Burden of disease attributed to anthropogenic air pollution in the United Arab Emirates: Estimates based on observed air quality data

This study quantifies the national burden of disease attributed to particulate matter (PM) and ozone (O₃) in ambient air in the United Arab Emirates (UAE), a rapidly growing nation in which economic development and climatic conditions pose important challenges for air quality management. Estimates of population exposure to these air pollutants are based on observed air quality data from fixed-site monitoring stations. We divide the UAE into small grid cells and use spatial-statistical methods to estimate the ambient pollutant concentrations in each cell based on the observed data. Premature deaths attributed to PM and O₃ are computed for each grid cell and then aggregated across grid cells and over a year to estimate the total number of excess deaths attributable to ambient air pollution. Our best estimate is that approximately 545 (95% CI: 132-1224) excess deaths in the UAE in the year 2007 are attributable to PM in ambient air. These excess deaths represent approximately 7% (95% CI: 2-17%) of the total deaths that year. We attribute approximately 62 premature deaths (95% CI: 17-127) to ground-level O₃ for the year 2007. Uncertainty in the natural background level of PM, due to the frequent dust storms occurring in the region, has significant impacts on the attributed mortality estimates. Despite the uncertainties associated with the integrated assessment framework, we conclude that anthropogenic ambient air pollution, in particular PM, causes a considerable public health impact in the UAE in terms of premature deaths. We discuss important uncertainties and scientific hypotheses to be investigated in future work that might help reduce the uncertainties in the burden of disease estimates.     

Ambient air pollution and daily mortality in Anshan, China: a time-stratified case-crossover analysis

Few case-crossover studies were conducted in China to investigate the acute health effects of air pollution. We conducted a time-stratified case-crossover analysis to examine the association between air pollution and daily mortality in Anshan, a heavily-polluted industrial city in northeastern China. Daily mortality, air pollution, and weather data in 2004-2006 in Anshan were collected. Time-stratified case-crossover approach was used to estimate the effect of air pollutants (PM₁₀, SO₂, NO₂ and CO) on total and cardiopulmonary mortality. Controls were selected as matched days of the week in the same month. Potential effect modifiers, such as gender and age, were also examined. We found significant associations between air pollution and daily mortality from cardiovascular diseases in Anshan. A 10 μg/m³ elevation of 2-day moving average (lag 01) concentration in PM₁₀, SO₂, NO₂ and CO corresponded to 0.67% (95% CI: 0.29%, 1.04%), 0.38% (95% CI: −0.06%, 0.83%), 2.11% (95% CI: 0.22%, 4.00%) and 0.04% (95% CI: 0.01%, 0.07%) increase of cardiovascular mortality. The associations for total and respiratory mortality were generally positive but statistically insignificant. The air pollution health effects were significantly modified by age, but not by gender. Conclusively, our study showed that short-term exposure to air pollution was associated with increased cardiovascular mortality in Anshan. These findings may have implications for local environmental and social policies.     

Exposure-response functions for health effects of ambient air pollution applicable for China -- a meta-analysis

Assessing the benefits of projects and policies to reduce air pollution requires quantitative knowledge about the relationship between exposure to air pollution and public health. This article proposes exposure-response functions for health effects of PM10 and SO2 pollution in China. The functions are based on Chinese epidemiological studies, and cover mortality, hospital admissions, and chronic respiratory symptoms and diseases. We derive the following coefficients for acute effects: a 0.03% (S.E. 0.01) and a 0.04% (S.E. 0.01) increase in all-cause mortality per microg/m3 PM10 and SO2, respectively, a 0.04% (S.E. 0.01) increase in cardiovascular deaths per microg/m3 for both PM10 and SO2, and a 0.06% (S.E. 0.02) and a 0.10% (S.E. 0.02) increase in respiratory deaths per microg/m3 PM10 and SO2, respectively. For hospital admissions due to cardiovascular diseases the obtained coefficients are 0.07% (S.E. 0.02) and 0.19% (S.E. 0.03) for PM10 and SO2, respectively, whereas the coefficients for hospital admissions due to respiratory diseases are 0.12% (S.E. 0.02) and 0.15% (S.E. 0.03) for PM10 and SO2, respectively. Exposure-response functions for the impact of long-term PM10 levels on the prevalence of chronic respiratory symptoms and diseases are derived from the results of cross-sectional questionnaire surveys, and indicate a 0.31% (S.E. 0.01) increase per microg/m3 in adults and 0.44% (S.E. 0.02) per microg/m3 in children. With some exceptions, Chinese studies report somewhat lower exposure-response coefficients as compared to studies in Europe and USA.     

Visibility, air quality and daily mortality in Shanghai, China

This study was designed to assess the association between visibility and air quality, and to determine whether the variations in daily mortality were associated with fluctuations in visibility levels in Shanghai, China. Mortality data were extracted from the death certificates, provided by Shanghai Municipal Center of Disease Control and Prevention, and visibility data were obtained from Shanghai Municipal Bureau of Meteorology. Air quality data (PM₁₀, PM_2.5, PM_10-2.5, SO₂, NO₂ and O₃) were obtained from Shanghai Environmental Monitoring Center. Generalized additive model (GAM) with penalized splines was used to analyze the mortality, visibility, air pollution, and covariate data. Among various pollutants, PM_2.5 showed strongest correlation with visibility. Visibility, together with humidity, was found appropriate in predicting PM_2.5 (R-squared: 0.64) and PM₁₀ (R-squared: 0.62). Decreased visibility was significantly associated with elevated death rates from all causes and from cardiovascular disease in Shanghai; one inter-quartile range (8 km) decrease in visibility corresponded to 2.17% (95%CI: 0.46%, 3.85%), 3.36% (95%CI: 0.96%, 5.70%), and 3.02% (95%CI: − 1.32%, 7.17%) increase of total, cardiovascular and respiratory mortality, respectively. The effect estimates using predicted PM_2.5 and PM₁₀ concentrations were similar to those assessed using actual concentrations. This is the first study in Mainland China assessing the association between visibility and adverse health outcomes. Our findings suggest the possibility of using visibility as a surrogate of air quality in health research in developing countries where air pollution data might be scarce and not routinely monitored.     

Association of ambient air pollution with hospital outpatient and emergency room visits in Shanghai, China

Few studies exist in China examining the association of ambient air pollution with morbidity outcomes. We conducted a time-series analysis to examine the association of outdoor air pollutants (PM₁₀, SO₂, and NO₂) with hospital outpatient and emergency room visits in Shanghai, China, using 3 years of daily data (2005-2007). Hospital and air pollution data were collected from the Shanghai Health Insurance Bureau and Shanghai Environmental Monitoring Center. Using a natural spline model, we examined effect of air pollutants with different lag structures including both single-day lag and multi-day lag. We examined effects of air pollution for the warm season (from April to September) and cool season (from October to March) separately. We found outdoor air pollution (SO₂ and NO₂) was associated with increased risk of hospital outpatient and emergency room visits in Shanghai. The effect estimates varied for different lag structures of pollutants’ concentrations. For lag 3, a 10 μg/m³ increase in concentration of PM₁₀, SO₂ and NO₂ corresponded to 0.11% (95%CI: −0.03%, 0.26%), 0.34% (95%CI: 0.06%, 0.61%) and 0.55% (95%CI: 0.14%, 0.97%) increase of outpatient visit; and 0.01% (95%CI: −0.09%, 0.10%), 0.17% (95%CI: 0.00%, 0.35%) and 0.08% (95%CI: −0.18%, 0.33%) increase of emergency room visit. The associations appeared to be more evident in the cool season than in the warm season. In conclusion, short-term exposure to outdoor air pollution was associated with increased risk of hospital outpatient and emergency room visits in Shanghai. Our analyses provide evidence that the current air pollution level has an adverse health effect and strengthen the rationale for further limiting air pollution levels in the city.     

Health benefits of improving air quality in the rapidly aging Korean society

Korea is experiencing an extraordinarily rapid demographic transition. We investigated the short-term association between air pollution and mortality and assessed the impact of improved air quality on mortality in a rapidly aging city, Seoul, Korea.The generalized additive model (GAM) was used to estimate the relative risks (RR) of mortality associated with changes in air pollution. The time trends, seasonal variations, day of the week effects, and weather effects were controlled in the models. To estimate the health benefits, we used the US Environmental Protection Agency's BenMAP.For people 0–64 years of age, elderly people (65+ years), and all age groups, an increase of 10 μg/m³ in PM₁₀ was associated with increases in daily death counts of 0.27% (95% CI: 0.04–0.50), 0.45% (95% CI: 0.27–0.64), and 0.37% (95% CI: 0.23–0.52), respectively. For ages 0–64 years, elderly people, and all age groups, a 10 ppb increase in 1-hour maximum ozone concentration resulted in an increased risk of daily death counts of 0.28% (95% CI: − 0.19–0.74), 0.96% (95% CI: 0.46–1.47), and 0.81% (95% CI: 0.35–1.26), respectively.For elderly people, it was estimated that the health benefits of attaining the World Health Organization's (WHO) air quality guidelines (AQGs) for PM₁₀ (24-hour average 50 μg/m³) would suggest an annual reduction of 964 (95% CI: 564–1366) premature deaths, and 329 (95% CI: 159–500) premature deaths could be prevented annually in 2015 from attaining the WHO's guidelines for ozone (8-hour average 100 μg/m³).The rapid increase of the elderly population has major consequences and implications for society and public health. This study showed that elderly people are at higher risk for the acute mortality effects of air pollution. Therefore, cleaner air will substantially contribute to improved public health in Seoul, given the growing concern about the adverse effects of air pollution for elderly people.     

Ambient carbon monoxide and daily mortality in three Chinese cities: the China Air Pollution and Health Effects Study (CAPES)

Ambient carbon monoxide (CO) is an air pollutant primarily generated by traffic. CO has been associated with increased mortality and morbidity in developed countries, but few studies have been conducted in Asian developing countries. In the China Air Pollution and Health Effects Study (CAPES), the short-term associations between ambient CO and daily mortality were examined in three Chinese cities: Shanghai, Anshan and Taiyuan. Poisson regression models incorporating natural spline smoothing functions were used to adjust for long-term and seasonal trend of mortality, as well as other time-varying covariates. Effect estimates were obtained for each city and then for the cities combined. In both individual-city and combined analysis, significant associations of CO with both total non-accidental and cardiovascular mortality were observed. In the combined analysis, a 1 mg/m³ increase of 2-day moving average concentrations of CO corresponded to 2.89% (95%CI: 1.68, 4.11) and 4.17% (95%CI: 2.66, 5.68) increase of total and cardiovascular mortality, respectively. CO was not significantly associated with respiratory mortality. Sensitivity analyses showed that our findings were generally insensitive to alternative model specifications. In conclusion, ambient CO was associated with increased risk of daily mortality in these three cities. Our findings suggest that the role of exposure to CO and other traffic-related air pollutants should be further investigated in China.     

Ambient sulfate concentration and chronic disease mortality in Beijing

In this study, ecological analysis was used to assess the relationship between ambient air pollution and human mortality. All the data on environmental measures and related factors, population size and number of deaths were collected for the city of Beijing, PR China and its eight districts for the years 1980-1992. In this study the concentration of SO(4)2- was selected as a main indicator of environmental pollution for the following reasons: (i) SO(4)2- data are available to cover all urban and suburban areas in Beijing compared with other air pollutants during the study period; (ii) SO(4)2- levels indicate the concentration of sulfide (include sulfate) and acid fog in the air, and they are significantly lower in cleaner districts than in others; and (iii) analyses showed that SO(4)2- levels are significantly correlated with daily mean concentrations of sulfur dioxide and nitrogen oxide, annual coal combustion, number of households using gas fuel, counts of motor vehicles and population density. Age-standardised mortality rates due to specific diseases were calculated using the Chinese population census data in 1990. Statistically significant correlations were observed between SO(4)2- concentration and total mortality and mortality due to cardiovascular disease, malignant tumour and lung cancer (r > 0.50 in all cases). The correlations were not only found between the current SO(4)2- concentration and these mortalities, but also for SO(4)2- levels measured up to 12 years prior to death, which may suggest long-term effects of air pollution. No significant correlations were observed for mortality from respiratory diseases and cerebrovascular diseases (r = 0.30-0.50). This study indicates that the concentration of SO(4)2- in air is a useful air pollution indicator in the areas where coal is used as the main source of energy. Areas with high levels of SO(4)2- experienced higher mortality due to a variety of chronic diseases.     

Exposure to household air pollution from biomass‐burning cookstoves and HbA1c and diabetic status among Honduran women

Household air pollution from biomass cookstoves is estimated to be responsible for more than two and a half million premature deaths annually, primarily in low and middle‐income countries where cardiometabolic disorders, such as Type II Diabetes, are increasing. Growing evidence supports a link between ambient air pollution and diabetes, but evidence for household air pollution is limited. This cross‐sectional study of 142 women (72 with traditional stoves and 70 with cleaner‐burning Justa stoves) in rural Honduras evaluated the association of exposure to household air pollution (stove type, 24‐hour average kitchen and personal fine particulate matter [PM_2.5] mass and black carbon) with glycated hemoglobin (HbA1c) levels and diabetic status based on HbA1c levels. The prevalence ratio (PR) per interquartile range increase in pollution concentration indicated higher prevalence of prediabetes/diabetes (vs normal HbA1c) for all pollutant measures (eg, PR per 84 μg/m³ increase in personal PM_2.5, 1.49; 95% confidence interval [CI], 1.11‐2.01). Results for HbA1c as a continuous variable were generally in the hypothesized direction. These results provide some evidence linking household air pollution with the prevalence of prediabetes/diabetes, and, if confirmed, suggest that the global public health impact of household air pollution may be broader than currently estimated.     

STEMS-Air: a simple GIS-based air pollution dispersion model for city-wide exposure assessment

Current methods of air pollution modelling do not readily meet the needs of air pollution mapping for short-term (i.e. daily) exposure studies. The main limiting factor is that for those few models that couple with a GIS there are insufficient tools for directly mapping air pollution both at high spatial resolution and over large areas (e.g. city wide). A simple GIS-based air pollution model (STEMS-Air) has been developed for PM₁₀ to meet these needs with the option to choose different exposure averaging periods (e.g. daily and annual). STEMS-Air uses the grid-based FOCALSUM function in ArcGIS in conjunction with a fine grid of emission sources and basic information on meteorology to implement a simple Gaussian plume model of air pollution dispersion. STEMS-Air was developed and validated in London, UK, using data on concentrations of PM₁₀ from routinely available monitoring data. Results from the validation study show that STEMS-Air performs well in predicting both daily (at four sites) and annual (at 30 sites) concentrations of PM₁₀. For daily modelling, STEMS-Air achieved r² values in the range 0.19-0.43 (p < 0.001) based solely on traffic-related emissions and r² values in the range 0.41-0.63 (p < 0.001) when adding information on ‘background’ levels of PM₁₀. For annual modelling of PM₁₀, the model returned r² in the range 0.67-0.77 (P < 0.001) when compared with monitored concentrations. The model can thus be used for rapid production of daily or annual city-wide air pollution maps either as a screening process in urban air quality planning and management, or as the basis for health risk assessment and epidemiological studies.     

Air pollution and lung cancer risks in China--a meta-analysis

Lung cancer is a serious health problem in China, as in the rest of the world. Many studies have already proved that air pollution as well as other environmental factors can increase the risk of lung cancer. Based on epidemiological studies carried out in China, this paper proposes odds ratios (OR) to evaluate the risk of lung cancer from indoor air pollution for the Chinese population by applying the method of meta-analysis. For domestic coal use for heating and cooking, the pooled OR values are 1.83 (95% CI: 0.62-5.41) and 2.66 (1.39-5.07) for women and both sexes, respectively. For indoor exposure to coal dust, the OR values are 2.52 (95% CI: 1.94-3.28) and 2.42 (1.62-3.63) for women and both sexes, respectively. Cooking oil vapor is another factor increasing lung cancer risk. The OR values are 2.12 (95%CI: 1.81-2.47), 1.78 (1.50-2.12) and 6.20 (2.88-13.32) for nonsmoking women, women, and both sexes, respectively. Regarding environmental tobacco smoke, the pooled OR values are 1.70 (95% CI: 1.32-2.18) and 1.64 (1.29-2.07) for nonsmoking women and both sexes, respectively. Funnel plots with statistical test have been applied to examine the publication bias, and the results implied that the analysis of coal consumption and cooking oil pollution might be affected by publication bias. The meta-analysis results confirm the association between lung cancer and indoor air pollution for the Chinese population.     

Impact of extreme temperature on hospital admission in Shanghai, China

No previous study exists in China examining the impact of extreme temperature on morbidity outcomes. In this study, we investigated the impact of heat waves and cold spells on hospital admission in Shanghai, China. Daily hospital admission data between January 1, 2005 and December 31, 2008 were collected from the Shanghai Health Insurance Bureau. The heat wave was defined as a period of at least 7 consecutive days with daily maximum temperature above 35.0 °C and daily average temperatures above the 97th percentile during the study period. The cold spell was defined as a period of at least 7 consecutive days with daily maximum temperature and daily average temperatures below the 3rd percentile during the study period. We calculated excess cases of hospitalization and rate ratios (RRs) to estimate the impacts of both heat wave and cold spell on hospital admission. We identified one heat wave period (from 24 July to 2 August, 2007) and one cold spell period (from 28 January to 3 February, 2008) between 2005 and 2008. The heat wave was associated with 2% (95% CI: 1%-4%), 8% (95%CI: 5%-11%), and 6% (95%CI: 0%-11%) increase of total, cardiovascular and respiratory hospital admission. The cold spell was associated with 38% (95%CI: 35%, 40%), 33% (95%CI: 28%, 37%) and 32% (95%CI: 24%, 40%) increase of total, cardiovascular and respiratory hospital admission. The differences between heat wave and cold spell-related hospital admission were statistically significant for all causes and cardiovascular causes, but not for respiratory causes. In conclusion, both heat wave and cold spell were associated with increased risk of hospital admissions in Shanghai. Cold spell seemed to have a larger impact on hospital admission than heat wave. Public health programs should be tailored to prevent extreme temperature-related health problems in the city.     

Burden of disease attributable to air pollutants from municipal solid waste incinerators in Seoul, Korea: a source-specific approach for environmental burden of disease

Few studies have attempted to quantify the integrated health burden, incorporating both mortality and morbidity as these factors pertain to air pollutants, on the population in the vicinity of the incinerators. The aims of this study are to estimate the attributable burden of disease caused by incinerators in Seoul, Korea and to present an approach based on source-specific exposure for the estimation of the environmental burden of disease (EBD). With particular attention on the development of a measurement means of the source-specific, exposure-based population attributable fraction (PAF), we integrated air dispersion modeling, Geographic Information Systems (GIS), the population distribution of exposure, and the exposure-response relationship. We then estimated the PAFs caused by additional concentrations of four air pollutants (PM₁₀, NO_2, SO₂, and CO) emitted from four municipal solid waste incinerators (MSWIs) in Seoul in 2007. We, finally, estimated the attributable burden of disease, using the estimated PAF and the disability-adjusted life years (DALY) method developed by the Global Burden of Disease Group of the World Health Organization (WHO).The PAF for NO₂ to all-cause mortality was assessed at approximately 0.02% (95% CI: 0.003-0.036%), which was the highest among all air pollutants. The PAFs for respiratory and cardiovascular disease were 0.12% (95% CI: 0.01-0.16%) and 0.10% (95% CI: 0.04-0.16%), respectively. The sum of the attributable burden of disease for four pollutants was about 297 person-years (PYs) (95% CI: 121-472 PYs) when the incinerators observed to the emission standards. The attributable burdens of respiratory disease and cardiovascular disease were about 0.2% and 0.1%, respectively, of the total burden of respiratory disease and cardiovascular disease of Seoul citizens for the year 2007. Although the air emissions from one risk factor, an incinerator, are small, the burden of disease can be significant to the public health when population exposure is considered.     

Air quality,mortality, and economic benefits of a smoke – free workplace law for non‐smoking Ontario bar workers

We estimated the impact of a smoke‐free workplace bylaw on non‐smoking bar workers' health in Ontario, Canada. We measured bar workers' urine cotinine before (n = 99) and after (n = 91) a 2004 smoke‐free workplace bylaw. Using pharmacokinetic and epidemiological models, we estimated workers' fine‐particle (PM_2.5) air pollution exposure and mortality risks from workplace secondhand smoke (SHS). workers' pre‐law geometric mean cotinine was 10.3 ng/ml; post‐law dose declined 70% to 3.10 ng/ml and reported work hours of exposure by 90%. Pre‐law, 97% of workers' doses exceeded the 90th percentile for Canadians of working age. Pre‐law‐estimated 8‐h average workplace PM_2.5 exposure from SHS was 419 μg/m³ or ‘Very Poor’ air quality, while outdoor PM_2.5 levels averaged 7 μg/m³, ‘Very Good’ air quality by Canadian Air Quality Standards. We estimated that the bar workers' annual mortality rate from workplace SHS exposure was 102 deaths per 100 000 persons. This was 2.4 times the occupational disease fatality rate for all Ontario workers. We estimated that half to two‐thirds of the 10 620 Ontario bar workers were non‐smokers. Accordingly, Ontario's smoke‐free law saved an estimated 5–7 non‐smoking bar workers' lives annually, valued at CA $50 million to $68 million (US $49 million to $66 million).     

The association of noise sensitivity with coronary heart and cardiovascular mortality among Finnish adults

The association of coronary heart and cardiovascular mortality with noise sensitivity was studied. We also investigated how this association is affected by self-reported lifetime noise exposure. In 1988 a case-control study, based on the Finnish Twin Cohort, was carried out to investigate the relationship between noise and hypertension (n=1495). Potential confounders were obtained from questionnaire in 1981 for the same individuals. Data on deaths and causes of death were obtained from record linkage to the nationwide register of death certificates. All deaths that occurred among the study population during the 15 years of follow-up were classified as being due to all causes (n=382), to cardiovascular diseases (n=193), including the number of deaths due to coronary heart diseases (n=111) and to other causes than cardiovascular diseases (n=189). Cardiovascular mortality (Hazard ratio 1.80, 95% CI 1.07-3.04) was significantly increased among noise-sensitive women. Among men, there were no statistically significant effects. Noise sensitivity may be a risk factor for cardiovascular mortality in women.     

Air quality and outpatient visits for asthma in adults during the 2008 Summer Olympic Games in Beijing

To fulfill its commitment to a successful 2008 Olympic and Paralympic Games, the Chinese government made unprecedented efforts to improve the air quality in Beijing. We report findings on air quality and outpatient visits for asthma among adults in Beijing during the 2008 Summer Olympic Games. Three study periods were defined: summer baseline (June 1-June 30: before any air pollution controls), pre-Olympics (July 1-August 7: transportation restrictions in effect), and Olympics (August 8-September 20: further restrictions on industrial emissions). Daily data on outpatient asthma visits were obtained from the asthma registry of Beijing Chaoyang Hospital. We used time-series Poisson regression models to estimate the relative risk (RR) for asthma visits associated with pollution levels. The average numbers of outpatient visit for asthma were 12.5 per day at baseline and 7.3 per day during the Olympics. Compared with baseline, the Games were associated with a significant reduction in asthma visits (RR 0.54, 95%CI: 0.39-0.75). Our analysis showed that even in a heavily-polluted city, decreased concentrations of small particles were associated with some reduction in asthma visits in adults.     

Objective recognition of cough sound as biomarker for aerial pollutants

A relationship among air quality, respiratory health, and comfort in man and animal is widely shown. In general, a state of respiratory discomfort is prevailed by an increase in acoustic audible symptoms. The general concept of sound analysis as an objective contactless non-invasive biomarker for aerial pollution is studied on free-field cough sound of 12 Belgian Landrace piglets. A citric-acid-induced cough sound recognition algorithm with recognition rate of 95% is applied to cough sounds registered in the presence of distinct types of aerial pollutants: irritating gas (ammonia), respirable particles (dust), and temperature. The recognition performance for all aerial pollutants was >90% and maintained 94% on average. It is concluded that sound analysis allows an effective biomarker for all three types of aerial pollution. The generality of the biomarker is hypothesized to be due to the common mechanism involved in protective cough. As a consequence, it is suggested to use sound analysis as a biomarker for respiratory state in studies of exposure to air pollutants.     

Elevated concentrations of 1-hydroxypyrene in schoolchildren during winter in Christchurch, New Zealand

Particulate air pollution is significantly elevated during the winter in Christchurch, New Zealand, largely attributable to use of wood burners for domestic home heating, topography, and meteorological conditions. Polycyclic aromatic hydrocarbons (PAHs) are a key component of airborne particulate matter (PM) and urinary 1-hydroxypyrene (1-OHP) has previously been used to assess exposure of people to PAHs. We examined urinary 1-OHP in Christchurch male non-smoking schoolchildren (12-18 yr) on two occasions after high pollution events (48 and 72 microg PM(10)/m(3) 24-h average) and two occasions during periods of low pollution (19 and 12 microg PM(10)/m(3)). Concentrations of urinary 1-OHP were significantly elevated in the students during high pollution events (median (mean+/-SD) 0.043 (0.051+/-0.032) and 0.042 (0.060+/-0.092) micromol OHP/mol creatinine respectively) compared with low pollution periods (median (mean+/-SD) 0.019 (0.026+/-0.032) and 0.025 (0.028+/-0.018) micromol/mol creatinine respectively). The observed 1-OHP concentrations are at the lower end of those determined in children and non-occupationally exposed adults in international studies and suggest a generally low exposure to PAHs. The increased urinary 1-OHP concentrations following nights of elevated particulate concentrations in ambient air suggest increased exposure to ambient air pollution during winter time, and could potentially be used as a biomarker of exposure in this population.     

Spatiotemporal relationship between particle air pollution and respiratory emergency hospital admissions in Brisbane, Australia

The nature of spatial variation in the relationship between air pollution and health outcomes within a city remains an open and important question. This study investigated the spatial variability of particle matter air pollution and its association with respiratory emergency hospital admissions across six geographic areas in Brisbane, Australia. Data on particles of 10 microm or less in aerodynamic diameter per cubic metre (PM10), meteorological conditions, and daily respiratory emergency hospital admissions were obtained for the period of 1 January 1998 to 31 December 2001. A Poisson generalised linear model was used to estimate the specific effects of PM10 on respiratory emergency hospital admissions for each geographic area. A pooled effect of PM10 was then estimated using a meta-analysis approach for the whole city. The results of this study indicate that the magnitude of the association between particulate matter and respiratory emergency hospital admissions varied across different geographic areas in Brisbane. This relationship appeared to be stronger in areas with heavy traffic. We found an overall increase of 4.0% (95% confidence interval [CI]: 1.1-6.9%) in respiratory emergency hospital admissions associated with an increase of 10 microg /m3 in PM10 in the single pollutant model. The association was weaker but still statistically significant (an increase of 2.6%; 95% CI: 1.0-5.5%) after adjusting for O3, but did not appear to be affected by NO2. The effect estimates of PM10 were generally consistent for three spatial methods used in this study, but appeared to be underestimated if the spatial nature of the data was ignored. Therefore, the spatial variation in the relationship between PM10 and health outcomes needs to be considered when the health impact of air pollution is assessed, particularly for big cities.     

Does the presence of desert dust modify the effect of PM10 on mortality in Athens, Greece?

Recent reports investigate whether windblown desert dust may exacerbate the short-term health effects associated with particulate pollution in urban centers. We have tested this hypothesis by using daily air pollution and mortality data for Athens, Greece during the period 2001-2006.We investigated the effects of exposure to particulate matter with aerodynamic diameter < 0 μg/m³ (PM₁₀) on total and cause specific mortality, during days with and without windblown desert dust, for all ages, stratified by age groups and by sex. We identified 141 dust days between 2001 and 2006. We used Poisson regression models with penalized splines to control for possible confounding by season, meteorology, day of the week and holiday effect.A 10 μg/m³ increase in PM₁₀ was associated with a 0.71% (95% confidence interval (CI): 0.42% to 0.99%) increase in all deaths. The effects for total and cause specific mortality were greater for those ≥ 75 years of age, while for total mortality higher effects were observed among females. The main effect of desert dust days and its interaction with PM₁₀ concentrations were significant in all cases except for respiratory mortality and cardiovascular mortality among those < 75 years. The negative interaction pointed towards lower particle effects on mortality during dust events.We found evidence of modification of the adverse health effects of PM₁₀ on mortality in Athens, Greece with desert dust events: the particle effects were significantly higher during non-desert dust days. Our analyses indicate that traffic related particles, which prevail on non-desert dust days, have more toxic effects than the ones originating from long-range transport, such as Sahara dust.