Traffic-Related Air Pollution and Risk of Lung, Breast, and Urinary Tract Cancer in Halifax, Nova Scotia.

OBJECTIVES: We assessed the association of traffic-related air pollution (TRAP) with the incidence of lung, breast, and urinary tract cancer in Halifax, Nova Scotia. METHODS: Our case-control study included 2315 cancers and 8501 age-sex-matched controls. Land-use regression was used to estimate TRAP concentrations. Logistic regression was used to assess cancer risk in relation to TRAP, adjusting for community social and material deprivation. RESULTS: There was no association between the risk of lung, breast, or urinary tract cancer in relation to TRAP. Lung cancer risk was significantly increased in the most deprived communities, whereas breast cancer risk was highest in the least deprived communities. CONCLUSIONS: In a city characterized by low levels of ambient air pollution, there was no evidence of a linear increased lung, breast, or urinary tract cancer risk in relation to TRAP.

Quasi-Randomized Trial of Contact With Nature and Effects on Attention in Children.

Children today spend less time in nature than previous generations and there is concern that this shift negatively impacts children's cognitive abilities, particularly their ability to direct their attention. Theories, such as the Attention Restoration Theory (ART), suggest that contact with nature may replenish endogenous attention (e.g., directed, voluntary attention). There is a lack of rigorous research on how contact with nature is associated with attentional performance in children. This study employed a quasi-experimental design and included a sample of typically developing children to investigate performance on computerized endogenous and exogenous attention tasks before and after exposure to one of two interventions - a 30-min walk in either an urban (n = 30) or natural (forested, n = 30) environment. The two experimental groups were equivalent with regard to sex ratio, age, IQ, and connectedness to nature. Attention was assessed using the Combined Attention Systems Test (CAST), a state-of-the-art assessment tool designed to evaluate exogenous and endogenous attention characteristics. Bayesian hierarchical modeling of both response time (RT) and error rate (ER) was employed to evaluate the fixed effect of attentional measures and interactions with session and group. Consistent with predictions of ART, results support credible effects of the nature intervention on two measures of endogenous attention: Alerting RT: d = 0.85 (95% CI: 0.21-1.8), Orienting ER: d = 1.45 (95% CI: 0.17-7.18), but not on any of the measures of exogenous attention. Clinical Trial Registration: https://www.isrctn.com/, identifier ISRCTN17762011.

A small-area analysis of inequalities in chronic disease prevalence across urban and non-urban communities in the Province of Nova Scotia, Canada, 2007-2011.

BACKGROUND: Small-area studies of health inequalities often have an urban focus, and may be limited in their translatability to non-urban settings. Using small-area units representing communities, this study assessed the influence of living in different settlement types (urban, town and rural) on the prevalence of four chronic diseases (heart disease, cancer, diabetes and stroke) and compared the degrees of associations with individual-level and community-level factors among the settlement types. METHODS: The associations between community-level and individual-level characteristics and prevalence of the chronic diseases were assessed using logistic regression (multilevel and non-multilevel) models. Individual-level data were extracted from the Canadian Community Health Survey (2007-2011). Indices of material deprivation and social isolation and the settlement type classification were created using the Canadian Census. RESULTS: Respondents living in towns were 21% more likely to report one of the diseases than respondents living in urban communities even after accounting for individual-level and community-level characteristics. Having dependent children appeared to have protective effects in towns, especially for males (OR: 0.49 (95% CI 0.27 to 0.90)). Unemployment had a strong association for all types of communities, but being unemployed appeared to be particularly damaging to health of males in urban communities (OR: 2.48 (95% CI 1.43 to 4.30)). CONCLUSIONS: The study showed that those living in non-urban settings, particularly towns, experience extra challenges in maintaining health above and beyond the socioeconomic condition and social isolation of the communities, and individual demographic, behavioural and socioeconomic attributes. Our findings also suggest that health inequality studies based on urban-only settings may underestimate the risks by some factors. Ways to devise meaningful small-area units comparable in all settlement types are necessary to help plan effective provision of chronic disease-related health services and programmes on a regional scale.

Should we enhance the commonly used deprivation index for a regional context?

BACKGROUND/OBJECTIVES: Versions of deprivation indices have been increasingly used to monitor patterns and magnitudes of inequality in health. For policy-makers, it is of interest to assess whether they need to construct regionally tailored indices, or whether the existing indices perform sufficiently in detecting inequalities in their respective jurisdiction. Few studies have explored the benefits of constructing a more tailored index for a regional context. METHODS: The study examined, in linear regression models, the proportion of variance (adjusted R2) explained in age-standardized cardiovascular disease (CVD) incidence rate ratios by an index emulating a now-widely-used multiple deprivation index created in Quebec (INSPQI), and a newly created index for Nova Scotia with additional census variables. The magnitudes of inequality were compared by the differences between mean incidences of most and least deprived groups. RESULTS: The newly created deprivation index did not explain as well as the INSPQI-like index the community-level variability in CVD incidences. The gap in mean CVD incidences between the most and least deprived groups was somewhat narrower with the new index, indicating that the new index is not necessarily more sensitive to the inequality attributed to community social disadvantages. CONCLUSIONS: Complicating the indices may not necessarily be of benefit when used for surveillance of population health inequalities. For public health practitioners and decision makers who need to make quick decisions in provisions of services and programs, a generic, well-established deprivation index such as INSPQI can serve well in a regional context.

Risk factors predisposing to pedestrian road traffic injury in children living in Lima, Peru: a case-control study.

OBJECTIVE: To describe the epidemiology of pedestrian road traffic injury in Lima and to identify associated child-level, family-level, and school travel-related variables. DESIGN: Case-control study. SETTING: The Instituto Nacional de Salud del Niño, the largest paediatric hospital in the city. PARTICIPANTS: Cases were children who presented because of pedestrian road traffic injury. Controls presented with other diagnoses and were matched on age, sex and severity of injury. RESULTS: Low socioeconomic status, low paternal education, traffic exposure during the trip to school, lack of supervision during outside play, and duration of outside play were all statistically significantly associated with case-control status. In multivariate logistic regression, a model combining the lack of supervision during outside play and the number of the streets crossed walking to school best predicted case-control status (p<0.001). CONCLUSIONS: These results emphasise that an assessment of children's play behaviours and school locations should be considered and integrated into any plan for an intervention designed to reduce pedestrian road traffic injury. A child-centred approach will ensure that children derive maximum benefit from sorely needed public health interventions.

Ecological complexity and West Nile virus: perspectives on improving public health response.

The emergence of West Nile Virus, as well as other emerging diseases, is linked to complex ecosystem processes such as climate change and constitutes an important threat to population health. Traditional public health intervention activities related to vector surveillance and control tend to be reactive and limited in their ability to deal with multiple epidemics and in their consideration of population health determinants. This paper reviews the current status of West Nile Virus in Canada and describes how complex systems and geographical perspectives help to acknowledge the influence of ecosystem processes on population health. It also provides examples of how these perspectives can be integrated into population-based intervention strategies.

Synoptic weather patterns and modification of the association between air pollution and human mortality.

To assess whether meteorological conditions modify the relationship between short-term exposure to ambient air pollution and mortality, an examination of air pollution and human mortality associations (ecologic) using hybrid spatial synoptic classification procedures was conducted. Concentrations of air pollutants and human mortality from all non-accidental and cardiorespiratory causes were examined according to typical winter and summer synoptic climatologies in Toronto, Canada, between 1981 and 1999. Air masses were derived using a hybrid spatial synoptic classification procedure associating each day over the 19-year period with one of six different typical weather types, or a transition between two weather types. Generalized linear models (GLMs) were used to assess the risk of mortality from air pollution within specific air mass type subsets. Mortality follows a distinct seasonal pattern with a maximum in winter and a minimum in summer. Average air pollution concentrations were similar in both seasons with the exception of elevated sulfur dioxide levels in winter and elevated ozone levels in summer. Subtle changes in meteorological composition can alter the strength of pollutant associations with health outcomes, especially in the summer season. Although there does not appear to be any systematic patterning of modification, variation in pollutant concentrations seems dependent on the type of synoptic category present.

The role of air pollution in the relationship between a heat stress index and human mortality in Toronto.

In this study we considered confounding from air pollutants and chronological variables in the relation between humidex, a summer temperature and humidity index, and nonaccidental mortality, from 1980-1996 in Toronto, Canada. Changes in the risk of death by age group, gender, and combined cardiac-respiratory cause of death were estimated for both 1 degree C and 50-95th percentile increases in humidex using a generalized additive linear model. With air pollution terms in the models, relative risk (RR) point estimates narrowly exceeded 1.0 for all groups. Humidex effects were most apparent for females (RR=1.006, 95% CI=1.004-1.008 per 1 degree C humidex and RR=1.089, 95% CI=1.058-1.121 for 50th to 95th percentile humidex). When air pollution was omitted from the model, RR in the 50-95th percentile analysis increased less than 1.71% for all groups except females, for which RR decreased 1.42%. Differences in RR per 1 degree C humidex were all less than 0.12%. Confidence intervals narrowed slightly for all groups investigated. Heat stress has a statistically significant, yet minimal impact on Toronto populations, and air pollution does appear to have a small, but consistent confounding effect on humidex effect estimates.