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Bioécologie

Articles avec #ecotoxicologie

Neurodevelopmental Disorders and Prenatal Residential Proximity to Agricultural Pesticides: The CHARGE Study

3 Février 2016,

Publié par Bioécologie

By Janie F. Shelton, Estella M. Geraghty, Daniel J. Tancredi, Lora D. Delwiche, Rebecca J. Schmidt, Beate Ritz, Robin L. Hansen, and Irva Hertz-Picciotto. June 2014.

  • Background: Gestational exposure to several common agricultural pesticides can induce developmental neurotoxicity in humans, and has been associated with developmental delay and autism.

    Objectives: We evaluated whether residential proximity to agricultural pesticides during pregnancy is associated with autism spectrum disorders (ASD) or developmental delay (DD) in the Childhood Autism Risks from Genetics and Environment (CHARGE) study.

    Methods: The CHARGE study is a population-based case–control study of ASD, DD, and typical development. For 970 participants, commercial pesticide application data from the California Pesticide Use Report (1997–2008) were linked to the addresses during pregnancy. Pounds of active ingredient applied for organophophates, organochlorines, pyrethroids, and carbamates were aggregated within 1.25-km, 1.5-km, and 1.75-km buffer distances from the home. Multinomial logistic regression was used to estimate the odds ratio (OR) of exposure comparing confirmed cases of ASD (n = 486) or DD (n = 168) with typically developing referents (n = 316).

    Results: Approximately one-third of CHARGE study mothers lived, during pregnancy, within 1.5 km (just under 1 mile) of an agricultural pesticide application. Proximity to organophosphates at some point during gestation was associated with a 60% increased risk for ASD, higher for third-trimester exposures (OR = 2.0; 95% CI: 1.1, 3.6), and second-trimester chlorpyrifos applications (OR = 3.3; 95% CI: 1.5, 7.4). Children of mothers residing near pyrethroid insecticide applications just before conception or during third trimester were at greater risk for both ASD and DD, with ORs ranging from 1.7 to 2.3. Risk for DD was increased in those near carbamate applications, but no specific vulnerable period was identified.

    Conclusions: This study of ASD strengthens the evidence linking neurodevelopmental disorders with gestational pesticide exposures, particularly organophosphates, and provides novel results of ASD and DD associations with, respectively, pyrethroids and carbamates.

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La Mort est dans le pré

2 Décembre 2015,

Publié par Bioécologie

Dans son film, Eric Gueret enquête sur les conséquences de l'utilisation de pesticides pouvant provoquer des maladies graves chez les agriculteurs. Il montre comment et pourquoi les paysans tombent malades à cause des produits phytosanitaires utilisés au quotidien sur leurs terres.

Constraints to adaptation: The “oily guppies” of southern Trinidad

10 Novembre 2015,

Publié par Bioécologie

This post is from Gregor Rolshausen

Arguably, among the most interesting shifts in evolutionary thinking in the past decades is an increased recognition of the limits on rates, directions, and outcomes of evolution. For instance, classic expectations of the adaptive process, such as trait divergence between environments and higher fitness of local vs. non-local individuals, are often not met in natural populations. Effective local adaptation might be hampered by migration and maladaptive gene flow that drags population away from local fitness peaks. Furthermore, instances of (local) maladaptation appear to be particularly pronounced in the context of abrupt and extensive anthropogenic disturbance such as climate change, habitat fragmentation, or pollution. An understanding of the constraints to evolutionary dynamics on the population level therefore needs to become an important cornerstone of ongoing conservation efforts and biodiversity management plans. I here review a recent empirical study from the Hendry lab that investigates constraints to local adaptation in natural fish populations and reveals some interesting contradictions to classical expectations of local adaptation: the “oily guppies” (Poecilia reticulata) of southern Trinidad – a system in which severe crude-oil pollution has a strong impact on the condition of seemingly locally adapted populations.

More information here

Taira Y, Hayashida N, Tsuchiya R, Yamaguchi H, Takahashi J, et al. (2013) Vertical Distribution and Estimated Doses from Artificial Radionuclides in Soil Samples around the Chernobyl Nuclear Power Plant and the Semipalatinsk Nuclear Testing Site. PLoS ONE 8(2): e57524.

23 Juin 2015,

Publié par Bioécologie

Des îles de déchets ?

19 Juin 2015,

Publié par Bioécologie

"Les courants océaniques subtropicaux portent des déchets qui viennent former une concentration d’amas de plastiques dans le Pacifique Nord. Appelés îles des déchets ou septième continent, ils ne constituent pas une masse solide mais une zone où la mer est saturée par les débris plastiques. L'émission de télévision, le Dessous des Cartes, explore ce symbole du dérèglement de notre monde."

Source : Arte - Le dessous des cartes - Février 2011.

Przewalski's Horses in Chernobyl

15 Mai 2015,

Publié par Bioécologie

The rare and endangered Przewalski's Horse was introduced to the Chernobyl Zone following the nuclear disaster. Here is an aerial view taken using a DGI Phantom 2 Vision Plus V.3.

Pr. Tim Mousseau and these colleagues just completed a census of the population which will be published later this year.

Serum microRNAs are early indicators of survival after radiation-induced hematopoietic injury

14 Mai 2015,

Publié par Bioécologie

Indicating Radiation Injury. Three Mile Island, Chernobyl, and Fukushima were catastrophic nuclear power plant accidents. The radiation from these accidents not only took an immediate toll on human lives, but will also persist long-term, as individuals will suffer from cancer, gut damage, and infections. On the cover, engineers at the Fukushima Daiichi Nuclear Power Plant fix the "ice wall" to reduce radiation-contaminated water from entering clean groundwater, and thus protect people from future radiation injury. In another effort to protect human health, Acharya et al. identified microRNAs associated with hematopoietic damage and long-term survival in mice exposed to different sublethal doses of total body irradiation. Such RNA signatures may distinguish humans with mild radiation-related injury from those with more severe (often nonrecoverable) bone marrow damage. Studies with human samples will allow for validation of such indicators, as well as investigation into new intervention measures, to improve patient care and to enhance survival after radiation exposure. [CREDIT: K. MAYAMA/EPA/CORBIS]
Indicating Radiation Injury. Three Mile Island, Chernobyl, and Fukushima were catastrophic nuclear power plant accidents. The radiation from these accidents not only took an immediate toll on human lives, but will also persist long-term, as individuals will suffer from cancer, gut damage, and infections. On the cover, engineers at the Fukushima Daiichi Nuclear Power Plant fix the "ice wall" to reduce radiation-contaminated water from entering clean groundwater, and thus protect people from future radiation injury. In another effort to protect human health, Acharya et al. identified microRNAs associated with hematopoietic damage and long-term survival in mice exposed to different sublethal doses of total body irradiation. Such RNA signatures may distinguish humans with mild radiation-related injury from those with more severe (often nonrecoverable) bone marrow damage. Studies with human samples will allow for validation of such indicators, as well as investigation into new intervention measures, to improve patient care and to enhance survival after radiation exposure. [CREDIT: K. MAYAMA/EPA/CORBIS]

S. S. Acharya, W. Fendler, J. Watson, A. Hamilton, Y. Pan, E. Gaudiano, P. Moskwa, P. Bhanja, S. Saha, C. Guha, K. Parmar, D. Chowdhury, Serum microRNAs are early indicators of survival after radiation-induced hematopoietic injury. Sci. Transl. Med. 7, 287ra69 (2015).

Abstract

Accidental radiation exposure is a threat to human health that necessitates effective clinical planning and diagnosis. Minimally invasive biomarkers that can predict long-term radiation injury are urgently needed for optimal management after a radiation accident. We have identified serum microRNA (miRNA) signatures that indicate long-term impact of total body irradiation (TBI) in mice when measured within 24 hours of exposure. Impact of TBI on the hematopoietic system was systematically assessed to determine a correlation of residual hematopoietic stem cells (HSCs) with increasing doses of radiation. Serum miRNA signatures distinguished untreated mice from animals exposed to radiation and correlated with the impact of radiation on HSCs. Mice exposed to sublethal (6.5 Gy) and lethal (8 Gy) doses of radiation were indistinguishable for 3 to 4 weeks after exposure. A serum miRNA signature detectable 24 hours after radiation exposure consistently segregated these two cohorts. Furthermore, using either a radioprotective agent before, or radiation mitigation after, lethal radiation, we determined that the serum miRNA signature correlated with the impact of radiation on animal health rather than the radiation dose. Last, using humanized mice that had been engrafted with human CD34+ HSCs, we determined that the serum miRNA signature indicated radiation-induced injury to the human bone marrow cells. Our data suggest that serum miRNAs can serve as functional dosimeters of radiation, representing a potential breakthrough in early assessment of radiation-induced hematopoietic damage and timely use of medical countermeasures to mitigate the long-term impact of radiation.