Correction to: Pesticide resurrection

Environmental Chemistry Letters -     

Partial compensation of the sublethal effect of deltamethrin on the sex pheromonal communication of Trichogramma brassicae

Pyrethroid insecticides are widely used and lead to a sizable environmental pollution that could interfere with the population biology of insects. Trichogramma is a beneficial insect used in biological control and which natural populations contribute to the control of Lepidopterus pests. In this work, we determined the effect of a sublethal dose of deltamethrin on the sex pheromonal communication of Trichogramma. The dose used (LD 0.1) induces no detectable mortality (the theoretical mortality is only one insect over 1000) and can be a good representation of contamination by this insecticide from environmental pollution. The insecticide was shown to have opposite effects on the sex pheromonal communication of Trichogramma, depending on which sex was exposed (Delpuech, J.M., Legallet, B., Terrier, O., Fouillet, P., 1999. Chemosphere 38, 729–739). We show that, when both sexes are simultaneously exposed to the insecticide, this effect is only partially neutralized. The mean response of treated males responding to the sex pheromone from treated females is not significantly different from that of controls, but the kinetics of their response is not the same. When both sexes are treated, the response of males to the sex pheromone is lower at the beginning but their response does not decrease during time contrary to controls and becomes finally higher than that of controls. Therefore, the sublethal effect of deltamethrin in the field can be either advantageous or disadvantageous depending on the difficulty in finding females and their scarcity.     

Radionuclide release and transport from nuclear underground tests performed at Mururoa and Fangataufa — predictions under uncertainty

In the context of a study by the International Geomechanical Commission (IGC) and the International Atomic Energy Agency (IAEA) on the effects of nuclear tests at the atolls of Mururoa and Fangataufa, release to the biosphere is estimated for 35 radionuclides originating from 147 nuclear underground tests. Based on a qualitatively characterised hydrogeological situation of atolls and relatively scarce site-specific data, a model chain was developed to conservatively estimate the radionuclide fluxes via groundwater, from their sources, the explosion cavities, towards the biosphere, the ocean or lagoon.Finite element hydro-thermal modelling was used to describe water flow. Parameters were calibrated by a very few measured pre-test temperature profiles in bore holes. The impact of the tests on groundwater flow and mechanical impact on rock was considered. Estimates were made to quantify spatial extensions and temporal evolution of impact by using measurements on refilling rate of the cavities. Tests were categorised according to their specific yield and location although detailed data were missing. A base case parameter set was defined for the hydraulic conditions and for the initial radionuclide inventory of individual tests. Models were used to describe the concentration of radionuclides in the cavities as a function of time. Radionuclide transport from the cavities to the biosphere was represented by two different approaches: a double porosity model for the fractured volcanic rock and a single porosity model for the overlaying, highly porous carbonates. Results consist of conservative estimates on radionuclide release into the environment, or concentration in the lagoon or ocean water. Their sensitivity was investigated using different models and parameters. A few measured data (concentrations in a few cavities, in the deep carbonates and in the lagoons for selected radionuclides, such as ³H, ¹⁴C, ³⁶Cl, ⁹⁰Sr, ¹²⁹I, ¹³⁷Cs²³⁹, ²⁴⁰Pu and ²⁴¹Am) were available for a comparison with the calculations. In view of the lack and uncertainty of site-specific data, the agreement is of acceptable quality.     

Habitat Matrix Effects on Pond Occupancy in Newts

Abstract: In farmlands, the population viability of many amphibians is suspected to depend on the resistance the matrix of crop fields presents to movements between ponds and terrestrial sites and movements among ponds. Over recent decades the increase in cereal growing at the expense of cattle breeding has caused a drastic change in habitat matrix in many European regions. We investigated the effect of such change on populations of three newt species (   Triturus helveticus , T. alpestris , and T. cristatus ) by comparing their abundances in sites that varied in amount of cultivated ground. A multivariate regression analysis of the relationship of newt abundance to both pond and landscape variables demonstrated the negative influence of cultivated ground on abundance. The width of the uncultivated sector linking the pond to the forest was a good predictor of abundance after the influences of both pond area and fish presence were removed. Moreover, newt presence was positively related to the number of ponds within that 50-ha surrounding area, highlighting the role of metapopulation functioning in newt occupancy of ponds. The relationship between newt abundance and width of uncultivated sectors agrees with present knowledge of the orientation mechanisms that underlie migration movements in urodeles. Such a relationship between connectedness and sector width shows that narrow, linear corridors such as hedgerows may not be useful in newt conservation. Our study also highlights the need to incorporate a behavioral component of habitat use into models of connectivity in conservation biology.     

A theoretical and methodological framework for studying and modelling drivers’ mental representations

This article provides a synthetic overview of the research programme carried out at INRETS-LESCOT over the last 10 years, in view to studying and modelling the mental representations of car drivers. Theoretically, this research is in line with two complementary scientific traditions: Human Information Processing theories on the one hand, and theories of Operative Activity on the other. As discussed in Section 1 of the article, attention is given to the functional representations of drivers, constructed “by” and “for” the action, such as they are implemented in a driving situation, and taking into account both implicit and explicit dimensions. This aim directly impacts on the methodological approach implemented, in so far as it entails defining an “experimental continuum” ranging from naturalistic observations of the driving activity (on the open road), to setting up more controlled experimental protocols in order to permit in-depth, systematic and reproducible scientific investigations of drivers’ cognition. Section 2 of the article presents a synthetic view of these methods, while Section 3 presents several significant results obtained with them. Lastly, the final part of the article focuses on the computational formalism defined at INRETS-LESCOT (i.e. the driving schemas) designed to model driver knowledge and mental representations, and developed in a COgnitive Simulation MOdel of the DRIVEr called COSMODRIVE.     

Horizontal environmental assessment of building products in relation to the construction products directive (CPD)

According to the European Construction Products Directive (89/106/EC), construction products must satisfy specified essential requirements (ER). To comply with ER 3, on hygiene, health and environment, the construction works must be designed and built in such a way that they will not be a threat to the hygiene and health of the occupants and neighbours, nor to the environment. Standardised test methods for the release of substances that are hazardous to health and environment need to be developed at the European level. A horizontal approach is considered the best route for such test development and consists of the development of a test method applicable for different products used in a certain scenario (across the fields of different Technical Committees). The work presented here regards the emission of pollutants towards soil and water and has been carried out on monolith products, based on three types of matrices: concrete, wood and metal (zinc). The aim of the work is to study the parameters (nature of leachant, temperature, liquid-to-solid ratio) that could influence the release behaviour of substances in water. The knowledge acquired from these tests will allow the identification of some parameters needed for the development of a horizontal test.     

Trends in Chemical Composition of Wet-only Precipitation at Rural French Monitoring Stations Over the 1990–2003 Period

The long-term monitoring of precipitation and its chemical composition are important for identifying trends in rain quality and for assessing the effectiveness of pollution control strategies. A statistical test has been used to the atmospheric concentrations measured in the French rural monitoring network (MERA) in order to bring out spatio-temporal trends in precipitation quality in France over the period 1990–2003. The non-parametric Mann–Kendall test which has been developed for detecting and estimating monotonic trends in the time series was used and applied in our study at annual values of wet-only precipitation concentrations. The emission data suggest that SO₂ and NO _x emissions decreased (−3.3 and −2.0% year⁻¹, respectively) contrary to NH₃ emissions that increased slightly (+0.2% year⁻¹) over the period 1990–2002 in France. On the national scale, the pH values have a significant decreasing trend of −0.025 ± 0.02 unit pH year⁻¹. and concentrations in precipitation have a significant decreasing trend, −3.0 ± 1.6 and −3.3 ± 0.6% year⁻¹, respectively, corresponding with the downward trends in SO₂ emissions in France (−3.3% year⁻¹). A good correlation (R ² = 0.84) between SO₂ emissions and concentrations was obtained. The decreasing trend of was more significant (−5.4 ± 5.2% year⁻¹) than that of (−1.3 ± 2.4% year⁻¹). Globally, the concentration of the major ions showed a clear downward trend including marine and alkaline ions. In addition, the relative contribution of HNO₃ to acidity precipitation increased by 51% over the studied period.     

Modelling the geochemical fate and transport of wastewater-derived phosphorus in contrasting groundwater systems

A 1D reactive transport model (RTM) is used to obtain a mechanistic understanding of the fate of phosphorus (P) in the saturated zone of two contrasting aquifer systems. We use the field data from two oxic, electron donor-poor, wastewater-impacted, sandy Canadian aquifers, (Cambridge and Muskoka sites) as an example of a calcareous and non-calcareous groundwater system, respectively, to validate our reaction network. After approximately 10 years of wastewater infiltration, P is effectively attenuated within the first 10 m down-gradient of the source mainly through fast sorption onto calcite and Fe oxides. Slow, kinetic sorption contributes further to P removal, while precipitation of phosphate minerals (strengite, hydroxyapatite) is quantitatively unimportant in the saturated zone. Nitrogen (N) dynamics are also considered, but nitrate behaves essentially as a conservative tracer in both systems. The model-predicted advancement of the P plume upon continued wastewater discharge at the calcareous site is in line with field observations. Model results suggest that, upon removal of the wastewater source, the P plume at both sites will persist for at least 20 years, owing to desorption of P from aquifer solids and the slow rate of P mineral precipitation. Sensitivity analyses for the non-calcareous scenario (Muskoka) illustrate the importance of the sorption capacity of the aquifer solids for P in modulating groundwater N:P ratios in oxic groundwater. The model simulations predict the breakthrough of groundwater with high P concentrations and low N:P ratios after 17 years at 20 m from the source for an aquifer with low sorption capacity (<0.02% w/w Fe(OH)(3)). In this type of system, denitrification plays a minor role in lowering the N:P ratios because it is limited by the availability of labile dissolved organic matter.