In this study, we assessed the transportability of zero valent iron nanoparticles (nano-Fe⁰) coated with different organics (carboxy methyl cellulose (CMC), poly acrylic acid (PAA), and xanthan gum) in standard porous sand and in real aquifer sediments. Our results suggest that the organic surface coatings optimized for nano-Fe⁰ in porous sand media do not necessarily reflect the same transportability in real field aquifer sediment. Xanthan gum-coated nano-Fe⁰ showed highest transportability in standard porous sand, but the performance was much lower in real aquifer sediment, whereas the PAA-coated nano-Fe⁰ particle showed better transportability both in aquifer sediment and in porous sand media. Nano-Fe⁰ without organic surface coating exhibited very low transportability and was largely retained by the porous medium. Our results suggest that the molecular weight and surface charge density of the organic may play a role in transportability of these nanoparticles. To assess the impact of organic coating on the nanoparticle reactivity with contaminants, we also conducted batch tests to follow TCE degradation using different surface coatings and found no significant difference albeit a minor delay in kinetics. Using theoretical calculations, we also estimated the potential distance traveled by nanoparticles in porous sand as well as in aquifer sediment. Our results suggest that using xanthan gum and PAA as surface coating, nano-Fe⁰ could travel up to 9.8 and 4.1 m, respectively, in the porous sand media as compared to 0.2 and 0.9 m in real aquifer sediment, respectively. Graphical abstract Nanoparticle mobility in porous sand vs and aquifer sediment.

Franciscana dolphins are the most impacted small cetacean in the Southwestern Atlantic Ocean, classified as Vulnerable A3d by IUCN. Essential (Fe, Mo, Mn, Cr, Ni, Co) and non-essential (Ag, Pb, Sn) trace elements (TEs) were measured in liver, kidney, and brain samples of by-catch Franciscana dolphins that were living in estuarine (n = 21) and marine (n = 21) habitats (1) to assess whether TEs posed a threat and (2) to evaluate the suitability of TEs for discriminating ecological populations of this species in Argentinean waters. Essential TEs showed little variation in tissues from both groups in agreement with levels reported for other cetaceans and suggesting that these concentrations correspond to normal physiological levels. Non-essential TEs were higher in estuarine juveniles and adults dolphins than in marine specimens. These results suggest anthropogenic sources associated with estuarine area and that Franciscana dolphins are good sentinels of the impact of the environment. The difference in the concentrations of TEs beetwen ecological populations appeared to be related to distinct exposures in both geographical areas, and it is suggested that Ag and Sn concentrations in adults are good chemical tracers of anthropogenic input of TEs. These results provide additional information for improved management and regulatory policy.

Volatilization may represent a major dissipation pathway for pesticides applied to soils or crops, and these losses may be modified by soil surface conditions or in the presence of plant residues. This paper investigates the effect of surface conditions on volatilization through experimental results. The two experiments consisted of volatilization flux measurements for 3 days after an application of S-metolachlor together with benoxacor: one with two wind tunnels to compare the effect of the presence of crop residues on the soil on volatilization losses and another one at the field scale from bare soil without crop residues. Volatilization fluxes were large immediately after application (between 77 and 223 ng m⁻² s⁻¹ for S-metolachlor depending on experimental conditions), decreasing down to a few nanograms per square meter per second on the last day. Volatilization fluxes followed a diurnal cycle driven by environmental conditions. The losses found for both compounds were in accordance with their physicochemical properties. The crop residue on the soil surface modified soil surface conditions—primarily the soil water content essentially, the degradation of S-metolachlor, and the dynamics of volatilization loss.

Urban stormwater samples were collected from five aquatic systems in Melbourne, Australia, on six occasions between October 2011 and March 2012 and tested for 30 herbicides and 14 trace metals. Nineteen different herbicides were observed in one or more water samples from the five sites; chemicals observed at more than 40% of sites were simazine (100%), MCPA (83%), diuron (63%) and atrazine (53%). Using the toxicity unit (TU) concept to assess potential risk to aquatic ecosystems, none of the detected herbicides were considered to pose an individual, group or collective short-term risk to fish or zooplankton in the waters studied. However, 13 herbicides had TU values suggesting they might have posed an individual risk to primary producers at the time of sampling. Water quality guideline levels were exceeded on many occasions for Cd, Cu, Cr, Pb and Zn. Similarly, RQₘₑd and RQₘₐₓ exceeded 1 for Cd, Cr, Cu, Mn, Ni, Pb, V and Zn. Almost all the metals screened exceeded a log₁₀TU of −3 for every trophic level, suggesting that there may have been some impact on aquatic organisms in the studied waterbodies. Our data indicate that Melbourne’s urban aquatic environments may be being impacted by approved domestic, industrial and sporting application of herbicides and that stormwater quality needs to be carefully assessed prior to reuse. Further research is required to understand the performance of different urban stormwater wetland designs in removing pesticides and trace metals. Applying the precautionary principle to herbicide regulation is important to ensure there is more research and assessment of the long-term ‘performance’ standard of all herbicides and throughout their ‘life cycle’. Implementing such an approach will also ensure government, regulators, decision makers, researchers, policy makers and industry have the best possible information available to improve the management of chemicals, from manufacture to use.

Ultra-violet C (UV-C) treatment is commonly used in sterilization processes in industry, laboratories, and hospitals, showing its efficacy against microorganisms such as bacteria, algae, or fungi. In this study, we have eradicated for the first time all proliferating biofilms present in a show cave (the La Glacière Cave, Chaux-lès-Passavant, France). Colorimetric measurements of irradiated biofilms were then monitored for 21 months. To understand the importance of exposition of algae to light just after UV radiation, similar tests were carried out in laboratory conditions. Since UV-C can be deleterious for biofilm support, especially parietal painting, we investigated their effects on prehistoric pigment. Results showed complete eradication of cave biofilms with no algae proliferation observed after 21 months. Moreover, quantum yield results showed a decrease directly after UV-C treatment, indicating inhibition of algae photosynthesis. Furthermore, no changes in pigment color nor in chemical and crystalline properties has been demonstrated. The present findings demonstrate that the UV-C method can be considered environmentally friendly and the best alternative to chemicals. This inexpensive and easily implemented method is advantageous for cave owners and managers.

Biochar amendments, i.e., the solid product of biomass pyrolysis, reduce soil metal availability, which may lower the toxicity of metal-contaminated soils. A direct link between the decrease in soil metal availability and improved plant development is however often difficult to establish, as biochar may induce undesirable side effects on plant growth, e.g., a modification to plant nutrition. In order to investigate toxicity processes at a cellular level, roots of Vicia faba were exposed for 7 days to three metal-contaminated substrates and one control soil, amended with a 0 or 5% (w/w) addition of a wood-derived biochar. Exposure to pure biochar was also tested. Root tip cells were then observed to count the number of micronuclei as an estimation of DNA damage and the number of cells at mitosis stage. Results showed that biochar amendments led to a significant decrease in soil metal availability (Cd, Cu, Ni, Pb, and Zn) and to enhance root development on acidic substrates. The micronucleus frequency in root tip cells was positively correlated and the number of mitotic cells negatively, to the extractability of Zn in soils and to the concentration of Zn in secondary roots. Exposure to pure biochar caused a lower production of roots than most soil substrates, but led to the lowest number of observed micronuclei. In conclusion, biochar amendments can reduce the genotoxicity associated with the presence of metallic contaminants in soils, thereby potentially improving plant growth.

New models for estimating bioaccumulation of persistent organic pollutants in the agricultural food chain were developed using recent improvements to plant uptake and cattle transfer models. One model named AgriSim was based on K OW regressions of bioaccumulation in plants and cattle, while the other was a steady-state mechanistic model, AgriCom. The two developed models and European Union System for the Evaluation of Substances (EUSES), as a benchmark, were applied to four reported food chain (soil/air-grass-cow-milk) scenarios to evaluate the performance of each model simulation against the observed data. The four scenarios considered were as follows: (1) polluted soil and air, (2) polluted soil, (3) highly polluted soil surface and polluted subsurface and (4) polluted soil and air at different mountain elevations. AgriCom reproduced observed milk bioaccumulation well for all four scenarios, as did AgriSim for scenarios 1 and 2, but EUSES only did this for scenario 1. The main causes of the deviation for EUSES and AgriSim were the lack of the soil-air-plant pathway and the ambient air-plant pathway, respectively. Based on the results, it is recommended that soil-air-plant and ambient air-plant pathway should be calculated separately and the K OW regression of transfer factor to milk used in EUSES be avoided. AgriCom satisfied the recommendations that led to the low residual errors between the simulated and the observed bioaccumulation in agricultural food chain for the four scenarios considered. It is therefore recommended that this model should be incorporated into regulatory exposure assessment tools. The model uncertainty of the three models should be noted since the simulated concentration in milk from 5th to 95th percentile of the uncertainty analysis often varied over two orders of magnitude. Using a measured value of soil organic carbon content was effective to reduce this uncertainty by one order of magnitude.

The use of ultrasonication for cyanobacterial control in freshwater bodies has become increasingly popular during the last decades despite controversial efficiency on large scale application. Apart from that, little information is currently available regarding ultrasound toxicity potential towards non-target species. This work was designed to address this issue in the common carp using a low-power (7–9 W output) and dual-frequency (23 and 46 kHz) anti-cyanobacterial ultrasound device. Results showed that carps were unaffected by ultrasound exposure when exposed in floating cages in fish ponds over a 30-day period. The experiment duration was the main factor influencing all measured biological parameters in exposed and non-exposed organisms. Indeed, it was positively associated with an increase in fish condition factor. Cortisol level also tended to slightly increase over the number of days of experiment but its variation did not enable to sort out any ultrasound exposure-related stress. Moreover, an overall diminution along the experimental period of the expression level of a set of biomarkers could be reported, encompassing cellular antioxidant enzyme activities such as superoxide dismutase (SOD), glutathione peroxydase (GPx), catalase and glutathione S-transferase (GST), and lactate dehydrogenase activity. Subtle changes in these biomarkers were dependent of the type of enzyme activity and especially of the origin of fish (i.e., sampled pond) regardless of the presence of ultrasound equipment, reflecting thereby fish adaptation to local environmental conditions in each pond. In conclusion, this study does not provide indication that ultrasonication in the aforementioned conditions affects the welfare and physiological homeostasis of carps.

This article describes a stochastic method to calculate the annual pollutant loads and its application over several years at the outlet of three catchments drained by separate storm sewers. A stochastic methodology using Monte Carlo simulations is proposed for assessing annual pollutant load, as well as the associated uncertainties, from a few event sampling campaigns and/or continuous turbidity measurements (representative of the total suspended solids concentration (TSS)). Indeed, in the latter case, the proposed method takes into account the correlation between pollutants and TSS. The developed method was applied to data acquired within the French research project “INOGEV” (innovations for a sustainable management of urban water) at the outlet of three urban catchments drained by separate storm sewers. Ten or so event sampling campaigns for a large range of pollutants (46 pollutants and 2 conventional water quality parameters: TSS and total organic carbon (TOC)) are combined with hundreds of rainfall events for which, at least one among three continuously monitored parameters (rainfall intensity, flow rate, and turbidity) is available. Results obtained for the three catchments show that the annual pollutant loads can be estimated with uncertainties ranging from 10 to 60%, and the added value of turbidity monitoring for lowering the uncertainty is demonstrated. A low inter-annual and inter-site variability of pollutant loads, for many of studied pollutants, is observed with respect to the estimated uncertainties, and can be explained mainly by annual precipitation.

During biological effect monitoring studies of endocrine active compounds with the snail Assiminea grayana in 2007–2013, reproductive disorders including atresia, transformation of capsule/albumen glands into prostates in females and ovotestis, transformation of prostates to capsule/albumen glands, disruption of spermatogenesis, and calcification of tubules in males, were encountered in several years. The search of sources of endocrine active substances was first directed to antifouling biocides from paint particles and extended to leaching compounds from polymeric materials. In contrast to the reference sites, most of the observed disorders occurred at a station near harbors and dockyards polluted with residues from antifouling paints and polymeric materials. Beside of investigations about the potential ingestion of polymer particles by the snails, further investigations of compounds of polymeric materials with endocrine potential should follow.