Air monitoring of solvent exposed workers with passive samplers in comparison to “biological monitoring (BM)"†

A study was performed comparing ambient air monitoring (AM) and biological monitoring (BM) in order to evaluate the reliability of passive sampling (PS) in occupational medicine.

Five groups of persons (total number = 188) exposed to tetrachloroethene, isopropanol, toluene, xylene and styrene at the workplace were examined.

AM was performed over several hours using one or two brands of passive samplers (Monitor 3500 and/or ORSA 5). BM includes the determination of the solvent and specific metabolites resp. in blood or urine samples taken at the end of workshift. On the basis of our results we recommend that PS can supply relevant data for the estimation of external exposure to several solvents like chlorinated‐ and aromatic‐hydrocarbons.     

Management of fat reserves in tufted titmice (Parus bicolor ): evidence against a trade-off with food hoards

Caching species can manage their energy supply by adjusting body fat, number of caches, or both. It has been hypothesized that because body fat has a higher fitness cost than caches, small food-hoarding birds respond to increased starvation risk by increasing the number of their caches rather than their fat load. This hypothesis predicts that when birds cannot cache they should compensate for the loss of external energy storage by (1) shifting the time of their daily body mass accumulation toward earlier in the day and (2) increasing the overall level of their fat reserves. During the winter of 1995–1996, we tested these predictions with a caching species, the tufted titmouse (Parus bicolor). Each of six experimental birds was fed a diet of uncachable sunflower seed powder for 6 days, preceded and followed by 6-day control periods during which they were fed cachable sunflower seeds. The daily pattern of body mass gain was unaffected by the opportunity to cache. Furthermore, when unable to cache, the birds did not increase either their mean daily body mass, body mass in the middle of the day, or evening body mass compared to the two control periods. These results argue against the hypothesis of a trade-off between fat reserves and food caches in tufted titmice, and suggest that fat reserves are managed independently of external food caches. Received: 9 April 1997 / Accepted after revision: 30 August 1997     

Comparison of macroinvertebrate community structure in urban (Shenzhen City) streams with typical habitat characteristics北大核心CSCD

2020年12月在深圳市城市区域典型生境特征溪流——城市山区源头溪流金龟河、国家地质公园保护区入海溪流杨梅坑河与黑臭水体治理后溪流石溪河,开展底栖动物多样性与生境质量状况取样,通过多元统计分析探明各溪流底栖动物群落结构差异及其主要环境影响因子.结果表明:(1)金龟河底质异质性(SI)最高;杨梅坑河水质最好且流态异质性(Fr)最优,石溪河水质最差且底质异质性(Fr)最低.(2)共采集鉴定大型底栖动物118个分类单元,隶属于3门6纲14目87科.水生昆虫均占绝对优势,其中金龟河67属(81.7%),杨梅坑河62属(95.4%),石溪河12属(52.2%).金龟河中底栖动物Shannon-Wiener多样性指数、改进的Shannon-Wiener多样性指数、Pielou均匀度均高于杨梅坑河与石溪河.(3)金龟河的主要功能摄食类群是滤食者(45.5%),杨梅坑河(38.3%)与石溪河(58.7%)的主要功能摄食类群均为收集者.(4)冗余分析(RDA)结果显示,氨氮、海拔、湿宽、水温、溶氧、底质异质性(SI)、电导率和流态异质性(Fr)为影响深圳市溪流的大型底栖动物群落结构的主要环境因子.研究表明:(1)深圳市的山区溪流可作为深圳市生物多样性保护的重点区域.(2)在城市溪流生态系统中,水环境化学因子并非为主要影响因子,生境多样性发挥了重要作用.(图6表3参43)     

Spatial changes in the distributions of deep-sea “Cerviniidae” (Harpacticoida, Copepoda) and their associations with environmental factors in the bathyal zone around Sagami Bay, Japan

To estimate species turnover rates on scales of several tens of km in deep-sea benthic animals, we analyzed spatial and inter-annual changes in species diversity and composition of cerviniids, a typical group of deep-sea harpacticoids, at stations in and around Sagami Bay, central Japan. Associations with environmental factors were also investigated. Generally, bathymetrical patterns in diversity of benthos are unimodal and peak at depths of 2,000–3,000 m. In Sagami Bay, cerviniid diversity did not follow this trend; both species richness and evenness were negatively correlated with water depth. Multivariate analyses [detrended correspondence analysis (DCA) and non-metric multi-dimensional scaling] suggested that temporal changes in species composition of cerviniids are smaller than spatial changes that occur on horizontal scales of several tens of km. Community structure does not change completely on these scales in the bathyal zone around Sagami Bay. DCA also showed that bathymetrical changes in species composition can be regulated by certain factors associated with water depth.     

河流湿地土壤芘的降解和生物有效性模型与酶活性动态变化(Model of Pyrene Degradation and Bioavailability and Dynamic Changes of Enzymatic Activities in the Riverine Wetland Soil)

在淹水和非淹水条件下,在河流湿地土壤中加入高浓度(10mg·kg-1)和极高浓度(200mg·kg-1)芘,研究了芘降解过程、芘生物有效性和土壤酶活性的长期动态变化.结果表明,培养91d后,高浓度芘处理的土壤中芘的残留率在淹水和非淹水条件下分别为79.0%和51.4%,而极高浓度处理的芘残留率在淹水和非淹水条件下分别为61.1%和33.9%.利用Tenax-ta树脂提取快速解吸态生物有效芘,结果发现,有效芘浓度在高浓度芘处理的两种土壤中的值比较接近,分别为1.01mg·kg-1和1.23mg·kg-1;而有效芘浓度在极高浓度处理的两种土壤的相应值差别较大,分别为20.31mg·kg-1和9.44mg·kg-1.采用四参数Logistic模型能够精确地拟合芘降解过程和生物有效性变化过程(p<0.0001).土壤蔗糖酶、脲酶和多酚氧化酶对芘污染敏感,而过氧化氢酶对芘污染不敏感.实验结果揭示了河流湿地土壤芘在淹水条件下降解活跃阶段持续时间短和芘生物有效性高的特征以及土壤蔗糖酶、脲酶和多酚氧化酶活性可以作为评估芘污染影响的候选指标.     

Trace element contents in fine particulate matter (PM<Subscript>2.5</Subscript>) in urban school microenvironments near a contaminated beach with mine tailings,Chañaral,Chile

Air quality in schools is an important public health issue because children spend a considerable part of their daily life in classrooms. Particulate size and chemical composition has been associated with negative health effects. We studied levels of trace element concentrations in fine particulate matter (PM_2.5) in indoor versus outdoor school settings from six schools in Chañaral, a coastal city with a beach severely polluted with mine tailings. Concentrations of trace elements were measured on two consecutive days during the summer and winter of 2012 and 2013 and determined using X-ray fluorescence. Source apportionment and element enrichment were measured using principal components analysis and enrichment factors. Trace elements were higher in indoor school spaces, especially in classrooms compared with outdoor environments. The most abundant elements were Na, Cl, S, Ca, Fe, K, Mn, Ti, and Si, associated with earth’s crust. Conversely, an extremely high enrichment factor was determined for Cu, Zn, Ni and Cr; heavy metals associated with systemic and carcinogenic risk effects, whose probably origin sources are industrial and mining activities. These results suggest that the main source of trace elements in PM_2.5 from these school microenvironments is a mixture of dust contaminated with mine tailings and marine aerosols. Policymakers should prioritize environmental management changes to minimize further environmental damage and its direct impact on the health of children exposed.