Mean segmental transit time of radiopaque markers through the right colon, left colon and rectosigmoid areas of adults and children has been calculated form their distribution on consecutive plain films of the abdomen. Overall mean transit does not differ significantly in the large bowel between adults and children. However, there are regional differences within the colon in relation to age. Mean transit time in the right colon is 13.8 hours in adults and 7.7 in children (p less than 0.01). Corresponding values in the left colon are 14.1 and 8.7 hours (p less than 0.02) and, in the rectum, 11 and 12.4 hours (p = NS). The percentage of the mean total large bowel transit time spent in the right colon, left colon and rectosigmoid area are respectively for adults and children 33 +/- 4 and 28 +/- 3 per cent (p = NS); 39 +/- 4 and 32 +/- 4 per cent (p = NS); and 28 +/- 4 and 41 +/- 4 per cent (p less than 0.05), indicating a relative stagnation in the rectosigmoid area of children. These physiologic differences may have implications in diseased states.
ObjectivesThis review assessed the confounding effect of one traffic-related exposure (noise or air pollutants) on the association between the other exposure and cardiovascular outcomes.MethodsA systematic review was conducted with the databases Medline and Embase. The confounding effects in studies were assessed by using change in the estimate with a 10 % cutoff point. The influence on the change in the estimate of the quality of the studies, the exposure assessment methods and the correlation between road noise and air pollutions were also assessed.ResultsNine publications were identified. For most studies, the specified confounders produced changes in estimates <10 %. The correlation between noise and pollutants, the quality of the study and of the exposure assessment do not seem to influence the confounding effects.ConclusionsResults from this review suggest that confounding of cardiovascular effects by noise or air pollutants is low, though with further improvements in exposure assessment, the situation may change. More studies using pollution indicators specific to road traffic are needed to properly assess if noise and air pollution are subjected to confounding.
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 Québec, 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 (O3) levels were estimated at the child’s residence for all births 1999–2010, and nitrogen dioxide (NO2) levels during 1996–2006 were estimated for births on the Montreal Island. Satellite based concentrations of fine particles (PM2.5) were estimated at a 10 km × 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 NO2 (5.45 ppb), O3 (3.22 ppb), and PM2.5 (6.50 μg/m3) 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 O3 and PM2.5 estimated with time-varying Cox models were similar to those estimated using exposure at birth, whereas the effect of NO2 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 PM2.5, O3 and NO2.Citation:Tétreault LF, Doucet M, Gamache P, Fournier M, Brand A, Kosatsky T, Smargiassi A. 2016. Childhood exposure to ambient air pollutants and the onset of asthma: an administrative cohort study in Québec. Environ Health Perspect 124:1276–1282; http://dx.doi.org/10.1289/ehp.1509838
Adenoid hypertrophy has several variable symptoms. In this study, symptoms were divided into minor and major. A lateral radiograph of the nasopharynx was performed in 114 patients to study the superior and antroadenoid diameters. With proper statistical analysis, a correlation was made between the various clinical groups (scores) and the adenoid measurements. Our results support Hibbert's findings that the antroadenoid width is a better indicator of the symptom-producing adenoid than adenoid mass measurements with their loosely defined norms. A thorough history and physical examination remain paramount in the diagnosis and management of adenoid hypertrophy.
Noise exposure generated by air traffic has been linked with sleep disturbances. The purpose of this systematic review is to clarify whether there is a causal link between aircraft noise exposure and sleep disturbances. Only complete, peer-reviewed articles published in scientific journals were examined. Papers published until December 2010 were considered. To be included, articles had to focus on subjects aged 18 or over and include an objective evaluation of noise levels. Studies were classified according to quality. Given the paucity of studies with comparable outcome measures, we performed a narrative synthesis using a best-evidence synthesis approach. The primary study findings were tabulated. Similarities and differences between studies were investigated. Of the 12 studies surveyed that dealt with sleep disturbances, four were considered to be of high quality, five were considered to be of moderate quality and three were considered to be of low quality. All moderate- to high-quality studies showed a link between aircraft noise events and sleep disturbances such as awakenings, decreased slow wave sleep time or the use of sleep medication. This review suggests that there is a causal relation between exposure to aircraft noise and sleep disturbances. However, the evidence comes mostly from experimental studies focusing on healthy adults. Further studies are necessary to determine the impact of aircraft noise on sleep disturbance for individuals more than 65 years old and for those with chronic diseases.
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