Levels and trends of persistent organic pollutants in ringed seals (Phoca hispida) from Central West Greenland, with particular focus on polybrominated diphenyl ethers (PBDEs)

Polybrominated diphenyl ethers (PBDEs) and the organochlorine compounds polychlorinated biphenyls (PCBs), DDTs, HCB, chlordane-related pesticides, HCH and toxaphene were analysed in blubber of juvenile ringed seals from Central West Greenland collected between 1982 and 2006. The longest time series could be established for PBDEs, partly based on archived material, while PCBs and DDTs covered a study period from 1994-2006. All organochlorines showed decreasing trends, most pronounced for DDT and HCH with an annual change of 8%. BDE-47 had a significantly increasing trend of 5% annually. It was the only BDE congener consistently above the detection limit, with annual median concentrations between 0.78 ng/g lw to 3.54 ng/g lw, i.e. about 10 times lower than values from East Greenland observed in a similar time trend study on ringed seal blubber [Rigét F, Vorkamp K, Dietz R, Rastogi SC. Temporal trend studies on polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in ringed seals from East Greenland. J Environ Monit 2006; 8: 1000-5]. A clear East>West difference was also found for PCBs and DDTs, but not for chlordanes, toxaphene or HCHs. Sigma 10-PCB, Sigma DDT and Sigma Chlordanes had similar annual median concentrations, typically exceeding SigmaPBDE by two orders of magnitude. The concentrations of HCH and toxaphene were in an intermediate group, with highest annual median concentrations of 135 ng/g lw and 20 ng/g lw, respectively. For most compound groups, the circumpolar trend previously established under for example the Arctic Monitoring and Assessment Programme was confirmed, but apparently, more data are needed for chlordane-related compounds and toxaphene. Statistical analyses of the compound patterns in the ringed seal samples revealed significantly greater differences between seals from East and West than between different sampling years. Higher proportions of PCBs and DDTs and lower proportions of chlordanes and HCHs were found in seals from East Greenland than in those from West Greenland. Based on principal component analysis of individual congener and compounds, seals from East Greenland were found to contain higher proportions of the higher chlorinated CB congeners. Varying patterns between sampling locations may be caused by different exposure situations related to contaminant emissions and transport, but different feeding habits may also affect the contaminant composition.     

Benefits of adapting to sea level rise: the importance of ecosystem services in the French Mediterranean sandy coastline

Regional Environmental Change - This article proposes an innovative approach to assess the benefits of adapting to sea level rise (SLR) in a coastal area on a regional scale. The valuation...     

Inactivation of bacteria by sun light in a solar reactor with Immobilised TiO2

The photocatalytical inactivation of bacteria (Escherichia coli, Staphylococcus epidermidis,...) in the flow‐through plate solar reactor by sunlight was investigated. The low stability of bacteria in the reactor was attributed to bacteria sensitivity to mixing and/or gas bubbling. Sunlight inactivation proceeds with sufficient rate even under cloudy conditions.     

Interpopulational variation in chemosensory responses to selected steroids from femoral secretions of male lizards, Podarcis hispanica, mirrors population differences in chemical signals

Chemical signals are important for mate and species recognition. If variation in chemical signals occurs between populations of the same species, these differences could later preclude mating between populations and lead to speciation. In the Iberian wall lizard, Podarcis hispanica, the lipophilic fraction of femoral secretions of males is mainly a mix of steroids and fatty acids. Among steroids, the most abundant compounds are cholesterol and cholesta-5,7-dien-3-ol, which are implicated in intraspecific communication and sexual selection. Interpopulational differences in chemical signals of males, and in response to these chemicals, could contribute to reproductive isolation between populations, which would explain the known genetic differences between these populations. Chemical analyses indicated that five distinct populations of this lizard from Madrid (Central Spain) differed in the proportions of two steroids (cholesterol and cholesta-5,7-dien-3-ol) in femoral secretions. Moreover, lizards discriminated and had high chemosensory responses (i.e., high tongue-flick rates) to these steroids, but showed interpopulational differences. Lizards from populations with cold temperatures and high relative humidity (i.e., northern Madrid) elicited higher responses to these steroids, whereas the converse occurred for lizards from populations occupying dry and hot habitats (i.e., southern Madrid). Interestingly, the magnitude of the chemosensory responses to cholesta-5,7-dien-3-ol in each population mirrored the abundance of this compound in secretions of males of that population. These results suggest that the importance of cholesta-5,7-dien-3-ol in males’ secretions might be lower for lizards from the southern populations. These differences in the relative importance of chemical signals could explain reproductive isolation and cryptic speciation between populations of this lizard.     

Freeze-thaw effects on phosphorus loss in runoff from manured and catch-cropped soils

Concern over nonpoint source P losses from agricultural lands to surface waters in frigid climates has focused attention on the role of freezing and thawing on P loss from catch crops (cover crops). This study evaluated the effect of freezing and thawing on the fate of P in bare soils, soils mixed with dairy manure, and soils with an established catch crop of annual ryegrass (Lolium multiflorum L.). Experiments were conducted to evaluate changes in P runoff from packed soil boxes (100 by 20 by 5 cm) and P leaching from intact soil columns (30 cm deep). Before freezing and thawing, total P (TP) in runoff from catch-cropped soils was lower than from manured and bare soils due to lower erosion. Repeated freezing and thawing significantly increased water-extractable P (WEP) from catch crop biomass and resulted in significantly elevated concentrations of dissolved P in runoff (9.7 mg L(-1)) compared with manured (0.18 mg L(-1)) and bare soils (0.14 mg L(-1)). Catch crop WEP was strongly correlated with the number of freeze-thaw cycles. Freezing and thawing did not change the WEP of soils mixed with manures, nor were differences observed in subsurface losses of P between catch-cropped and bare soils before or after manure application. This study illustrates the trade-offs of establishing catch crops in frigid climates, which can enhance P uptake by biomass and reduce erosion potential but increase dissolved P runoff.     

Attitudes towards the conservation of biological diversity—A case study in Kristianstad Municipality,Sweden

Human actions towards land, freshwater and oceans have already caused biodiversity to decline. This study aims to investigate attitudes towards the conservation of biological biodiversity among different groups in a Swedish city, Kristianstad. An inquiry including statements measuring attitudes towards the conservation of habitats, animals and plants, to the biological diversity within selected local areas, to global and national areas, and to societal issues, was replied to by 271 persons. Deciduous forests, birds and wild flowers were given highest priority. An area categorized as wetland including lakeshore meadows with a rich bird life was prioritized as most important for conservation while a forest area was chosen as best for recreation. The experts gave lower priority to arable land, urban parks, domestic animals, agricultural and garden plants and to conifer forests compared to the other groups. Knowledge about what people in general value as important could facilitate the future planning of nature areas in the city of Kristianstad.     

Analysis of indoor gaseous formic and acetic acid, using radial diffusive samplers

A diffusive sampling method for the determination of gaseous acetic and formic acids, using a radial symmetry diffusive sampler, has been optimised for a 7-day exposure time in this study. Sampling rate determinations were performed on data obtained from a dynamic exposure chamber, simulating the indoor conditions of an empty, closed, room, at room temperature and minimal wind speed. Analysis has been performed by means of ion chromatography. The sampling rates for formic acid concentrations of 128 microg m(-3) and 1248 microg m(-3) were determined to be 91.2 +/- 3.9 ml min(-1) and 111.6 +/- 2.8 ml min(-1), respectively. The acetic acid sampling rate was independent of the concentration in the range 160 microg m(-3)-1564 microg m(-3), and amounted to 97.3 +/- 3.1 ml min(-1). Experimentally determined sampling rates showed deviations of 3% for acetic acid, and 3-21% for formic acid, in relation to theoretically derived values. The blank values were as low as 1.69 +/- 0.07 microg for formic acid and 1.21 +/- 0.14 microg for acetic acid, and detection limits lower than 0.5 microg m(-3) could be achieved, which is an improvement of 98-99% compared to previously validated diffusive sampling methods. This study describes the first step of an extended validation program in which the applicability of these types of samplers for the measurement of organic acids will be validated and optimised for the environmental conditions typical for museum showcases.     

Diurnal and intra-urban particle concentrations in relation to windspeed and stability during the dry season in three African cities

The spatial and temporal variations of PM(2.5), PM(10) and TSP in three African cities of different sizes (Dar es Salaam, Ouagadougou and Gaborone) were investigated using portable particle counters. Three different areas (downtown, green residential and traditional residential) and a reference site were designated in each of the cities in order to detect intra-urban and temporal variability. Morning, noon and night measurements were conducted in the urban areas while observations at reference stations were made continuously over the field periods. A clear diurnal pattern in particle concentrations was found in inland Gaborone and Ouagadougou, with morning and night peaks where the latter was the highest. However, in coastal Dar es Salaam the night peak was almost absent due to delayed stabilisation of the air. Particle concentrations at the Ouagadougou reference station were extreme. The direct contribution of vehicle emissions are of secondary importance since the PM(2.5)/PM(10) ratios are low (0.1-0.3). Much of the particles are supposed to be soil particles that are entrained in the air by daytime high windspeeds followed by nighttime subsidence as the air is stabilised and windspeed decreases. However, in all three cities, resuspension are important as areas with a network of unpaved roads showed the highest concentrations of suspended particles. Generally, the central business district had the lowest concentrations of particulate matter.     

Carbon monoxide concentrations in outdoor wood-fired kitchens in Ouagadougou,Burkina Faso—implications for women’s and children’s health

A majority of households in developing countries rely on biomass fuel for cooking, typically burned in open fires or simple stoves. The incomplete combustion of these fuels causes adverse health effects such as respiratory diseases, especially among women and children. However, quantitative data on pollution levels and on associated diseases are limited. We examined cooking habits and self-reported health in 31 households with outdoor open wood fires in Ouagadougou, Burkina Faso, using structured interviews. In eight households, carbon monoxide (CO) was measured using passive sampling. In addition, meteorology and ambient CO concentrations were assessed. The average CO concentration during cooking was 4.3 ppm, with a maximum of 65.3 ppm and minimum of 0.3 ppm (1-min values). A clear daily pattern was observed, with relatively low concentrations during the day and high during the evening, occasionally exceeding the World Health Organization 1- and 8-h guidelines when the air stabilised. On average, CO concentrations were 43 % higher in kitchens located in closed yards than in those located in open yards, showing that fireplace location affected the levels. Eye irritation and coughing among women and children were reported by 30 % of the households. Based on previously reported relations between CO concentrations and fine particles (<2.5 μm), the exposure to biomass smoke appears to be high enough to pose a considerable health risk among women and children in households with outdoor open wood fires. The results suggest that burning should be limited between sunset and dawn and in areas with limited ventilation to reduce pollutions levels.     

Effects of aquatic humic substances on a hydrophobic ultrafiltration membrane

Natural humic surface water (pH 5.9), ion exchanged samples of the same water (pH 5.5), and aqueous solutions of isolated humic substances at pH 4.5, 5.5 and 6.5, respectively, were ultrafiltered (15°C, 0.5 bar) using hydrophobic polysulfone membranes (GR51) in a cross-flow flat sheet module. The used membrane did not completely retain natural organic matter from the surface water and the addition of complexing metals did not affect the retention any further. The changes which were induced in the membranes during each filtration run were studied by simultaneous streaming potential and flux measurements in 0.01 M KCl solutions. Zeta potentials were calculated based on the streaming potentials and the results showed changes towards more negative values for all the samples due to adsorption of organic matter onto the surface of the membrane pores. Humic acid affected the membrane charges more than fulvic acid. High ionic strength and low pH enhanced flux reduction and fouling. Filtration of natural waters caused more pore plugging and flux reduction than filtration of solutions of the isolated humic substances.