Comparison of MTBE concentrations in groundwater of urban and nonurban areas in Germany

The occurrence of the gasoline oxygenate methyl tert-butyl ether (MTBE) in groundwater samples from known fuel-contaminated sites (n=29 samples), nonurban (n=74) and urban sites (n=67) in Germany was investigated. The analyses revealed detection frequencies of 58% (contaminated sites), 24% (nonurban sites) and 63% (urban sites) at a detection limit of 0.01 microgL(-1). Median (maximum) MTBE concentrations were calculated for nonurban and urban samples as 0.18 microgL(-1) (2.2 microgL(-1)) and 0.06 microgL(-1) (48 microg L(-1)). The data from nonurban samples revealed MTBE detections mainly at public supply wells with higher pumping rates than monitoring wells. MTBE was more frequently detected in urban samples, most probably due to the higher atmospheric input and direct liquid emissions from motorways or gas stations. Higher concentrations above 1.0 microgL(-1) in urban areas were found in wells located at industrial sites, where also a MTBE plume was accidentally detected during the study. The prevalence of MTBE in shallow aquifers was comparable to those in the USA.     

Polycyclic aromatic hydrocarbons (PAH) in some algae and invertebrates from moderately polluted parts of the coast of Norway

Analysis of PAH in mussels, snails, other invertebrates and algae demonstrated that PAH often were present even in areas far from any specific sources. In samples with distinct PAH profiles, 20–30 compounds were identified and quantitated by means of glass capillary gas chromatography. Total PAH concentrations were mostly in the range 0.3–3 mg kg⁻¹ dry weight, in a few cases up to 12 mg kg⁻¹. Supposedly cancerogenic species usually constituted less than 5% of the total, benzo(a)pyrene rarely more than 0.5–1%. In most, but not all cases, the variation in PAH levels were explainable in terms of difference in general diffuse loading at the localities investigated. The results agree fairly well with previous investigations in moderately polluted or pristine areas in other parts of the world. PAH profiles were somewhat differing from one species to another at the same locality. Thus the use of more than one indicator species often is recommendable. The potential conflict between mariculture and elevated PAH levels is briefly discussed.     

Indoor and outdoor concentrations of ultrafine particles in some Scandinavian rural and urban areas

The concentration of ultrafine particles (0.01 to greater than 1 microm) was measured in some rural and urban areas of Sweden and Denmark. The instruments used are handheld real-time condensation particle counters, models CPC 3007 and P-Trak 8525, both manufactured by TSI. Field measurements in Sweden were conducted in a few residential and office buildings, while in Denmark the measurement sites comprised two office buildings, one of them located in a rural area. The concentration of UFPs was measured simultaneously indoors and outdoors with condensation particle counters. The results revealed that the outdoor-generated particle levels were major contributors to the indoor particle number concentration in the studied buildings when no strong internal source was present. The results showed that in office buildings, the UFP concentrations indoors were typically lower and correlated fairly well to the number concentration outdoors. The determined indoor-outdoor ratios varied between 0.5 and 0.8. The indoor levels of UFPs in offices where smoking is allowed was sometimes recorded higher than outdoor levels, as in one of the Danish offices. In residential buildings, the indoor number concentration was strongly influenced by several indoor activities, e.g., cooking and candle burning. In the presence of significant indoor sources, the indoor/outdoor (IO) ratio exceeded unity. The magnitude of UFP concentrations was greater in the large city of Copenhagen compared to the medium-size city of Gothenburg and lowest at more rural sites.     

Non-linear uptake and hormesis effects of selenium in red-winged blackbirds (Agelaius phoeniceus)

Effects of selenium on reproductive success were assessed in red-winged blackbirds (Agelaius phoeniceus). Mean egg selenium (MES) ranged from 2.96 to 21.7 mg/kg dry weight with individual eggs up to 40 mg/kg. Uptake was non-linear: increments in MES declined as aqueous selenium increased; the asymptote was approximately 23 mg/kg. Eggs were heavier and more were laid in 2004 compared to 2005, a year of record rainfall and below-normal temperatures. Mortality of embryos that were incubated to full term was low (2.6% in 2004 and 3.2% in 2005), as was the prevalence of embryonic defects (2.7% in 2004 and 5.1% in 2005). Abnormalities in nestlings were also rare. Egg mortality was caused by predation, weather, and parental abandonment. Nestlings died from predation, starvation, and hypothermia associated with rain and cold, drowning, and bacterial infections. Nestling liver concentrations reached 81 mg/kg dry wt. selenium and were highest at the most highly selenium-exposed sites. Blood glutathione peroxidase (a selenium-dependent enzyme indicative of selenium exposure) was unrelated to liver selenium concentrations, egg selenium, or ambient selenium exposure. The selenium concentration in prey that parents fed to nestlings was higher at the selenium-exposed sites (up to 37 mg/kg dry wt. Se) compared to reference sites. Aqueous selenate:selenite ratios were related to redox differences and were much higher at the site with the highest MES, liver selenium, and prey item selenium concentrations. Hatchability showed U-shaped, or hormesis, relationships with MES: productivity increased with selenium concentrations at low exposures and decreased at high exposures. The effects threshold was approximately 22 mg/kg dry wt. MES.     

Atmospheric concentrations and air-soil gas exchange of polycyclic aromatic hydrocarbons (PAHs) in remote, rural village and urban areas of Beijing-Tianjin region, North China

Forty passive air samplers were deployed to study the occurrence of gas and particulate phase PAHs in remote, rural village and urban areas of Beijing-Tianjin region, North China for four seasons (spring, summer, fall and winter) from 2007 to 2008. The influence of emissions on the spatial distribution pattern of air PAH concentrations was addressed. In addition, the air-soil gas exchange of PAHs was studied using fugacity calculations. The median gaseous and particulate phase PAH concentrations were 222 ng/m³ and 114 ng/m³, respectively, with a median total PAH concentration of 349 ng/m³. Higher PAH concentrations were measured in winter than in other seasons. Air PAH concentrations measured at the rural villages and urban sites in the northern mountain region were significantly lower than those measured at sites in the southern plain during all seasons. However, there was no significant difference in PAH concentrations between the rural villages and urban sites in the northern and southern areas. This urban-rural PAH distribution pattern was related to the location of PAH emission sources and the population distribution. The location of PAH emission sources explained 56%-77% of the spatial variation in ambient air PAH concentrations. The annual median air-soil gas exchange flux of PAHs was 42.2 ng/m²/day from soil to air. Among the 15 PAHs measured, acenaphthylene (ACY) and acenaphthene (ACE) contributed to more than half of the total exchange flux. Furthermore, the air-soil gas exchange fluxes of PAHs at the urban sites were higher than those at the remote and rural sites. In summer, more gaseous PAHs volatilized from soil to air because of higher temperatures and increased rainfall. However, in winter, more gaseous PAHs deposited from air to soil due to higher PAH emissions and lower temperatures. The soil TOC concentration had no significant influence on the air-soil gas exchange of PAHs.     

Vertical distributions of SO(2) and NO(2) in the lower atmosphere in Beijing urban areas, China

Measurements of SO(2) and NO(2) were conducted from January to March 2001 and August 2003 at a 325 m meteorological tower in Beijing. The concentrations of SO(2) and NO(2) observed by passive samplers at ten heights showed complex vertical distributions in winter and summer. The vertical profiles of pollutants were influenced by source emissions, meteorological conditions, urban canopy and other factors. The comparison analysis of winter and summer pollutant concentrations suggests that the decrease in SO(2) concentration was significant in summer, and the reduction of NO(2) was relatively not distinctive. Domestic heating and industrial sources were major sources of SO(2) in urban areas of Beijing. Differing from SO(2,) urban NO(2) was closely related to traffic emission. Meteorological evidence suggests that strong temperature inversions influence vertical distribution of air pollutants over urban Beijing. The high levels of SO(2) and NO(2) concentrations were due to the accumulation of pollutants resulting from the stable atmosphere prevalent during the measurement period. The vertical distributions of air pollutants were controlled and affected by atmospheric dynamical characteristics.     

Stochastic modeling of total suspended solids (TSS) in urban areas during rain events

The load of total suspended solids (TSS) is one of the most important parameters for evaluating wet-weather pollution in urban sanitation systems. In fact, pollutants such as heavy metals, polycyclic aromatic hydrocarbons (PAHs), phosphorous and organic compounds are adsorbed onto these particles so that a high TSS load indicates the potential impact on the receiving waters. In this paper, a stochastic model is proposed to estimate the TSS load and its dynamics during rain events. Information on the various simulated processes was extracted from different studies of TSS in urban areas. The model thus predicts the probability of TSS loads arising from combined sewer overflows (CSOs) in combined sewer systems as well as from stormwater in separate sewer systems in addition to the amount of TSS retained in treatment devices in both sewer systems. The results of this TSS model illustrate the potential of the stochastic modeling approach for assessing environmental problems.     

长株潭星级乡村旅游区(点)空间分布研究

以首批长株潭地区的星级乡村旅游区(点)为研究样本,综合分析该类旅游目的地系统的空间分布特征:空间分布类型属于凝聚型;县区层面空间分布相对比较集中;星级乡村旅游区(点)空间分布呈现组团状凝聚分布的格局,分布密度最高处为长沙市三环线以内区域。     

Pollutant concentrations and fluxes in both stormwater and wastewater at the outlet of two urban watersheds in Nantes (France)

A two-year study of pollutants in both the stormwater and wastewater of urban watersheds has been conducted in Nantes (France). The present paper discusses the characteristics of pollutants transported by stormwater and wastewater collection networks in two urban watersheds. A physicochemical characterisation of the effluents was performed, along with an estimation of pollutant fluxes discharged into the Gohards River. Suspended solids (SS), trace metals, polycyclic aromatic hydrocarbons (PAHs) and pesticides were studied. SS, Zn, Cu and glyphosate were the main pollutants in stormwater and wastewater. In the watersheds examined, the pyrolitic origin of PAHs (mainly from traffic) was determined through ratios, with fluoranthene and pyrene being predominant. Despite a reduction in the use of pesticides in Nantes Metropolitan area, herbicides containing glyphosate were still detected in stormwater. It should be noted that this herbicide is widely used by homeowners, a fact that may explain its occurrence in stormwater.     

Public health evaluation of cadmium concentrations in liver and kidney of moose (Alces alces) from four areas of Alaska

Liver and/or kidney samples were collected from 139 hunter-killed moose from four areas of Alaska during 1986. The concentration of cadmium in organ tissue was determined by direct-current plasma atomic emission spectrometry. All results are reported as mug/g wet weight. Concentrations of cadmium in liver ranged from 0.06 microg/g to 9.0 microg/g; in the kidney cortex they ranged from 0.10 microg/g to 65.7 microg/g. Cadmium levels were significantly associated with location and age. The highest geometric mean liver (2.11 microg/g) and kidney cortex (20.2 microg/g) cadmium concentrations were detected in moose harvested near Galena, Alaska. Limited dietary information from Alaska and Canada indicates that the intake of moose liver or kidney does not exceed, in most individuals, the World Health Organization recommendations for weekly cadmium consumption of 400 microg to 500 microg. Additionally, human biomonitoring data from Canada and Alaska indicate exposure to cadmium is low except for individuals who smoke cigarettes. Given the nutritional and cultural value of subsistence foods, the Alaska Division of Public Health continues to support the consumption of moose liver and kidney as part of a well-balanced diet. Human biomonitoring studies are needed in Alaska to determine actual cadmium exposure in populations with a lifelong history of moose liver and kidney consumption.     

Trace element concentrations in blood of harbor seals (Phoca vitulina) from the Wadden Sea

Concentrations of 23 elements (Be, Al, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Rb, Sr, Mo, Pd, Cd, Sn, Pt, Pb) were evaluated in whole blood samples of live harbor seals (Phoca vitulina) from two different locations in the Wadden Sea, the Lorenzenplate in Germany, and the Danish island R?m?. Elemental blood levels were compared to data from literature of seals, other marine mammals and humans. While homeostatically controlled elements showed no differences, concentrations of As, Cr, Mn, Mo, Se, and V were higher than human levels. Furthermore, animals from both locations showed significant geographical differences in whole blood concentrations of Al, Mn, Cu, and Pt. These findings could be explained by differences in feeding areas. The element pattern was not affected by gender. In conclusion, these findings indicate an impact of the environment on biochemical blood parameters of the harbor seals. The significant differences of elements in blood samples of two groups of seals, which were associated with geographical variations of prey support the use of element pattern in blood as tool for investigation of environmental impact on seals.     

Lead, cadmium, and zinc concentrations in plaster and mortar from structures in Jasper and Newton Counties, Missouri (Tri-State Mining District)

The primary goal of this study was to evaluate anecdotal evidence that within Jasper and Newton Counties, Missouri, two counties within the Tri-State Mining District, granular mine tailings were commonly used in place of river sands in wall plasters and mortar. Interior wall plaster and mortar samples from structures in this mining district were analyzed for lead, cadmium, and zinc, and compared to samples from Springfield, MO (comparison site). The Jasper and Newton County samples showed elevated concentrations of the three elements, consistent with the inclusion of mine tailings, with a number of samples containing lead and cadmium at concentrations greater than EPA remediation targets for yard soil. X-ray diffraction studies showed the presence of the zinc ore minerals, sphalerite and hemimorphite, in high level samples. Thin section optical studies identified the major component of the aggregate as chert, a mineral abundant within the tailing piles. Because dust from crumbling plaster and mortar could represent an avenue for significant heavy metal exposure to building occupants, we suggest that there may be associated health consequences that should be further evaluated.     

The natural environment in socialist modernity: three case studies of new urban areas in Czechoslovakia (1966–1991)

ABSTRACT

This article presents three case studies of projects to construct new urban areas situated around the capital city of Prague. These urban areas were among the largest Czechoslovak urban planning projects and were intended as comprehensive environmental planning. Indeed, all of these projects included a formal declaration of the importance of protecting the existing environment while also creating a new environment for socialist people. The first of these case studies is the unrealized project of the city of Etarea (1967) planned for 135.000 inhabitants and based on an eco-friendly systems approach. The two other case studies represent implemented projects: Ji?ní Město (South City) which was, in 1971 planned for 64.000 inhabitants (then in the 1980s for more than 100.000 inhabitants) and Jihozápadní Město (Southwest City) which was, in 1968 planned for 80.000 inhabitants (then in the 1980s for more than 147.000 inhabitants).     

Lead (Pb) legacy from vehicle traffic in eight California urbanized areas: Continuing influence of lead dust on children's health

This article describes the magnitude of U.S. lead (Pb) additives in gasoline from 1927 to 1994 and estimated quantities of Pb dispersed by vehicle traffic in eight urbanized areas (UAs) of California from 1950 to 1982. The findings are the basis for predicting the health impact of Pb on children living in UA of California. Quantitative U.S. national data for 1927-1994 were from the U.S. Senate hearing of the 1984 Airborne Lead Reduction Act. Vehicle traffic data, fuel efficiency, percentage leaded gasoline, and quantities of Pb in gasoline were obtained for 1982 from public and corporate records to estimate vehicle Pb emissions for small to very large UAs of California. California fuel consumption records and yearly quantities of Pb additives per gallon were the basis for estimating the 1950-1982 dispersion of Pb in each UA. Lead additives were calculated by multiplying annual vehicle fuel used by average Pb per gallon. The proportion of Pb additive for each UA was calculated from vehicle miles traveled (VMT) driven in 1982 divided by miles per gallon fuel consumption times the ratio of leaded to unleaded fuel times Pb additive per gallon. U.S. Environmental Protection Agency calculations of the fates of Pb were used to estimate Pb aerosol dispersal in each UA. About 108 billion miles of travel in 1982 within 8 UAs accounts for 3200 metric tons of Pb additives or ∼ 60% total Pb additives in California. Between the 1950-1982 peak of Pb additives, about 258,000 metric tons are accounted for out of the state 412,000 metric tons total during the same time period. The estimates of the quantities of Pb dust that accumulated within various UAs in California assists with predicting the continuing influences of Pb on children's exposure. Mapping the soil Pb reservoir assists with establishing the priority for enhancing environments of children.     

Comparison of short-term exposure to particle number, PM10 and soot concentrations on three (sub) urban locations

Recent interest has focused on the health effects of ultrafine particles because of the documented toxicity and the larger concentration contrast near motorways of UFP than for PM10 or PM2.5. There are only few studies that have measured UFP at inner-city streets simultaneously with other PM components.The aim of this study was to compare the contrast of UFP, PM₁₀ and soot measured simultaneously at 3 inner-city locations, namely a moderately busy street (15,000 vehicles/day), a city and a suburban background location.Simultaneously, measurements of particle number concentrations (PNC), PM₁₀ and soot have been conducted on three locations in and around Utrecht, a medium-sized city in the Netherlands for 20 weekdays in autumn 2008. Measurements were done for 6-h during afternoon and early evening.The mean PNC at the street location was more than 3 times higher than at the two background locations. The contrast was similar for soot concentrations. In PM₁₀ concentrations less contrast was found, namely 1.8 times. Mean PNC concentrations were poorly correlated with PM₁₀ and soot. At the street location, high temporal variation of PNC concentrations occurred within each sampling day, probably related to variations in traffic volumes, high-emission individual vehicles and wind direction. Temporal variation was smaller at the two background locations. Occasional unexplained short-term peaks occurred at the suburban background location. A relatively high correlation between PNC minute values at the two background locations was found, pointing to similar area-wide sources. Typically low correlations were found with the street locations, consistent with the dominant impact of local traffic.A large contrast between two background locations and a moderately busy urban street location was found for PNC and soot, comparable to previous studies of much busier motorways. Temporal variation of PNC was higher at the street location and uncorrelated with background variations.     

Lead and cadmium in maternal blood, umbilical cord blood, amniotic fluid and placenta of cows and buffaloes after foetal death (abortion) and after normal parturition

The cause of abortion in dairy animals is not yet exactly known. Concentrations of lead and cadmium in maternal blood, umbilical cord blood, amniotic fluid and placenta under foetal death (abortion) conditions and after normal parturition has demonstrated that these tissues in aborting cows and buffaloes accumulate much more lead and cadmium as compared to the normally delivering cows and buffaloes. It is believed that the toxic metals cause damage to the placenta and thus foetal death.     

追求特色 繁荣城乡（下）——析广西地方城镇特色的轨迹

三、广西地方特色的艺术价值 探究广西地方特色的艺术性,本文特指城乡建设范畴的美学问题,实际上艺术涵盖许多内容,这里主要从城乡建设的需要,挖掘地方建筑特色的艺术性。广西建筑特色的艺术特点: (一)以桂林为例,是“山青、水秀、石美、洞奇”四绝为特征,而且有碑刻、题刻100多件。以南宋嘉泰元年(1201年)广南西路刑狱权知王正功在桂林独秀峰读书岩题刻“桂林山水甲天下,玉碧萝青意可参”的诗句最为著名,“桂林山水甲天下”遂声名远播。 (二)《花山崖画》,壮语说“岜来”,汉译为“有画的石山”,花山崖画位于宁明县驮龙乡耀达村花…     

Emissions variation in urban areas resulting from the introduction of natural gas vehicles: Application to Barcelona and Madrid Greater Areas (Spain)

On-road traffic is the major contributor to pollutant emissions in urban areas. Nowadays different emission abatement strategies are being tested in order to improve urban air quality (e.g. the European Commission currently promotes the use of natural gas as an alternative fuel). Several feasible scenarios regarding the introduction of natural gas vehicles (NGV) are studied in the two main cities of Spain (Barcelona and Madrid) by using the HERMES emission model. The most suitable emission factors to NGV are selected among those available in the literature. The account of emissions in the base case scenario estimated for a typical summertime polluted day of the year 2004 reflects that in Barcelona 86% of primary pollutants come from on-road traffic compared to 93% in Madrid, because of the heavier industrial activity in the former. The introduction of NGV in urban zones would have a positive effect on emissions, whose extent largely depends on the substituted fleets and the conurbation characteristics. Maximum reductions in NO_x emissions in Madrid are attributed to the substitution of 10% of the oldest diesel and petrol cars, while in Barcelona the change of 50% of the oldest commercial light vehicles becomes more effective. PM_2.5 and SO₂ emissions can be significatively reduced with the introduction of NGV instead of the oldest commercial light vehicles. The substitution of conventional fuels by natural gas must reach around 4% to achieve significative reductions in traffic emissions (larger than 5%). This work focuses on air quality issues, therefore GHG emissions are not included, nevertheless this kind of associated impact has to be considered by the decision makers. Assessing the efficacy of environmental improvement strategies entails a realistic design of emission scenarios and their evaluation. The detailed emission account provides a fundamental basis for the air quality modelling and its comparison among scenarios.