and firstly identified the formation of nitrobenzo[a]pyrenes which are the special metabolites of B [a]P induced by peroxynitrite.     

Combined effect of tributyltin and benzo[a] pyrene on the levels of sex hormone and vitellogenin in female Sebastiscus marmoratus

Tributyltin（TBT）, an organometal used as an antifouling biocide, has been reported to induce masculinization of fish. Benzo [a]pyrene （BaP）, a widespread carcinogenic polycyclic aromatic hydrocarbon, has been reported that its microsomal metabolites can produce an estrogenic response when tested in vitro. This study was therefore designed to examine the potential in vivo influence of TBT, BaP and their mixture on sex hormone levels in serum of Sebastiscus marmoratus, which were given 2 separate intraperitoneally （ip） injections（a single injection every 7 d） of TBT（0.5, 1, 5 and 10 mg/kg）, BaP（0.5, 1, 5 and 10 mg/kg）, or both in combination（0.5, 1, 5 and 10 mg/kg）; control fish received olive oil vehicle only. Six days after the 2nd injection, serum samples were collected and analyzed for sex hormone levels and alkali labile protein phosphorus （ALPP）, which is related to the yolk precursor protein vitellogenin. The pollutants at all doses significantly reduced serum testosterone, estradiol and ALPP content after 2 injections compared with the corresponding controls. The reduction of the estradiol levels should be response for the decrease of the vitellogenin levels. The results in the present study suggested that aromatase seems not the major target acted by TBT and BaP in fish. This study demonstrated that TBT or BaP exposure both inhibit the reproductive potential in female Sebastiscus marmoratus. Combined effect of TBT and BaP on the serum testosterone, estradiol and ALPP was not antagonism from the anticipation.     

Enhanced oxidation of benzo[a]pyrene by crude enzyme extracts produced during interspecific fungal interaction of Trametes versicolor and Phanerochaete chrysosporium

The effects of interspecific fungal interactions between Trametes versicolor and Phanerochaete chrysosporium on laccase activity and enzymatic oxidation of polycyclic aromatic hydrocarbons (PAHs) were investigated. A deadlock between the two mycelia rather than replacement of one fungus by another was observed on an agar medium. The laccase activity in crude enzyme extracts from interaction zones reached a maximum after a 5-day incubation, which was significantly higher than that from regions of T. versicolor or P. chrysosporium alone. The enhanced induction of laccase activity lasted longer in half nutrition than in normal nutrition. A higher potential to oxidize benzo[a]pyrene by a crude enzyme preparation extracted from the interaction zones was demonstrated. After a 48 hr incubation period, the oxidation of benzo[a]pyrene by crude enzyme extracts from interaction zones reached 26.2%, while only 9.5% of benzo[a]pyrene was oxidized by crude extracts from T. versicolor. The oxidation was promoted by the co-oxidant 2,2'-azinobis-3-ethylbenzthiazoline-6-sulphonate diammonium salt (ABTS). These findings indicate that the application of co-culturing of white-rot fungi in bioremediation is a potential ameliorating technique for the restoration of PAH-contaminated soil.     

Photochemical behavior of benzo[a]pyrene on soil surfaces under UV light irradiation

The rates of photodegradation and photocatalysis of benzo [a]pyrene （BaP） on soil surfaces under UV light have been studied. Different parameters such as temperature, soil particle sizes, and soil depth responsible for photodegradation, catalyst loads and wavelength of UV irradiation blamed for photocatalysis have been monitored. The results obtained indicated that BaP photodegradation follows pseudo-first-order kinetics. BaP photodegradation was the fastest at 30℃ . The rates of BaP photodegradation at different soil particle size followed the order： less than 1 mm〉less than 0.45 mm〉less than 0.25 mm. When the soil depth increased from 1 mm to 4 ram, the half-life increased from 13.23 d to 17.73 d. The additions of TiO2 or Fe2O3 accelerated the photodegradation of BaP, and the photocatalysis of BaP follows pseudo-first-order kinetics. Changes in catalyst loads of TiO2 （0.5%, 1%, 2%, and 3% （wt）） or Fe203 （2%, 5%, 7%, and 10% （wt）） did not significantly affect the degradation rates. Both BaP photocatalysis in the presence of TiO2 and Fe2O3 were the fastest at 254 nm UV irradiation.     

苯并[a]芘降解菌的分离筛选及其降解条件的研究

从被石油污染的土壤样品中,以苯并[a]芘为唯一碳源反复驯化,分离筛选出1株高效降解苯并[a]芘的菌株JL 14 .经形态及生理生化特征分析,初步鉴定属于氮单胞菌属(Azomonas) .菌株JL 14在苯并[a]芘浓度为5mg·L- 1 ,2 8℃振荡培养10d ,苯并[a]芘的降解率达到48. 9% .培养基初始pH值分别为4、6、8、10时,2 8℃振荡培养10d ,苯并[a]芘的降解率分别为7 1% ,2 4 8% ,49 6%和2 5 9% .JL 14在苯并[a]芘浓度分别为10mg·L- 1 与2 0mg·L- 1 的条件下,2 8℃振荡培养10d ,苯并[a]芘的降解率分别为3 8. 2 %与2 7. 6% .Zn2 + (2 0 0mg·L- 1 )、Cd2 + (5 0mg·L- 1 )与Pb2 + (2 0 0mg·L- 1 )不影响JL 14对苯并[a]芘的降解作用,但Cu2 + (5 0mg·L- 1 )、Cr2 + (5 0mg·L- 1 )对JL 14有毒性;菲和蔗糖均可促进菌株JL 14对苯并[a]芘的降解作用.