Urban and rural ozone concentrations in Alberta,Canada

Ozone concentrations in Alberta cities typically exhibit a maximum in May (up to 35 ppb) and a minimum in November (as low as 4 ppb). This behaviour is similar to that of rural Alberta O₃ concentrations. Annual O₃ concentrations at six urban monitoring stations vary from 11 ppb to 22 ppb and are about one-half the values at rural stations. In winter, urban O₃ concentrations are always smaller than rural concentrations and the cities act as sinks for O₃. Although urban stations do not exceed Canada's maximum acceptable levels of daily (25 ppb) and annual (15 ppb) O₃ concentrations as often as rural stations, the frequency is still quite large. Canada's hourly maximum desirable level (50 ppb) is exceeded 11 times more often at the remote (rural) station than at the downtown (urban) stations.     

Occurrence of organotin compounds in house dust in Berlin (Germany)

In a study in the year 2000 on the occurrence of hazardous environmental contaminants house dust samples from 28 Berlin apartments were measured for the presence and concentrations of six organotin compounds, monobutyltin (MBT), dibutyltin (DBT), tributyltin (TBT), monooctyltin (MOT), dioctyltin (DOT) and triphenyltin (TPT). The concentrations of MBT and DBT determined ranged considerably from 0.01 mg kg-1 to 1.5 mg kg-1 (median: 0.05 mg kg-1) and 0.01 to 5.6 mg kg-1 (median: 0.03 mg kg-1), respectively. Maximum levels of TBT and MOT were only 0.08 mg kg-1 and 0.04 mg kg-1. The maximum total value of the organotins was 7.2 mg kg-1 (median: 0.11 mg kg-1). MBT was found in 86% and DBT in 82% of the samples above the limit of quantification, TBT and MOT only in 50% and DOT in 43%. The focus of ecotoxicology is on the risks arising from organotin compounds (especially butyltins) when used as biocides in antifouling paints. TBT acts as an endocrine disrupter in animals, inducing masculinization (imposex) in female gastropods of different species by increasing testosterone levels. The most critical organ site in experimental animals is the cellular immune system, where lymphocyte depletion in the thymus and peripheral lymphoid tissues takes place. Our study does not provide data on the basis of which population exposure could be estimated; house dust containing harmful organotins could, however, under some conditions, become a relevant intake possibility for young children.     

Urban and rural ambient air aldehyde levels in Schenectady,New York and on Whiteface Mountain,New York

The air in the city of Schenectady, NY was sampled daily and analyzed for the presence of low molecular weight aldehydes during the months of June–August 1983. The diurnal variation of the aldehyde concentrations was also determined over a two day period during August. The dominant aldehyde was formaldehyde and its concentration varied from about 1–31 ppb. There was also observed a significant daily variation that appeared to correlate with traffic conditions. The technique was also used to monitor the aldehyde levels on the summit of Whiteface Mountain in Wilmington, NY at the SUNYA Atmospheric Sciences Research Center. The monitoring was done on a daily basis during the week of 14–20 August and, during that week, every 3 h for a 3-day period. The two dominant aldehydes were formaldehyde and acetaldehyde and they varied in concentration from about 0.8–2.6 and 0.2–0.8 ppb, respectively.     

Methyl tert-butyl ether (MTBE) in urban and rural precipitation in Germany

The use of the oxygenate methyl tert-butyl ether (MTBE) in gasoline has led to detectable concentrations in urban and rural air up to 160 ppbV. Results from MTBE measurement in precipitation have not been reported so far. In the present study, 120 samples of precipitation collected at 17 sampling locations all over Germany have been analyzed for their MTBE content. Analysis is performed by a combination of headspace-solid-phase microextraction (HS-SPME) and gas chromatography/mass spectrometry (GC-MS). A 75 μm poly(dimethylsiloxane)/Carboxene fiber and a cryostat is used for SPME. The detection limit is 10 ng/l. In precipitation samples, MTBE was detected in wintertimes only with a maximum concentration of 85 ng/l. Measurement at Frankfurt/M City from 6 September 2000 to 12 March 2001 provided for 49% of the data concentrations in the range of 30–85 ng/l (n=17). Sampling in winter 2000/2001 at several German cities and rural locations showed that MTBE is more often detectable in urban (86%, n=78) than in rural (18%, n=42) precipitation. By comparing the results with corresponding temperatures and amounts of precipitation it can be concluded that the detection of MTBE in urban precipitation is observed at ambient temperatures lower than about 10–15°C. Moreover, the first precipitation after a dry period accumulates more MTBE than precipitation during or at the end of a wet period (wash-out effect). Highest concentrations occurred in snow samples. Corresponding mean air equilibrium concentrations of 0.04 ppbV (urban samples) and 0.01 ppbV (rural samples) are calculated. This is about one magnitude lower than year round and summertime measurements in the US and in Switzerland. Urban runoff (n=12) and corresponding precipitation sampling indicate that urban runoff might be composed of about 20% MTBE that is already transported by air and precipitation, whereas about 80% may be attributed to direct uptake of vehicle emissions and leakage near the road during precipitation.     

Atmospheric concentration characteristics and gas-particle partitioning of PCBs in a rural area of eastern Germany

Atmospheric concentrations of polychlorinated biphenyls (PCBs) were measured in 14 successive daytime and nighttime air samples collected from Melpitz, a rural site in eastern Germany. The average total concentration of PCBs was 110+/-80 pg m-3 and they were predominately present in the gas phase (approximately 95%). Composition of individual congeners closely resembled those of Clophen A30 and Aroclor 1232. Partial vapor pressures of PCBs were well correlated with temperature and the steep slopes obtained from Clausius-Clapeyron plots (-4500 to -8000) indicated that evaporation from adjacent land surfaces still controls the atmospheric levels of these pollutants. Particle-gas partitioning coefficients (KP) of PCBs were well correlated with the respective sub-cooled vapor pressures (PLo), but the slopes obtained from logKP versus logPLo plots (-0.16 to -0.59) deviated significantly from the expected value of -1. Overall, gas-particle partitioning of PCBs was better simulated by Junge-Pankow than octanol/air partition coefficient-based model.     

Occurrence of psychoactive compounds and their metabolites in groundwater downgradient of a decommissioned sewage farm in Berlin (Germany)

Purpose

Psychoactive compounds??meprobamate, pyrithyldione, primidone, and its metabolites, phenobarbital, and phenylethylmalonamide??were detected in groundwater within the catchment area of a drinking water treatment plant located downgradient of a former sewage farm in Berlin, Germany. The aim of this study was to investigate the distribution of the psychoactive compounds in anoxic groundwater and to assess the risk of drinking water contamination. Groundwater age was determined to achieve a better understanding of present hydrogeological conditions.

Methods

A large number of observation and production wells were sampled. Samples were analyzed using solid-phase extraction and ultrahigh-performance liquid chromatography?Ctandem mass spectrometry. Groundwater age was estimated using the helium?Ctritium (³He?C³H) dating method.

Results

Concentrations of psychoactive compounds up to 1???g/L were encountered in the contamination plume. Generally, concentrations of phenobarbital and meprobamate were the highest. Elevated concentrations of the analytes were also detected in raw water from abstraction wells located approximately 2.5?km downgradient of the former sewage farm. Concentrations in the final drinking water were below the limit of quantification owing to dilution. The age of shallow groundwater samples ranged from years to a decade, whereas groundwater was up to four decades old at 40?m below ground. Concentrations of the compounds increased with groundwater age.

Conclusions

Elevated concentrations of psychoactive drugs indicate a strong persistence of these compounds in the environment under anoxic aquifer conditions. Results suggest that the heritage of sewage irrigation will affect raw water quality in the area for decades. Therefore, further monitoring of raw and final drinking water is recommended to ensure that contaminant concentrations remain below the health-based precautionary value.     

PCDDs/PCDFs and coplanar PCBs in eels (Anguilla anguilla) from different areas of the rivers Havel and Oder in the state of Brandenburg (Germany)

In 1996 forty-nine eels were caught from different locations along the rivers Oder (Hohenwutzen and Schwedt) and from 11 locations along the Havel river. They were analysed for PCDDs/PCDFs and the coplanar PCBs (PCB 77, PCB 126, PCB 169). Their contribution to 2,3,7,8-TCDD equivalents were estimated. In case of PCDDs/PCDFs these amounted between 1.8 and 15.2 pg/g fat (mean 6.1 pg/g; median 5.2 pg/g), in case of coplanar PCBs between 2.4 and 170.5 pg/g fat (mean 47.7 pg/g; median 36.1 pg/g). Lakes which are associated with but not directly located at the main stream of the river Havel contributed much less to contamination of the eels than the river segments situated in the more urbanised or industrialised sites along the main river.     

Urban and rural ultrafine (PM0.1) particles in the Helsinki area

In June 1996–June 1997 Berner low-pressure impactors were used at an urban and at a rural site in the Helsinki area for sampling ultrafine particles (UFP, PM_0.1). Ten sample pairs, each pair measured simultaneously, were collected in the size range of 0.03–15 μm of particle aerodynamic diameter. More than 40 chemical components were measured. Surprisingly, the average UFP mass concentration was higher at the rural site (520 ng/m³) than at the urban site (490 ng/m³). The average chemical composition of UFP was similar at the two sites. The most abundant of the measured components were sulphate (32 and 40 ng/m³ for the urban and rural sites, respectively), ammonium (22 and 25 ng/m³), nitrate (4 and 11 ng/m³) and the Ca²⁺ ion (5 and 7 ng/m³). The most important metals at both sites were Ca, Na, Fe, K and Zn with concentrations between 0.7 and 5 ng/m³. Of the heavy metals, Ni, V, Cu, and Pb were important with average ultrafine concentrations between about 0.1 and 0.2 ng/m³. Also the organic anions oxalate (urban 2.1 ng/m³ and rural 1.9 ng/m³) and methanesulphonate (1.3 and 1.7 ng/m³) contributed similarly at both sites. The measured species accounted for only about 15–20% of the total ultrafine mass. The fraction that was not measured includes mainly carbonaceous material and water. It was estimated that the amount of water was about 10% (50 ng/m³) and that of carbonaceous material about 70% (350 ng/m³) at both sites. Aitken modes were observed for most components with the average mass mean mode diameters being between about 0.06 and 0.12 μm. The average concentrations in the Aitken mode differed clearly from those in the UFP for several components.The average contribution of ultrafine mass to the fine particle mass (PM_2.5) was about 7% at the urban site and 8.5% at the rural site. At both sites the contribution of ultrafine to fine was especially high for Se, Ag, B, and Ni (10–20%) and at the rural site also for Co (20%), Ca²⁺ (16%) and Mo (11%). Enrichment in the ultrafine particles suggests that local sources may exist for these elements.Aitken modes turned out to be useful indicators of local sources for several components. The Aitken modes of Ba, Ca, Mg and Sr were similar in several samples, suggesting a common local combustion source for these elements, possibly traffic exhaust. Co, Fe, Mo and Ni formed another group of elements often having similar Aitken modes, the likely source being combustion of heavy fuel oil.     

Recent atmospheric Pb deposition at a rural site in southern Germany assessed using a peat core and snowpack,and comparison with other archives

In a peat bog from Black Forest, Southern Germany, the rate of atmospheric Pb accumulation was quantified using a peat core dated by ²¹⁰Pb and ¹⁴C. The most recent Pb accumulation rate (2.5 mg m⁻² y⁻¹) is similar to that obtained from a snowpack on the bog surface, which was sampled during the winter 2002 (1 to 4 mg m⁻² y⁻¹). The Pb accumulation rates recorded by the peat during the last 25 yr are also in agreement with published values of direct atmospheric fluxes in Black Forest. These values are 50 to 200 times greater than the “natural” average background rate of atmospheric Pb accumulation (20 μg m⁻² y⁻¹) obtained using peat samples from the same bog dating from 3300 to 1300 cal. yr B.C. The isotopic composition of Pb was measured in both the modern and ancient peat samples as well as in the snow samples, and clearly shows that recent inputs are dominated by anthropogenic Pb. The chronology and isotopic composition of atmospheric Pb accumulation recorded by the peat from the Black Forest is similar to the chronologies reported earlier using peat cores from various peat bogs as well as herbarium samples of Sphagnum and point to a common Pb source to the region for the past 150 years. In contrast, Pb contamination occurring before 1850 in southwestern Germany, differs from the record published for Switzerland mainly due to the mining activity in Black Forest. Taken together, the results show that peat cores from ombrotrophic bogs can yield accurate records of atmospheric Pb deposition, provided that the cores are carefully collected, handled, prepared, and analysed using appropriate methods.     

Temporal variations of surface water quality in urban, suburban and rural areas during rapid urbanization in Shanghai, China

As the economic and financial center of China, Shanghai has experienced an extensive urban expansion since the early 1980s, with an attendant cost in environmental degradation. We use an integrated pollution index to study the temporal variations of surface water quality in urban, suburban and rural areas between 1982 and 2005. Data on monitored cross-sections were collected from the Shanghai Environmental Monitoring Center. The results indicated that the spatial pattern of surface water quality was determined by the level of urbanization. Surface water qualities in urban and suburban areas were improved by strengthening the environmental policies and management, but were worsening in rural areas. The relationship between economic growth and surface water quality in Shanghai showed an inversed-U-shaped curve, which reflected a similar pattern in most developed countries. This research suggests that decision makers and city officials should be more aware of the recent pollution increases in Shanghai.     

Long-term atmospheric bulk deposition of polycyclic aromatic hydrocarbons (PAHs) in rural areas of Southern Germany

A novel passive sampling technique using a funnel–adsorber–cartridge device was adopted and validated in the field during a long-term monitoring program on the atmospheric deposition of polycyclic aromatic hydrocarbons (PAHs) in three rural regions of southern Germany. Apart from seasonal variations, fairly stable annual deposition rates around 200 μg m⁻² yr⁻¹ for the sum of PAHs were obtained. The time-integrating passive samplers showed that spatial variability due to topography was negligible and differences between open-field and forest deposition were within a factor of 2. Based on correlations with ambient temperature, advection was identified as the most important factor that controls the atmospheric deposition of PAHs. Gas-adsorption contributes significantly to the deposition of the semivolatile compounds in forests, but particle deposition seems to be the major pathway for all PAHs.     

Fate of para-toluenesulfonamide (p-TSA) in groundwater under anoxic conditions: modelling results from a field site in Berlin (Germany)

This article reports on a field modelling study to investigate the processes controlling the plume evolution of para-toluenesulfonamide (p-TSA) in anoxic groundwater in Berlin, Germany. The organic contaminant p-TSA originates from the industrial production process of plasticisers, pesticides, antiseptics and drugs and is of general environmental concern for urban water management. Previous laboratory studies revealed that p-TSA is degradable under oxic conditions, whereas it appears to behave conservatively in the absence of oxygen (O₂). p-TSA is ubiquitous in the aquatic environment of Berlin and present in high concentrations (up to 38 μg L^?1) in an anoxic aquifer downgradient of a former sewage farm, where groundwater is partly used for drinking water production. To obtain refined knowledge of p-TSA transport and degradation in an aquifer at field scale, measurements of p-TSA were carried out at 11 locations (at different depths) between 2005 and 2010. Comparison of chloride (Cl^?) and p-TSA field data showed that p-TSA has been retarded in the same manner as Cl^?. To verify the transport behaviour under field conditions, a two-dimensional transport model was setup, applying the dual-domain mass transfer approach in the model sector corresponding to an area of high aquifer heterogeneity. The distribution of Cl^? and p-TSA concentrations from the site was reproduced well, confirming that both compounds behave conservatively and are subjected to retardation due to back diffusion from water stagnant zones. Predictive simulations showed that without any remediation measures, the groundwater quality near the drinking water well galleries will be affected by high p-TSA loads for about a hundred years.     

Effects of oil sands tailings compounds and harsh weather on mortality rates, growth and detoxification efforts in nestling tree swallows (Tachycineta bicolor)

Oil sands mining companies in Alberta, Canada, are evaluating the feasibility of using wetlands to detoxify oil sands process material (OSPM) as a reclamation strategy. Reproductive success, nestling growth, survival and ethoxyresorufin-o-deethylase (EROD) activity were measured in tree swallows (Tachycineta bicolor) on experimental wetlands. In 2003, harsh weather triggered a widespread nestling die-off. Mortality rates on the control site reached 48% while they ranged from 59% to 100% on reclaimed wetlands. The odds of dying on the most process-affected sites were more than ten times higher than those on the control site. In 2004, weather was less challenging. Mortality rates were low, but nestlings on reclaimed wetlands weighed less than those on the control site, and had higher EROD activity. These results indicate that compared with reference birds, nestlings from OSPM-impacted wetlands may be less able to withstand additional stressors, which could decrease their chances of survival after fledging.     

Levels of synthetic musks; bromocyclene and PCBs in eel (Anguilla anguilla) and PCBs in sediment samples from some waters of Berlin/Germany.

The purpose of this study was to identify firstly the extent of contamination both of the aquatic biota and of sediments and secondly any regional differences in the concentrations of these compounds. In 1996, polychlorinated biphenyls (PCBs, including their coplanar congeners) were measured in 58 eel and 50 sediment samples. Furthermore, the veterinary pharmacetical bromocyclene and the nitro musks were determined in 84 (1995) and 122 (1996) eel samples. Polycyclic musk fragrances were additionally determined in analyses carried out in 1996. The mean values obtained during the two measurement periods (1995 and 1996) were 24 and 12 micrograms/kg fw. for musk xylene, 41 and 39 micrograms/kg fw. for musk ketone, 14 and 7 micrograms/kg fw. for bromocyclene and, in 1996, 592 micrograms/kg fw. for HHCB (maximum: 4131 micrograms/kg fw.). Decreasing contamination levels are seen for musk xylene and bromocylene but not for musk ketone. This tendency, and the high amounts of polycyclic musk fragrances in the edible parts of eel show that these musks are widely being used in place of nitro musks and that they reach the aquatic system via waste waters, especially those of sewage treatment plants. The mean levels of PCBs in the biota samples of a highly polluted area were 1227 micrograms/kg fw. or 119 pgTEQ/g (sediment: 203 micrograms/kg dw.) and of a slightly polluted area 340 micrograms/kg fw. or 49 TEQ/g (sediment: 47 micrograms/kg dw.).     

Arsenic and Mn levels in Isaza (Gymnogobius isaza) during the mass mortality event in Lake Biwa, Japan

The present study measured the concentrations of 25 elements (Li, Mg, V, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Rb, Sr, Mo, Ag, Cd, In, Sn, Sb, Cs, Ba, Hg, Tl, Pb and Bi) in the whole body of Isaza which is an endemic fish species to Lake Biwa, Japan, and compared the values in the specimens from the mass mortality Isaza (MMI) and normal fresh Isaza (NFI). The mean levels of Mn and total As (T-As) were relatively higher in MMI than in NFI. In the T-As, highly toxic inorganic As was detected in MMI. Moreover we found Mn and As concentrations in surface sediment were extremely high and temporally increased. From all these results, we could infer that the dissolution of Mn and As from surface sediment of Lake Biwa might have been one of the cause for the mass mortality of Isaza.     

Estimation of PAHs dry deposition and BaP toxic equivalency factors (TEFs) study at Urban, Industry Park and rural sampling sites in central Taiwan, Taichung

The concentrations of polycyclic aromatic hydrocarbons (PAHs) in gas phase and particle bound were measured simultaneously at industrial (INDUSTRY), urban (URBAN), and rural areas (RURAL) in Taichung, Taiwan. And the PAH concentrations, size distributions, estimated PAHs dry deposition fluxes and health risk study of PAHs in the ambient air of central Taiwan were discussed in this study. Total PAH concentrations at INDUSTRY, URBAN, and RURAL sampling sites were found to be 1650 +/- 1240, 1220 +/- 520, and 831 +/- 427 ng/m3, respectively. The results indicated that PAH concentrations were higher at INDUSTRY and URBAN sampling sites than the RURAL sampling sites because of the more industrial processes, traffic exhausts and human activities. The estimation dry deposition and size distribution of PAHs were also studied. The results indicated that the estimated dry deposition fluxes of total PAHs were 58.5, 48.8, and 38.6 microg/m2/day at INDUSTRY, URBAN, and RURAL, respectively. The BaP equivalency results indicated that the health risk of gas phase PAHs were higher than the particle phase at three sampling sites of central Taiwan. However, compared with the BaP equivalency results to other studies conducted in factory, this study indicated the health risk of PAHs was acceptable in the ambient air of central Taiwan.     

Comparison of Ozone Temporal Scales for Large Urban,Small Urban,and Rural Areas in Georgia

Abstract

Ground‐level ozone (O₃) time series are characterized by the sum of several distinct temporal scales: long‐term, seasonal, synoptic, diurnal (daily), and intraday variation. In this study, the authors use a Kolmorogov‐Zurbenko filter to separate the 1981–2001 O₃ time‐series from many sites in and around Georgia into these various components. The authors compare the temporal components to examine differences between small and large metropolitan areas and between urban and rural areas. They then focus on the synoptic component to define a predominant transport region or airshed for each site.     

Urban aerosol evolution and particle formation during wintertime temperature inversions

Aerosol temporal and spatial distributions during wintertime temperature inversions in Gothenburg, Sweden, have been characterized by ground-based and airborne particle measurements combined with lidar measurements. Ground inversions frequently developed during evenings and nights with stable cold conditions, and the low wintertime insolation often resulted in near neutral boundary layer conditions during day-time. Under these conditions ground level aerosol concentrations peaked during morning rush hours and often remained relatively high throughout the day due to inefficient ventilation. The particle number concentrations decreased slowly with increasing altitude within the boundary layer, and measurements slightly above the boundary layer suggested limited entrainment of polluted air into the free troposphere. High concentrations of ultrafine particles were observed throughout the boundary layer up to altitudes of 1100 m, which suggested that nucleation took place within the residual layer during the night and early morning. Recently formed particles were also observed around midday when the layer near ground was ventilated by mixing into the boundary layer, which indicated that ultrafine particles were either transported down from the residual layer to ground level or formed when the polluted surface layer mixed with the cleaner air above.