Air pollution and hospital admissions for respiratory and cardiovascular diseases in Hong Kong.

267

156

The relationship between stroke and air pollution has not been adequately studied. We conducted a time-series study to examine the evidence of an association between air pollutants and stroke over 4 years (January 1995-December 1998) in Seoul, Korea. We used a generalized additive model to regress daily stroke death counts for each pollutant, controlling for seasonal and long-term trends and meteorologic influences, such as temperature, relative humidity, and barometric pressure. We observed an estimated increase of 1.5% [95% confidence interval (CI), 1.3-1.8%] and 2.9% (95% CI, 0.3-5.5%) in stroke mortality for each interquartile range increase in particulate matter < 10 microm aerodynamic diameter (PM(10)) and ozone concentrations in the same day. Stroke mortality also increased 3.1% (95% CI, 1.1-5.1%) for nitrogen dioxide, 2.9% (95% CI, 0.8-5.0%) for sulfur dioxide, and 4.1% (95% CI, 1.1-7.2%) for carbon monoxide in a 2-day lag for each interquartile range increase in single-pollutant models. When we examined the associations among PM(10) levels stratified by the level of gaseous pollutants and vice versa, we found that these pollutants are interactive with respect to their effects on the risk of stroke mortality. We also observed that the effects of PM(10) on stroke mortality differ significantly in subgroups by age and sex. We conclude that PM(10) and gaseous pollutants are significant risk factors for acute stroke death and that the elderly and women are more susceptible to the effect of particulate pollutants.

Section: Discussionmentioning

confidence: 99%

Effects of air pollutants on acute stroke mortality.

Hong

Lee

Kim

et al. 2002

267

156

“…Those that have been established so far, using the approaches of APHEA (Air Pollution and Health: a European Approach) Phase I (4) and Phase II (5) and NMMAPS (National Mortality and Morbidity Air Pollution Study) (6,7), are confined to the temperate climatic zones. Hong Kong is a large city in a subtropical region where there is evidence of adverse effects of air pollution (8,9). London, United Kingdom, is a city of similar size for which adverse health effects of air pollution have also been reported (10,11).…”

mentioning

confidence: 99%

A tale of two cities: effects of air pollution on hospital admissions in Hong Kong and London compared.

Wong

Atkinson

Anderson

et al. 2002

173

The causal interpretation of reported associations between daily air pollution and daily admissions requires consideration of residual confounding, correlation between pollutants, and effect modification. If results obtained in Hong Kong and London--which differ in climate, lifestyle, and many other respects--were similar, a causal association would be supported. We used identical statistical methods for the analysis in each city. Associations between daily admissions and pollutant levels were estimated using Poisson regression. Nonparametric smoothing methods were used to model seasonality and the nonlinear dependence of admissions on temperature, humidity, and influenza admissions. For respiratory admissions (> or = 65 years of age), significant positive associations were observed with particulate matter < 10 microm in aerodynamic diameter (PM(10), nitrogen dioxide, sulfur dioxide, and ozone in both cities. These associations tended to be stronger at shorter lags in Hong Kong and at longer lags in London. Associations were stronger in the cool season in Hong Kong and in the warm season in London, periods during which levels of humidity are at their lowest in each city. For cardiac admissions (all ages) in both cities, significant positive associations were observed for PM(10), NO(2), and SO(2) with similar lag patterns. Associations tended to be stronger in the cool season. The associations with NO(2) and SO(2) were the most robust in two-pollutant models. Patterns of association for pollutants with ischemic heart disease were similar in the two cities. The associations between O(3) and cardiac admissions were negative in London but positive in Hong Kong. We conclude that air pollution has remarkably similar associations with daily cardiorespiratory admissions in both cities, in spite of considerable differences between cities in social, lifestyle, and environmental factors. The results strengthen the argument that air pollution causes detrimental short-term health effects.

“…In London, England, Atkinson et al (6) found that the PM 10 effect was strongest in the lowest temperature tertile but did not provide numerical details of their analysis. In Hong Kong, Wong et al (7) found that the effect of PM 10 disappeared during the cold season, but, in this tropical climate, the cold season is the more comfortable time of year. In Tucson, Arizona, Schwartz (4) found that the PM 10 effect was reduced during periods of warm temperature, but not significantly so.…”

Section: Consideration Of Temperaturementioning

confidence: 99%

“…Through a MEDLINE search for all papers published before August 2000 that considered PM 10 or PM 2.5 exposure and cardiovascular disease together with a review of references listed in those articles, I identified 12 published studies of hospital admissions for cardiovascular disease (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12). These studies are listed in Table 1.…”

mentioning

confidence: 99%

Airborne particulates and hospital admissions for cardiovascular disease: a quantitative review of the evidence.

Morris

2001

This is a quantitative review of studies characterizing the relationship between exposure to airborne particulates and hospital admissions for cardiovascular disease. A MEDLINE search and a review of reference lists were conducted to identify time-series studies that considered particles less than 10 microm or 2.5 microm in diameter (PM(10) and PM(2.5), respectively) and their association with day-to-day variation in cardiovascular admissions. The results of these studies were standardized to give estimates of the percentage increase in hospital admissions associated with an increase in ingestion of ambient particles of 10 microg/m3. The results were grouped and compared on the basis of the specific outcomes and exposure measures. When studies that considered the association between PM(10) exposure and specific cardiovascular outcomes were pooled (after exclusion of outliers), a 10-microg/m(3) increase in PM(10) was associated with increases in admission rates of 0.8% (95% confidence interval [CI]: 0.5, 1.2%) for congestive heart failure, 0.7% (95% CI: 0.4, 1.0%) for ischemic heart disease, and 0.2% (95% CI: -0.2, 0.6%) for cerebrovascular accidents. These effects tended to diminish substantially when gaseous co-pollutants were considered. The extent to which these effects are due to fine particles is unclear. The available studies indicate that exposure to airborne particles is associated with hospital admissions for cardiovascular disease; but the magnitude of this effect depends strongly on the specific disease category being considered, the time lag used in the analysis, and the type and amount of co-pollutants. Future studies should include careful consideration of the role of co-pollutants in this association, the interaction of particles with temperature, the impact of particle size on this effect, and the extent to which the observed effect involves short-term "harvesting."