The Effective Vertical Anisotropy of Layered Aquifers.

Many sedimentary aquifers consist of small layers of coarser and finer material. When groundwater flow in these aquifers is modeled, the hydraulic conductivity may be simulated as homogeneous but anisotropic throughout the aquifer. In practice, the anisotropy factor, the ratio of the horizontal divided by the vertical hydraulic conductivity, is often set to 10.

Chronic exposure to drinking water nitrate and trihalomethanes in the French CONSTANCES cohort.

Trihalomethanes (THMs) and nitrate are widespread chemicals in drinking water. Chronic exposure has been associated with increased cancer risk despite inconclusive evidence, partly due to the challenges in long-term exposure assessment and potential exposure misclassification. We estimated concentrations of nitrate and THMs in drinking water using a public regulatory monitoring database (SISE-Eaux) for CONSTANCES, a French population-based prospective cohort.

Biocide and other semi-volatile organic compound concentrations in settled indoor dust of CRESPI daycare centers and implication for public health.

This study investigates the presence of biocides and other semi-volatile organic compounds (SVOCs) in cleaning products used in daycare centers and health impact through ingestion of settled dust by young children. In Paris metropolitan area, 106 daycares area were investigated between 2019-2022. Fifteen substances were analyzed in settled indoor dust by gas chromatography-tandem mass spectrometry.

Characterization of organic contaminants in hair for biomonitoring purposes.

Biological monitoring is one way to assess human exposure to contaminants. Blood and urine are often used as biological matrices, but hair is an innovative and effective tool for quantifying more biomarkers over a wider exposure window. In order to improve the use of hair in exposure assessment, this article identifies relevant compounds in the literature to investigate hair contamination.

Meconium Concentrations of Pesticides and Risk of Hypospadias: A Case-Control Study in Brittany, France.

Background: Hypospadias is a male genital tract defect for which an increase in prevalence has been documented over the last few decades. A role for environmental risk factors is suspected, including prenatal exposure to pesticides.

Objectives: To study the risk of hypospadias in association with multiple pesticide measurements in meconium samples.

Exposure to Disinfectants and Cleaning Products and Respiratory Health of Workers and Children in Daycares: The CRESPI Cohort Protocol.

Although cleaning tasks are frequently performed in daycare, no study has focused on exposures in daycares in relation to respiratory health. The CRESPI cohort is an epidemiological study among workers (n~320) and children (n~540) attending daycares. The purpose is to examine the impact of daycare exposures to disinfectants and cleaning products (DCP) on the respiratory health of workers and children.

Serum persistent organic pollutants and diminished ovarian reserve: a single-exposure and mixture exposure approach from a French case-control study.

Study Question: Are persistent organic pollutants (POPs) associated with a diminished ovarian reserve (DOR) in women of reproductive age?

Summary Answer: Amongst 17 POPs detected in over 20% of serum samples, only p,p'-DDE was significantly associated with an increased risk of DOR, and β-hexachlorocyclohexane (β-HCH) was significantly associated with a decreased risk of DOR whilst mixture analyses yielded non-significant associations and did not detect any interactions between POPs.

What Is Known Already: Animal studies have shown that several POPs can alter folliculogenesis and increase follicle depletion. However, only a few studies have been conducted in humans, with small sample sizes and inconsistent results.

Determination of glyphosate and AMPA in indoor settled dust by hydrophilic interaction liquid chromatography with tandem mass spectrometry and implications for human exposure.

The widespread application of glyphosate leads to significant contamination of outdoor environmental compartments, notably air and soil, which can contaminate indoor air and dust. This study assessed the contamination of indoor household dust for the first time in France and potential exposure to glyphosate through the inadvertent ingestion of dust. A specific and new analytical method was developed using HILIC MS/MS (hydrophilic interaction liquid chromatography with tandem mass spectrometry) to measure polar pesticides, such as glyphosate, aminomethylphosphonic acid, and glufosinate, in indoor dust, with a low quantification limit (25 ng/g).

Insights into the molecular mechanisms of pesticide tolerance in the Aporrectodea caliginosa earthworm.

Diffuse pollution of the environment by pesticides has become a major soil threat to non-target organisms, such as earthworms for which declines have been reported. However some endogeic species are still abundant and persist in intensively cultivated fields, suggesting they become tolerant to long-term anthropogenic pressure. We thus considered the working hypothesis that populations of Aporrectodea caliginosa earthworms from conventionally managed fields developed a tolerance to pesticides compared with those from organically managed fields.

Characterization of multiple pesticide exposure in pregnant women in Brittany, France.

Background: France is one of the biggest users of pesticides in Europe and exposure to pesticides is a current concern, especially when it occurs early in life.

Objective: The aim of this study was to assess the exposure of pregnant women in Brittany (western France) with high pesticide use.

Methods: The pesticides were selected according to agricultural practices.

Infant neurodevelopment and behavior in Guadeloupe after lead exposure and Zika maternal infection during pregnancy.

Background: Prenatal lead exposure is known to have neurotoxic effects on the developing fetus, while some viral infections may have a tropism for the central nervous system. Our objective was to study whether the effects of prenatal lead exposure on infant development and behaviors at 18 months of age are modified by the occurrence of a maternal infection to Zika virus (ZIKV) during pregnancy.

Methods: During the ZIKV epidemic in Guadeloupe in 2016 a cohort of pregnant women was set up.

Pre- and post-natal exposure of children to organophosphate flame retardants: A nationwide survey in France.

The use of organophosphate flame retardants (OPFRs) has been on the rise ever since many brominated flame retardants were banned, back in the 2000 s. The objectives of this study are to describe the pre- and post-natal exposure of children to OPFRs, and to explore their possible determinants. A total of 259 children aged 3.

Disentangling personalized treatment effects from "time-of-the-day" confounding in mobile health studies.

Ideally, a patient's response to medication can be monitored by measuring changes in performance of some activity. In observational studies, however, any detected association between treatment ("on-medication" vs "off-medication") and the outcome (performance in the activity) might be due to confounders. In particular, causal inferences at the personalized level are especially vulnerable to confounding effects that arise in a cyclic fashion.

High lead level in the Alps in XIXth century, learning from the analysis of 138 historical hair stands.

Analysis of hair is known to provide useful information about environmental and toxic exposures. Very little historical use has been made of this type of investigation. Here we study 138 human hair samples from 19th century in France.

Remote smartphone monitoring of Parkinson's disease and individual response to therapy.

Remote health assessments that gather real-world data (RWD) outside clinic settings require a clear understanding of appropriate methods for data collection, quality assessment, analysis and interpretation. Here we examine the performance and limitations of smartphones in collecting RWD in the remote mPower observational study of Parkinson's disease (PD). Within the first 6 months of study commencement, 960 participants had enrolled and performed at least five self-administered active PD symptom assessments (speeded tapping, gait/balance, phonation or memory).

Pre-conception serum ferritin concentrations are associated with metal concentrations in blood during pregnancy: A cohort study in Benin.

Background: Iron deficiency is a common nutritional deficiency that impacts maternal health and fetal development and is also associated with increased uptake of toxic metals. Women in sub-Saharan Africa are highly exposed to both iron deficiency and metals in the environment. As research on the developmental origins of health and disease increasingly shows impacts of pre-conception maternal health on pregnancy and fetal health, these environmental exposures are of concern.

The Isotopic Signature of Lead Emanations during the Fire at Notre Dame Cathedral in Paris, France.

When Notre Dame de Paris cathedral caught fire on 15 April 2019, lead particles were deposited in its surroundings. Our objective was to determine whether the lead plume had a homogeneous isotopic signature (i.e.

Improving Exposure Assessment Using Non-Targeted and Suspect Screening: The ISO/IEC 17025: 2017 Quality Standard as a Guideline.

The recent advances of novel methodologies such as non-targeted and suspect screening based on high-resolution mass spectrometry (HRMS) have paved the way to a new paradigm for exposure assessment. These methodologies allow to profile simultaneously thousands of small unknown molecules present in environmental and biological samples, and therefore hold great promises in order to identify more efficiently hazardous contaminants potentially associated with increased risks of developing adverse health outcomes. In order to further explore the potential of these methodologies and push the transition from research applications towards regulatory purposes, robust harmonized quality standards have to be implemented.

Semivolatile organic compounds in French schools: Partitioning between the gas phase, airborne particles and settled dust.

The indoor environmental quality in classrooms can largely affect children's daily exposure to indoor chemicals in schools. To date, there has not been a comprehensive study of the concentrations of semivolatile organic compounds (SVOCs) in French schools. Therefore, the French Observatory for Indoor Air Quality (OQAI) performed a field study of SVOCs in 308 nurseries and elementary schools between June 2013 and June 2017.

Assessment of the research program's informed consent process.

Informed consent is the gateway to research participation. We report on the results of the formative evaluation that follows the electronic informed consent process for the Research Program. Of the nearly 250,000 participants included in this analysis, more than 95% could correctly answer questions distinguishing the program from medical care, the voluntary nature of participation, and the right to withdraw; comparatively, participants were less sure of privacy risk of the program.

Toward setting public health guidelines for chemicals in indoor settled dust?

Indoor settled dust may result in substantial human exposure to chemicals, especially by ingestion following hand-to-mouth or hand-to-object-to-mouth contact. As with other environmental media related to exposure, dust may thus be subject to regulation. An international scientific workshop was convened in Paris in September 2019 firstly to assess the relevance for public health of setting guidelines for indoor settled dust, and secondly to discuss scientific and technical challenges related to such guidelines.

Organophosphorus Flame Retardants: A Global Review of Indoor Contamination and Human Exposure in Europe and Epidemiological Evidence.

We aimed to identify high-priority organophosphorus flame retardants for action and research. We thus critically reviewed literature between 2000 and 2019 investigating organophosphorus flame retardants' presence indoors and human exposure in Europe, as well as epidemiological evidence of human effects. The most concentrated compounds indoors were tris(2-butoxyethyl)phosphate (TBOEP), tris(1-chloro-2-propyl)phosphate (TCIPP), tris(2,3-dichloropropyl)phosphate (TDCIPP).

Evaluation of single-extraction methods to estimate the oral bioaccessibility of metal(loid)s in soils.

Incidental ingestion of polluted soil particles exposes the population to toxic metal(loid)s. To refine the methods of exposure and risk assessment, it is relevant to use bioaccessible concentrations of metal(loid)s determined via in vitro digestion methods. However, some validated methods are complex and costly, involving high technical skills and numerous reagents.

Emissions of VOCs, SVOCs, and mold during the construction process: Contribution to indoor air quality and future occupants' exposure.

Building materials and human activities are important sources of contamination indoors, but little information is available regarding contamination during construction process which could persist during the whole life of buildings. In this study, six construction stages on two construction sites were investigated regarding the emissions of 43 volatile organic compounds (VOCs), 46 semi-volatile organic compounds (SVOCs), and the presence of 4 genera of mold. Results show that the future indoor air quality does not only depend on the emissions of each building product but that it is also closely related to the whole implementation process.