Sediment profiles from ten excessively limed lakes were used to study the occurrence of lime residues as a result of incomplete lime dissolution and the influence of treatment with very high lime doses on the sequestration of metals in lake sediments. The sediment profiles were subjected to multi-element analysis and compared to sediment profiles from previous studies of lakes limed with normal lime doses and untreated reference lakes. The high lime doses were found to result in large lime residues in the sediment, with lime concentrations of up to 70% of the dry sediment in the studied lakes. Excessive liming, like liming with normal doses, was found to cause increased sequestration in sediments of, e.g. Cd, Co, Ni and Zn, metals where the mobility is known to be highly pH dependent, compared to non-limed reference lakes. No effect of liming on the sequestration of Cu, Cr, Pb and V could be shown. The size of the lime dose did not seem to influence the metal sequestration in the sediment, since no difference between the excessively limed lakes and lakes limed with normal doses was found. On the contrary, the large lime residues were found to cause a dilution of the metal concentrations in the sediments, since lime products used for lake liming generally have lower metal concentrations compared to the sediments.

Soils are an important sink for persistent organic pollutants (POPs), and high mountain soils are considered a stable reservoir for many compounds due to their high organic matter content. This study focuses on the small-scale variability on the environmental distribution of dichlorodiphenyltrichloroethane (DDT) in mountain soils. Several soil samples taken from May 2007 to June 2008 in a small area at around 1,900 m a.s.l. (Italian Central Alps) were analyzed for DDT compounds. Pedological analyses were done as well. Organic matter content, soil layer, differences in solar radiation, and sampling period were considered as possible variability factors. Organic matter content can account for a DDT concentration difference of a factor 3 among different sites, soil layer can account for a concentration difference of a factor near 2, differences in solar radiation values do not seem to affect DDT concentrations, whereas the sampling period has the greatest influence with a difference factor of three to four among different sampling dates. Summing all these variability factors together, even though operating on such a small scale, we obtain a predicted spatial variability depending on the considered variables near to one order of magnitude. In particular, it was surprising that seasonal variations could be so great. If this conclusion is to be confirmed in the future, this element must be considered very carefully by scientists and environmental agencies during monitoring campaigns.

The goal of this project was to develop a method to measure the total gaseous mercury (TGM) concentrations in unsaturated soils. Existing methods did not allow for easy replication, were costly, and were more suited for other gases, such as CO2, that do not react with collection surfaces. To overcome these problems, we developed a method that simultaneously collects up to ten soil pore air samples. We used a single mass flow controller, one pump, and two banks of rotameters to draw soil air out of the ground at 25 smL min−1 onto gold-coated quartz traps. Analysis of the gold traps was performed with a Tekran 2500 CVAFS mercury detector. The system was field tested at the Piney Reservoir Ambient Air Monitoring Station in western Maryland. Our system was relatively precise and accurate. For example, replicate TGM concentrations differed by less than 25% and recovery of known amounts of mercury were greater than 95%. Field measurements showed that the maximum soil pore air TGM concentrations, between 3 and 4 ng m−3, occurred at the Oe–A soil horizon interface. At all other depths, the total mercury concentrations were lower than the ambient air concentrations of 1.8 ng m−3. We believe our new method can be used to precisely and accurately measure the TGM concentrations in unsaturated soils at multiple locations simultaneously.

The concentrations of major heavy metals in organs of two cyprinid fish and in water collected from three sections of the Kor River, Iran, were determined using the induction coupled plasma method. The concentrations of heavy metals in tissue of fish from the middle sampling zone were significantly higher (p < 0.05) than those from the other two sampling zones, whereas no significant differences (p > 0.05) were detected between the two sexes and species. Estradiol in females and progesterone and testosterone in males from the middle study site were significantly (p < 0.05) lower than values from the other two sites. Pathological changes in blood cells, liver, and kidneys of fishes were significantly higher in highly polluted areas (middle sampling zone). So heavy metals exposure can effectively decreases estrogenic and androgenic secretion in fish. These results show that industrial activities have polluted the river and that heavy metals exposure can induce pathological changes in fish organs.

The concentrations of Hg, Cu, Pb, Cd, and Zn accumulated by regional macrophytes were investigated in three tropical wetlands in Colombia. The studied wetlands presented different degrees of metal contamination. Cu and Zn presented the highest concentrations in sediment. Metal accumulation by plants differed among species, sites, and tissues. Metals accumulated in macrophytes were mostly accumulated in root tissues, suggesting an exclusion strategy for metal tolerance. An exception was Hg, which was accumulated mainly in leaves. The ranges of mean metal concentrations were 0.035–0.953 mg g−1 Hg, 6.5–250.3 mg g−1 Cu, 0.059–0.245 mg g−1 Pb, 0.004–0.066 mg g−1 Cd, and 31.8−363.1 mg g−1 Zn in roots and 0.033–0.888 mg g−1 Hg, 2.2–70.7 mg g−1 Cu, 0.005–0.086 mg g−1 Pb, 0.001–0.03 mg g−1 Cd, and 12.6–140.4 mg g−1 Zn in leaves. The scarce correlations registered between metal concentration in sediment and plant tissues indicate that metal concentrations in plants depend on several factors rather than on sediment concentration only. However, when Cu and Zn sediment concentrations increased, these metal concentrations in tissues also increased in Eichhornia crassipes, Ludwigia helminthorriza, and Polygonum punctatum. These species could be proposed as Cu and Zn phytoremediators. Even though macrophytes are important metal accumulators in wetlands, sediment is the main metal compartment due to the fact that its total mass is greater than the corresponding plant biomass in a given area.

The Illinois River Watershed is a multi-facet basin with ecological and economic importance to its local stakeholders in northwest Arkansas and northeast Oklahoma, USA. The numbers, transport and sources of fecal bacteria in streams was identified as a research priority of the USDA NRI Water and Watershed Program in 2006, and the objective of this study was to evaluate the relation between fecal bacteria and other measured physicochemical parameters in water samples collected from selected sites throughout the Illinois River Watershed. An existing database (i.e., National Water Information Systems, NWIS) from the US Geological Survey (USGS) was used in this project. The data obtained includes discharge, pH, temperature, dissolved oxygen, Escherichia coli (E. coli), fecal coliform, and fecal streptococci among several other physic-chemical parameters. A synthetic model, based on multi-regression analysis, was developed to predict fecal bacteria numbers at these selected sites based on available USGS NWIS data, and the multiple regressions were significant at almost every site for all three bacteria groups. However, the physicochemical parameters used in the equations were very different across sites and fecal bacteria groups, suggesting that the development of such predictive models is site and bacteria group specific even within one watershed.

The number of chemical compounds in sewage and consequently their release into the environment is increasing. Some of them are toxic and many of them are considered endocrine disrupters. Here, the capacity of three wastewater treatment plants (WWTPs) to remove caffeine, hormones and bisphenol-A was investigated. Bisphenol-A and caffeine are highly water-soluble compounds, as opposed to hormones (estradiol, estriol, and ethynilestradiol) which are hydrophobic compounds. In the Sewage Treatment Plant (SWT)1 the sewage is treated by activated sludge process, in the second plant, SWT2, sewage is treated by upflow anaerobic sludge blanket reactors followed by dissolved air flotation, and in the third, SWT3 sewage is treated by stabilization lagoons. The first lagoon is 3.5 m deep, thus facultative and polishment processes occur. It was speculated that there was a difference in efficiency between the three plants in removing micropollutants. Small differences were found in the amounts removed, probably accounted for by retention time. The caffeine and bisphenol-A were almost completely removed, higher than 90% for both compounds (bisphenol-A and caffeine) in all WWTPs. The hormones, however, had a smaller rate of removal, between 70% and 87%. It is suspected that retention time is essential for removal efficiency, together with type of treatment. In fact, the hormones, caffeine, and bisphenol-A found in the environment definitely come from untreated sewage.

Lake Mallusjärvi in the cultural landscape of Mallusjoki, southern Finland, suffers from algal blooms during summers and oxygen depletions during winters due to increased nutrient input resulting from extensive agricultural activities in the catchment. In this study, a sediment profile from the lake was studied using fossil midge (Diptera: Nematocera) analysis and a hypolimnetic oxygen transfer function was applied to establish baseline conditions of hypolimnetic oxygen. In addition, physical properties of the sediment were determined. The inferred late winter hypolimnetic oxygen content was elevated in the beginning of the sediment sequence, but decreased dramatically at ca. 200 cal BP, as the inferred values indicated frequently anoxic condition coinciding with increased agricultural use in the catchment. The results indicated that dramatic changes have occurred in the taxon composition. The high-oxygen Stempellina–Ablabesmyia monilis-type community first changed to moderate-oxygen Procladius–Stempellinella community, and finally to low-oxygen Microchironomus tener–Chironomus plumosus-type community, following the eutrophication process. These changes in macrobenthic faunal assemblages reproduced considerably higher inferred hypolimnetic oxygen reference condition values for hypolimnetic oxygen, compared to the present status.

Polycyclic aromatic hydrocarbons (PAHs) were analyzed in 70 soils distributed in mountain areas such as Montseny (300–1,700 m), Pyrenees (1,500–2,900 m), Alps (1,100–2,500 m), and Tatras (1,400–1,960 m). Average total PAH concentrations, excluding retene and perylene, were about 400 ng/g in the Pyrenees and 1,300–1,600 ng/g in the other mountain ranges. No correlations between PAH concentrations and total organic carbon were observed. Retene was the major PAH in the Pyrenean soils of lower altitude. No altitudinal dependence was found between soil PAH concentrations and elevation for the whole dataset. However, in the Tatra soils a statistically significant correlation with altitude was observed involving higher concentrations at higher altitude. This correlation was due to the statistically significant altitudinal dependence of the more volatile PAHs. Another observed altitudinal trend concerned the benz[a]anthracene/(benz[a]anthracene + chrysene + triphenylene) and the benzo[a]pyrene/(benzo[a]pyrene + benzo[e]pyrene) ratios that exhibited a decrease in the more chemically labile compounds, benz[a]anthracene and benzo[a]pyrene, respectively, in the soils located at higher altitude. This observation is consistent with the expected higher photooxidation at higher mountain altitude.

It was recently reported that tetracycline could enhance the mobility of manure-derived Escherichia coli within saturated porous media (Walczak et al. (Water Research 45:1681–1690, 2011)). It was also shown, however, that E. coli from various sources could display marked variation in their mobility (Bolster et al. (Journal of Environmental Quality 35:1018–1025, 2009)). The focus of this research was to examine if the observed difference in the mobility of manure-derived tetracycline-resistant (tetR) and tetracycline-susceptible (tetS) E. coli strains was source-dependent. Specifically, E. coli were isolated from Lake Michigan, and the influence of tetracycline resistance on Lake Michigan-derived E. coli was investigated through column transport experiments. Additionally, a variety of cell morphology and surface properties were determined and related to the observed bacterial transport behavior. Our experimental results showed that, consistent with previous observations, the deposition rate coefficients of the tetR E. coli strain was ∼20–100% higher than those of the tetS E. coli strain. The zeta potential of the tetR E. coli cells was ∼25 mV more negative than the tetS E. coli cells. Because the surfaces of the E. coli cells and the quartz sands were negatively charged, the repulsive electrostatic double-layer interaction between the tetR E. coli cells and the quartz sands was stronger, and the mobility of the tetR E. coli cells in the sand packs was thus higher. The tetR E. coli cells were also more hydrophilic than the tetS E. coli cells. Results from migration to hydrocarbon phase (MATH) tests showed that about ∼35% more tetS E. coli cells partitioned to the hydrocarbon phase. As it was previously shown that cell hydrophobicity could enhance the attachment of bacterial cells to quartz sand, the difference in cell hydrophobicity could also have contributed to the observed higher mobility of the tetR E. coli cells. The size of the tetR and tetS E. coli cells were similar, suggesting that the observed difference in their mobility was not size-related. Characterization of cell surface properties also showed that tetR and tetS E. coli cells differed slightly in cell-bound lipopolysaccharide contents and had distinct outer membrane protein profiles. Such difference could alter cell surface properties which in turn led to changes in cell mobility.