We studied the effects of liming on fish and crustaceans in a watershed which is in a region known to have one of the highest diversity of aquatic biota in Norway. This watershed, Enningdal, is shared between Norway (1/3) and Sweden (2/3) and includes 61 lakes > 1.0 ha in Norway. Liming started on a large scale in the 1980s. Currently, a total of 26 of lakes (43%) are limed, covering 93% of the total lake area. The mean value ± S.D. of pH and the concentration of inorganic labile Al in these lakes is 6.62 ± 0.35 and 3 ± 4 μg l-¹, respectively. Historical data of fish communities have been obtained from surveys, while test-fishing and sampling of crustaceans were conducted in 24 lakes in recent years (2002-2004). The present study shows that crustaceans to a greater extent than fish has responded to improved water quality after more than 20 years of liming. Of a total of 120 fish populations, 42 (35%) have gone extinct. Only five of the lost fish populations (12%) have been re-established, all due to human re-introductions. Physical barriers are considered to be the main factor preventing fish from invading limed lakes. In contrast, crustaceans have been re-established in most limed lakes. This may be mainly due to their good spreading capacity. However, they might also have survived in refuges within the watershed, or as resting-eggs in the sediment.

In order to test the hypothesis of aluminium toxicity induced by acid deposition, an experimental acid irrigation was carried out in a mature Norway spruce stand in Southern Germany (Höglwald). The experiment comprised three plots: no irrigation, irrigation (170 mm a-¹), and acid irrigation with diluted sulphuric acid (pH of 2.6-2.8). During the seven years of acid irrigation (1984-1990) water containing 0.43 molc m-² a-¹ of protons and sulphate was added with a mean pH of 3.2 (throughfall + acid irrigation water) compared to 4.9 (throughfall) on both control plots. Most of the additional proton input was consumed in the organic layer and the upper mineral soil. Acid irrigation resulted in a long lasting elevation of sulphate concentrations in the seepage water. Together with sulphate both aluminium and appreciable amounts of base cations were leached from the main rooting zone. The ratio between base cations (Ca + Mg + K) and aluminium was 0.79 during acid irrigation and 0.92 on the control. Neither tree growth and nutrition nor the pool of exchangeable cations were affected significantly. We conclude that at this site protection mechanisms against aluminium toxicity exist and that additional base cation runoff can still be compensated without further reduction of the supply of exchangeable base cations in the upper mineral soil.

Samples of pig slurry, as well as dairy and poultry manures collected in Brittany (western France) were analysed to test the ability of sterol profiles to provide a fingerprint of pig slurry contribution to soil organic matter. The data show that the 5β-stanol, known as coprostanol, is the most abundant sterol present in pig slurry, whereas this compound occurs only in minor amounts in both poultry and dairy manures. Moreover, systematic variations of (campesterol + sitosterol)/cholesterol (i.e., C₂₈₊₂₉/C₂₇) and (coprostanol + epi-coprostanol)/cholesterol (i.e., 5β/C₂₇) ratios allow to discriminate clearly pig slurry from poultry and dairy manures. The robustness of the pig slurry “sterol fingerprint” was tested by analysing the sterol profiles of soil samples from an experimental field that had received a massive pig slurry input between 10 to 14 years ago. The results indicate that the specific sterol profile of pig slurry is conservative once the slurry has been incorporated into the soil. In particular, the diagnostic 5β/C₂₇ ratio proves to be constant with time in soils having received pig slurry application, even 10 years after the end of the application. The “sterol fingerprint” of pig slurry is thus sufficiently distinctive from dairy and poultry manures, and also sufficiently time-resistant, to be of diagnostic value in determining whether a soil sample was once contaminated by pig slurry.

The use of vegetated wetlands for accelerating pesticide removal from agricultural runoff is gaining acceptance as a best management practice. In this study, the dissipation of five cotton pesticides – endosulfan, chlorpyrifos, aldicarb, prometryn and diuron – was quantified in cotton field runoff water contained in glasshouse columns, under light or dark conditions. Two water samples sourced from large, non-vegetated storage dams were compared with two other water samples obtained from vegetated wetlands receiving runoff from cotton fields. All pesticides studied except chlorpyrifos dissipated significantly faster from the storage dam samples than the vegetated wetland samples. Suggested reasons include a greater number of pesticide-degrading microorganisms in the storage dam waters and/or the presence of more organic matter in the wetland samples, limiting contaminant volatilisation and hydrolysis. Exposure to light significantly reduced the rate of endosulfan removal, whereas light increased the rate of chlorpyrifos removal. Half-lives are presented for each pesticide where appropriate.

The potential for colloid-facilitated migration in contaminated sites is well known, and remediation techniques such as ultrafiltration are often considered for contaminant removal. Although this approach could be successful, the stability of the contaminant species in groundwater and the removal efficiency need to be investigated to ensure proper decontamination of moving aquifers. In our study, we have sampled contaminated groundwater near a former radioactive liquid disposal area at Chalk River, Ontario, Canada. Samples were taken in 2002 and 2004 to determine the behaviour of radiocontaminants by size fractionation using ultrafiltration, with emphasis on ⁶⁰Co and ¹³⁷Cs. The contaminant concentrations varied significantly for both contaminants in the two samples (34.5 and 25.5 Bq/l for ⁶⁰Co, 25.5 and 97.2 Bq/l for ¹³⁷Cs). On the other hand, the size fractionation (5,000 Daa nominal cut-off) remained consistent between the 2002 and 2004 samples, as most of the ⁶⁰Co (72%-83%) remained in the filtrate, while almost all of the ¹³⁷Cs (>98%) was retained along with the colloidal-sized material. Release of ⁶⁰Co and ¹³⁷Cs from the colloidal material yielded desorption coefficients (K D₋des) of 7.8 x 10⁵ and 1.7 x 10⁸ ml/g for ⁶⁰Co and ¹³⁷Cs, respectively.

Suspended particulate matter is significantly related to the degradation of air quality in urban agglomerations, generating adverse health effects. Therefore, the ability to make accurate predictions of particulate ambient concentrations is important in order to improve public awareness and air quality management. This study aims at developing models using multiple regression and neural network (NN) methods that might produce accurate 24-h predictions of daily average (DA) value of PM10 concentration and at comparatively assessing the above mentioned techniques. Pollution and meteorological data were collected in the urban area of Volos, a medium-sized coastal city in central Greece, whose population and industrialization is continuously increasing. Both models utilize five variables as inputs, which incorporate meteorology (difference between daily maximum and minimum hourly value of ground temperature and DA value of wind speed), persistency in PM10 levels and weekly and annual variation of PM10 concentration. The validation of the models revealed that NN model showed slightly better skills in forecasting PM10 concentrations, as the regression and the NN model can forecast 55 and 61% of the variance of the data, respectively. In addition, several statistical indexes were calculated in order to verify the quality and reliability of the developed models. The results showed that their skill scores are satisfying, presenting minor differences. It was also found that both are capable of predicting the exceedances of the limit value of 50 μg/m³ at a satisfactory level.

The use of solid-state fermentation (SFF) of low cost substrates by fungal species to generate organic acid solutions for washing of lead from a contaminated soil was evaluated in this study. SFF filtrates were generated by fermentation of four substrates (corn cobs, apple pomace, rice and hay) with three fungal species (Aspergillus niger NRRL 2001 (A. niger 1), Aspergillus niger ATCC 64065 (A. niger 2), Aspergillus foetidus NRRL 337) at three fermentation times. The concentration and speciation of organic acids of the filtrates was found to be a function of the substrate type, the fungal species and the fermentation time. Fermentation of rice resulted in the highest concentrations of citric acid while fermentation of corn cobs, apple pomace and hay tended to generate oxalic acid with an increasing fraction of this acid as the fermentation progressed. Batch extraction tests that employed the SSF filtrates revealed that soluble lead concentrations as high as 35 mg/l could be achieved. Filtrates containing elevated concentrations of citric acid resulted in the greatest lead extraction while oxalic acid inhibited solubilization. Due to the buffering of pH that was provided by the soil in the batch tests this factor did not appear to influence lead extraction. Lead extraction was observed over an extended period of time in a column test. Lead extraction was strongly influenced by the pH of the soil column and less strongly influenced by the organic acid content of the SSF filtrate. The speciation of organic acids was substantially modified from primarily citric acid in the SSF filtrate to gluconic acid in the soil column discharge.

A multi-stage particle sampling instrument and a particle counter were operated at the ground monitoring site in Fukuoka where was directly exposed to the outflow of air masses from the Asian continent during the springtime of 2005. The bulk and individual dust particles were analyzed simultaneously by ICP-MS and micro-PIXE, respectively. The ground-based observation of dust storm by the Japan Meteorological Agency and by the NOAA HYSPLIT dispersion-trajectory model indicated that dust storm was driven from the Chinese continent including dust source area. The number concentration of gigantic particles (e.g., larger than 5 μm) was measured to be 10 times higher in an Asian dust storm (hereafter called “ADS”) period than in a non-ADS period. There is an outstanding increase of mass concentration in the range of 3.5-7.7 μm in ADS event. In ADS event, soil fraction accounts 57.9-70.1% of particle mass concentration in coarse particles larger than 3.5 μm. Micro-PIXE analysis enables us to classify individual dust particles into several types. The particles with 3.5-5.1, 5.1-7.7, and 7.7-10.9 μm experienced aging processes by 60.6, 69.2, and 77.2%, respectively. On the basis of the reconstructed elemental maps by micro-PIXE analysis, the chemical transformation of dust particles was also presumed.

A biomonitoring study using the ozone-sensitive bioindicator plant Nicotiana tabacum cv. Bel-W3 was conducted in the city of Valencia (eastern Spain) and surrounding areas in 2002. Plants were exposed to ambient air at seven sites, including four traffic-exposed urban sites, a large urban garden and a suburban and a rural station, for six consecutive 2-week periods using highly standardised methods. Foliar injury was registered at all stations in at least one of the exposure periods. The urban stations submitted to intense traffic showed lower ozone injury than the less traffic-exposed stations. Strong changes in the intensity of ozone injury were observed for the different exposure periods. Leaf injury was significantly related to both mean ozone values (24 and 12 h means) and cumulative exposure indices (AOT20, AOT40). However, correlation strength was moderate (r s = 0.39 to 0.58), suggesting that the plant response to ozone was modified by environmental factors. The use of sensitive bioindicators like tobacco Bel-W3 in cities provides complementary information to that of continuously operating air quality monitors, as the impact of ambient ozone levels is directly measured.

Aerosol samples were collected during the wintertime from Nov. 24, 1998 to Feb. 12, 1999 in Beijing, China. Chemical composition was determined using several analytical techniques, including inductive coupled plasma atomic emission spectroscopy (ICP-AES), graphite furnace atomic absorption spectroscopy (GFAAS) and flame atomic absorption spectroscopy (FAAS) for trace elements, ion chromatography (IC) for water-soluble ions and CHN elemental analyzer for organic carbon (OC) and elemental carbon (EC). The average concentration of aerosol was 375 ± 169 μg m⁻³, ranging from 136 to 759 μg m⁻³. Multilinear regression (MLR) analysis was performed and crustal matter, secondary particles and organics were identified as three major components of aerosol in wintertime in Beijing, accounting for 57.3% ± 9.8%, 13.4% ± 8.0%, and 22.8% ± 5.9% of the total concentration, respectively. Based on performance evaluation, Al, SO₄ ²⁻ and OC were selected as tracers of the three components, with the regression coefficients of 23.5, 1.78 and 1.26, respectively. A regression constant of 19.6 was obtained, which accounts for other minor components in aerosol. On average 93.5% of the total aerosol concentration, ranging from 82% to 105%, was explained by crustal matter, secondary particle and organics. Meteorological conditions are important factors that can influence the concentration level and chemical composition of aerosols. Wind would be favorable for the pollutant dilution, leading to low aerosol levels, whereas too strong a wind may cause regional soil dust and local road dust to be resuspended resulting in a high contribution of crustal matter. Circuitous air movement, high RH% and low wind speed facilitated the secondary particle formation, not only inorganic salts, such as sulfate and nitrate, but also secondary organic carbon in a similar way.