The Association between Ambient Carbon Monoxide Levels and Daily Mortality in Toronto, Canada

Abstract

The role of ambient levels of carbon monoxide (CO) in the exacerbation of heart problems in individuals with both cardiac and other diseases was examined by comparing daily variations in CO levels and daily fluctuations in nonaccidental mortality in metropolitan Toronto for the 15-year period 1980-1994. After adjusting the mortality time series for day-of-the-week effects, nonparametic smoothed functions of day of study and weather variables, statistically significant positive associations were observed between daily fluctuations in mortality and ambient

Air pollution and daily mortality in three U.S. counties.

“…Insofar as single-pollutants are concerned, the most striking finding of these analyses is the strong association between CO and total and cause-specific mortality, especially in Los Angeles County. Associations between CO and a number of health end points, including hospital admissions (5,18), and mortality (12), have been reported in recent papers. In a study of daily mortality in Toronto, Burnett et al (12) reported that once the effect of CO had been taken into account total suspended particulate matter (TSP) contributed only a small amount to the daily mortality.…”

“…These early analyses concluded that particulate matter, rather than sulfur dioxide, was the likely culprit in the excess mortality attributed to air pollution. More recent analyses have reported associations between other pollutants, such as CO (10,12) and NO2 (13), and mortality. It is not my intention to summarize the rather substantial epidemiologic literature on air pollution and mortality that has appeared in the last decade.…”

“…The results of multipollutant analyses have been much more variable. Some studies have reported robust associations between indices of particulate matter and mortality (10), but others, particularly those that have appeared since the mid-1990s and considered a number of copollutants, have reported that the effect of the gaseous pollutants dominates that of particulate matter (11,12). Interestingly, a large multicity study of air pollution and mortality in Europe (8) Figure 1.…”

“…Reported effects of air pollution include decreased lung function (1,2), increased emergency room visits for asthma (3), increased hospital admissions (4,5) and, most importantly, increased mortality (6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16). Although human populations are exposed to a complex mixture of air pollutants that vary in composition with geography and climatic conditions, much of the recent work on air pollution epidemiology has focused on individual components of air pollution, rather than sources of pollution or the entire pollution mix.…”

Neurogenic Inflammation and Particulate Matter (PM) Air Pollutants

“…asthma, bronchitis, airway hyperresponsiveness) and mortality associated with PM exposure are marked by a sensitive sub-population component, characterized by increased sensitivity in the young and old, asthmatics, smokers and in those with pre-existing respiratory or cardiopulmonary conditions (Pope, 2000;Utell and Frampton, 2000). While the epidemiological association between PM pollutants and adverse health effects is clear (Dockery et al, 1992;Dockery and Pope, 1994;Schwartz, 1994Schwartz, , 1996Pope, 1996Pope, , 2000Burnett et al, 1998;Liao et al, 1999;Hoek et al, 2000), mechanisms of action to explain ambient PM toxicity and its sensitive subpopulation phenomenon are lacking.…”