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Abstract Background The evaluation of exposure to ambient temperatures in epidemiological studies has generally been based on records from meteorological stations which may not adequately represent local temperature variability. Here we propose a spatially explicit model to estimate local exposure to temperatures of large populations under various meteorological conditions based on satellite and meteorological data. Methods A general linear model was used to estimate surface temperatures using 15 LANDSAT 5 and LANDSAT 7 images for Quebec Province, Canada between 1987 and 2002 and spanning the months of June to August. The images encompassed both rural and urban landscapes and predictors included: meteorological records of temperature and wind speed, distance to major water bodies, Normalized Differential Vegetation Index (NDVI), land cover (built and bare land, water, or vegetation), latitude, longitude, and week of the year. Results The model explained 77% of the variance in surface temperature, accounting for both temporal and spatial variations. The standard error of estimates was 1.42°C. Land cover and NDVI were strong predictors of surface temperature. Conclusions This study suggests that a statistical approach to estimating surface temperature incorporating both spatially explicit satellite data and time-varying meteorological data may be relevant to assessing exposure to heat during the warm season in the Quebec. By allowing the estimation of space- and time-specific surface temperatures, this model may also be used to assess the possible impacts of land use changes under various meteorological conditions. It can be applied to assess heat exposure within a large population and at relatively fine-grained scale. It may be used to evaluate the acute health effect of heat exposure over long time frames. The method proposed here could be replicated in other areas around the globe for which satellite data and meteorological data is available.

Abstract Background While the effects of daily fine particulate exposure (PM) have been well reviewed, the epidemiological and physiological evidence of cardiovascular effects associated to sub-daily exposures has not. We performed a theoretical model-driven systematic non-meta-analytical literature review to document the association between PM sub-daily exposures (≤6 hours) and arrhythmia, ischemia and myocardial infarction (MI) as well as the likely mechanisms by which sub-daily PM exposures might induce these acute cardiovascular effects. This review was motivated by the assessment of the risk of exposure to elevated sub-daily levels of PM during fireworks displays. Methods Medline and Elsevier's EMBase were consulted for the years 1996-2008. Search keywords covered potential cardiovascular effects, the pollutant of interest and the short duration of the exposure. Only epidemiological and experimental studies of adult humans (age > 18 yrs) published in English were reviewed. Information on design, population and PM exposure characteristics, and presence of an association with selected cardiovascular effects or physiological assessments was extracted from retrieved articles. Results Of 231 articles identified, 49 were reviewed. Of these, 17 addressed the relationship between sub-daily exposures to PM and cardiovascular effects: five assessed ST-segment depression indicating ischemia, eight assessed arrhythmia or fibrillation and five considered MI. Epidemiologic studies suggest that exposure to sub-daily levels of PM is associated with MI and ischemic events in the elderly. Epidemiological studies of sub-daily exposures suggest a plausible biological mechanism involving the autonomic nervous system while experimental studies suggest that vasomotor dysfunction may also relate to the occurrence of MI and ischemic events. Conclusions Future studies should clarify associations between cardiovascular effects of sub-daily PM exposure with PM size fraction and concurrent gaseous pollutant exposures. Experimental studies appear more promising for elucidating the physiological mechanisms, time courses and causes than epidemiological studies which employ central pollution monitors for measuring effects and for assessing their time course. Although further studies are needed to strengthen the evidence, given that exposure to sub-daily high levels of PM (for a few hours) is frequent and given the suggestive evidence that sub-daily PM exposures are associated with the occurrence of cardiovascular effects, we recommend that persons with cardiovascular diseases avoid such situations.

Abstract Background The project "Assessment and prevention of acute health effects of weather conditions in Europe" (PHEWE) had the aim of assessing the association between weather conditions and acute health effects, during both warm and cold seasons in 16 European cities with widely differing climatic conditions and to provide information for public health policies. Methods The PHEWE project was a three-year pan-European collaboration between epidemiologists, meteorologists and experts in public health. Meteorological, air pollution and mortality data from 16 cities and hospital admission data from 12 cities were available from 1990 to 2000. The short-term effect on mortality/morbidity was evaluated through city-specific and pooled time series analysis. The interaction between weather and air pollutants was evaluated and health impact assessments were performed to quantify the effect on the different populations. A heat/health watch warning system to predict oppressive weather conditions and alert the population was developed in a subgroup of cities and information on existing prevention policies and of adaptive strategies was gathered. Results Main results were presented in a symposium at the conference of the International Society of Environmental Epidemiology in Paris on September 6th 2006 and will be published as scientific articles. The present article introduces the project and includes a description of the database and the framework of the applied methodology. Conclusion The PHEWE project offers the opportunity to investigate the relationship between temperature and mortality in 16 European cities, representing a wide range of climatic, socio-demographic and cultural characteristics; the use of a standardized methodology allows for direct comparison between cities.

Pyrethroids are a class of plant-derived insecticides and their man-made analogues that are increasingly applied in Canada as first choice for pest control in many agricultural and residential settings. Their popularity is partly due to their alleged safety compared to the older organochlorine and organophosphate insecticides. Application of pyrethroids is expanding because of recent increases in the level of pest infestations--such as bed bugs and the decreased susceptibility of target species to many pest control products. Pyrethroid residues have been documented in homes, child care centres and food. While pyrethroids are considered of low health risk for humans, their increased use is of concern. Our current understanding of the adverse effects of pyrethroids derives mainly from studies of short-term effects in laboratory animals, case reports of self-and accidental poisonings, and high-dose occupational exposures, for which the levels and formulations of pyrethroid products differ from those relevant for long-term exposure in the general population. The available data suggest that the reproductive and nervous systems, endocrine signalling pathways, and early childhood development may be targets for adverse effects in the case of repeated exposure to pyrethroid formulations. Given uncertainty about the existence of long-term health effects of exposure to pyrethroids, particularly under realistic scenarios, we should be cautious when promoting pyrethroid products as safe methods for pest control. Key words: Pyrethrins; environmental exposure; endocrine disrupting chemicals; toxicology; risk assessment Les pyrethrinoides, une categorie d'insecticides derives des plantes et leurs analogues synthetiques, sont de plus en plus utilises au Canada comme premier choix dans la lutte antiparasitaire dans bien des contextes agricoles et residentiels. Leur popularite est due en partie a leur innocuite presumee comparativement aux insecticides organochlores et organophosphores plus anciens. La demande de pyrethrinoides augmente en raison des hausses recentes du niveau d'infestations par des insectes nuisibles (comme les punaises de lit) et de la vulnerabilite reduite des especes cibles a de nombreux produits de lutte antiparasitaire. Des residus de pyrethrinoides ont ete detectes dans des logements, des centres de la petite enfance et des aliments. Bien que l'on considere que les pyrethrinoides presentent peu de risques pour la sante humaine, leur utilisation croissante est un probleme. Nos connaissances actuelles des effets indesirables des pyrethrinoides decoulent principalement d'etudes de leurs effets a court terme sur des animaux de laboratoire, d'etudes de cas d'empoisonnement volontaire et accidentel, et de cas d'exposition professionnelle a des doses elevees; or, dans ces situations, les niveaux et les formulations des produits aux pyrethrinoides different de ceux qui s'appliqueraient a l'etude de leurs risques a long terme dans la population generale. Selon les donnees disponibles, l'appareil genital, le systeme nerveux, les voies de signalisation endocrinienne et le developpement du jeune enfant pourraient etre la cible d'effets indesirables en cas d'exposition repetee a des formulations a base de pyrethrinoides. Etant donne l'incertitude entourant l'existence d'effets a long terme sur la sante a la suite d'une exposition aux pyrethrinoides, surtout dans des scenarios realistes, la prudence est de mise lorsqu'on presente les produits aux pyrethrinoides comme des outils de lutte antiparasitaire sans danger. Mots cles : pyrethrine; exposition environnementale; perturbateurs endocriniens; toxicologie; evaluation du risque, Pyrethroid insecticides and naturally occurring pyrethrins are commonly used for insect control in households and in agriculture. (1) Reasons for this are increasing restrictions in the use of organophosphate and [...]

Objective: To share four Canadian cities' experiences with bed bug infestations and to explore public health roles in managing them. Methods: We summarize presentations from a workshop at the 2010 Canadian Public Health Association Conference which examined the re-emergence of bed bugs in Canada and compared management approaches of municipal and public health authorities in four large Canadian cities. We include updates on their activities since the workshop. Results: Cities across Canada have observed an increase in complaints of bed bug infestations over recent years. Toronto Public Health considers bed bugs to be a threat to health and has been heavily involved in the front-line response to bed bug complaints. In Winnipeg, Montreal and Vancouver, city inspectors are responsible for investigating complaints, and public health plays a supporting or secondary role. We identified factors that may contribute to successful management of bed bugs: sufficient funding, partnerships among many stakeholders, training and education, and surveillance and evaluation. Conclusion: Various public health agencies in Canadian cities have played key roles in the fight against bed bugs through new initiatives, education, and encouragement and support for others. By working with the public, owners, tenants, the health sector and other stakeholders, public health practitioners can begin to curb the resurgence of bed bugs and the social strains associated with them. Key words: Bed bug; Cimex lectularuis; environmental health; public health Objectifs: Relater l'experience de quatre villes canadiennes aux prises avec des infestations de punaises de lit et analyser le role joue par la sante publique pour maitriser ces infestations. Methode: Nous resumons les presentations d'un atelier donne a la Conference 2010 de l'Association canadienne de sante publique, oU l'on a examine la reemergence des punaises de lit au Canada et compare les approches de prise en charge des autorites municipales et sanitaires dans quatre grandes villes canadiennes. Nous incluons des nouvelles de leurs activites depuis l'atelier. Resultats: De nombreuses villes du Canada observent une hausse des plaintes d'infestations de punaises de lit depuis quelques annees. Le Service de sante publique de Toronto, qui considere les punaises de lit comme une menace pour la sante, est tres implique dans les interventions de premiere ligne en cas de plainte d'infestation. A Winnipeg, Montreal et Vancouver, ce sont les inspecteurs de la ville qui sont charges d'enqueter sur les plaintes, la sante publique jouant un role secondaire ou de soutien. Nous avons recense les facteurs pouvant contribuer a une prise en charge efficace des punaises de lit : des fonds suffisants, des partenariats entre les nombreux acteurs du milieu, la formation et la sensibilisation, ainsi que la surveillance et l'evaluation. Conclusion: Divers organismes de sante publique dans les villes canadiennes jouent un role cle dans la lutte contre les punaises de lit en menant de nouvelles initiatives, en faisant de la sensibilisation, et en offrant soutien et encouragement a d'autres. En travaillant avec le public, les proprietaires, les locataires, le secteur de la sante et les autres acteurs, les praticiens de la sante publique peuvent esperer juguler la reapparition des punaises de lit et les tensions sociales qui en resultent. Mots cles: punaise lit; Cimex lectularuis; sante environnementale; sante publique, Bed bugs (Cimex lectularuis) are small, elusive insects that feed almost exclusively on human blood. Bed bug infestations have become prominent worldwide, generating increased public concern. (1,2) Despite the attention [...]