新疆焉耆盆地农田土壤重金属污染及健康风险评价

为研究新疆焉耆盆地绿洲农田土壤重金属的污染及潜在健康风险,选取194个样点采集土壤样品,测定As、Cd、Cr、Cu、Ni、Pb和Zn共7种重金属元素含量。利用地质累积指数(I_(geo))评价农田土壤污染水平,采用US EPA健康风险评价模型,对农田土壤重金属污染的潜在健康风险进行评估。结果表明,研究区农田土壤7种重金属平均含量均未超出《食用农产品产地环境质量评价标准》中的限值,但Cd、Cr、Ni、Pb和Zn含量平均值分别超出新疆灌耕土背景值的1.67、1.41、1.30、3.01和6.78倍。农田土壤中Zn呈现轻度污染,Cd与Pb呈现轻微污染,As、Cr、Cu与Ni呈现无污染态势。健康风险评估结果表明,经手-口摄入是研究区农田土壤重金属日均暴露量及健康风险主要途径。农田土壤7种重金属通过3种暴露途径的非致癌风险商(HQ)与非致癌风险指数(HI),单项致癌风险指数(CR)与总致癌风险指数(TCR)均小于安全阈值,属于可接受风险水平。研究区农田土壤重金属对儿童的非致癌风险低于成人,致癌风险高于成人。研究区农田土壤中As与Pb是最主要的非致癌风险因子,As是最主要的致癌风险因子,研究区农田土壤中As对人体的健康风险应当引起重视。     

Medical geochemistry research in Spišsko-Gemerské rudohorie Mts., Slovakia

This study presents an assessment of the potential impact of geological contamination of the environment on the health of the population in Spišsko-Gemerské rudohorie Mts. (SGR Mts.). The concentration levels of potentially toxic elements (mainly As, Cd, Cu, Hg, Pb, Sb, and Zn) were determined in soils, groundwater, surface water, and stream sediments as well as in the food chain (locally grown vegetables). A medical study included some 30 health indicators for all 98 municipalities of the study area. The As and Sb contents in human fluids and tissues were analyzed in one municipality identified to be at the highest risk. Based on element content, environmental and health risks were calculated for respective municipalities. Out of 98 municipalities 14 were characterized with extremely high environmental risk and 10 were characterized with very high carcinogenic risk from arsenic (groundwater). Extensive statistical analysis of geochemical data (element contents in soils, groundwater, surface water, and stream sediments) and health indicators was performed. Significant correlations between element contents in the geological environment and health indicators, mainly cancer and cardiovascular diseases, were identified. Biological monitoring has confirmed the transfer of elements from the geological environment to human fluids and tissues as well as to the local food chain.     

Risk remaining from fine particle contaminants after vacuum cleaning of hard floor surfaces

In the indoor environment, settled surface dust often functions as a reservoir of hazardous particulate contaminants. In many circumstances, a major contributing source to the dust pool is exterior soil. Young children are particularly susceptible to exposure to both outdoor derived soil and indoor derived dust present in the indoor dust pool. This is because early in life the exploratory activities of the infant are dominated by touching and mouthing behavior. Inadvertent exposure to dust through mouth contact and hand-to-mouth activity is an inevitable consequence of infant development. Clean-up of indoor dust is, in many circumstances, critically important in efforts to minimize pediatric exposure. In this study, we examine the efficiency of vacuum cleaner removal of footwear-deposited soil on vinyl floor tiles. The study utilized a 5 × 10 foot (c. 152.5 × 305 cm) test surface composed of 1-foot-square (c. 30.5 × 30.5 cm) vinyl floor tiles. A composite test soil with moderately elevated levels of certain elements (e.g., Pb) was repeatedly introduced onto the floor surface by footwear track-on. The deposited soil was subsequently periodically removed from randomly selected tiles using a domestic vacuum cleaner. The mass and loading of soil elements on the tiles following vacuuming were determined both by wet wipe collection and by subsequent chemical analysis. It was found that vacuum cleaner removal eliminated much of the soil mass from the floor tiles. However, a small percentage of the mass was not removed and a portion of this residual mass could be picked up by moistened hand-lifts. Furthermore, although the post-vacuuming tile soil mass was sizably reduced, for some elements (notably Pb) the concentration in the residual soil was increased. We interpret this increased metal concentration to be a particle size effect with smaller particles (with a proportionately higher metal content) remaining in situ after vacuuming.     

Contamination indices and heavy metal concentrations in urban soil of Ibadan metropolis, southwestern Nigeria

An assessment was conducted on soils of Ibadan metropolis using geochemical approach in order to establish the concentration of heavy metals and develop geoaccumulation index maps. Petrographic studies and X-ray diffractograms showed that soils of Ibadan were derived from the weathering of the bedrocks. The concentrations of Cu, Pb, and Zn were found to be greater in soils more than the background. Positive correlation occurred between Cu, Pb, and Zn indicated a common anthropogenic source in the soil while Mn, Cr, and Ni were found to be naturally enriched. The geoaccumulation index maps revealed significant enrichment factor (Ef > 20) and index of geoaccumulation (Igeo) beyond class four (heavily contaminated) for Cu, Pb, and Zn in densely populated and industrial areas, whereas Cd is enriched in sparsely populated areas, agricultural areas and a few spots in densely populated areas.     

The effect of wind direction on ozone levels: a case study

This paper provides an illustrative case study on how the wind direction plays an important role in determining the ozone levels, in a suburb of Houston. Circular correlation and circular regression methods are used in the analysis and the primary goal is to illustrate how circular data analytic methods help in analyzing certain environmental issues. Received: August 2003/Revised: June 2004     

The effect of outdoor air pollutants and greenness on allergic rhinitis incidence rates: a cross-sectional study in Seoul,Korea

Air pollution poses a serious threat to human health in Asia. This study analyzes the association of air pollutants and greenness with incidence rates of allergic rhinitis in Seoul at the administrative district level to gain insight into district-level urban policies to improve public health. A spatial regression model is constructed to investigate the correlation between allergic rhinitis incidence rates and five air pollutants measured at 128 air pollution monitoring stations around Seoul: sulfur dioxide (SO₂), particulate matter less than 10 μm (PM₁₀), ozone (O₃), nitrogen dioxide (NO₂), and carbon monoxide (CO). The allergic rhinitis incidence data are derived from the National Health Insurance Service’s database that includes the number of allergic rhinitis-related clinic visits by the patients over 20 years of age and living in Seoul. A kriging geostatistical interpolation was used to estimate average air pollution level of 423 administrative districts. To assess pollen concentrations that can affect allergic rhinitis, the average normalized difference vegetation index (NDVI) is measured based on the urban greenness. The model, controlling for built environment and socio-economic attributes, identifies the possibility of a weak association between allergic rhinitis incidence rates and carbon monoxide levels. The NDVI value is negatively correlated with allergic rhinitis incidence rates, implying a complicated aspect in relation to the effect of urban greenness.     

Pollution status,ecological risk assessment and source identification of heavy metals in road dust from an Industrial Estate in Trinidad,West Indies

Road dust in an industrial estate could potentially contain toxic heavy metals as a result of various anthropogenic sources. This study investigated sixteen samples from various locations throughout the Point Lisas Industrial Estate in Trinidad, West Indies. Samples were acid-digested and analysed by Flame Atomic Absorption Spectroscopy, which revealed that concentrations for Cd, Cr, Cu, Mn, Ni, Pb and Zn ranged from 2.48–5.45?μg/g, 14.2–70.5?μg/g, 15.3–130?μg/g, 219–1330?μg/g, 20.0–62.1?μg/g, 43.5–113?μg/g and 105–1154?μg/g, respectively. Different methods (Geoaccumulation index, pollution index, integrated pollution index, enrichment factor and ecological risk assessment) of assessing heavy metal contamination in road dust indicated negligible to moderate degrees of pollution, in which the associated potential ecological risk was considered low. Principal component analysis (PCA) and Cluster analysis (CA) grouped the heavy metals according to potential sources and indicated that the accumulation of heavy metals in the road dust of the Estate were influenced mainly by vehicular and industrial processes.     

污染场地土壤多环芳烃（PAHs）生物可利用浓度的健康风险评价方法

随土壤不慎经口摄入是PAHs对人体健康造成危害的重要途径之一,目前该暴露途径下PAHs的健康风险计算主要基于土壤中总PAHs浓度进行计算。但是,这种计算方法并未考虑PAHs在土壤中的赋存状态及经口摄入后在人体不同器官中的毒理动力学过程,导致计算结果过于保守,修复目标过于严格,修复成本过高。针对这一问题国外相关研究人员已开展基于土壤中PAHs生物可利用性的健康风险评价研究并取得较大进展,但在国内就如何在风险评价过程中引入PAHs生物可利用性及其面临的障碍缺乏系统性报道。在对土壤中PAHs赋存形态及其随土壤经口腔摄入后在人体消化及循环系统中的动态分配最新研究成果进行综述的基础上,通过对该暴露途径下现有风险计算模型存在问题及原因进行分析,提出基于土壤中PAHs可利用浓度进行风险计算,并对相应计算模型进行推导以及模型参数的获取方法进行了简要概括,以解决目前模型计算结果过于保守的问题。同时,对于在现有分层次进行场地健康风险评价思路中如何科学地纳入基于土壤中PAHs可利用浓度进行风险计算的思路以及在实际风险评价中应用该思路还需进行的研究工作进行了简要讨论。     

Weak-wind mesoscale meandering in the nocturnal boundary layer

This study examines the strength and statistical behavior of mesoscale motions on time scales up to 1 h using eight data sets over different surface types. The mesoscale motions include internal gravity waves, microfront-like structures, horizontal modes, and a complex variety of other signatures, perhaps resulting from superposition of different modes. With weak large-scale flow, the mesoscale motions lead to meandering of the wind direction, as found in previous studies. However, the meandering often takes the form of sudden wind shifts rather than oscillation of wind direction. The relative strength and impact of such mesoscale motions are examined in terms of the constancy of the wind vector, the within-record standard deviation of the wind direction and the ratio of a meso-velocity scale to the speed of the large-scale flow. The strength of the mesoscale flow varies by an order of magnitude between nights at a given site and varies systematically between sites. The statistics of the vertical structure of such motions are examined for two of the data sets, both with sonic anemometers at seven levels.     

Characterizing cumulative impacts using a brook trout population dynamics model

An individuals-based modelling framework is used to characterize the nature of exploitation and toxaphene stressors acting simultaneously on a population of brook trout (Salvelinus fontinalis) in terms of age 0 + and adult abundance, survivorship and population size-structure. A no-stressor control case was estimated against which exploitation-only, toxaphene-only and cumulative exploitation and toxaphene stressor cases were compared to determine the extent and significance of impacts. Single stressor case results were used to predict cumulative impacts by assuming additivity and predictions compared to modelled cumulative stressor results. Comparisons indicated the inadequacy of assuming additivity in predicting cumulative impacts. A factorial experimental design was used to estimate the size and significance of interactive effects. Effects are substantial and underscore the necessity of interpreting probable impacts of increases in a single stressor in conjunction with knowledge of other stressors acting on a population. A positive functional relationship between variability in population abundance and stress was estimated and is suggested as a potentially useful means of characterizing risks posed to populations by increases in, or additions to, population stressors. Multiple stressors were also demonstrated to effectively eliminate the significance of density-dependent mortality processes in determining age 0 + and adult abundance. Taken together, results indicate the inappropriateness of attempting to predict additional perturbation impacts without considering the sum of population stressors and their associated interactions.     

Uncertainty in the assessment of hazard,exposure and risk

The terminology, concepts and current approaches to uncertainty in the assessment of hazard, exposure and risk are reviewed. Five generic questions are discussed on uncertainty, including sources, levels, when and how it should be dealt with or reduced, what are our gaps in understanding and how they can be addressed. A case study of lead exposure of children in Lavrion, Greece, is used to exemplify these questions and possible answers. Estimation of uncertainty may be improved by the use of interorganisational studies to capture sources of uncertainty that are often overlooked. Gaps identified in our understanding of uncertainty include: a limitation in the availability of basic measurements, a lack of knowledge of the environmental processes, an inability to predict the effects of mixtures, the aetiology of disease and devising procedures for optimal resource allocation in impact assessment.     

污染场地土壤多环芳烃(PAHs)生物可利用浓度的健康风险评价方法

随土壤不慎经口摄入是PAHs对人体健康造成危害的重要途径之一,目前该暴露途径下PAHs的健康风险计算主要基于土壤中总PAHs浓度进行计算。但是,这种计算方法并未考虑PAHs在土壤中的赋存状态及经口摄入后在人体不同器官中的毒理动力学过程,导致计算结果过于保守,修复目标过于严格,修复成本过高。针对这一问题国外相关研究人员已开展基于土壤中PAHs生物可利用性的健康风险评价研究并取得较大进展,但在国内就如何在风险评价过程中引入PAHs生物可利用性及其面临的障碍缺乏系统性报道。在对土壤中PAHs赋存形态及其随土壤经口腔摄入后在人体消化及循环系统中的动态分配最新研究成果进行综述的基础上,通过对该暴露途径下现有风险计算模型存在问题及原因进行分析,提出基于土壤中PAHs可利用浓度进行风险计算,并对相应计算模型进行推导以及模型参数的获取方法进行了简要概括,以解决目前模型计算结果过于保守的问题。同时,对于在现有分层次进行场地健康风险评价思路中如何科学地纳入基于土壤中PAHs可利用浓度进行风险计算的思路以及在实际风险评价中应用该思路还需进行的研究工作进行了简要讨论。     

应用GIS模拟城市大气污染物浓度分布

从点源大气污染扩散模型出发,借助GIS的栅格与数据库运算功能,结合自已设计的推算流程,对兰州市大气污染物SO2的空间分布情况进行了模拟。经检验,该方法能够较准确的反映出兰州大气污染物的空间分布特征,较应用实测值进行插值的方法简便,具有较好的应用前景。     

评估斑马鱼胚胎毒性试验在农药危害筛选中的应用

考虑到人类社会中大量使用化学物质,想要准确有效地评估这些化学物质对人类和生态受体的潜在风险,研发有效的手段和方法是至关重要的。鱼胚胎急性毒性试验是其中一种工具,已表现出与幼鱼急性毒性标准试验的预测结果高度吻合,而幼鱼试验对资源消耗更多。然而,也有证据表明,对于某些类型的化学物质,包括神经毒素,鱼类胚胎的敏感性低于幼鱼。本文利用已发表的斑马鱼胚胎毒性数据,与3种常用检测用鱼幼鱼(虹鳟鱼、蓝鳃太阳鱼、羊鲷)的半致死浓度50%(LC₅₀)数据进行比较,研究了鱼类胚胎对农药危害评估的效用。在将农药视为单因素的情况下,斑马鱼胚胎和幼鱼毒性数据相关性较差,差异显著(r²=0.28;p2=0.64;p精选自Glaberman, S., Padilla, S. and Barron, M. G. (2017), Evaluating the zebrafish embryo toxicity test for pesticide hazard screening. Environmental Toxicology and Chemistry, 36: 1221–1226. doi: 10.1002/etc.3641
详情请见http://onlinelibrary.wiley.com/doi/10.1002/etc.3641/full
     

基于分形插值模型的平寨水库水质评价

平寨水库是黔中水利枢纽唯一源头水库,其水环境质量直接影响包括安顺和贵阳在内的整个黔中地区的农业灌溉和城市居民饮水安全.为了深入分析平寨水库的水环境质量状况,于2018年1月、5月、8月和11月对平寨水库7个监测断面水样进行采集,测定TP、TN、NH3-N、COD和DO等5个监测指标,基于分形维数权重建立水质评价模型,对...     

Hidden Markov models for circular and linear-circular time series

We introduce a new class of circular time series based on hidden Markov models. These are compared with existing models, their properties are outlined and issues relating to parameter estimation are discussed. The new models conveniently describe multi-modal circular time series as dependent mixtures of circular distributions. Two examples from biology and meteorology are used to illustrate the theory. Finally, we introduce a hidden Markov model for bivariate linear-circular time series and use it to describe larval movement of the fly Drosophila. Received: September 2003 / Revised: March 2004     

The effect of humic substances on Cu migration in the soil profile

Humic substances (HS) are widely used for diverse purposes. The effect of HS on the metal’s status in contaminated soils is contradictory. The aim of this work was to investigate the Cu migration in soils treated with HS. A model field experiment with the addition of Cu (1.243?mg?Cu/kg) and HS Extra® (potassium humate) was performed. The Cu addition resulted in acidification (by 0.7 pH) after 3 months. The major part of the added Cu remained in the upper 7-cm-thick soil layer; 4% reached the lower soil layer, while only 0.1% were removed beyond the profile. The addition of HS mitigated soil acidification increased the content of Cu bound to solid-phase organic substances and abruptly reduced the Cu activity in the soil liquid phase. Simultaneously, the HS addition increased the water-soluble organic substances (WSOS) by four times, including those in the hydrophilic and hydrophobic fractions, resulting in a twofold increase in the content of soluble Cu. Copper complexes with hydrophilic WSOS mainly reached lysimeters, and hydrophobic organic substances were absorbed by the soil. The HS addition to a slightly acidic soil can accelerate the migration of Cu to adjacent environments.     

青藏高原五条冰川表雪中痕量元素的空间分布及污染评估

为了认识青藏高原雪冰中痕量元素的空间分布特征与污染程度,对2013年4-5月采自求勉雷克、煤矿、玉珠峰、小冬克玛底和古仁河口冰川的表面样和雪坑样进行消解处理,并利用高分辨扇形磁场等离子体质谱仪（ICP-SFMS）测试了样品中19种痕量元素（Al、As、Ba、Co、Cr、Cs、Cu、Fe、Li、Mn、Mo、Pb、Rb、Sb、Sr、Ti、Tl、U、V）的总浓度.通过对5条冰川表面样进行空间对比,发现痕量元素在唐古拉山以北的求勉雷克、煤矿和玉珠峰冰川中浓度较高,在3条冰川中元素浓度的平均值在0.05 ng·g-1（Tl）—6579.62 ng·g-1（Al）之间,痕量元素在唐古拉山小冬克玛底冰川及唐古拉山以南的古仁河口冰川中浓度较低,在小冬克玛底冰川中元素的浓度介于0.004 ng·g-1（Tl）—103.44 ng·g-1（Al）之间,在古仁河口冰川中元素的浓度介于0.006 ng·g-1（Tl）—361.83 ng·g-1（Al）之间.计算痕量元素总浓度的富集系数（EF）表明,在5条冰川雪冰中的V、Mn、U、Ba、Rb主要来自于地壳粉尘,Sb、Mo、Pb、Cu、As在一些冰川雪冰中具有明显或较为严重的污染（EF≥5）,这5种元素可能来自于有色金属冶炼、交通排放、化石燃料燃烧等人类活动.利用后向轨迹的聚类分析表明,5条冰川在非季风时期主要受到盛行西风的影响,其中求勉雷克、煤矿和玉珠峰冰川中的痕量元素主要来自中亚及新疆等地,小冬克玛底和古仁河口冰川中的痕量元素则主要来自于南亚及青藏高原西部地区.     

Soils and geomedicine

Geomedicine is the science dealing with the influence of natural factors on the geographical distribution of problems in human and veterinary medicine. Discussions on potential harmful impacts on human and animal health related to soil chemistry are frequently focused on soil pollution. However, problems related to natural excess or deficiency of chemical substances may be even more important in a global perspective. Particularly problems related to trace element deficiencies in soils have been frequently reported in agricultural crops as well as in livestock. Deficiencies in plants are often observed for boron, copper, manganese, molybdenum, and zinc. In animals deficiency problems related to cobalt, copper, iodine, manganese, and selenium are well known. Toxicity problems in animals exposed to excess intake have also been reported, e.g., for copper, fluorine, and selenium. Humans are similar to mammals in their relations to trace elements and thus likely to develop corresponding problems as observed in domestic animals if their supply of food is local and dependent on soils providing trace element imbalances in food crops. In large parts of Africa, Asia, and Latin America, people depend on locally grown food, and geomedical problems are common in these parts of the world. Well-known examples are Keshan disease in China associated with selenium deficiency, large-scale arsenic poisoning in Bangladesh and adjacent parts of India, and iodine deficiency disorders in many countries. Not all essential elements are derived only from the soil minerals. Some trace elements such as boron, iodine, and selenium are supplied in significant amounts to soils by atmospheric transport from the marine environment, and deficiency problems associated with these elements are therefore generally less common in coastal areas than farther inland. For example, iodine deficiency disorders in humans are most common in areas situated far from the ocean. There is still a great need for further research on geomedical problems.