in four major Canadian cities. Identical surveys and methodology were used to collect this data: random sample telephone selection within the identified telephone exchanges, computerassisted telephone interviews, overselection of children and weekends in the 24 -h recall diary and the same interviewers. Very similar response rates were obtained: 63% ( NHAPS ) and 64.5% ( CHAPS ). Results of comparisons by age within major activity and location groups suggest activity and location patterns are very similar ( most differences being less than 1% or 14 min in a 24 -h day ) with the exception of seasonal differences. Canadians spend less time outdoors in winter and less time indoors in summer than their U.S. counterparts. When exposure assessments use time of year or outdoor / indoor exposure gradients, these differences may result in significant differences in exposure assessments. Otherwise, the 24 -h time activity patterns of North Americans are remarkably similar and use of the combined data set for some exposure assessments may be feasible.

To determine if the severity of osteoporosis and its resultant hyperkyphosis cause measurable impairment of lung function, 74 women referred for osteoporosis evaluation underwent pulmonary function testing. Women with thoracic wedge compression fractures secondary to osteoporosis had significantly lower percent predicted FVC than did those without fractures. In hierarchical regression analysis, after controlling for age and arm span, there was a significant effect on FVC of the degree of hyperkyphosis as measured by Cobb's angle (increment in R2 = 0.14, p less than 0.001). The addition of the number of vertebral fractures to the model was also significant (increment in R2 = 0.06, p less than 0.002), but cortical bone volume, bone mineral density, and smoking status did not significantly improve the model. From one half of subjects tested, a regression equation was generated relating %FVC and the number of thoracic fractures: %FVC = 103.4 - 9.4 x number of fractures. When used to predict lung function impairment in the second half of study subjects, the correlation between measured and %FVC was r = 0.59 (p less than 0.002). Kyphosis and thoracic compression fractures caused by osteoporosis produce modest but predictable declines in vital capacity in women.

BackgroundRelatively few studies have been conducted of the association between air pollution and emergency department (ED) visits, and most of these have been based on a small number of visits, for a limited number of health conditions and pollutants, and only daily measures of exposure and response.MethodsA time-series analysis was conducted on nearly 400,000 ED visits to 14 hospitals in seven Canadian cities during the 1990s and early 2000s. Associations were examined between carbon monoxide (CO), nitrogen dioxide (NO2), ozone (O3), sulfur dioxide (SO2), and particulate matter (PM10 and PM2.5), and visits for angina/myocardial infarction, heart failure, dysrhythmia/conduction disturbance, asthma, chronic obstructive pulmonary disease (COPD), and respiratory infections. Daily and 3-hourly visit counts were modeled as quasi-Poisson and analyses controlled for effects of temporal cycles, weather, day of week and holidays.Results24-hour average concentrations of CO and NO2 lag 0 days exhibited the most consistent associations with cardiac conditions (2.1% (95% CI, 0.0–4.2%) and 2.6% (95% CI, 0.2–5.0%) increase in visits for myocardial infarction/angina per 0.7 ppm CO and 18.4 ppb NO2 respectively; 3.8% (95% CI, 0.7–6.9%) and 4.7% (95% CI, 1.2–8.4%) increase in visits for heart failure). Ozone (lag 2 days) was most consistently associated with respiratory visits (3.2% (95% CI, 0.3–6.2%), and 3.7% (95% CI, -0.5–7.9%) increases in asthma and COPD visits respectively per 18.4 ppb). Associations tended to be of greater magnitude during the warm season (April – September). In particular, the associations of PM10 and PM2.5with asthma visits were respectively nearly three- and over fourfold larger vs. all year analyses (14.4% increase in visits, 95% CI, 0.2–30.7, per 20.6 μg/m3 PM10 and 7.6% increase in visits, 95% CI, 5.1–10.1, per 8.2 μg/m3 PM2.5). No consistent associations were observed between three hour average pollutant concentrations and same-day three hour averages of ED visits.ConclusionIn this large multicenter analysis, daily average concentrations of CO and NO2 exhibited the most consistent associations with ED visits for cardiac conditions, while ozone exhibited the most consistent associations with visits for respiratory conditions. PM10 and PM2.5 were strongly associated with asthma visits during the warm season.