Benoit Roig

Effect of Endocrine Disruptor Pesticides: A Review

Endocrine disrupting chemicals (EDC) are compounds that alter the normal functioning of the endocrine system of both wildlife and humans. A huge number of chemicals have been identified as endocrine disruptors, among them several pesticides. Pesticides are used to kill unwanted organisms in crops, public areas, homes and gardens, and parasites in medicine. Human are exposed to pesticides due to their occupations or through dietary and environmental exposure (water, soil, air). For several years, there have been enquiries about the impact of environmental factors on the occurrence of human pathologies. This paper reviews the current knowledge of the potential impacts of endocrine disruptor pesticides on human health.

Microbial Contamination Detection in Water Resources: Interest of Current Optical Methods, Trends and Needs in the Context of Climate Change

Microbial pollution in aquatic environments is one of the crucial issues with regard to the sanitary state of water bodies used for drinking water supply, recreational activities and harvesting seafood due to a potential contamination by pathogenic bacteria, protozoa or viruses. To address this risk, microbial contamination monitoring is usually assessed by turbidity measurements performed at drinking water plants. Some recent studies have shown significant correlations of microbial contamination with the risk of endemic gastroenteresis. However the relevance of turbidimetry may be limited since the presence of colloids in water creates interferences with the nephelometric response. Thus there is a need for a more relevant, simple and fast indicator for microbial contamination detection in water, especially in the perspective of climate change with the increase of heavy rainfall events. This review focuses on the one hand on sources, fate and behavior of microorganisms in water and factors influencing pathogens’ presence, transportation and mobilization, and on the second hand, on the existing optical methods used for monitoring microbiological risks. Finally, this paper proposes new ways of research.

Environmental concentration of nonylphenol alters the development of urogenital and visceral organs in avian model.

Nonylphenol (NP) is an endocrine disruptor with harmful effects including feminization and carcinogenesis on various organisms. This substance is a degradation product of nonylphenol ethoxylates (NPEO) that is used in several industrial and agricultural processes. In this paper, we examined the assessment of NP exposure on chick embryo development, using a concentration consistent with the environmental concentrations of NP. With this aim, NP (between 0.1 and 50 μg/egg) was injected into the yolk of egg through a small needle hole in the shell. We report the effect of NP on chick reproductive system development although the effect we observed is lower than those observed by exposition to other endocrine disruptors. However, histological analysis highlighted a decrease of intraluminal seminiferous surface area in 64.12% of case (P=0.0086) and an heterogeneous organization of the renal tubules when 10 μg/egg were injected. Moreover, an impairment of liver development with an abnormal bile spillage was observed when higher concentration of NP was injected (50 μg/egg).

Monitoring of methotrexate chlorination in water

Anti-cancer drugs are an important class of pharmaceutical products. Methotrexate (MTX) is a folic acid antagonist used in high doses as antimetabolite in anti-cancer treatment as well as in low doses for the treatment of rheumatoid arthritis and adults psoriasis. In the past, several anti-cancer drugs, including methotrexate, have been found in the environment. Their presence in water, especially if used for the production of drinking water, is even in low concentrations of particular interest, due to the risk to retrieve them in the consumed water and their high activity and grave effects. But prior to usage as drinking water, raw waters are treated and chlorination is a common practice in several countries. As such a treatment can lead to the formation of organochlorine in water, the study of the fate of MTX during chlorination in a batch trial was carried out. The reaction was monitored by dissolved organic carbon (DOC) and by fluorescence and UV spectroscopy. Investigation of by-products formed was done with liquid chromatography/mass spectrometry (LC/MS). Under the given experimental conditions, Methotrexate was eliminated rapidly (t1/2 around 21xa0min). However, DOC elimination was incomplete. Monitoring with LC-MS showed the formation of a monochlorinated transformation product of MTX. In silico analysis of the proposed transformation products for different carcinogenic, mutagenic and genotoxic endpoints with different software platforms provided no clear evidence that the possible transformation products after chlorination might be more toxic than the parent compound. However, since a number of alerts is altered after chlorination, it cannot be excluded that the toxicity of these transformation products might be modulated compared with the parent compound.

Spatial distribution of triazine residues in a shallow alluvial aquifer linked to groundwater residence time

At present, some triazine herbicides occurrence in European groundwater, 13xa0years after their use ban in the European Union, remains of great concern and raises the question of their persistence in groundwater systems due to several factors such as storage and remobilization from soil and unsaturated zone, limited or absence of degradation, sorption in saturated zones, or to continuing illegal applications. In order to address this problem and to determine triazine distribution in the saturated zone, their occurrence is investigated in the light of the aquifer hydrodynamic on the basis of a geochemical approach using groundwater dating tracers (3H/3He). In this study, atrazine, simazine, terbuthylazine, deethylatrazine, deisopropylatrazine, and deethylterbuthylazine are measured in 66 samples collected between 2011 and 2013 from 21 sampling points, on the Vistrenque shallow alluvial aquifer (southern France), covered by a major agricultural land use. The frequencies of quantification range from 100 to 56xa0% for simazine and atrazine, respectively (LQxa0=xa01xa0ngxa0L−1). Total triazine concentrations vary between 15 and 350xa0ngxa0L−1 and show three different patterns with depth below the water table: (1) low concentrations independent of depth but related to water origin, (2) an increase in concentrations with depth in the aquifer related to groundwater residence time and triazine use prior to their ban, and (3) relatively high concentrations at low depths in the saturated zone more likely related to a slow desorption of these compounds from the soil and unsaturated zone. The triazine attenuation rate varies between 0.3 for waters influenced by surface water infiltration and 4.8 for water showing longer residence times in the aquifer, suggesting an increase in these rates with water residence time in the saturated zone. Increasing triazine concentrations with depth is consistent with a significant decrease in the use of these pesticides for the last 10xa0years on this area and highlights the efficiency of their ban.

Assessment of poly-L-lysine dendrigrafts for virus concentration in water: use of MS2 bacteriophage as proof of concept.

Virus detection has often been difficult due to a low concentration in water. In this study, we developed a new procedure based on concentration of virus particles on an innovative support: poly‐l‐lysine dendrigrafts (DGL), coupled with directed nucleic acid extraction and real‐time PCR quantification.

Impact of biochemical design on estrogen receptor/estrogen response element interaction by surface plasmon resonance technology

The estrogen receptor (ER) is a transcription factor that binds under 17-β-estradiol (E2) stimulation as homodimer to a short DNA consensus sequence named estrogen response element (ERE). The ER/ERE interaction has been assessed by several research groups through different methodologies notably by surface plasmon resonance (SPR) techniques. The biochemical parameters and conditions (solvent, ER concentration, salt, time and temperature) used to prepare samples before analysis were very different from one study to another. But no studies have aimed to compare the effect of these modifications on ER/ERE interaction. Therefore the main objective of the present paper was to assess the influence of biochemical parameters onto the ER/ERE interaction with the final aim to improve the comprehension of this interaction. Our results highlighted that parameters like solvent, ER concentration, salt and surfactant concentration, temperature and time deeply modify ER/ERE interaction. Nevertheless, the dimer formation under E2 stimulation occurred with all tested conditions. Altogether, incubation parameters of ER with E2, deeply modify its binding level onto ERE. These data constitute an important key point to consider for the improvement of ER/ERE detection method depending upon the aim of the study (interaction measurement, environmental detection, development of new technologies or devices).

Automatic and predictive fractionation of organic micropollutants in contaminated water

Environmental context The safeguarding of water supplies and drinking water is a major issue when considering human health risk management. In this context, an automatic and on-site fractionation system for the detection of organic contaminants has been developed. The main goal of this system is to establish an initial diagnosis by identifying a class of substances involved in a case of pollution. Abstract This paper proposes a new approach for the preconcentration, fractionation, prediction and detection of organic micropollutants in water. The main aim of this study was to implement an innovative fractionation method and a prediction model based on the physicochemical properties of compounds and interactions with the sorbent of solid-phase extraction cartridges. Two sorbents (Strata-SAX and Oasis-HLB) and three specific eluting solvents (mixture of methanol and sodium chloride and mixtures of acetonitrile and ultrapure water) were used to separate organic compounds into five specific fractions according to their physicochemical properties (anionic and cationic or neutral compounds with various polarity). More than 75 molecules (43 molecules individually studied and a mixture with 43 molecules, including 11 molecules individually studied) including pesticides, pharmaceuticals, endocrine disruptors and polycyclic aromatic hydrocarbons, with various properties were studied, and the results showed that the elution fraction can be predicted for more than 85% of the compounds. This methodology could simplify the analytical chain by reducing detailed analysis on limited categories of compounds, and could be used for a rapid and on-site screening of organic compounds.

Dynamics and sources of pharmaceutically active compounds in a coastal Mediterranean river during heavy rains

Concentrations of pharmaceutically active compounds (PACs) in freshwater systems depend on numerous factors such as land use and hydrometeorological conditions. In the Mediterranean, heavy rain events are of particular importance as they highly influence the concentration of micropollutants found in freshwater and are a source of recurrent first foul flushes due to combined sewer overflows (CSOs). In this study, we seek to assess the dynamics of pharmaceuticals during storm events in coastal Mediterranean rivers at a fine scale and to determine their contribution to multicontamination phenomena owing to CSOs. Our results showed that, while dissolved PACs followed the same trend as other contaminants, i.e., they increased significantly during CSOs, PACs in the total fraction did not peak yet maintained their already high concentrations for slightly longer due to their release via CSOs. Pharmaceutical concentrations for both the dissolved and the total fraction were dramatically diluted during the peak river flow. A fine-scale follow-up of PACs dynamics in the total fraction, including the differentiation of sewer overflows from both the right and left river banks, as well as the analyses of a large amount of PACs molecules, allowed us to clearly identify their major sources. While domestic inputs were dominated by nicotine and caffeine, the use of gadolinium (an MRI contrast agent) as a marker, attributed the main source of medical drugs such as tramadol, ibuprofen, and diclofenac to the major public hospital of the region. Thus, identifying major sources of PACs and implementing adapted water treatments directly at those sources would be the most cost-efficient alternative to cope with pharmaceutical drugs in coastal Mediterranean aquatic environments. Moreover, PACs behavior differed depending on the molecules considered and the source of these molecules, but we could not establish a direct link between their behavior and their chemical or physical properties. Our study highlights the importance of monitoring at strategic locations and with a high frequency sampling in order to better understand fate, sources, and behavior of pharmaceuticals in aquatic environments.

Estrogen receptor preparation effects on the receptor–DNA interaction by surface plasmon resonance

Up to now, several studies have investigated estrogen receptor (ER)–estrogen response element (ERE) interaction using biosensors such as surface plasmon resonance. These strategies have aimed to understand the molecular mechanism of such interaction as well as the effect of the ligand on this interaction. These approaches start to be used to determine the mechanisms of protein/DNA interaction, in particular in the context of drug discovery or environmental applications. However, some physical and biochemical parameters (incubation time, temperature, protease inhibitor cocktail, and bovine serum albumin (BSA)) are not completely described in the literature and could deeply modify the obtained results. This paper aims to focus not only on the preliminary steps of sample preparation such as protein thawing and incubation conditions (time and temperature) but also on the evaluation of protease inhibitor cocktail and BSA effect on the measurement of ER–ERE interactions.