PCDDs, PCDFs and dioxin-like PCBs in food of animal origin (Slovakia)

The levels of 17 toxic polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and 12 non-ortho and mono-ortho polychlorinated biphenyls (PCBs) in 73 foodstuff samples of animal origin collected from shops and small farms in selected districts of Slovak Republic are presented in this paper. The concentrations expressed as WHO-TEQ in analysed samples ranged for PCDDs/PCDFs from 0.25 pg/g fat in pork to 75 pg/g fat in cod liver. The TEQ concentrations of non-ortho PCBs were between 0.007 and 181 pg/g fat and mono-ortho PCBs between 0.0083 and 66.5 pg/g fat. The mean concentrations in freshwater fish and imported species of marine fish were 0.089 pg TEQ/g fresh weight for PCDDs/PCDFs, 0.17 pg TEQ/g fresh weight for non-ortho PCBs and 0.034 pg TEQ/g fresh weight for mono-ortho PCBs. The mean total concentration of PCDDs/PCDFs and dioxin-like PCBs in samples of infant milk formula imported from EU countries was 0.98 pg TEQ/g fat.     

Three-dimensional ultrasound in prenatal diagnosis of skeletal dysplasia

A lethal form of bone dysplasia, platylospondylic lethal chondrodysplasia, was diagnosed prenatally using three-dimensional ultrasound. The various types of three-dimensional imaging mode provided diagnostic details not available by conventional two-dimensional ultrasound. The diagnosis was made after referral in the 23rd week of gestation, allowing termination of pregnancy due to the poor prognosis. Prenatal sonograms were compared with postnatal radiographs.     

Bioenergetics of fishes in a high-energy surf-zone

Energy budgets are proposed for four teleost and two elasmobranch species as well as for the main icthyofauna groups for a surf-zone ecosystem. The ecology of surf-zone fishes of eastern Cape beaches, Algoa Bay South Africa, is reviewed. Using the equationC=F+U+R _d +R _R +B, the following general energy budgets were derived for fishes: teleosts – 100=10+4+21+23+42; elasmobranchs – 100=11+2+16+24+48; whereC: food consumption;F: faeces;U: nonfaecal excretion;R _d : apparent specific dynamic action;R _R : routine metabolism;B: growth. These show that most of the energy consumed is used in metabolism (R _d +R _R ) and growth (B) whereas excretion (U) only accounts for a small portion. The energy budgets developed are within ranges recorded for other species. The main feeding groups of surf-zone icthyofauna are the southern mulletLiza richardsonii, the sandsharkRhinobatos annulatus, benthic feeders, zooplankton feeders, omnivorous and piscivorous fish with biomass values of 1000, 1000, 3000, 2400, 400 and 400 kJ m^–1, respectively; and annual consumption budgets of 22107, 13725, 65710, 65476, 9758 and 8517 kJ m^–1 yr^–1, respectively.L. richardsonii feeds mainly on surf diatoms, consuming 0.5% of total diatom production. Zooplankton production supplies 91%, and macrobenthic production 9%, of the energy needs of other non-piscivorous carnivorous fishes. Piscivorous fishes consume 30% of the available fish production. Nonfaecal-energy production (8229 kJ m^–1 yr^–1) is utilised by surf diatoms, and faecal-energy production (30 341 kJ m^–1 yr^–1), is returned to the detritus pool to be utilised by the microbial loop in surf-waters. Our current knowledge of surf-zone energetics indicates that fishes are important predators. This study confirms the concept that the ecosystem generates adequate food for the fish assemblage. Fishes recycle energy, as excretory products, via the detritus pool and surf-diatoms, while fishes moving across the outer boundary of the surf-zone export energy from the system. Data presented, therefore, also support the general concept of a self-sustaining beach/surf-zone ecosystem.Please address all correspondence and requests for reprints to Dr Du Preez at his present address: Research Unit for Fish Biology, Rand Afrikaans University, P.O. Box 524, Johannesburg 2000, Republic of South Africa     

Source Release-Rate Estimation of Atmospheric Pollution from a Non-Steady Point Source at a Known Location

The goal is to build up an inverse model capable of finding the release history of atmospheric pollution by using measured gas concentration data at just one location on the ground and identify the factors which affects the accuracy of the model predictions. The problem involves a non-steady point source of pollution at a known location in the atmosphere. This problem of finding the release rate is an ill-posed inverse problem and its solution is extremely sensitive to errors in the measurement data. Special regularisation methods, which stabilise the process of the solution, must be used to solve the problem. The method described in this paper is based on linear least-squares regression and Tikhonov regularisation, coupled with the solution of an advection-diffusion equation for a non-steady point source. The accuracy of the method is examined by imposing normally-distributed relative noise into the concentration data generated by the forward model as well as some real experimental data.     

European environmental assistance to the region of Pskov in northwest Russia: sustainability,effectiveness and implications for environmental governance

The paper explores the impact and sustainability of environmental assistance coming to Russia from EU-based public and private foundations, and its implications for environmental governance. Geographically, the study ’encompassed all the assistance projects awarded in 1991–2016 involving beneficiaries from Pskovskaya Oblast’. This region is potentially an important target for EU investments in environmental infrastructure, due to its location by the EU border and high value of natural capital. The study demonstrates how the assumptions offered by the international aid literature (mostly derived from the global South) apply to Russia. We found major limitations to the assumption that co-financing provided by recipients ensures project effectiveness (demonstrating the acceptance of the donor's agenda) or sustainability (providing interest to the maintenance of outputs). Tangible assets are normally co-financed only if the investment was in agenda anyway (and therefore the donor gets only time gains, although this can be a valid purpose too); soft outputs (plans, surveys, policies, etc.) are usually co-financed in-kind, and therefore cannot secure any additional commitment. Likewise, physical infrastructure often ends up mismanaged due to low or no maintenance budgets available, while maintenance of soft outputs is too much dependent on contextual factors beyond the co-finance paradigm.     

Automatic classification of climate change effects on marine species distributions in 2050 using the AquaMaps model

Environmental and Ecological Statistics - Habitat modifications driven by human impact and climate change may influence species distribution, particularly in aquatic environments. Niche-based...     

A non-absorbable dietary fat substitute enhances elimination of persistent lipophilic contaminants in humans.

For individuals contaminated with persistent lipophilic pollutants, there is an urgent need for a therapy to enhance contaminant elimination from the body and hence reduce long term exposure. This study investigated the possibility of enhancing the excretion of native chemical via the faeces by augmenting the lipophilic properties of the faeces with the non-absorbable lipid substitute olestra. The faecal excretion of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), and hexachlorobenzene (HCB) was measured in 3 volunteers. The excretion while eating an olestra-free diet was compared with the excretion while eating a diet supplemented wit 25 g/d of olestra. The excretion while on the olestra diet was higher by a factor of 1.5-11, depending on the compound. This resulted from higher concentrations of the contaminants in the faeces and higher excretion of faeces dry mass due to the food additive. Using 2,3,7,8-Cl4DD as an example, it was estimated that ingestion of 25 g/d of olestra would more than double the overall rate of elimination of this compound from the body. It is concluded that regular consumption of olestra may provide a therapeutic approach for reducing the body burden of persistent lipophilic contaminants.