Temporal variations of concentrations of currently used pesticides in the atmosphere of Strasbourg, France

Atmospheric samples have been collected in Strasbourg between April 18 and May 29, 2007 and were analyzed for 71 current-use pesticides, of which 38 were detected. Average concentrations ranged from 0.09 ng m⁻³ for Fenarimol to 110.42 ng  m⁻³ for Dimethachlor, which was slightly higher than the concentrations reported from other, comparable agricultural regions.Significant temporal variations were observed for 30 pesticides, and for most of them it could be shown that these were linked to time, temperature or atmospheric pressure. In several cases this helped to identify pesticide application just before or at the beginning of the sampling period, or ongoing treatment. Humidity, in contrast to previous reports, could not be linked to these variations. For the other 8 pesticides, only very little temporal variations were observed. Generally, these concentrations were low (less than 1 ng m⁻³), and it was assumed that they are not in use in Alsace at present.     

Temporal variation of Tubularia indivisa (Cnidaria, Tubulariidae) and associated epizoites on artificial habitat communities in the North Sea

We have analyzed the composition, diversity, density and biomass of a temporal series of samples taken in a Tubularia indivisa community, which dominates a shipwreck in the North Sea waters (N 51°23′,730–E 02°29′,790, 17 nautical miles from the coast, 30 m depth). This shipwreck has structures emerging up to 8 m above the seabed. Water temperature ranged from 4.2°C in March to 20.3°C in August. Salinity showed few variations around 33.9 psu. Bottom tidal currents followed a semi-diurnal cycle and were preferentially NE oriented with 84% of them in the range 0.25–0.75 m s⁻¹. The mean value for total suspended matter was 6.2 mg l⁻¹ with large variations on a monthly scale. The species richness of samples varied from 15 in October to 42 in August with a mean value of 33 species. Diversity indices were higher during autumn and winter because of the strong dominance of a few crustacean species during the warmer months. The total density of individuals ranged from 6,500 ind m⁻² in October to 445,800 ind m⁻² in July, most of these individuals belonging to the amphipod species Jassa herdmani. The biomass of the T. indivisa community varied from 9 g AFDW m⁻² in October to 1,106 g AFDW m⁻² in July, with T. indivisa itself constituting between 59 and 82% of the total biomass. The biomass of T. indivisa was positively correlated with species richness and with the density of 23% of the species identified on this community, suggesting that T. indivisa plays an important structural role in this habitat. This was further confirmed by the number of species associated with T. indivisa which was generally superior to 55% of the sorted species. Multivariate analysis indicated strong differences between spring/summer−autumn/winter assemblages mostly but not solely due to the abundance patterns of species. These findings support the conclusion that shipwrecks in Belgian waters allow the development of assemblages dominated by a high biomass of T. indivisa which in turn provides shelter for high densities and biomass of epizoites. These assemblages will further show large monthly variations in densities and composition due to large variation in T. indivisa biomass under an apparent repetitive annual cycle. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Effects of Cd2+ on K+, Ca2+ and N uptake in two halophytes Sesuvium portulacastrum and Mesembryanthemum crystallinum: consequences on growth

One of the limits of Cd2+-phytoextraction is the high toxicity of this metal to plants. Growth restriction, chlorosis and necrosis are usually accompanied with a large disturbance of the uptake of essential elements. This work aims to study the effects of cadmium (Cd2+) on potassium (K+), calcium (Ca2+) and nitrogen (N) acquisition, and their consequences on growth in two halophytes species: Sesuvium portulacastrum and Mesembryanthemum crystallinum. Seedlings were grown for 30 days in split-root conditions. One half of the root system was immersed in complete nutrient solution (Basal medium (B)) supplemented with 100 microM Cd2+, and the other half was immersed in a Cd2+-free medium, containing all nutrients (B/Cd plants) or deprived of potassium ((B-K)/Cd) or calcium ((B-Ca)/Cd) or nitrogen ((B-N)/Cd). Using this approach, we demonstrated that K+ and Ca2+ uptake was impaired in roots exposed to Cd2+. Concerning N, we noticed no indication of uptake inhibition by Cd2+. However, restriction of K+ uptake by roots was compensated by an increase in the K+-use efficiency, so that growth was not inhibited. Calcium uptake was strongly limited by Cd2. This inhibition was accompanied by a reduction in growth of ((B-Ca)/Cd) plants. Thus, we conclude that Cd2+ limits growth of both halophytes through restriction imposed on Ca2+ uptake. We suggest that the increase of Ca2+ availability in soils could improve the growth of both species in the presence of Cd2+. This would be essential for improving their utility for extraction of this metal by from salty contaminated soils.     

Utilization of long duration high-volume sampling coupled to SPME-GC-MS/MS for the assessment of airborne pesticides variability in an urban area (Strasbourg,France) during agricultural application

Atmospheric samples have been collected between 14 March and 12 September 2012 on a 2-week basis (15 days of sampling and exchange of traps each 7 days) in Strasbourg (east of France) for the analysis of 43 pesticides. Samples (particle and gas phases) were separately extracted using Accelerated Solvent Extraction (ASE) and pre-concentrated by Solid Phase Micro-Extraction (SPME) before analysis by gas chromatography coupled to tandem mass spectrometry (GC-MS/MS). Four SPME consecutive injections at distinct temperatures were made in order to increase the sensitivity of detection for the all monitored pesticides. Currently used detected pesticides can be grouped in four classes; those used in maize crops (acetochlor, benoxacor, dicamba, s-metolachlor, pendimethalin, and bromoxynil), in cereal crops (benoxacor, chlorothalonil, fenpropimorph, and propiconazole), in vineyards (tebuconazole), and as herbicides for orchards, meadows of green spaces (2,4-MCPA, trichlopyr). This is in accordance with the diversity of crops found in the Alsace region and trends observed are in accordance with the period of application of these pesticides. Variations observed permit also to demonstrate that the long time sampling duration used in this study is efficient to visualize temporal variations of airborne pesticides concentrations. Then, long time high-volume sampling could be a simple method permitting atmospheric survey of atmospheric contamination without any long analysis time and consequently low cost.     

Vitellogenin content in European eel (Anguilla anguilla) in Flanders, Belgium

As part of a large-scale monitoring program of bioaccumulating contaminants in the European eel (Anguilla anguilla) in Flanders (Belgium), we investigated potential effects of xenoestrogens in these fish. The present paper describes the results of the plasma vitellogenin (VTG) content, measured in 142 eels sampled at 20 different locations, in relation to the internal pollution levels. To validate the blood VTG assays, a small number of eels (n=8) was exposed to 10 microg ethinylestradiol/l (EE2) for 9 days. In this experiment, VTG was detected as a protein with a molecular weight of 214 kDa and confirmed by Western blotting. Compared with the solvent controls, significantly higher concentrations of VTG were measured in EE2 exposed eel. However, the VTG content was relatively low compared with other fish species exposed to high concentrations of estrogens. The plasma VTG content of eels from the field study was very low, despite a very high internal load of endocrine disrupters. These results, together with previously published studies, suggest that immature yellow European eel might not be the best sentinel species to study the effects of estrogenic compounds on VTG levels of wild fish populations.     

Development of a software package for trend detection in temporal series: Application to water and industrial effluent quality data for the St. Lawrence River

Despite the considerable amount of effort and resources involved in monitoring water quality, water quality assessment and environmental follow-up are sometimes carried out with simple statistics, the main reason being the lack of appropriate statistical methods adapted to the nature of sampled water quality data.A survey of the classical methods used for trend detection and of their limitations is first presented, including the most recent non-parametric techniques adapted to the structure of the sampled data and to the possible types of trends occuring. This paper then presents an interactive user-friendly software package developed for microcomputers making use of these latest adapted techniques. Afterwards, some applications of the software are described pertaining to the concentrations measured at long-term stations on the St. Lawrence River and to the mass loadings discharged by regulated industries. Finally, conclusions are drawn about the assumptions, performance and limitations of the package as well as about the research needs to improve the usefulness and applicability of the software.     

Quantitative determination of hexamethylene diisocyanate (HDI), 2,4-toluene diisocyanate (2,4-TDI) and 2,6-toluene diisocyanate (2,6-TDI) monomers at ppt levels in air by alkaline adduct coordination ionspray tandem mass spectrometry

Occupational exposures to isocyanates can lead to occupational asthma. Once sensitized, some workers could react to isocyanate monomers at concentrations below 1% of the Permissible Exposure Limit of 5 ppb in air. Currently available methods are not sufficiently sensitive to adequately evaluate isocyanates present at these levels in workplace air. This article describes a novel method for isocyanate determination allowing the ultratrace quantification in workplace air of hexamethylene diisocyanate, 2,4-toluene diisocyanate and 2,6-toluene diisocyanate monomers. Sampling is performed during a complete workshift at a flow rate of 1 L min(-1) with a cassette containing a 1-(2-methoxyphenyl)piperazine-impregnated 25 mm filter. Analysis is performed using liquid chromatography hyphenated with coordination ionspray tandem mass spectrometry. The analytical method's linearity was measured for a concentration range varying from the limit of detection of 0.04-0.13 ng mL(-1), depending on the monomer, up to approximately 32 ng mL(-1) for every isocyanate monomer, all with correlation coefficients (R(2)) greater than 0.999. The analytical method's lower limit of quantification combined with an adapted sampling strategy allow the quantification of isocyanate monomers down to 0.04 ppt for an 8 h work shift when a lithium adduct is used, which is more than 300 times lower than the most sensitive method currently available. This novel method can be used to confirm the very low level of isocyanate monomers for the safe reassignment of sensitized workers and it is also useful for charting the isocyanate dispersion tail in workplace environments.     

Determination of VOCs in yellow eel from various inland water bodies in Flanders (Belgium)

Twenty freshwater eels caught in Flanders (Belgium) were analysed by GC-MS for a total of 52 VOCs. The most prominent VOCs are the BTEX and a number of chlorinated compounds such as chloroform and tetrachloroethene. The observed concentrations which, typically, were in the low ng/g wet weight range, could be linked to the major emission sources and the present study gives new evidence that combustion of fossil fuels is a major source of BTEX in the environment. The concentration levels in eels seem to be a reflection of the actual concentrations in their environment. For eels from the same location similar patterns and concentrations were observed, and the concentrations agree with what can be expected from those of the water column. Generally speaking, the observed concentrations do not seem to pose a threat for organisms. More definite statements will, however, require a larger dataset. The study suggests that the yellow eel can possibly be used as a biomonitor or sentinel organism for VOCs.