Recent sediment accumulation rates in contrasting lakes in the Carpathians (Romania): impacts of shifts in socio-economic regime

Longer-term environmental studies are increasingly used to better understand contemporary ecosystems conditions and for forecasting their future trajectories. Here, we use radiometric measurements and the characterisation of sediment properties from six mountain and a lowland lake in Central Eastern Europe with the aim to assess temporal and spatial variability in sediment accumulation rates (SARs) in relation to three socio-economic regimes: traditional (1840–1948), socialist (1948–1989) and post-socialist (post-1990). We also set out to determine reference conditions for these lakes i.e. conditions before significant human impact. Our results show a trend of increasing SARs from basal sediments (pre 1840) towards the present at only two sites. This contrasts with findings from Western and Central European lakes where SARs have predominantly increased from 1850 towards the top of cores. We highlight the differential impacts of the traditional, socialist and post-socialist periods on the SARs at these lakes. Lowland and mid-elevations lakes (n = 2) were most markedly impacted by the socialist period of land use regime; lakes from the southern Carpathians (n = 2) were more impacted in the traditional period (transhumance pastoral activities), whereas those from the north (n = 3) in the socialist and post-socialist periods (summer pastoralism). Results from our study show a continuous anthropogenic impact during the entire period considered, even in remote mountain areas. This suggests that a temporal frame of 100–150 years is too short to meaningfully register the reference conditions of these lakes. Furthermore, a predominantly natural state may not have existed for centuries in this region.     

Predictive model for chloroform during disinfection of water for consumption,city of Montevideo

The objective of this study was to predict chloroform formation resulting from the process of disinfecting water, particularly trihalomethane which is most frequently produced. A statistical model was used which included repeated measurements of water parameters used for monitoring water quality at 51 sites covering the municipal water system of Montevideo. Samples were taken considering different seasons from June 2009 to July 2011 in Montevideo. Total samples (n?=?330) were analytically studied using the headspace-gas chromatography method coupled with mass spectrometry. Chloroform was the dependent variable and the covariables were pH, temperature, free chlorine, and total chlorine. A Tobit analysis with an unstructured correlation matrix was performed, and a significant interaction was found between pH and free chlorine for the prediction of chloroform formation. We concluded that parameters for the continuous control of water quality for consumption can be used to predict the levels of chloroform that may be present. Given the large measurement to variability found in the repeated measurements, the use of averages that include more than one season is not recommended to determine the degree of compliance with acceptable levels established by norms.     

Steel mill waste application in soil: dynamics of potentially toxic elements in rice and health risk perspectives

Environmental Science and Pollution Research - Potentially toxic elements (PTEs) are of great concern in steel mill wastes. Therefore, in order to use them as potential fertilizers in soil, risk...     

Impact of municipal solid waste dumpsites on trace metal contamination levels in the surrounding area: a case study in West Africa,Abidjan, Cote d’Ivoire

Environmental Science and Pollution Research - The impact of uncontrolled municipal dumping sites on metal contamination in the surrounding waters, sediments, and soils are of great concern in many...     

Exposure to toxic waste containing high concentrations of hydrogen sulphide illegally dumped in Abidjan, C?te d’Ivoire

Introduction

On August 2006, a cargo ship illegally dumped 500?t of toxic waste containing high concentrations of hydrogen sulphide in numerous sites across Abidjan. Thousands of people became ill. Seventeen deaths were associated with toxic waste exposure.

Materials and methods

This study reports on environmental and health problems associated with the incident. A cross-sectional transect study was conducted in five waste dumping site areas.

Results

Of the households, 62.1% (n?=?502) were exposed to the effects of the pollutants and 51.1% of the interviewed people (n?=?2,368) in these households showed signs of poisoning. Most important symptoms were cough (37.1%), asthenia (33.1%), pruritus (29.9%) and nausea (29.1%).

Discussion

The health effects showed different frequencies in the five waste impact sites. Among the poisoned persons, 21.1% (n?=?532) presented symptoms on the survey day (i.e., 4?months after incident). Transect sampling allowed to determine a radius of vulnerability to exposure of up to 3?km from the point of toxic waste disposal.

Conclusion

The area of higher vulnerability is influenced by various environmental factors, such as size and severity of pollution site, duration of toxic waste pollution on the impact site and locally climatic conditions. The surveillance of effects on environment and human health is warranted to monitor the development.     

Brominated flame retardants and organochlorines in the European environment using great tit eggs as a biomonitoring tool

Large-scale studies are essential to assess the emission patterns and spatial distribution of organohalogenated pollutants (OHPs) in the environment. Bird eggs have several advantages compared to other environmental media which have previously been used to map the distribution of OHPs. In this study, large-scale geographical variation in the occurrence of OHPs, such as polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and organochlorine pesticides (OCPs), was investigated throughout Europe using eggs of a terrestrial residential passerine species, the great tit (Parus major). Great tit eggs from 22 sampling sites, involving urban, rural and remote areas, in 14 European countries were collected and analysed (5-8 eggs per sampling site). The environmentally most important congeners/compounds of the analysed pollutants were detectable in all sampling locations. For PCBs, PBDEs and OCPs, no clear geographical contamination pattern was found. Sum PCB levels ranged from 143 ng/g lipid weight (lw) to 3660 ng/g lw. As expected, PCB concentrations were significantly higher in the sampled urban compared to the remote locations. However, the urban locations did not show significantly higher concentrations compared to the rural locations. Sum PBDEs ranged from 4.0 ng/g lw to 136 ng/g lw. PBDEs were significantly higher in the urbanized sampling locations compared to the other locations. The significant, positive correlation between PCB and PBDE concentrations suggests similar spatial exposure and/or mechanisms of accumulation. Significantly higher levels of OCPs (sum OCPs ranging from 191 ng/g lw to 7830 ng/g lw) were detected in rural sampling locations. Contamination profiles of PCBs, PBDEs and OCPs differed also among the sampling locations, which may be due to local usage and contamination sources. The higher variance among sampling locations for the PCBs and OCPs, suggests that local contamination sources are more important for the PCBs and OCPs compared to the PBDEs. To our knowledge, this is the first study in which bird eggs were used as a monitoring tool for OHPs on such a large geographical scale.     

Effect of cobalt sorption on metal fractionation in anaerobic granular sludge

A sequential extraction procedure was applied to two anaerobic methanogenic sludges (Eerbeek and Nedalco) to examine the speciation of micro- and macronutrients in the sludges after cobalt sorption by exposing the sludge to a 1 mM Co solution for 4 d at pH 7 and 30 degrees C. The effect of different physicochemical conditions on cobalt sorption was studied as well: effect of pH (6-8), effect of competition by a second trace element (Ni or Fe), modification of the granular matrix by glutaraldehyde or heat treatment, and EDTA (ethylenediaminetetraacetic acid) addition. Sorbed Co was found to distribute between the carbonates, organic matter + sulfides, and residual fractions. Cobalt adsorption resulted in an antagonistic interaction with other metals present in the granular matrix, evidenced by the solubilization of other trace elements (e.g., Ni, Cu, and Zn) as well as macronutrients (especially Ca and Fe). Modification of the sludge matrix by glutaraldehyde or heat treatment, or exposure to EDTA, led to serious modifications of the Co sorption capacity and strong interactions with multivalent cations (i.e., Ca(2+) and Fe(2+)).     

Assessment of spatial variation of cesium-137 in small catchments

Surface contamination by bomb-derived and Chernobyl-derived 137Cs has been subject to changes due to physical decay and lateral transport of contaminated soil particles, which have resulted in an on-going transfer of radionuclides from terrestrial ecosystems to surface water, river bed sediments, and flood plains. Knowledge of the different sources of spatial variation of 137Cs is particularly essential for estimating 137Cs transfer to fluvial systems and for successfully applying 137Cs as an environmental tracer in soil erosion studies. This study combined a straightforward sediment redistribution model and geostatistical interpolation of point samples of 137Cs activities in soil to distinguish the effects of sediment erosion and deposition from other sources of variation in 137Cs in the small Mochovce catchment in Slovakia. These other sources of variation could then be interpreted. Besides erosion and deposition processes, the initial pattern of 137Cs deposition, floodplain sedimentation, and short-range spatial variation were identified as the major sources of spatial variation of the 137Cs inventory.