Short-term Effects Of Air Pollution Research Articles

Traffic Related Air Pollution Associated with Mild Stroke Hospital Admissions in Copenhagen, Denmark

ISEE-0166 Background and Objective: We studied the short-term effect of air pollution on stroke separately for ischemic (IS) and hemorrhagic (HS) strokes. To study the effect on IS of primarily embolic origin, IS were separated into IS with and without atrial fibrillation (AF). Finally, we stratified patients by stroke severity into mild and severe strokes. Methods: We applied a time-stratified case-crossover design to evaluate the association between particulate (PM10, PM2.5, UFP (particles <0.1 μm diameter)) and gaseous (Nitrogen oxides (NOx), Carbon Monoxide (CO), ozone (O3) air pollution to stroke hospital admissions in Copenhagen (2003-2006). We used conditional logistic regression analysis, adjusting for temperature, relative humidity and wind speed, to examine the air pollution effect for a 0-4 day lag. Computed tomography was used to differentiate IS and HS. AF was determined by electrocardiography. Admission stroke severity was measured by the Scandinavian Stroke Scale (SSS). Results: Out of 7485 stroke admissions, 6798 were IS and 687 were HS, 3485 were mild and 2248 were severe strokes (1752 missing SSS), and 1278 were with and 5811 were without AF (396 were missing information on AF). We observed a significant positive association between NOx, CO and UFPs and IS; NOx, CO and UFPs and strokes without AF; and finally UFPs and mild strokes, all at lag 4. No associations were observed between air pollution and HS, IS with AF or with severe strokes. Among 2822 cases with mild IS without AF, the effect of UFPs (per inter-quartile range, 5-day average) was a 21% (95% confidence interval: 4-41%) increase in admissions. Conclusion: We found an air pollution effect on stroke admissions in patients with mild, IS without AF. Traffic related air pollutants, especially UFPs, were most relevant. Our findings indicate that the effect of air pollution is on small IS of thrombotic origin rather than HS and large embolic strokes.

A Novel Approach to Estimate Distributed Lag Model Between Hospital Admissions and Ozone: A Multi-City Time Series Analysis

ISEE-0507 Background and Objective: Time series analyses have been extensively used to examine the short-term effects of air pollution on health. Standard methods have been used to eliminate confounding by long term and seasonal trends. Distributed lag models have been used to examine whether the exposure effect persists for some time. This creates two issues; first ozone concentrations are serially correlated over time, leading to oscillations in the effect size from lag to lag. Second, from a causal modeling viewpoint, it is preferable to have the exposure as close as possible to randomly assigned. Haugh and Box proposed filtering exposure to remove all autocorrelation, resulting in random fluctuations in differences from expected exposure over time. We apply this approach to season specific analyses to examine the distributed lag between ozone and cardiovascular and respiratory hospital admissions in 92 US cities for the years 1985–2003, for the months May to September. Methods: We fit a city-specific quasi Poisson regression model controlling for seasonality, temperature, and day of the week. We used ARIMA models to pre-filter the ozone series and its lags. Results: We found a 0.14% increase (95% CI: 0.05–0.23) and a 0.10% increase (95% CI:0.01–0.20) in CVD admissions for 10 ppb increase in the same day 8-hour mean ozone when using the original and pre-filtered ozone respectively. The sum of the six day distributed lag increased from −0.23% (95% CI: −0.46 −0.01) to 0.53% (95% CI: 0.23–0.81) for CVD and from 2.11% (95% CI: 1.67–2.54) to 4.4% (95% CI: 3.8–4.9) for respiratory disease when using the pre-filtered ozone vs. the original series. Conclusions: This study presents a new approach to examine distributed lag models and shows that the collinearity between lags could underestimate the exposure health effects. Funded by: EPA RD83241601 and EPA STAR grant R832752010.

Short-Term Effects of Air Pollution on Exhaled Nitric Oxide in Diabetic Patients

ISEE-0328 Background and Objective: Ambient particulate air pollution has been associated with biomarkers of pulmonary and systemic inflammation. In this study we examine if ambient particle levels are associated with exhaled nitric oxide (NO), a marker for pulmonary inflammation, in a sample of subjects with type 2 diabetes from the Boston Metropolitan area. Methods: This analysis is based on data from the first 37 participants who completed an ongoing repeated measures study that started in September 2006. Breath samples were collected during bi-weekly clinic visits. Hourly fine particulate matter (PM2.5), sulfate (SO42-), Black Carbon (BC), and gases were measured at a central ambient monitoring station. Linear mixed models were used to examine the effects of an interquartile increase in air pollution on exhaled NO. The models contained random subject effects, fixed effects of gender, season, NO room air, and ambient pollution, and a first-order auto-regressive term. Results: The number of visits per subject ranged from two to five, with a total of 170 exhaled NO measurements. Ambient particle levels on the days preceding the clinic visit were consistently associated with levels of exhaled NO. A 4.1 μg/m3 increase in mean 48-hour PM2.5 level was associated with an increase of 0.87 ppb (0.19 to 1.56), and a 1.8 μg/m3 increase in mean 48-hour sulfate level was associated with an increase of 0.98 ppb (0.11 to 1.84) in exhaled NO. Associations with black carbon were similar. We found no associations between exhaled NO and ambient gases. Conclusion: These results suggest that in this population of diabetic subjects increased ambient levels of particulate air pollution are associated with changes in airway inflammatory status as measured by exhaled NO. This work is supported by funding from the NIEHS (ES-09825, RD-83241601).

Investigating the Synergistic Effects Between Meteorological Variables and Air Pollutants: Results from the European PHEWE, EUROHEAT and CIRCE Projects

ISEE-0929 Backgroundand Objectives: In the past 20 years, extensive scientific evidence demonstrated and quantified the short-term effects of air pollution and weather extremes on health. However, the studies formally addressing synergy between pollutants and meteorological variables are relatively few. Within the multi-centre European projects PHEWE, EUROHEAT and CIRCE we have investigated the interaction between the effects of air pollutants and meteorological variables on mortality. Methods: We used data from 22 cities in Europe and around the Mediterranean, including daily values for total and cause-specific mortality, air pollutants concentrations (PM10, NO2, O3, SO2, CO) and meteorological variables (apparent temperature, wind speed and direction, “heat-waves”). A GEE modeling approach was applied assuming a Poisson distribution on the outcome variable. Results: We found evidence for an interaction between high temperatures and high ozone and PM10 concentrations. This was particularly evident for “heat-wave” days. For the age group 75–84 years, the estimated heat wave effect is 54% larger on high ozone days. During high PM10 days the heat-wave effects on mortality, for both the 75–84 and the 85+ years age groups, are significantly larger. Differences between cities in Northern Europe, Southern Europe and non-European cities around the Mediterranean were also investigated. It was noted that failure to adjust for air pollution when estimating the temperature effects on mortality may lead to overestimation of the heat and heat-wave effects by up to 30%. Conclusions: The effects of heat-wave days on mortality are larger during high ozone and PM10 days. For ozone this is more evident for those aged 75–84 years compared to those older than 85. In contrast, the interaction with PM10 appears to affect the elderly to a larger extent, probably due to the high penetration of PM indoors. There was no evidence for interaction between heat-wave days and the concentrations of NO2, SO2 and CO.

Estimating Mortality Effects of Fine Particulate Matter in Japan: A Comparison of Time-Series and Case-Crossover Analyses

Small particles can reach alveoli without being trapped in the upper respiratory tract and may have a greater impact on health than larger particles. Given the limited knowledge on health effects of fine particulate matter (PM2.5) in Japan, the short-term effects of PM2.5 on daily mortality using the generalized additive model (GAM), generalized linear model (GLIM), and time-stratified case-crossover analysis were estimated. Daily mortality data were obtained from the Ministry of Health, Labor, and Welfare. Air pollution and meteorological data in 20 areas were obtained from the National Institute for Environmental Studies and the Japan Meteorological Agency, respectively. The three methods were compared, adjusting for meteorological variables and co-pollutants, for area-specific analyses and combined area-specific results using meta-analysis with a random-effects model. Daily mortality for elderly aged 65 and over varied from 0.5 to 127.3 by area. The 24-hr mean concentration of PM2.5 ranged from 11.8 to 22.8 μg/m3. Area-specific analyses revealed regional heterogeneity. Furthermore, combined results showed that a 10-μg/m3 increase in PM2.5 for the single-pollutant model at lag1 was associated with a 0.53, 0.77, and 0.88% increase in all-cause mortality for the GAM, GLIM, and case-crossover analysis, respectively. These findings provide robust evidence for the short-term effects of air pollutants on daily mortality in Japan and suggest that differences in estimates obtained from different statistical models should be considered when multipollutant models are used.

Short-term effects of air pollution: a panel study of blood markers in patients with chronic pulmonary disease

BackgroundGrowing evidence indicates that ambient air pollution is associated with exacerbation of chronic diseases like chronic pulmonary disease. A prospective panel study was conducted to investigate short-term changes of blood markers of inflammation and coagulation in response to daily changes in air pollution in Erfurt, Germany. 12 clinical visits were scheduled and blood parameters were measured in 38 male patients with chronic pulmonary disease during winter 2001/2002. Additive mixed models with random patient intercept were applied, adjusting for trend, weekday, and meteorological parameters. Hourly data on ultrafine particles (UFP, 0.01-0.1 μm), accumulation mode particles (ACP, 0.1-1.0 μm), PM10 (particulate matter <10 μm in diameter), elemental (EC) and organic carbon (OC), gaseous pollutants (nitrogen monoxide [NO], nitrogen dioxide [NO2], carbon monoxide [CO], and sulphur dioxide [SO2]) were collected at a central monitoring site and meteorological data were received from an official network. For each person and visit the individual 24-hour average of pollutants immediately preceding the blood withdrawal (lag 0) up to day 5 (lag1-4) and 5-day running means were calculated.ResultsIncreased levels of fibrinogen were observed for an increase in one interquartile range of UFP, PM10, EC, OC, CO, and NO revealing the strongest effect for lag 3. E-selectin increased in association with ACP and PM10 with a delay of one day. The ACP effect was also seen with the 5-day-mean. The pattern found for D-dimer was inconsistent. Prothrombin fragment 1+2 decreased with lag 4 consistently for all particulate pollutants. Von Willebrand factor antigen (vWF) showed a consistent decrease in association with almost all air pollutants with all lags except for lag 0. No associations were found for C-reactive protein, soluble intercellular adhesion molecule 1, serum amyloid A and factor VII.ConclusionThese results suggest that elevated concentrations of air pollution are associated with changes in some blood markers of inflammation and coagulation in patients with chronic pulmonary disease. The clinical implications of these findings need further investigation.

Are the Short-term Effects of Air Pollution Restricted to Cardiorespiratory Diseases?

Short-term effects of air pollution on common morbidity are largely unknown. The authors explored links between daily levels of air pollution (nitrogen dioxide, ozone, and particulate matter less than 10 microm in diameter (PM(10))) and medical home visits made for diverse reasons in Bordeaux, France, during 2000-2006. Daily numbers of visits were obtained from a network of general practitioners. The excess relative risk (ERR) of a visit for each indicator associated with increased pollutant levels was estimated by fitting a Poisson regression model, controlling for well-known confounding factors and temporal trends. Positive and significant associations were found between air pollution and most health indicators. A 10-microg/m(3) increase in PM(10) levels was associated with increases in visits for upper and lower respiratory diseases (ERRs were 1.5% (95% confidence interval (CI): 0.3, 2.7) and 2.5% (95% CI: 0.5, 4.4), respectively), headache and asthenia (ERR = 3.5%, 95% CI: 1.3, 5.9), and skin rash and conjunctivitis (ERR = 3.2%, 95% CI: -0.2, 6.8). Significant associations were also found between nitrogen dioxide and ozone and several health indicators. Distributed-lag models showed no harvesting effect, and some effects persisted up to 15 days after exposure increased. These results suggest that considering only the most severe effects of air pollution leads to underestimation of its impact on public health.

Health impact assessment of particulate pollution in Tallinn using fine spatial resolution and modeling techniques

BackgroundHealth impact assessments (HIA) use information on exposure, baseline mortality/morbidity and exposure-response functions from epidemiological studies in order to quantify the health impacts of existing situations and/or alternative scenarios. The aim of this study was to improve HIA methods for air pollution studies in situations where exposures can be estimated using GIS with high spatial resolution and dispersion modeling approaches.MethodsTallinn was divided into 84 sections according to neighborhoods, with a total population of approx. 390 000 persons. Actual baseline rates for total mortality and hospitalization with cardiovascular and respiratory diagnosis were identified. The exposure to fine particles (PM2.5) from local emissions was defined as the modeled annual levels. The model validation and morbidity assessment were based on 2006 PM10 or PM2.5 levels at 3 monitoring stations. The exposure-response coefficients used were for total mortality 6.2% (95% CI 1.6–11%) per 10 μg/m3 increase of annual mean PM2.5 concentration and for the assessment of respiratory and cardiovascular hospitalizations 1.14% (95% CI 0.62–1.67%) and 0.73% (95% CI 0.47–0.93%) per 10 μg/m3 increase of PM10. The direct costs related to morbidity were calculated according to hospital treatment expenses in 2005 and the cost of premature deaths using the concept of Value of Life Year (VOLY).ResultsThe annual population-weighted-modeled exposure to locally emitted PM2.5 in Tallinn was 11.6 μg/m3. Our analysis showed that it corresponds to 296 (95% CI 76528) premature deaths resulting in 3859 (95% CI 10236636) Years of Life Lost (YLL) per year. The average decrease in life-expectancy at birth per resident of Tallinn was estimated to be 0.64 (95% CI 0.17–1.10) years. While in the polluted city centre this may reach 1.17 years, in the least polluted neighborhoods it remains between 0.1 and 0.3 years. When dividing the YLL by the number of premature deaths, the decrease in life expectancy among the actual cases is around 13 years. As for the morbidity, the short-term effects of air pollution were estimated to result in an additional 71 (95% CI 43–104) respiratory and 204 (95% CI 131–260) cardiovascular hospitalizations per year. The biggest external costs are related to the long-term effects on mortality: this is on average €150 (95% CI 40–260) million annually. In comparison, the costs of short-term air-pollution driven hospitalizations are small €0.3 (95% CI 0.2–0.4) million.ConclusionSectioning the city for analysis and using GIS systems can help to improve the accuracy of air pollution health impact estimations, especially in study areas with poor air pollution monitoring data but available dispersion models.

Shortness of breath at night and health status in congestive heart failure: Effects of environmental conditions and health-related and dietary factors

Objectives Recent studies suggest that persons with congestive heart failure (CHF) may be at higher risk for the short-term effects of air pollution. We carried out this daily diary panel study in Montreal, Quebec, to determine whether indicators of self-reported health status and shortness of breath at night were associated with selected health-related and dietary factors, weather conditions, and air pollution. Methods Thirty-one subjects with CHF participated in this study in 2002 and 2003. Over a 2-month period, they measured their oxygen saturation, pulse rate, weight, and temperature each morning and recorded these and other data in a daily diary. Every morning they recorded on visual analogue scales their assessments of their general health, shortness of breath, and weakness, their weight, temperature and other data in a daily diary. Air pollution and weather conditions were obtained from fixed-site monitoring stations. This paper deals only with the daily self-reported health outcomes of general health and shortness of breath. We made use of mixed regression models, adjusting for within-subject serial correlation and temporal trends, to determine the association between oxygen saturation and pulse rate and health-related, dietary and environmental variables. Depending on the model, we accounted for the effects of a variety of health-related and dietary variables as well as NO 2, ozone, maximum temperature and change in barometric pressure at 8:00AM from the previous day. Results Of the many associations for self-reported general health and shortness of breath, we found only a few statistically significant predictors, although increases in many variables showed decrements in self-reported general health and shortness of breath. The statistically significant associations with general health were increases in daily pulse rate and body weight, higher maximum ambient air temperature, higher relative humidity, and ozone (on the concurrent day). Statistically significant predictors of worsened shortness of breath at night were increases in blood pressure, body weight, and higher maximum ambient air temperature (lag 0 and 1 days). We also found that there was little confounding between environmental variables and health and dietary factors. Conclusions The findings from the present investigation suggest that certain health-related indices and environmental conditions affect self-reported health and shortness of breath in CHF patients, although larger studies are needed to confirm these findings.

Short-term Associations of Air Pollution with Postneonatal Infant Death in Seoul, Korea, 1999-2003

Objective to assess whether exposure to air pollutants is associated with postneonatal infant death, using a timeseries methodology, between 1999 and 2003 in Seoul, Korea.. Methods We investigated the short-term effects of air pollution for 548,725 live births during the study period. The daily count of postneonatal infant deaths from all causes and from SIDS (sudden infant death syndrome) by birth order was analyzed by a Generalized Additive Poisson model, with controlling for the effects of seasonal trends, air temperature, relative humidity, barometric pressure, and day of the week as covariates. Results During the study period, we observed 699 deaths from all causes and 47 deaths from SIDS. We did not find any significant associations between daily mortality and ambient levels of air pollutants except for CO and <TEX>$NO_2$</TEX>. The estimated relative risk of postneonatal infant death from all causes was 1.17 (95% CI=1.04-1.32) and 1.16 (95% CI=1.03-1.29) by IQR (interquartile range) for CO and <TEX>$NO_2$</TEX> respectively. Also, we observed no clear trend of the mortality effects of air pollution by birth orders. Conclusion In conclusion, our findings suggest that air pollution, in general, influenced adversely postneonatal infant death from all-cause and SIDS although it was not statistically significant. This study may support that the rationale.

Modification by Influenza on Health Effects of Air Pollution in Hong Kong

BackgroundBoth influenza viruses and air pollutants have been well documented as major hazards to human health, but few epidemiologic studies have assessed effect modification of influenza on health effects of ambient air pollutants.ObjectivesWe aimed to assess modifying effects of influenza on health effects of ambient air pollutants.MethodsWe applied Poisson regression to daily numbers of hospitalizations and mortality to develop core models after adjustment for potential time-varying confounding variables. We assessed modification of influenza by adding variables for concentrations of single ambient air pollutants and proportions of influenza-positive specimens (influenza intensity) and their cross-product terms.ResultsWe found significant effect modification of influenza (p < 0.05) for effects of ozone. When influenza intensity is assumed to increase from 0% to 10%, the excess risks per 10-μg/m3 increase in concentration of O3 increased 0.24% and 0.40% for hospitalization of respiratory disease in the all-ages group and ≥ 65 year age group, respectively; 0.46% for hospitalization of acute respiratory disease in the all-ages group; and 0.40% for hospitalization of chronic obstructive pulmonary disease in the ≥ 65 group. The estimated increases in the excess risks for mortality of respiratory disease and chronic obstructive pulmonary disease in the all-ages group were 0.59% and 1.05%, respectively. We found no significant modification of influenza on effects of other pollutants in most disease outcomes under study.ConclusionsInfluenza activity could be an effect modifier for the health effects of air pollutants particularly for O3 and should be considered in the studies for short-term effects of air pollutants on health.

A panel study in congestive heart failure to estimate the short-term effects from personal factors and environmental conditions on oxygen saturation and pulse rate

Objectives: Recent studies suggest that persons with congestive heart failure (CHF) may be at higher risk for short-term effects of air pollution. This daily diary panel study in Montreal, Quebec,...

Public Health and Air Pollution in Asia (PAPA): A Multicity Study of Short-Term Effects of Air Pollution on Mortality

Background and objectivesAlthough the deleterious effects of air pollution from fossil fuel combustion have been demonstrated in many Western nations, fewer studies have been conducted in Asia. The Public Health and Air Pollution in Asia (PAPA) project assessed the effects of short-term exposure to air pollution on daily mortality in Bangkok, Thailand, and in three cities in China: Hong Kong, Shanghai, and Wuhan.MethodsPoisson regression models incorporating natural spline smoothing functions were used to adjust for seasonality and other time-varying covariates that might confound the association between air pollution and mortality. Effect estimates were determined for each city and then for the cities combined using a random effects method.ResultsIn individual cities, associations were detected between most of the pollutants [nitrogen dioxide, sulfur dioxide, particulate matter ≤ 10 μm in aerodynamic diameter (PM10), and ozone] and most health outcomes under study (i.e., all natural-cause, cardiovascular, and respiratory mortality). The city-combined effects of the four pollutants tended to be equal or greater than those identified in studies conducted in Western industrial nations. In addition, residents of Asian cities are likely to have higher exposures to air pollution than those in Western industrial nations because they spend more time outdoors and less time in air conditioning.ConclusionsAlthough the social and environmental conditions may be quite different, it is reasonable to apply estimates derived from previous health effect of air pollution studies in the West to Asia.

Socioeconomic disparities in air pollution-associated mortality

This study aimed to determine whether individuals with lower socioeconomic status (SES) were more susceptible to the acute effects of ambient air pollution than those with higher SES. We included 24,357 Hong Kong Chinese aged 30 or above who died of natural causes in 1998. Information on individual socioeconomic characteristics was obtained by interviewing proxy informants with a standardized questionnaire in all four death registries. Individual SES was indicated by three measures: type of housing, occupational group and education attainment. Poisson regression was performed to assess the short-term effects of ambient air pollution measured by PM 10, NO 2, SO 2 and O 3 on mortality for each SES group. The differences in the effects between SES groups were estimated by the interaction between air pollution and SES. We found that PM 10 and NO 2 were associated with greater risk of mortality on people living in public rental housing than in private housing. The effects of all four pollutants were significantly greater in blue-collar workers than the never-employed and white-collar groups ( p<0.05). However, we found no compelling evidence of effect modification by education attainment. Our results provide new evidence on the role of individual's SES as effect modifiers of the short-term effects of air pollution on mortality. The reduction of risks associated with air pollution for socially disadvantaged populations should be a high priority in public health and environmental policies.

Air Quality Risk Assessment and Management

This article provides (1) a synthesis of the literature on the linkages between air pollution and human health, (2) an overview of quality management approaches in Canada, the United States, and the European Union (EU), and (3) future directions for air quality research. Numerous studies examining short-term effects of air pollution show significant associations between ambient levels of particulate matter (PM) and other air pollutants and increases in premature mortality and hospitalizations for cardiovascular and respiratory illnesses. Several well-designed epidemiological studies confirmed the adverse long-term effects of PM on both mortality and morbidity. Epidemiological studies also document significant associations between ozone (O3), sulfur (SO2), and nitrogen oxides (NOx) and adverse health outcomes; however, the effects of gaseous pollutants are less well documented. Subpopulations that are more susceptible to air pollution include children, the elderly, those with cardiorespiratory disease, and socioeconomically deprived individuals. Canada-wide standards for ambient air concentrations of PM2.5 and O3 were set in 2000, providing air quality targets to be achieved by 2010. In the United States, the Clean Air Act provides the framework for the establishment and review of National Ambient Air Quality Standards for criteria air pollutants and the establishment of emissions standards for hazardous air pollutants. The 1996 European Union's enactment of the Framework Directive for Air Quality established the process for setting Europe-wide limit values for a series of pollutants. The Clean Air for Europe program was established by the European Union to review existing limit values, emission ceilings, and abatement protocols, as set out in the current legislation. These initiatives serve as the legislative framework for air quality management in North America and Europe.

Short-term Effects of Air Pollution on Cardiovascular Mortality in Elderly in Niš, Serbia

The short-term effects of air pollution on cardiovascular mortality in elderly were investigated in Nis, during the 2001-2005. Daily measurements of black smoke (BS) and sulphur dioxide (SO2), as well as the daily number of cardiovascular death among person > or =65 yrs of age, were collected. Generalized linear model extending Poisson regression was applied. The effects of time trend, seasonal variations, day of week, temperature, relative humidity and barometric pressure were analysed. The results did not support findings from previous studies that had shown an increase in the number of cardiovascular death in elderly in association with air pollution.

Attributable Risks Calculation From Case-Crossover Study of Air Pollution and Asthma Attacks

ISEE-411 Objective: Case-crossover studies allow studying the short-term effects of air pollution for shorter study periods and smaller populations (eg, US census tracts) than time-series studies. To our knowledge, attributable risks of air pollution have never been calculated from case-crossover studies. Material and Methods: A case-crossover study of the relationship between daily PM10 concentrations modeled by small census units (IRIS, comparable with US Block Group) and 4683 emergency calls to mobile emergency practitioners for asthma attacks was carried out in an eastern France conurbation including 450,000 inhabitants (years 2000–2005). We obtained an overall odds ratio of 1.034 (95% CI: 0.996–1.074) for a 10 μg/m3 increase in PM10 (adjusted for meteorology, pollens, and influenza). This odds ratio was used to estimate the annual number of calls attributable to PM10 in the conurbation, using the method recommended by the French National Institute of Health Surveillance (InVS) for time series. Computation of this estimate integrated the pluri-annual (2000–2005) mean PM10 concentration of 22.5 μg/m3 observed in the conurbation. Results: The annual number of calls for asthma attacks attributable to the exceeding of the “baseline” PM10 concentration of 10 μg/m3 in the conurbation was 9 (95% CI: 0–15) for 100,000 inhabitants. This estimate assumes a causality link between ambient PM10 concentrations and asthma attacks, which is likely according to literature data. On the basis of these elements, we can at least assume that the number of calls attributable to PM10 should be inferior to the upper confidence interval of the estimate. Conclusions: Our results suggest that, in our study setting, the annual number of calls to mobile emergency practitioners for asthma attacks attributable to the exceeding of the “baseline” PM10 concentration of 10 μg/m3 is less than 15 for 100,000 inhabitants.

Short-Term Effects of Air Pollution on Oxygen Saturation in Senior Adults in Steubenville, OH

ISEE-271 Objective: Ambient particulate air pollution has been associated with various cardiovascular endpoints. In this study, we examine whether particle levels, including the regional nontraffic component SO42−, are associated with oxygen saturation in a cohort of 32 elderly subjects from Steubenville, Ohio, who were followed up repeatedly over 6 months during the summer and fall of 2000. Material and Methods: Electrocardiogram data were collected on weekly visits during a 30-minute standardized protocol, whereas oxygen saturation was continuously measured, and data were available at 30-seconds intervals. A central ambient monitoring station provided daily fine particle (PM2.5), sulfate (SO42−), and elemental carbon (EC) data. Linear mixed models were used to examine the effects of an interquartile increase in air pollution on the day before the health tests on median oxygen saturation, overall, and per protocol part. The models contained random subject effects, fixed effects of pollution, age, gender, race, obesity, time of day, and temperature, and a first-order autoregressive process for the within-subject residuals. Results: The number of visits per subject ranged from 4 to 24, with a total of 40,245 oxygen saturation measurements. A 13.4 mg/m3 increase in PM2.5 on the day before the health assessment was associated with a decrease of −0.090% in oxygen saturation (95% CI: −0.196 to 0.016). A 5.1 mg/m3 increase in SO42− on the previous day was associated with a decrease of −0.093% in oxygen saturation (95% CI: −0.193 to 0.006). These effects were strongest during the initial rest period: PM 2.5 was associated with a decrease of −0.172% (95% CI: −0.304 to −0.041) and SO42− with a decrease of −0.148% (95% CI: −0.270 to −0.026) in oxygen saturation, respectively. We found no associations with EC. Conclusions: These results suggest that in this population of elderly subjects, increased ambient levels of particulate air pollution may lead to small changes in oxygen saturation in the blood. These changes may result from particle-induced pulmonary inflammation or vascular responses.

Short-term effects of air pollution on cardiovascular diseases: outcomes and mechanisms.

The effects of air pollution on health have been intensively studied in recent years. Acute exposure to environmental pollutants such as particulate and gaseous matters (carbon monoxide, nitrogen oxides, sulphur dioxide and ozone) was associated with an increased rate of events and mortality because of cardiovascular diseases. These effects were investigated in short-term studies, which related day-to-day variations in air pollution to disease, and in long-term studies, which have followed cohorts of exposed individuals over time. The evidence from the literature on the short-term cardiovascular effects of air pollutants is discussed from clinical and mechanistic points of view.

Urban Air Pollution and Respiratory Emergency Visits at Pediatric Unit, Reggio Emilia, Italy

Short-term effects of air pollution on daily mortality and hospital admissions for respiratory causes are well documented. Few studies, however, explore the association between exposure to air pollution and daily emergency room visits for respiratory disorders, particularly in Italy and particularly among children as a susceptible population. A time-series analysis was conducted to explore the short-term association between air pollutants (PM10, total suspended particulates [TSP], NO2, SO2, CO, O3) and pediatric emergency room (ER) visits in a small city of northern Italy, Reggio Emilia, during the period 03/01/2001–03/31/2002. There were 1051 ER visits included in the study. Data were analyzed using generalized additive models (GAM), adjusting for various confounding variables, including temperature, humidity, and pollens (Graminaceae). The analyses were also stratified according to the nationality of children (Italians and foreigners). In single-pollutant models, the strongest associations were observed at lag 3 for a 10-μg/m3 increase of TSP (2.7% increase in ER, 95% CI 0.7–4.6) and PM10 (3.0% increase, 95% CI 0.4–5.7), and at lag 4 for a 10-μg/m3 increase of NO2 (11.0% increase in ER, 95% CI 3.6–18.8). At lag 3, the percentage increase in ER visits is similar for the 2 groups of children (Italians and foreigners) for TSP and PM10. The results of the study support the findings that air pollution is a relevant determinant of deterioration of respiratory health among children.