Bioaerosol sampling by a personal rotating cup sampler CIP 10-M

High concentrations of bioaerosols containing bacterial, fungal and biotoxinic matter are encountered in many workplaces, e.g. solid waste treatment plants, waste water treatment plants and sewage networks. A personal bioaerosol sampler, the CIP 10-M (M-microbiologic), has been developed to measure worker exposure to airborne biological agents. This sampler is battery operated; it is light and easy to wear and offers full work shift autonomy. It can sample much higher concentrations than biological impactors and limits the mechanical stress on the microorganisms. Biological particles are collected in 2 ml of liquid medium inside a rotating cup fitted with radial vanes to maintain an air flow rate of 10 l min(-1) at a rotational speed of approximately 7,000 rpm. The rotating cup is made of sterilisable material. The sampled particles follow a helicoidal trajectory as they are pushed to the surface of the liquid by centrifugal force, which creates a thin vertical liquid layer. Sterile water or another collecting liquid can be used. Three particle size selectors allow health-related aerosol fractions to be sampled according to international conventions. The sampled microbiological particles can be easily recovered for counting, incubation or further biochemical analysis, e.g., for airborne endotoxins. Its physical sampling efficiency was laboratory tested and field trials were carried out in industrial waste management conditions. The results indicate satisfactory collection efficiency, whilst experimental application has demonstrated the usefulness of the CIP 10-M personal sampler for individual bioaerosol exposure monitoring.     

Polynomial Surrogates for Open-Channel Flows in Random Steady State

Assessing epistemic uncertainties is considered as a milestone for improving numerical predictions of a dynamical system. In hydrodynamics, uncertainties in input parameters translate into uncertainties in simulated water levels through the shallow water equations. We investigate the ability of generalized polynomial chaos (gPC) surrogate to evaluate the probabilistic features of water level simulated by a 1-D hydraulic model (MASCARET) with the same accuracy as a classical Monte Carlo method but at a reduced computational cost. This study highlights that the water level probability density function and covariance matrix are better estimated with the polynomial surrogate model than with a Monte Carlo approach on the forward model given a limited budget of MASCARET evaluations. The gPC-surrogate performance is first assessed on an idealized channel with uniform geometry and then applied on the more realistic case of the Garonne River (France) for which a global sensitivity analysis using sparse least-angle regression was performed to reduce the size of the stochastic problem. For both cases, Galerkin projection approximation coupled to Gaussian quadrature that involves a limited number of forward model evaluations is compared with least-square regression for computing the coefficients when the surrogate is parameterized with respect to the local friction coefficient and the upstream discharge. The results showed that a gPC-surrogate with total polynomial degree equal to 6 requiring 49 forward model evaluations is sufficient to represent the water level distribution (in the sense of the \(\ell _2\) norm), the probability density function and the water level covariance matrix for further use in the framework of data assimilation. In locations where the flow dynamics is more complex due to bathymetry, a higher polynomial degree is needed to retrieve the water level distribution. The use of a surrogate is thus a promising strategy for uncertainty quantification studies in open-channel flows and should be extended to unsteady flows. It also paves the way toward cost-effective ensemble-based data assimilation for flood forecasting and water resource management.     

Adverse effects in wild fish living downstream from pharmaceutical manufacture discharges

A set of biochemical and histological responses was measured in wild gudgeon collected upstream and downstream of urban and pharmaceutical manufacture effluents. These individual end-points were associated to fish assemblage characterisation. Responses of biotransformation enzymes, neurotoxicity and endocrine disruption biomarkers revealed contamination of investigated stream by a mixture of pollutants. Fish from sampled sites downstream of the industrial effluent exhibited also strong signs of endocrine disruption including vitellogenin induction, intersex and male-biased sex-ratio. These individual effects were associated to a decrease of density and a lack of sensitive fish species. This evidence supports the hypothesis that pharmaceutical compounds discharged in stream are involved in recorded endocrine disruption effects and fish population disturbances and threaten disappearance of resident fish species. Overall, this study gives argument for the utilisation of an effect-based monitoring approach to assess impacts of pharmaceutical manufacture discharges on wild fish populations.     

DNA damage in caged Gammarus fossarum amphipods: a tool for freshwater genotoxicity assessment

The aim of this study was to propose a tool for freshwater environmental genotoxicity assessment using Gammarus fossarum, a high ecologically relevant species. In a first part, gammarids were caged upstream and downstream wastewater treatment plant effluent output. The sensitivity of genotoxic responses of haemocytes, oocytes and spermatozoa was compared using the Comet assay. Spermatozoa appeared to be the most sensitive, suitable and relevant cell type for genotoxicity risk assessment. In a second part, a watershed-scale study was conducted over 2 years to evaluate the applicability of our caging procedure. The genotoxic impact of a contamination was followed, taking into account seasonal variability. DNA damage in spermatozoa exhibited low basal level and low variability in control upstream sites, providing a reliable discrimination of polluted sites. Finally, DNA damage in caged G. fossarum has been proved to be a sensitive and reproducible tool for freshwater genotoxicity assessment.     

Atmospheric fate of non-volatile and ionizable compounds

A modified version of the Multimedia Activity Model for Ionics MAMI, including two-layered atmosphere, air-water interface partitioning, intermittent rainfall and variable cloud coverage was developed to simulate the atmospheric fate of ten low volatility or ionizable organic chemicals. Probabilistic simulations describing the uncertainty of substance and environmental input properties were run to evaluate the impact of atmospheric parameters, ionization and air-water (or air-ice) interface enrichment.The rate of degradation and the concentration of OH radicals, the duration of dry and wet periods, and the parameters describing air-water partitioning (K_AW and temperature) and ionization (pK_a and pH) are the key parameters determining the potential for long range transport. Wet deposition is an important removal process, but its efficiency is limited, primarily by the duration of the dry period between precipitation events.Given the underlying model assumptions, the presence of clouds contributes to the higher persistence in the troposphere because of the capacity of cloud water to accumulate and transport non-volatile (e.g. 2,4-D) and surface-active chemicals (e.g. PFOA). This limits the efficiency of wet deposition from the troposphere enhancing long-range transport.     

Isolation and characterization of mesotrione-degrading Bacillus sp. from soil

Dissipation kinetics of mesotrione, a new triketone herbicide, sprayed on soil from Limagne (Puy-de-Dôme, France) showed that the soil microflora were able to biotransform it.Bacteria from this soil were cultured in mineral salt solution supplemented with mesotrione as sole source of carbon for the isolation of mesotrione-degrading bacteria. The bacterial community structure of the enrichment cultures was analyzed by temporal temperature gradient gel electrophoresis (TTGE). The TTGE fingerprints revealed that mesotrione had an impact on bacterial community structure only at its highest concentrations and showed mesotrione-sensitive and mesotrione-adapted strains. Two adapted strains, identified as Bacillus sp. and Arthrobacter sp., were isolated by colony hybridization methods.Biodegradation assays showed that only the Bacillus sp. strain was able to completely and rapidly biotransform mesotrione. Among several metabolites formed, 2-amino-4-methylsulfonylbenzoic acid (AMBA) accumulated in the medium. Although sulcotrione has a chemical structure closely resembling that of mesotrione, the isolates were unable to degrade it.     

Environmental and economic life cycle assessment for sewage sludge treatment processes in Japan

Life cycle assessment for sewage sludge treatment was carried out by estimating the environmental and economic impacts of the six alternative scenarios most often used in Japan: dewatering, composting, drying, incineration, incinerated ash melting and dewatered sludge melting, each with or without digestion. Three end-of-life treatments were also studied: landfilling, agricultural application and building material application. The results demonstrate that sewage sludge digestion can reduce the environmental load and cost through reduced dry matter volume. The global warming potential (GWP) generated from incineration and melting processes can be significantly reduced through the reuse of waste heat for electricity and/or heat generation. Equipment production in scenarios except dewatering has an important effect on GWP, whereas the contribution of construction is negligible. In addition, the results show that the dewatering scenario has the highest impact on land use and cost, the drying scenario has the highest impact on GWP and acidification, and the incinerated ash melting scenario has the highest impact on human toxicity due to re-emissions of heavy metals from incinerated ash in the melting unit process. On the contrary, the dewatering, composting and incineration scenarios generate the lowest impact on human toxicity, land use and acidification, respectively, and the incinerated ash melting scenario has the lowest impact on GWP and cost. Heavy metals released from atmospheric effluents generated the highest human toxicity impact, with the effect of dioxin emissions being significantly lower. This study proved that the dewatered sludge melting scenario is an environmentally optimal and economically affordable method.     

Interaction webs in arctic ecosystems: Determinants of arctic change?

How species interact modulate their dynamics, their response to environmental change, and ultimately the functioning and stability of entire communities. Work conducted at Zackenberg, Northeast Greenland, has changed our view on how networks of arctic biotic interactions are structured, how they vary in time, and how they are changing with current environmental change: firstly, the high arctic interaction webs are much more complex than previously envisaged, and with a structure mainly dictated by its arthropod component. Secondly, the dynamics of species within these webs reflect changes in environmental conditions. Thirdly, biotic interactions within a trophic level may affect other trophic levels, in some cases ultimately affecting land–atmosphere feedbacks. Finally, differential responses to environmental change may decouple interacting species. These insights form Zackenberg emphasize that the combination of long-term, ecosystem-based monitoring, and targeted research projects offers the most fruitful basis for understanding and predicting the future of arctic ecosystems.     

Polycyclic aromatic hydrocarbons: bees, honey and pollen as sentinels for environmental chemical contaminants

Three beehive matrices, sampled in six different apiaries from West France, were analyzed for the presence of four polycyclic aromatic hydrocarbons (PAH4: benzo[a]pyrene, benzo[a]anthracene, benzo[b]fluoranthene and chrysene). Samples were collected during four different periods in both 2008 and 2009. Honey samples showed the lowest levels of PAH4 contamination (min = 0.03 μg kg⁻¹; max = 5.80 μg kg⁻¹; mean = 0.82 μg kg⁻¹; Sd = 1.17). Bee samples exhibited higher levels of PAH4 contamination (min = 0.32 μg kg⁻¹; max = 73.83 μg kg⁻¹; mean = 7.03 μg kg⁻¹; Sd = 17.83) with a great dispersion of the concentrations due to four main events of high concentrations. Pollen samples showed only one major episode with the highest PAH4 concentration found (min = 0.33 μg kg⁻¹; max = 129.41 μg kg⁻¹; mean = 7.10 μg kg⁻¹; Sd = 22.28). The PAH4 concentrations found were significantly influenced by the landscape context for all beehive samples.     

Carbamazepine, carbamazepine epoxide and dihydroxycarbamazepine sorption to soil and occurrence in a wastewater reuse site in Tunisia

Although a number of manufactured nanoparticles are applied for the medical and clinical purposes, the understanding of interaction between nanomaterials and biological systems are still insufficient. Using nematode Caenorhabditis elegans model organism, we here investigated the in vivo toxicity or safety of hydroxylated fullerene nanoparticles known to detoxify anti-cancer drug-induced oxidative damages in mammals. The survival ratio of C. elegans rapidly decreased by the uptake of nanoparticles from their L4 larval stage with resulting in shortened lifespan (20 d). Both reproduction rate and body size of C. elegans were also reduced after exposure to 100 μg mL⁻¹ of fullerol. We found ectopic cell corpses caused by apoptotic cell death in the adult worms grown with fullerol nanoparticles. By the mutation of core pro-apoptotic regulator genes, ced-3 and ced-4, these nanoparticle-induced cell death were significantly suppressed, and the viability of animals consequently increased despite of nanoparticle uptake. The apoptosis-mediated toxicity of nanoparticles particularly led to the disorder of digestion system in the animals containing a large number of undigested foods in their intestine. These results demonstrated that the water-soluble fullerol nanoparticles widely used in medicinal applications have a potential for inducing apoptotic cell death in multicellular organisms despite of their antioxidative detoxifying property.