235 research outputs found

    Development of a wearable global positioning system for place and health research

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    <p>Abstract</p> <p>Background</p> <p>An increasing number of studies suggest that characteristics of context, or the attributes of the places within which we live, work and socialize, are associated with variations in health-related behaviours and outcomes. The challenge for health research is to ensure that these places are accurately represented spatially, and to identify those aspects of context that are related to variations in health and amenable to modification. This study focuses on the design of a wearable global positioning system (GPS) data logger for the purpose of objectively measuring the temporal and spatial features of human activities. Person-specific GPS data provides a useful source of information to operationalize the concept of place.</p> <p>Results</p> <p>We designed and tested a lightweight, wearable GPS receiver, capable of logging location information for up to 70 hours continuously before recharging. The device is accurate to within 7 m in typical urban environments and performs well across a range of static and dynamic conditions.</p> <p>Discussion</p> <p>Rather than rely on static areal units as proxies for places, wearable GPS devices can be used to derive a more complete picture of the different places that influence an individual's wellbeing. The measures are objective and are less subject to biases associated with recall of location or misclassification of contextual attributes. This is important for two reasons. First, it brings a dynamic perspective to place and health research. The influence of place on health is dynamic in that certain places are more or less relevant to wellbeing as determined by the length of time in any location and by the frequency of activity in the location. Second, GPS data can be used to assess whether the characteristics of places at specific times are useful to explaining variations in health and wellbeing.</p

    The Role of a General Safety Requirement in Canada's Health Protection Regime

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    This research was supported in part by a financial contribution from the Health Policy Research Program, Health Canada

    Ambient Air Pollution and Cancer Mortality in the Cancer Prevention Study II

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    BACKGROUND: The International Agency for Research on Cancer classified both outdoor air pollution and airborne particulate matter as carcinogenic to humans (Group 1) for lung cancer. There may be associations with cancer at other sites; however, the epidemiological evidence is limited. OBJECTIVE: The aim of this study was to clarify whether ambient air pollution is associated with specific types of cancer other than lung cancer by examining associations of ambient air pollution with nonlung cancer death in the Cancer Prevention Study II (CPS-II). METHODS: Analysis included 623,048 CPS-II participants who were followed for 22 y (1982-2004). Modeled estimates of particulate matter with aerodynamic diameter <2.5microm (PM2.5) (1999-2004), nitrogen dioxide (NO2) (2006), and ozone (O3) (2002-2004) concentrations were linked to the participant residence at enrollment. Cox proportional hazards models were used to estimate associations per each fifth percentile-mean increment with cancer mortality at 29 anatomic sites, adjusted for individual and ecological covariates. RESULTS: We observed 43,320 nonlung cancer deaths. PM2.5 was significantly positively associated with death from cancers of the kidney {adjusted hazard ratio (HR) per 4.4 mug/m3=1.14 [95% confidence interval (CI): 1.03, 1.27]} and bladder [HR=1.13 (95% CI: 1.03, 1.23)]. NO2 was positively associated with colorectal cancer mortality [HR per 6.5 ppb=1.06 (95% CI: 1.02, 1.10). The results were similar in two-pollutant models including PM2.5 and NO2 and in three-pollutant models with O3. We observed no statistically significant positive associations with death from other types of cancer based on results from adjusted models. CONCLUSIONS: The results from this large prospective study suggest that ambient air pollution was not associated with death from most nonlung cancers, but associations with kidney, bladder, and colorectal cancer death warrant further investigation. https://doi.org/10.1289/EHP1249

    Severity scoring of manganese health effects for categorical regression

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    Characterizing the U-shaped exposure response relationship for manganese (Mn) is necessary for estimating the risk of adverse health from Mn toxicity due to excess or deficiency. Categorical regression has emerged as a powerful tool for exposure-response analysis because of its ability to synthesize relevant information across multiple studies and species into a single integrated analysis of all relevant data. This paper documents the development of a database on Mn toxicity designed to support the application of categorical regression techniques. Specifically, we describe (i) the conduct of a systematic search of the literature on Mn toxicity to gather data appropriate for dose-response assessment; (ii) the establishment of inclusion/exclusion criteria for data to be included in the categorical regression modeling database; (iii) the development of a categorical severity scoring matrix for Mn health effects to permit the inclusion of diverse health outcomes in a single categorical regression analysis using the severity score as the outcome variable; and (iv) the convening of an international expert panel to both review the severity scoring matrix and assign severity scores to health outcomes observed in studies (including case reports, epidemiological investigations, and in vivo experimental studies) selected for inclusion in the categorical regression database. Exposure information including route, concentration, duration, health endpoint(s), and characteristics of the exposed population was abstracted from included studies and stored in a computerized manganese database (MnDB), providing a comprehensive repository of exposure-response information with the ability to support categorical regression modeling of oral exposure data

    Options for basing Dietary Reference Intakes (DRIs) on chronic disease endpoints: report from a joint US-/Canadian-sponsored working group.

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    Dietary Reference Intakes (DRIs) are used in Canada and the United States in planning and assessing diets of apparently healthy individuals and population groups. The approaches used to establish DRIs on the basis of classical nutrient deficiencies and/or toxicities have worked well. However, it has proved to be more challenging to base DRI values on chronic disease endpoints; deviations from the traditional framework were often required, and in some cases, DRI values were not established for intakes that affected chronic disease outcomes despite evidence that supported a relation. The increasing proportions of elderly citizens, the growing prevalence of chronic diseases, and the persistently high prevalence of overweight and obesity, which predispose to chronic disease, highlight the importance of understanding the impact of nutrition on chronic disease prevention and control. A multidisciplinary working group sponsored by the Canadian and US government DRI steering committees met from November 2014 to April 2016 to identify options for addressing key scientific challenges encountered in the use of chronic disease endpoints to establish reference values. The working group focused on 3 key questions: 1) What are the important evidentiary challenges for selecting and using chronic disease endpoints in future DRI reviews, 2) what intake-response models can future DRI committees consider when using chronic disease endpoints, and 3) what are the arguments for and against continuing to include chronic disease endpoints in future DRI reviews? This report outlines the range of options identified by the working group for answering these key questions, as well as the strengths and weaknesses of each option

    The prevalence of food allergy in cesarean-born children aged 0–3 years: A systematic review and meta-analysis of cohort studies

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    PurposePrevious studies reported a higher risk of food allergy for cesarean-born children than vaginal-born children. This study aims to systematically compare the prevalence of food allergy among cesarean-born and vaginal-born children aged 0–3 years.MethodsThree English and two Chinese databases were searched using terms related to food allergies and cesarean sections. Cohort studies that reported the prevalence of food allergy in cesarean-born and vaginal-born children aged 0–3 years were included. Two reviewers performed study selection, quality assessment, and data extraction. The pooled prevalence of food allergy in cesarean-born and vaginal-born children was compared by meta-analysis.ResultsNine eligible studies, with 9,650 cesarean-born children and 20,418 vaginal-born children aged 0–3 years, were included. Of them, 645 cesarean-born children and 991 vaginal-born children were identified as having food allergies. The pooled prevalence of food allergy was higher in cesarean-born children (7.8%) than in vaginal-born children (5.9%). Cesarean section was associated with an increased risk of food allergy [odds ratio (OR): 1.45; 95% confidence interval (CI): 1.03–2.05] and cow's milk allergy (OR: 3.31; 95% CI: 1.98–5.53). Additionally, cesarean-born children with a parental history of allergy had an increased risk of food allergy (OR: 2.60; 95% CI: 1.28–5.27).ConclusionThis study suggests that cesarean sections was associated with an increased risk of food and cow's milk allergies in children aged 0–3 years. Cesarean-born children with a parental history of allergy demonstrated a higher risk for food allergy than did vaginal-born children. These results indicate that caregivers should be aware of the risks of food allergies in cesarean-born children, reducing the risk of potentially fatal allergic events. Further research is needed to identify the specific factors affecting food allergies in young children.Systematic Review Registrationhttp://www.crd.york.ac.uk/prospero, identifier: International Prospective Register of Systematic Reviews (NO. CRD42019140748)
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