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Objective: Estimate the number of awakenings additional to spontaneous awakenings, induced by the nighttime aircraft movements at an international airport in Montreal, in the population residing nearby in 2009. Methods: Maximum sound levels ([L.sub.AS,max]) were derived from aircraft movements using the Integrated Noise Model 7.0b, on a 28 x 28 km grid centred on the airport and with a 0.1 x 0.1 km resolution. Outdoor [L.sub.AS,max] were converted to indoor [L.sub.AS,max] by reducing noise levels by 15 dB(A) or 21 dB(A). For all grid points, [L.sub.AS,max] were transformed into probabilities of additional awakening using a function developed by Basner et al. (2006). The probabilities of additional awakening were linked to estimated numbers of exposed residents for each grid location to assess the number of aircraft-noise-induced awakenings in Montreal. Results: Using a 15 dB(A) sound attenuation, 590 persons would, on average, have one or more additional awakenings per night for the year 2009. In the scenario using a 21 dB(A) sound attenuation, on average, no one would be subjected to one or more additional awakenings per night due to aircraft noise. Conclusion: Using the 2009 flight patterns, our data suggest that a small number of Montreal residents are exposed to noise levels that could induce one or more awakenings additional to spontaneous awakenings per night. Key words: Noise; sleep; aircraft, risk assessment Objectif : Estimer le nombre de reveils additionnels aux reveils spontanes, generes par les mouvements aeriens nocturnes, de la population residant a proximite d'un aeroport international sur l'ile de Montreal en 2009. Methode : Les niveaux sonores maximaux ([L.sub.AS,max]) ont ete determines a partir des mouvements aeriens suite a l'aide de l'Integrated Noise Model 7,0b pour une grille de points de 28 x 28 km centree sur l'aeroport a une resolution de 0,1 x 0,1 km. Les [L.sub.AS,max] exterieurs ont ete convertis en [L.sub.AS,max] interieurs en les reduisant de 15 dB(A) ou 21 dB(A). Ensuite les [L.sub.AS,max] de chaque point de grille ont ete transformes en probabilite de reveils additionnels a l'aide d'une fonction developpee par Basner et coll. (2006). Les probabilites de reveils additionnels calculees ont ete associees au nombre de residents se trouvant a chaque point de grille afin d'estimer les reveils additionnels lies aux mouvements aeriens a Montreal. Resultats : En utilisant l'attenuation sonore de 15 dB(A), 590 individus auraient, en moyenne, un reveil additionnel ou plus par nuit en 2009. Cependant, en utilisant l'attenuation sonore de 21 dB(A), en moyenne, aucun individu n'eprouverait un reveil additionnel ou plus par nuit. Conclusion : Selon nos resultats, issus des mouvements aeriens de 2009, un nombre restreint de Montrealais seraient exposes a des niveaux sonores pouvant induire un reveil additionnel aux reveils spontanes ou plus par nuit. Mots cles : bruit; sommeil; avion; analyse de risque, In recent years, many studies on the adverse effects of environmental noise levels have been published. Increased environmental noise levels are associated with cardiovascular diseases, (1-3) annoyance, (4) cognitive performance [...]

BACKGROUND: Although it is well established that air pollutants can exacerbate asthma, the link with new asthma onset in children is less clear. OBJECTIVE: We assessed the association between the onset of childhood asthma with both time of birth and time-varying exposures to outdoor air pollutants. METHOD: An open cohort of children born in the province of Quebec, Canada, was created using linked medical-administrative databases. New cases of asthma were defined as one hospital discharge with a diagnosis of asthma or two physician claims for asthma within a 2 year period. Annual ozone ([O.sub.3]) levels were estimated at the child's residence for all births 1999-2010, and nitrogen dioxide (N[O.sub.2]) levels during 1996-2006 were estimated for births on the Montreal Island. Satellite based concentrations of fine particles (P[M.sub.2.5]) were estimated at a 10 km x 10 km resolution and assigned to residential postal codes throughout the province (1996-2011). Hazard ratios (HRs) were assessed with Cox models for the exposure at the birth address and for the time-dependent exposure. We performed an indirect adjustment for secondhand smoke (SHS). RESULTS: We followed 1,183,865 children (7,752,083 person-years), of whom 162,752 became asthmatic. After controlling for sex and material and social deprivation, HRs for an interquartile range increase in exposure at the birth address to N[O.sub.2] (5.45 ppb), [O.sub.3] (3.22 ppb), and P[M.sub.2.5] (6.50 µg/[m.sup.3]) were 1.04 (95% CI: 1.02, 1.05), 1.11 (95% CI: 1.10, 1.12), and 1.31 (95% CI: 1.28, 1.33), respectively. Effects of [O.sub.3] and P[M.sub.2.5] estimated with time-varying Cox models were similar to those estimated using exposure at birth, whereas the effect of N[O.sub.2] was slightly stronger (HR = 1.07; 95% CI: 1.05, 1.09). CONCLUSIONS: Asthma onset in children appears to be associated with residential exposure to P[M.sub.2.5], [O.sub.3] and N[O.sub.2]. http://dx.doi.org/10.1289/ehp.1509838, Introduction Asthma is one of the most common childhood chronic diseases worldwide (Asher et al. 2006; Garner and Kohen 2008; Williams et al. 1999). Although the link between exposure to [...]

Dear Editor: Risk estimates are frequently used in public health practice to guide authorities responsible for adopting policies that protect public health. There are uncertainties in all risk estimates, most [...]