HAL du Programme national de recherche environnement-santé-travail (PNR EST)
Not a member yet
917 research outputs found
Sort by
Repeated exposure to low doses of light induces retinal damage in vivo in a wavelength-dependent manner
No full textInternational audienceThe exposure of the general population to artificial light at night has dramatically increased in recent decades. Current standards for domestic lighting are based on acute exposure to light and consider blue wavelengths to be responsible for phototoxicity. However, meta-analyses pointed out the role of lifelong light exposure in the onset of age-related macular degeneration, suggesting a cumulative effect of light exposure. Here, we investigate the retinal phototoxicity of a repeated exposure to light emitting diodes of different spectral compositions in 6-week-old albino rats. Rats were exposed twice a day for 15 days to retinal doses that were safe in acute exposure (0.1 and 0.2 J/cm² for blue and white lights, 0.2 J/cm² for green light and 0.05 J/cm² for red light). We show that rats repeatedly exposed to blue and white lights display irreversible retinal damage, characterized by a degradation of the global retinal structure, a significant photoreceptor loss, and an increase of stress and inflammation markers. We highlight the role of green wavelengths in the phototoxicity of white light and show the protective effect of the addition of red light to mitigate the phototoxicity of blue light. All of this points out the need to rethink the current phototoxicity standards by taking into account the cumulative effect of the exposure to light and the role of the different parts of the emission spectrum
Multi-organ toxicity of ultrafine particles derived from air pollution: a sub-chronic exposure study in mice
No full textInternational audienc
Environmental yeasts differentially impact the development and oviposition behavior of the Asian tiger mosquito Aedes albopictus
No full textInternational audienceBackgroundWhile the Asian tiger mosquito (Aedes albopictus), a known vector of many arboviruses, establishes symbiotic associations with environmentally acquired yeasts, their impact on mosquito biology remains poorly investigated. To better understand these associations, we hypothesized that waterborne yeasts colonizing the larval gut differentially support mosquito development based on their capacity to produce riboflavin or recycle nitrogen waste into proteins by secreting uricase, as B vitamins and amino acids are crucial for mosquito development. To address this hypothesis, we used axenic and gnotobiotic insects to gauge the specific impact of different environmental yeasts on Ae. albopictus development and survival. We then evaluated whether the observed variations across yeast species could be linked to differential uricolytic activities and varying quantities of riboflavin and proteins in insecta. Finally, given that mosquito oviposition site selection favors conditions that enhance offspring performance, we tested whether yeasts that promote faster development mediate oviposition site selection by gravid females.ResultsDifferences in mosquito development times were observed based on the environmental yeast used. Yeasts like Rhodotorula mucilaginosa and Aureobasidium pullulans promoted rapid development and were associated with improved survival. Conversely, yeasts such as Torulaspora delbrueckii and Martiniozyma asiatica, which led to slower development, produced smaller adults. Notably, R. mucilaginosa, which promoted the fastest development, provided high riboflavin intakes and enhance nitrogenous waste recycling and protein synthesis through strong uricolytic-ureolytic activity. Behavioral experiments indicated that yeasts promoting rapid development "attract gravid females.ConclusionsOur findings highlight that a set of environmental yeasts present in natural larval breeding sites can be associated with improved mosquito development and survival by enhancing nutritional intake, thereby attracting gravid females. Variations in mosquito development time are likely linked to the differential levels of riboflavin production and nitrogenous waste recycling capacities among yeast species. This study opens new perspectives on the trophic interactions between mosquitoes and their mycobiota, emphasizing the importance of nitrogen-containing molecules such as essential amino acids, proteins, or vitamins provided by the mycobiota.6Ua-1ziLwgU49kVNDSxHywVideo AbstractConclusionsOur findings highlight that a set of environmental yeasts present in natural larval breeding sites can be associated with improved mosquito development and survival by enhancing nutritional intake, thereby attracting gravid females. Variations in mosquito development time are likely linked to the differential levels of riboflavin production and nitrogenous waste recycling capacities among yeast species. This study opens new perspectives on the trophic interactions between mosquitoes and their mycobiota, emphasizing the importance of nitrogen-containing molecules such as essential amino acids, proteins, or vitamins provided by the mycobiota.6Ua-1ziLwgU49kVNDSxHywVideo Abstrac
Multigenerational effects of nanoplastics on life-history traits and physiological responses in Drosophila melanogaster
No full textInternational audienceThe ubiquitous presence of nanoplastics (NP) in the environment has emerged as a global concern. Their impacts have been mostly studied in aquatic ecosystems and species, and more recently, in terrestrial species. In addition, the toxicity of NP on organisms exposed continuously to this pollutant and over multiple generations remains poorly considered. Our study focused on the effects of chronic exposure of a polydisperse mix of polystyrene NP (20, 80, and 200 nm) on the fruit fly Drosophila melanogaster to four NP concentrations (0, 1, 100, and 500 μg NP.g-1 of food) over 10 generations. Their toxicity was assessed at the first (F1) and tenth (F10) generations by evaluating phenotypic (viability, development time, body size and body weight) and physiological responses, through enzyme activities related to oxidative stress and the expression of specific target genes (e.g. apoptosis, immunity). Our results showed a decrease in organisms' key traits in the first and tenth generations, with a reduced viability and body size. Additionally, superoxide dismutase (SOD) activity was altered, with a decrease observed in the F1 generation, followed by an increase in F10, in flies exposed to 500 μg NP.g-1. Finally, the expressions of target genes involved in apoptosis and immune responses were either up- or down-regulated, depending on the generation. These results highlighted the effects NP can have on life-history or physiological traits without higher effect across generations. In addition, the study reveals the complex response across generation and highlights the importance to study long-term exposure
Meet-in-the-middle meets multi-omics identifying molecular signatures of environmental drivers of childhood overweight
No full textInternational audienceBackground: Obesity is a multi-cause chronic disease recognized across the lifespan, with childhood obesity prevalence rising over the past decades. Although exposome-wide association studies have identified early-life environmental drivers of child obesity, and explored the multi-omics signatures of the exposome of children, it is understudied whether the combined effects of multiple exposures are potentially mediated by multi-omics.Methods: Within the Human Early Life Exposome (HELIX) project, 1041 mother–child pairs were surveyed for a wide range of environmental exposures including over 354 prenatal and childhood exposures. Multi-omics molecular features were measured during childhood, encompassing the blood methylome and transcriptome, plasma proteins and urinary and serum metabolites. Exposome and multi-omics features were integrated into latent factors by Multi-omics Factor Analysis, based on which structural equation modelling was used to assess whether multi-omics mediated associations between exposome and child body mass index (BMI).Results: Key findings included: (i) prenatal nutrition, exercise, and passive smoking influencing BMI via DNA methylation of HOXA5 and Tenascin XB; (ii) childhood exposure to PCBs and phenols linked with BMI through inflammation and coagulation pathways; and (iii) childhood PCB and dietary exposures associated with BMI via immune pathways.Conclusions: This novel untargeted workflow elucidated biological mechanisms linking environmental exposures to child obesity, potentially supporting targeted public health interventions
Polymorphisms in circadian rhythm genes and the risk of differentiated thyroid cancer
No full textInternational audienceIntroduction: Circadian rhythms are controlled by biological clocks regulated at the molecular level by a set of circadian genes operating through a negative feedback loop. These genes also regulate key biological processes, including cell proliferation, cell cycle, and apoptosis. Methods: We investigated the role of circadian gene polymorphisms in the risk of differentiated thyroid cancer (DTC) and their interaction with DTC risk factors. Data were obtained from 463 DTC cases and 482 unrelated controls of European ancestry, selected from two population-based case-control studies conducted in France. Associations with 570 single nucleotide polymorphisms (SNPs) in 23 circadian genes were evaluated using multivariate logistic regression models. Gene- and pathway-level associations and gene–environment interactions were analyzed using the adaptive rank truncated product (ARTP) method. Results and discussion: We found no significant association between DTC risk and circadian gene polymorphisms at the SNP, gene, or pathway levels. However, we observed statistically significant interactions between smoking status and SNPs rs11204897 ( RORC ) and rs1012477 ( PER3 ), as well as with the PER3 gene and the overall circadian pathway. These results suggest that smoking status may modulate the association between DTC and polymorphisms in circadian genes. Further studies are needed to confirm these findings
Zebrafish exposed to a cocktail of pesticides during early development display long-lasting neurobehavioral alterations
No full textInternational audienceThe widespread use of pesticides is increasing the presence of environmental contaminants with potential impacts on biodiversity, ecosystems, and human health. Although long-term pesticide effects have been previously studied, the long-term impact of an acute pesticide exposure during critical early developmental periods remains poorly understood. Here, we used zebrafish to examine whether acute exposure to a pesticide mixture at 0.5 μg/L (the maximum allowed in drinking water) during the first 5 days post-fertilisation (dpf) of development has lasting effects at 28 dpf. Zebrafish were assessed behaviourally, morphologically, and molecularly both immediately after exposure at 5 dpf and later at 28 dpf. Our results show alterations in stress-response that start to emerge right after the developmental exposure and are associated with a less anxious-like phenotype at juvenile stages. Interestingly, despite the observed behavioural phenotype at 28 dpf, it did not lead to significant molecular changes in the hypothalamic-pituitary-interrenal (HPI) axis at this stage. On the contrary, a positive control group of juvenile fish subjected to a sustained pesticide exposure throughout the 28 dpf showed both reduced anxiety-like behaviour and HPI alterations. Our study suggests that even an acute exposure to a low-concentration of pesticides during critical developmental periods can result in enduring behavioural changes
Early-life exposure to mixture of phenols and respiratory health in pre-school children
No full textInternational audienceIntroduction: Exposure to synthetic phenols is suspected of affecting child respiratory health, but epidemiological findings are not consistent and studies on exposure during infancy are lacking. We aimed to investigate the association between exposure to a mixture of phenols in pregnancy and in infancy and children's respiratory health.Methods: Among 363 mother-child pairs from the SEPAGES cohort, twelve phenols were measured in weekly-pooled urine samples collected twice during pregnancy (second (T2) and third (T3) trimesters) and in infancy (2 months (M2) and 1 year (Y1)). Children's lung function was assessed through tidal breathing flow-volume loops and nitrogen multiple-breath washout at M2, and standard and intra-breath oscillometry at 3 years. Time-specific phenol exposure profiles were identified through cluster analysis and then studied in association with respiratory health using adjusted regression models.Results: Two exposure profiles were identified at each point in time, characterized by low versus high levels of several phenol compounds. Overall, high exposure profiles were associated with altered oscillometry parameters at 3 years, particularly between high exposure profile at T2 and higher frequency-dependence of resistance (R7–19) and lower volume-dependence of reactance (ΔX); high exposure profile at M2 and lower reactance at 7 Hz (X7), and high exposure at Y1 and higher area of the reactance curve (AX), resistance at 7 Hz (R7), and volume-dependence of resistance (ΔR).Conclusion: This study relying on repeated and accurate assessments of phenols exposure provides evidence of the deleterious effects of early-life exposures to a mixture of phenols on lung function in pre-school children
Levels and determinants of exposure to perfluoroalkyl substances in French pregnant women from the SEPAGES cohort
No full textInternational audienceBackground: Identifying the primary determinants of exposure to contaminants such as poly-and perfluoroalkyl substances (PFAS) is essential for establishing efficient regulations. We aimed to identify determinants of serum PFAS during pregnancy, a sensitive exposure window. Methods: This study relied on 450 pregnant women enrolled in a French cohort from 2014 to 2017. Sociodemographic, diet, water consumption and lifestyle factors were collected through questionnaires. Twenty-six PFAS were measured in maternal serum collected around 19 weeks of gestation (median). Multivariable linear or multinomial regressions were used to study the associations between determinants and individual PFAS, as well as with a three-category variable derived from clustering (categories representing women with the lowest (N = 163), moderate (N = 236) and highest (N = 51) concentration). Results: Seven PFAS were quantified in 83 % or more of the samples, while the remaining PFAS were quantified in less than 20 %. The highest median concentrations were observed for PFOS (3.95 ng/mL), PFOA (1.02 ng/mL) and PFHxS (0.69 ng/mL). Maternal age was positively associated with all PFAS, and parous women had lower levels of PFOA, PFNA, PFHxS, PFOS and PFHpS than nulliparous. Fish and liver consumption were consistently and positively associated with PFUnDA, PFDA and PFNA. Use of hormonal contraception was found to be associated with a higher PFOA concentration, where a high level of education (5 years after high school) was associated with higher PFUnDA and PFDA levels. Multinomial models on clusters of PFAS exposures showed the same associations for maternal characteristics. Conclusion: Among the factors associated with higher PFAS concentrations in our cohort, those related to the consumption of specific food items may offer actionable levers to reduce exposure. Strengthened regulatio
Skin Fibroblasts from Individuals Self-Diagnosed as Electrosensitive Reveal Two Distinct Subsets with Delayed Nucleoshuttling of the ATM Protein in Common
No full textInternational audienceElectromagnetic hyper-sensitivity (EHS) and its causal link with radio-frequencies raise a major question of public health. In the frame of the clinical study DEMETER, 26 adult volunteers self-diagnosed as EHS-positive agreed to reply to a self-assessment questionnaire and to provide a skin biopsy sampling to establish a primary fibroblast cell line. The questionnaire and the biological data revealed, independently, 2 subsets of donors associated each with a low background, highly responsive (LBHR) and a high background, lowly responsive (HBLR) phenotype. A couple of subsets based on questionnaire data and based on the yield of spontaneous DNA double-strand breaks were found to be composed of the same donors at 64% identity. After exposure to X-rays, and application of anti-γH2AX, pATM, and MRE11 immunofluorescence, all the DEMETER fibroblasts (26/26) elicited a delayed radiation-induced ATM nucleoshuttling (RIANS). The use of RIANS biomarkers showed that the 2 phenotypes described above corresponded to DEMETER donors with a high risk of cancer (LBHR) or high risk of accelerated aging (HBLR). By exposing DEMETER cells to H2O2 followed by an antioxidative agent, we confirmed that EHS may be related to the management of DNA strand breaks. A preliminary molecular model of EHS inspired by the RIANS model was proposed