Little attention has been devoted to the effects on children's respiratory health of exposure to sulphur dioxide (SO2) in ambient air from local industrial emissions. Most studies on the effects of SO(2) have assessed its impact as part of the regional ambient air pollutant mix.
To examine the association between exposure to stack emissions of SO(2) from petroleum refineries located in Montreal's (Quebec) east-end industrial complex and the prevalence of active asthma and poor asthma control among children living nearby.
The present cross-sectional study used data from a respiratory health survey of Montreal children six months to 12 years of age conducted in 2006. Of 7964 eligible households that completed the survey, 842 children between six months and 12 years of age lived in an area impacted by refinery emissions. Ambient SO(2) exposure levels were estimated using dispersion modelling. Log-binomial regression models were used to estimate crude and adjusted prevalence ratios (PRs) and 95% CIs for the association between yearly school and residential SO(2) exposure estimates and asthma outcomes. Adjustments were made for child's age, sex, parental history of atopy and tobacco smoke exposure at home.
The adjusted PR for the association between active asthma and SO(2) levels was 1.14 (95% CI 0.94 to 1.39) per interquartile range increase in modelled annual SO(2). The effect on poor asthma control was greater (PR=1.39 per interquartile range increase in modelled SO(2) [95% CI 1.00 to 1.94]).
Results of the present study suggest a relationship between exposure to refinery stack emissions of SO(2) and the prevalence of active and poor asthma control in children who live and attend school in proximity to refineries.
To share four Canadian cities' experiences with bed bug infestations and to explore public health roles in managing them.
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.
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.
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.
Home environmental exposures may aggravate asthma. Few population-based studies have investigated the relationship between asthma control in children and home environmental exposures.
Identify home environmental exposures associated with poor control of asthma among asthmatic children less than 12 years of age in Montreal (Quebec, Canada).
This cross-sectional population-based study used data from a respiratory health survey of Montreal children aged 6 months to 12 years conducted in 2006 (n = 7980). Asthma control was assessed (n = 980) using an adaptation of the Canadian asthma consensus report clinical parameters. Using log-binomial regression models, prevalence ratios (PRs) with 95% confidence intervals (95% CIs) were estimated to explore the relationship between inadequate control of asthma and environmental home exposures, including allergens, irritants, mold, and dampness indicators. Subjects with acceptable asthma control were compared with those with inadequate disease control.
Of 980 children with active asthma in the year prior to the survey, 36% met at least one of the five criteria as to poor control of their disease. The population's characteristics found to be related with a lack of asthma control were younger age, history of parental atopy, low maternal education level, foreign-born mothers, and tenant occupancy. After adjustments, children living along high-traffic density streets (PR, 1.35; 95% CI, 1.00-1.81) and those with their bedroom or residence at the basement level (PR, 1.30; 95% CI, 1.01-1.66) were found to be at increased risk of poor asthma control.
Suboptimal asthma control appears to be mostly associated with traffic, along with mold and moisture conditions, the latter being a more frequent exposure and therefore having a greater public health impact.
The objective of this paper is to describe Montreal's heat response plan and its application during the July 2010 heat wave.
The Montreal heat response plan is designed to ensure the surveillance of weather and health indicators during the summer season and to coordinate actions to be undertaken during this period to reduce morbidity and mortality due to heat, particularly when weather thresholds are reached or an increase in health indicators is observed. It was developed to coordinate and apply intervention measures on the Island of Montreal and has been in effect since 2004.
In the beginning of July 2010, Montreal experienced a heat wave that lasted 5 days. During this period, health indicators such as total mortality, prehospital emergency transports, calls to the health information line and hospital admissions were monitored by the Montreal public health surveillance system. The decision to implement emergency interventions and actions performed by regional and local public health and municipal partners (intervention level) was made following attainment of a predetermined weather threshold and increases in health indicators. The significant increase in daily observed mortality from all causes and in particular people dying at home or in the community prompted the Director of public health to conduct a chart review of all people deceased from July 5 to July 11, 2010 to determine cause of death and underlying health conditions.
During the heat wave, there were 304 reported deaths from all causes in Montreal residents, of which 106 were probably or possibly heat-related. Major underlying health conditions in heat-related deaths included cardiovascular problems and mental health illness. Furthermore, in the case of people with mental illness who died during the heat wave, the chart review revealed that many were contacted 24 hours prior to their death by health care professionals, family members, neighbours or friends.
Following the 2010 heat wave, the Montreal heat response plan and heat surveillance system were updated to include initiatives to better communicate preventive measures to the vulnerable populations and to intervene earlier during a heat wave.
We investigated whether the installation of a suicide prevention barrier on Jacques-Cartier Bridge led to displacement of suicides to other jumping sites on Montréal Island and Montérégie, Québec, the 2 regions it connects.
Suicides on Montréal Island and Montérégie were extracted from chief coroners' records. We used Poisson regression to assess changes in annual suicide rates by jumping from Jacques-Cartier Bridge and from other bridges and other sites and by other methods before (1990-June 2004) and after (2005-2009) installation of the barrier.
Suicide rates by jumping from Jacques-Cartier Bridge decreased after installation of the barrier (incidence rate ratio [IRR] = 0.24; 95% confidence interval [CI] = 0.13, 0.43), which persisted when all bridges (IRR = 0.39; 95% CI = 0.27, 0.55) and all jumping sites (IRR = 0.66; 95% CI = 0.54, 0.80) in the regions were considered.
Little or no displacement to other jumping sites may occur after installation of a barrier at an iconic site such as Jacques-Cartier Bridge. A barrier's design is important to its effectiveness and should be considered for new bridges with the potential to become symbolic suicide sites.
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.
Maximum sound levels (LAS,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 LAS,max were converted to indoor LAS,max by reducing noise levels by 15 dB(A) or 21 dB(A). For all grid points, LAS,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.
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.
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.
Comment In: Can J Public Health. 2013 May-Jun;104(3):e27523823900
Comment In: Can J Public Health. 2013 May-Jun;104(3):e27623823901
Exposure to traffic-related air pollutants plays a role in several health outcomes. A large body of evidence tends to link asthma in children with traffic exposure. Increasing asthma prevalence and incidence in children in Canadian cities has been of concern for public health authorities. The following study focuses on estimating the risk of asthma prevalence attributable to residing in proximity to major roads on the Island of Montreal, Canada.
Risk functions pertaining to asthma in children and residential proximity to major roads were selected from the literature and applied to Montreal. Asthma prevalence was taken from population-based studies. Population data were retrieved from Canadian census. Exposure was estimated using the proximity to major road and highway category of the Desktop Mapping Technologies Inc. database (DMTI Spatial Inc.).
Based on different studies, the percentage of prevalent asthma cases attributable to residing within 50 metres of a major road or highway for children aged 2, 4 and 6 years varied between 2.4% (0-4.3), 5.6% (0.1-8.6) and 5.9% (0.1-9.0). For the 5-7 year age group residing within 75 m of a major road or highway, the percent of cases was 6.4% (2.6-9.3). For children aged 8 to 10 residing within 75 m of a highway only, the percent of cases was 0.7% (0.2-0.9).
These numbers represent the best crude estimates and are an indication of a possible range of cases linked to residential proximity to major roads. As there are uncertainties linked to the application of exposure-response functions, these estimates will be reassessed as new evidence is gathered through further research.