Solid-Phase Microextraction As A Tool for Studying Volatile Compounds in Frog Skin

Solid-phase microextraction (SPME) is an effective technique for studying frog volatile secretions. Its primary advantage is in its application to sampling live animals. the ability to sample an organism over an extended period allows changes in an individual's chemical signature to be determined. the presence of eucalyptol in the skin secretion of Ewing's tree frog, Litoria ewingi, was used to assess the effectiveness of SPME in sampling frog volatiles. Rapid sample times coupled with the polydimethylsiloxane/divinylbenzene (PDMS/DVB) fibre provided the best signal/noise ratio for the majority of frog volatiles analysed, and importantly resulted in the least amount of stress to the animals involved.     

Future forest landscapes of the Carpathians: vegetation and carbon dynamics under climate change

Regional Environmental Change - Climate change will alter forest ecosystems and their provisioning of services. Forests in the Carpathian Mountains store high amounts of carbon and provide...     

Insights into low fish mercury bioaccumulation in a mercury-contaminated reservoir, Guizhou, China

We examined Hg biogeochemistry in Baihua Reservoir, a system affected by industrial wastewater containing mercury (Hg). As expected, we found high levels of total Hg (THg, 664-7421 ng g(-1)) and monomethylmercury (MMHg, 3-21 ng g(-1)) in the surface sediments (0-10 cm). In the water column, both THg and MMHg showed strong vertical variations with higher concentrations in the anoxic layer (>4m) than in the oxic layer (0-4 m), which was most pronounced for the dissolved MMHg (p < 0.001). However, mercury levels in biota samples (mostly cyprinid fish) were one order of magnitude lower than common regulatory values (i.e. 0.3-0.5 mg kg(-1)) for human consumption. We identified three main reasons to explain the low fish Hg bioaccumulation: disconnection of the aquatic food web from the high MMHg zone, simple food web structures, and biodilution effect at the base of the food chain in this eutrophic reservoir.     

Energy and environment as the foundations for sustainable development

Environmental Science and Pollution Research -     

The global impact of ozone on agricultural crop yields under current and future air quality legislation

In this paper we evaluate the global impact of surface ozone on four types of agricultural crop. The study is based on modelled global hourly ozone fields for the year 2000 and 2030, using the global 1°×1° 2-way nested atmospheric chemical transport model (TM5). Projections for the year 2030 are based on the relatively optimistic “current legislation (CLE) scenario”, i.e. assuming that currently approved air quality legislation will be fully implemented by the year 2030, without a further development of new abatement policies. For both runs, the relative yield loss due to ozone damage is evaluated based on two different indices (accumulated concentration above a 40 ppbV threshold and seasonal mean daytime ozone concentration respectively) on a global, regional and national scale. The cumulative metric appears to be far less robust than the seasonal mean, while the seasonal mean shows satisfactory agreement with measurements in Europe, the US, China and Southern India and South-East Asia.Present day global relative yield losses are estimated to range between 7% and 12% for wheat, between 6% and 16% for soybean, between 3% and 4% for rice, and between 3% and 5% for maize (range resulting from different metrics used). Taking into account possible biases in our assessment, introduced through the global application of “western” crop exposure–response functions, and through model performance in reproducing ozone-exposure metrics, our estimates may be considered as being conservative.Under the 2030 CLE scenario, the global situation is expected to deteriorate mainly for wheat (additional 2–6% loss globally) and rice (additional 1–2% loss globally). India, for which no mitigation measures have been assumed by 2030, accounts for 50% of these global increase in crop yield loss. On a regional-scale, significant reductions in crop losses by CLE-2030 are only predicted in Europe (soybean) and China (wheat).Translating these assumed yield losses into total global economic damage for the four crops considered, using world market prices for the year 2000, we estimate an economic loss in the range $14–$26 billion. About 40% of this damage is occurring in China and India. Considering the recent upward trends in food prices, the ozone-induced damage to crops is expected to offset a significant portion of the GDP growth rate, especially in countries with an economy based on agricultural production.     

The weight method: a new screening method for estimating pesticide deposition from knapsack sprayers in developing countries

Investigations of occupational and environmental risk caused by the use of agrochemicals have received considerable interest over the last decades. And yet, in developing countries, the lack of staff and analytical equipment as well the costs of chemical analyses make it difficult, if not impossible, to monitor pesticide contamination and residues in humans, air, water, and soils. A new and simple method is presented here for estimation of pesticide deposition in humans and soil after application. The estimate is derived on the basis of water mass balance measured in a given number of high absorbent papers under low evaporative conditions and unsaturated atmosphere. The method is presented as a suitable, rapid, low cost screening tool, complementary to toxicological tests, to assess occupational and environmental exposure caused by knapsack sprayers, where there is a lack of analytical instruments. This new method, called the “weight method”, was tested to obtain drift deposition on the neighbouring field and the clothes of the applicator after spraying water with a knapsack sprayer in one of the largest areas of potato production in Colombia. The results were confirmed by experimental data using a tracer and the same set up used for the weight method. The weight method was able to explain 86% of the airborne drift and deposition variance.     

Air protection programmes in Poland in the context of the low emission

Environmental Science and Pollution Research - The protection of the air against pollutants from individual boiler plants is a big challenge in Poland. It results mainly from the preference for...     

Biogeochemical Control of the Coupled CO2–O2 System of the Baltic Sea: A Review of the Results of Baltic-C

Past, present, and possible future changes in the Baltic Sea acid–base and oxygen balances were studied using different numerical experiments and a catchment–sea model system in several scenarios including business as usual, medium scenario, and the Baltic Sea Action Plan. New CO₂ partial pressure data provided guidance for improving the marine biogeochemical model. Continuous CO₂ and nutrient measurements with high temporal resolution helped disentangle the biogeochemical processes. These data and modeling indicate that traditional understandings of the nutrient availability–organic matter production relationship do not necessarily apply to the Baltic Sea. Modeling indicates that increased nutrient loads will not inhibit future Baltic Sea acidification; instead, increased mineralization and biological production will amplify the seasonal surface pH cycle. The direction and magnitude of future pH changes are mainly controlled by atmospheric CO₂ concentration. Apart from decreasing pH, we project a decreasing calcium carbonate saturation state and increasing hypoxic area.     

Pseudomorphs of barite and biogenic ZnS after phyto-crystals of calcium oxalate (whewellite) in the peat layer of a poor fen

Pseudomorphs of barite (BaSO₄) and Cd-rich ZnS after whewellite (CaC₂O₄·H₂O) occur within remnants of Scots pine bark tissues in the peat layer of a poor fen located near a zinc smelter in south Poland. A two-step formation of the pseudomorphs is postulated based on SEM observations: (1) complete dissolution of whewellite, possibly caused by oxalotrophic bacteria, and (2) subsequent bacterially induced precipitation of barite and spheroidal aggregates of ZnS together with galena (PbS) in voids left by the dissolved whewellite crystals. Local increase in pH due to microbial degradation of whewellite, elevated concentrations of Zn(II) and Ba(II) in pore water due to the decomposition of atmospheric particles of sphalerite and barite in the acidic (pH 3.5–3.8) environment, oxidation of S species during drying and rewetting of the peat layer, and subsequent partial reduction of sulfate anions by sulfur-reducing bacteria were all factors likely involved in the crystallization of ZnS and barite in the microenvironment of the post-whewellite voids.     

Evaluation of the impacts of mine drainage from a coal waste pile on the surrounding environment at Smolnica, southern Poland

Mine drainage impacts from a coal waste pile at Smolnica, Poland have been monitored. Groundwater in an unconfined aquifer downgradient from the pile has near-neutral pH, but high concentrations of sulfate (up to 3,827 mg/l), chloride (up to 903 mg/l), and sodium (up to 2,606 mg/l). Concentrations of iron and manganese are elevated only locally, and concentrations of other metals are low. The behavior of sulfate seems to be conservative in the downgradient aquifer, and gypsum may only be precipitating locally. Concentrations of iron and manganese seem to be controlled by the precipitation of ferric oxide and hydroxides and rhodochrosite, respectively. Complete neutralization of mine drainage by carbonates is consistent with high concentrations of calcium (up to 470 mg/l) and magnesium (up to 563 mg/l) and also with high strontium concentrations of up to 3.08 mg/l, observed in groundwater downgradient from the pile. Hydraulic head profiles at two sites within the river bottom sediments indicate upward flow toward the river with large local differences in groundwater recharge. Water chemistry profiles in the river bottom sediments and geochemical modeling suggest conservative behavior of Na, Cl, and SO₄ and precipitation of Fe and Mn at the groundwater/river water interface. Mine drainage enters the Bierawka River and causes increasing sulfate concentrations. In contrast, concentrations of sodium and chloride in the Bierawka River decrease downgradient from the pile because water in the river upgradient from the pile is already highly contaminated by these species from the discharge of mining waters. Concentrations of Fe and Mn in the river water are low, as a consequence of the precipitation of Fe and Mn oxide and hydroxides. Direct geochemical modeling was able to reproduce measured concentrations of conservative species (e.g., Na, Cl, and SO₄), but errors for metals and Ba were relatively large. In addition, calculated P_CO2 values in the river water are very high, suggesting that equilibrium with atmospheric P_CO2 and P_O2 has not been reached, and at least some reactions should be modeled as kinetic processes. High concentrations of Na, Cl, and SO₄ contribute to the contamination of the Odra River, which is joined by the Bierawka River farther downgradient, thus limiting the use of river water for recreation and other purposes.