Louise Vandelac

Hair manganese and hyperactive behaviors: pilot study of school-age children exposed through tap water.

Background Neurotoxic effects are known to occur with inhalation of manganese particulates, but very few data are available on exposure to Mn in water. We undertook a pilot study in a community in Québec (Canada) where naturally occurring high Mn levels were present in the public water system. Our objective was to test the hypothesis that greater exposure to Mn via drinking water would be reflected in higher Mn content in hair which, in turn, would be associated with increased level of hyperactive behaviors. Methods Forty-six children participated in the study, 24 boys and 22 girls, 6–15 years of age (median, 11 years). Their homes received water from one of two wells (W) with different Mn concentrations: W1: mean 610 μg/L; W2: mean 160 μg/L. The Revised Conners’ Rating Scale for parents (CPRS-R) and for teachers (CTRS-R) were administered, providing T-scores on the following subscales: Oppositional, Hyperactivity, Cognitive Problems/Inattention, and ADHD Index. Results Children whose houses were supplied by W1 had higher hair Mn (MnH) than those supplied by W2 (mean 6.2 ± 4.7 μg/g vs. 3.3 ± 3.0 μg/g, p = 0.025). MnH was significantly associated with T-scores on the CTRS-R Oppositional (p = 0.020) and Hyperactivity (p = 0.002) subscales, after adjustment for age, sex, and income. All children with Oppositional and Hyperactivity T-scores ≥ 65 had MnH > 3.0 μg/g. Conclusions The findings of this pilot study are sufficiently compelling to warrant more extensive investigations into the risks of Mn exposure in drinking water.

Toxic effects of PCDD/Fs mixtures on Eisenia andrei earthworms.

The earthworms Eisenia andrei were used to study the toxicity of PCDD/Fs mixtures to earthworms during 28 day of exposure. The experiments were performed on artificial soils contaminated with dioxins at levels of C1 (0.1 ng 2, 3, 7, 8-TCDD/g soil), C2 (1 ng 2, 3, 7, 8-TCDD/g soil) and C3 (1.5 ng 2, 3, 7, 8-TCDD/g soil). Effects of PCDD/Fs on survival, growth rate and immune responses; phagocytosis and NK-like cell activity, were determined. No mortality was observed at the lowest concentration (C1), while mortalities of 10 and 100% were noted at the highest concentrations tested C2 and C3, respectively. A significant reduction in growth rate was obtained at C2 and no effects at C1. Additionally, an inhibition of phagocytic activity and efficiency was observed at higher concentrations. In contrast, an enhancement of NK-like cell activity was shown at lower concentrations. Based on our results, we hypothesize that the PCDD/Fs mixtures tested at levels equal or higher to C2 (1 ng 2378-TCDD/g soil), lead to adverse effects on biotic potential and immune functions in E. andrei earthworms.

The International Team in NanosafeTy (TITNT): A Multidisciplinary group for an improvement of Nanorisk Assessment and Management

Nanotechnology allows the ability to design many new materials and devices with multiple applications, such as in medicine, electronics, and energy production. However, nanotechnology also raises several concerns about the toxicity and environmental impact of nanomaterials. A report published by the Council of Canadian Academies points out the necessity to respond about many uncertainties associated with risk assessment for ensuring the safety of health and environment. Nanotoxicology (or Nanosafety) is a part of the toxicology science that aims to study adverse effects of nanomaterials or nanoparticles on living organisms. This field includes different aspects from workers prevention to the environment protection. Group of researchers have initiated an international powerful interactive milieu for researchers to work in concert for a global and integrated study of many aspects of nanotoxicology. The International Team in NanosafeTy (TITNT) is composed of research scientists from 5 different countries (Canada, USA, Japan, France and Germany) working together on 6 different specific thematics, and organized as 9 different technology platforms (www.titnt.com). TITNT aims to study different features of nanomaterials related to nanosafety, such as in vivo and in vitro studies, life cycle, occupational protections and monitoring, early biomarkers detection, characterization and nanotoxicokinetic/dynamic assessment during and after nanoparticles synthesis and the societal, public policy and environmental aspects. While the rapid growth of nanotechnology is opening up a floodgate of opportunities, the legislation related is lagging behind mainly because of a lack of knowledge in the biosafety of most nanomaterials. The main goal of TITNT is to improve knowledge in nanosafety science for the benefit of the discipline, for better public policies and for the public itself.

L'« Enviropig » ou le dernier avatar transgénique de l'agrobusiness porcin

Quelle place occupe le guerir dans l’ecriture d’Helene Cixous ? Son dernier livre, Hyperreve, en amenant a s’interroger sur les temps ultimes, souleve paradoxalement cette question. Entre la mort toute recente de son ami Jacques Derrida et la presence du corps mourant de sa mere, Helene Cixous a situe le cadre et les conditions de son ecriture autobiographique.Ecrire et soigner le corps maternel mourant participent du meme geste qui tente d’approcher l’irremediable a venir, de le reintroduire dans le quotidien fait des promiscuites intolerables du reel. Ecrire pour venir doubler le corps maternel et tisser ainsi un premier linceul d’ecriture d’avant la mort elle-meme.Face a l’inexorable qui s’annonce, l’espace du reve ouvre une possibilite de « guerison » quand, un instant, vivants et morts se retrouvent. N’est-ce pas cette « guerison » de la mort qui constitue, face au reel, la voie ouverte par Hyperreve ?

Quand l’État confie la « protection » de la santé aux entreprises

Dans un premier temps, l’auteur accuse le ministere canadien de la Sante de travailler insidieusement au demantelement de la Direction generale de la protection de la sante pour dorenavant confier la responsabilite de veiller a la securite des aliments et des medicaments a l’industrie privee. Face a cette dangereuse deresponsabilisation des pouvoirs publics, l’auteur reproche ensuite aux instances ethiques leur instrumentalisation politique. Par opposition, il importe de mettre en place une ethique de la responsabilite, chien de garde des instances publiques de recherche, d’examen et de controle.