Application of probabilistic risk assessment at a coking plant site contaminated by polycyclic aromatic hydrocarbons

Application of Probabilistic Risk Assessment （PRA） and Deterministic Risk Assessment （DRA） at a coking plant site was compared. By DRA, Hazard Quotient （HQ） following exposure to Naphthalene （Nap） and Incremental Life Cancer Risk （ILCR） following exposure to Benzo（a）pyrene （Bap） were 1.87 and 2.12 × 104. PRA revealed valuable information regarding the possible distribution of risk, and risk estimates of DRA located at the 99.59th and 99.76th percentiles in the risk outputs of PRA, which indicated that DRA overestimated the risk. Cleanup levels corresponding acceptable HQ level of 1 and ILCR level of 104 were also calculated for both DRA and PRA. Nap and Bap cleanup levels were 192.85 and 0.14mg.kg-1 by DRA, which would result in only 0.25% and 0.06% of the exposed population to have a risk higher than the acceptable risk, according to the outputs of PRA. The application of PRA on cleanup levels derivation would lift the cleanup levels 1.9 times for Nap and 2.4 times for Bap than which derived by DRA. For this coking plant site, the remediation scale and cost will be reduced in a large portion once the method of PRA is used. Sensitivity analysis was done by calculating the contribution to variance for each exposure parameter and it was found that contaminant concentration in the soil （Cs）, exposure duration （ED）, total hours spent outdoor per day （ETout）, soil ingestion rate （IRs）, the air breathing rate （IRa） and bodyweight （BW） were the most important parameters for risk and cleanup levels calculations.     

Dissolved and dispersed petroleum hydrocarbons in the Aegean Sea

The distribution and transportation of Dissolved and Dispersed Petroleum Hydrocarbon (DDPH) were investigated in the Aegean Sea with the hydrodynamics of the water masses of the region. It is clear that distribution of this pollutant is strongly affected by physical dynamics of environment. The data were collected during cruises in November 1994, in the framework of National Marine Measurement and Monitoring Programme in the Aegean Sea. In the present study additionally the Chlorophyll‐a was measured fluorometrically and there is good correlation between petroleum hydrocarbon and chlorophyll‐a in the Aegean Sea. DDPH data was used to search origin of hydrocarbons: biogenic or non biogenic.     

Relation between Occupancy and Abundance for a Territorial Species,the California Spotted Owl

Land and resource managers often use detection–nondetection surveys to monitor the populations of species that may be affected by factors such as habitat alteration, climate change, and biological invasions. Relative to mark‐recapture studies, using detection–nondetection surveys is more cost‐effective, and recent advances in statistical analyses allow the incorporation of detection probability, covariates, and multiple seasons. We examined the efficacy of using detection–nondetection data (relative to mark‐recapture data) for monitoring population trends of a territorial species, the California Spotted Owl (Strix occidentalis occidentalis). We estimated and compared the finite annual rates of population change (λ_t) and the resulting realized population change (Δ_t) from both occupancy and mark‐recapture data collected over 18 years (1993–2010). We used multiseason, robust‐design occupancy models to estimate that territory occupancy declined during our study (Δ_t = 0.702, 95% CI 0.552–0.852) due to increasing territory extinction rates ( = 0.019 [SE 0.012]; = 0.134 [SE 0.043]) and decreasing colonization rates ( = 0.323 [SE 0.124]; = 0.242 [SE 0.058]). We used Pradel's temporal‐symmetry model for mark‐recapture data to estimate that the population trajectory closely matched the trends in territory occupancy (Δ_t = 0.725, 95% CI 0.445–1.004). Individual survival was constant during our study ( = 0.816 [SE 0.020]; = 0.815 [SE 0.019]), whereas recruitment declined slightly ( = 0.195 [SE 0.032]; = 0.160 [SE 0.023]). Thus, we concluded that detection–nondetection data can provide reliable inferences on population trends, especially when funds preclude more intensive mark‐recapture studies. Relación entre Ocupación y Abundancia en una Especie Territorial, el Búho Moteado de California     

土壤B[a]P叠加污染对蚯蚓体腔细胞SOD、POD和MDA的毒性效应

采用累积试验方法,研究土壤苯并[a]芘（B[a]P）多次叠加污染对赤子爱胜蚓（Eisenia foetida）体腔细胞超氧化物歧化酶（SOD）、过氧化物酶（POD）和丙二醛（MDA）的毒性效应.结果表明,随着土壤中B[a]P暴露时间的延长,蚯蚓体腔细胞的SOD、POD活力和MDA含量呈初期（1～14 d）下降速率较快,尔后（14～56 d）下降速率减小的变化趋势.在叠加污染条件下,0～ 20 cm深度土壤中蚯蚓体腔细胞SOD活力和MDA含量在14d时分别比一次污染低20.97％和15.96％,POD活力比一次污染高20.44％;而在＞20～40 cm深度土壤中蚯蚓体腔细胞SOD、POD活力和MDA含量在14d时分别比一次污染低52.89％、18.00％和70.60％.表明B[a]P叠加污染土壤中蚯蚓体腔细胞的毒性效应低于一次污染.     

地质灾害危险性评估分级因素的探讨

地质灾害危险性评估工作级别由建设项目重要性和评估区地质环境条件复杂程度这两个因素决定.在分析现行相关标准和研究成果的基础上,指出建设项目重要性可依次由省部级相关技术标准、项目行政审批权限级别、预估灾后损失程度顺序确定,以先符合者为准;指出评估区地质环境条件复杂程度可由地质灾害发育程度、地形与地貌复杂程度、地质构造复杂程度、岩土体工程地质性质、水文地质条件、破坏地质环境的人类工程活动程度等6项判定因素确定,并初步确定了地质灾害发育程度、地形与地貌复杂程度、地质构造复杂程度、岩土体工程地质性质、水文地质条件和破坏地质环境的人类工程活动程度等分级评价标准.     

Effect of the chemical composition of organic extracts from environmental and industrial atmospheric samples on the genotoxicity of polycyclic aromatic hydrocarbons mixtures

Particulate organic matter (PM) present in the atmosphere is a complex mixture of chemicals like polycyclic aromatic hydrocarbons (PAH) that may exert adverse health effects including respiratory and cardiovascular disturbances and cancer. In this study, airborne samples from environmental or industrial areas exhibiting different physicochemical composition were compared for their capacities to induce DNA damage in human hepatocytes HepG2. DNA strand breaks and DNA adducts formed by benzo[a]pyrene-7,8-dihydrodiol-9,10-epoxide (BPDE), the most reactive metabolite of the carcinogenic benzo[a]pyrene (B[a]P), were measured with the comet assay and by high-performance liquid chromatography (HPLC)/mass spectrometry, respectively. Cells were exposed to organic matter extracted from PM. Experiments were performed either at a constant concentration of B[a]P or at concentrations corresponding to fixed air volumes. Results show that industrial extracts tend to produce more benzo[a]pyrene diol epoxide-N ²-2′-deoxyguanosine (BPDE-N ²-dGuo) DNA adducts than strand breaks, whereas the opposite was observed with environmental extracts. The chemical composition of the extracts significantly impacts the nature and levels of DNA damage. The amount of B[a]P and interaction with other contaminants in the extracts need to be considered to explain the formation of DNA damage. These results emphasize the use of in vitro tests as promising and complementary tools to widely used toxic equivalent factor (TEF) approach in order to assess health hazards related to chemical exposure of the general population.     

双酚A对斑马鱼成鱼肝脏功能基因转录调控的影响

运用实时定量即时聚合链式反应RT-PCR方法,研究了双酚A对斑马鱼成鱼肝脏的功能基因转录水平的影响。结果显示,28 d半静水暴露以后,FGF8A和STAU 2 表现出传统的正剂量—效应关系,CLDN 1和CALCA的表达为倒剂量—抑制效应关系,SP 4基因在15 μg·L^-1 双酚A时表现为显著抑制效应,但是在150 和1 500 μg·L^-1却表现为显著的诱导效应。 试验进一步探讨了这些表达异常的基因在双酚A干扰去除后能否自我调节和修复。结果显示,CLDN 1能恢复到正常表达水平,而其他4个基因在低剂量组却维持原来的高毒性作用水平甚至表现出更高的毒性作用。研究证明双酚A对斑马鱼成鱼肝脏的基因转录调控具有一定的非单调剂量—效应作用。     

苯并[a]芘对马氏珠母贝D型面盘幼虫发育的影响

苯并芘(B[a]P)已广泛分布于海洋环境中,低等海洋无脊椎动物从受精卵开始整个生长发育过程都面临着B[a]P等多环芳烃类污染物(PAHs)的威胁。本实验以热带海洋优势贝类马氏珠母贝(Pinctada maetensii)作为材料,研究B[a]P对马氏珠母贝D型面盘幼虫发育的影响。将幼虫暴露于不同浓度(1、2、4、10和15μg·L-1)B[a]P中,在暴露后第12、24、36、48、72、84小时,分别测定其D型面盘幼虫的死亡率和畸形数。结果表明:B[a]P对D型面盘幼虫死亡率的影响明显,死亡率与时间呈正相关,其中4和10μg·L-1浓度组的响应最敏感。在1～10μg·L-1浓度范围内,死亡率与浓度呈正相关;B[a]P暴露对马氏珠母贝D型面盘幼虫的形态也有显著影响,且随着浓度的增大产生畸形个体的时间越短。另外,B[a]P对马氏珠母贝D型面盘幼虫的半数致死浓度(LC50)随着时间的推移逐渐降低后趋于稳定,48h时LC50趋于稳定,为21.56μg·L-1。研究表明,B[a]P对马氏珠母贝D形幼虫的发育具有不利影响,并可能影响其种群结构。     

镍对栅藻深度处理生活污水的影响研究

将栅藻包埋固定在海藻酸钙凝胶珠中,对人工污水进行深度净化,研究其在不同质量浓度Ni2+条件下对污水中氨氮和正磷酸盐的净化效率,以及净化过程中藻类叶绿素a质量浓度、过氧化物酶(POD)活性变化和去污过程中藻细胞富集Ni2+的情况。结果表明,低质量浓度Ni2+可引起藻细胞应激性反应,光合活性提高,解毒机制增强,未影响氨氮和正磷酸盐的净化效率;高质量浓度Ni2+会造成藻细胞伤害,光合活性减弱,POD活性下降,氨氮和正磷酸盐的净化效率减小。Ni2+对栅藻深度处理生活污水影响程度依据其在水体中的质量浓度。