Short-Term Exposure to Sulfur Dioxide and Nitrogen Monoxide and Risk of Out-of-Hospital Cardiac Arrest.

BACKGROUND & AIMS: Over the past decades, particulate matter (PM), especially fine PM <2.5 µm in aerodynamic diameter (PM2.5) has been a major research focus. However, the air pollutant is a mixture of gases or vapour-phase compounds, such as carbon monoxide (C), nitrogen oxides (NOx), photochemical oxidants (Ox), and sulfur dioxide (SO2). Little is known about their cardiovascular effect, individually or in combination with PM. Thus, we aimed to determine the associations between the incidence of acute cardiac events and both gaseous and PM using a case-crossover design. METHODS: Cardiovascular cases were identified through the Gunma Prefectural Ambulance Activity Database in Japan in 2015 (1,512 out-of-hospital cardiac arrest [OHCA] and 1,002 heart failures from 53,006 ambulance cases). Air quality data from the nearest station was for day of the arrest (lag0) and 1-2 days before the arrest (lag1, lag2) and the moving average across days 0-1 (lag0-1). Conditional logistic regression was used for unadjusted and adjusted analysis for temperature and humidity. RESULTS: Independent associations of OHCA were daily concentrations of SO2 at lag1 (OR 1.173, 95%CI 1.004, 1.370; p=0.044) and lag0-1 (OR 1.203, 95%CI 1.015, 1.425; p=0.033); and daily NO concentrations at lag2 (OR 1.039, 95%CI 1.007, 1.072; p=0.016). The incidence of heart failure was significantly associated with daily concentrations of Ox on the day of the event in univariable model but not after adjustment for temperature and humidity. No associations were found for other pollutants. CONCLUSIONS: Short-term exposure to SO2 and NO are associated with an increased risk of OHCA.

Survival of people with cystic fibrosis in Australia.

Survival statistics, estimated using data from national cystic fibrosis (CF) registries, inform the CF community and monitor disease progression. This study aimed to estimate survival among people with CF in Australia and to identify factors associated with survival. This population-based cohort study used prospectively collected data from 23 Australian CF centres participating in the Australian CF Data Registry (ACFDR) from 2005-2020. Period survival analysis was used to calculate median age of survival estimates for each 5-year window from 2005-2009 until 2016-2020. The overall median survival was estimated using the Kaplan-Meier method. Between 2005-2020 the ACFDR followed 4,601 people with CF, noting 516 (11.2%) deaths including 195 following lung transplantation. Out of the total sample, more than half (52.5%) were male and 395 (8.6%) had undergone lung transplantation. Two thirds of people with CF (66.1%) were diagnosed before six weeks of age or by newborn/prenatal screening. The overall median age of survival was estimated as 54.0 years (95% CI: 51.0-57.04). Estimated median survival increased from 48.9 years (95% CI: 44.7-53.5) for people with CF born in 2005-2009, to 56.3 years (95% CI: 51.2-60.4) for those born in 2016-2020. Factors independently associated with reduced survival include receiving a lung transplant, having low FEV1pp and BMI. Median survival estimates are increasing in CF in Australia. This likely reflects multiple factors, including newborn screening, improvement in diagnosis, refinements in CF management and centre-based multidisciplinary care.

Long-term exposure to low air pollutant concentrations and hospitalisation for respiratory diseases in older men: A prospective cohort study in Perth, Australia.

Background: Acute exposure to ambient air pollution even at low concentrations has been associated with increased hospitalisation for respiratory diseases but the effects of long-term exposure are less certain. In this study, we investigated the associations between long-term exposures to PM2.5, PM2.5 absorbance and NO2 and hospitalisation for asthma, chronic obstructive pulmonary disease and pneumonia in a cohort of older men living in Perth, Western Australia, a city where the levels of air pollutants are well below the world standards. Materials and methods: The study population of 11,156 men with no prior hospitalisation for respiratory disease was drawn from the Health in Men Study (HIMS) cohort of men aged >65 years living in Perth, Western Australia between 1996-1999. PM2.5, PM2.5 absorbance (PM2.5a) and NO2 were measured across the Perth metropolitan area over three seasons in 2012. Land use regression (LUR) models were used to estimate annual concentrations of PM2.5, PM2.5 absorbance and NO2 at the residential address of each participant from inception (1996) to 2015. Hospitalisation for respiratory disease between inception and 2015 was ascertained using the Western Australian Data Linkage System. The association between exposure to air pollution with hospitalisation for respiratory disease was examined using Cox regression analysis. Results: No statistically significant associations were observed in the fully adjusted models. However, positive associations were observed with first hospitalisation for pneumonia (HR 1.08, 95% CI: 1.01-1.16) when adjusted for age, year of enrolment, smoking status, education, BMI and physical activity. Conclusions: In this longitudinal study of older men we found no evidence of associations between increased long-term exposure to low-level air pollution with increased risk of hospitalisation for respiratory diseases in Perth, Australia. More studies on respiratory morbidity associated with exposure to low levels of air pollution are needed for more comprehensive understanding of the overall risk.

Ultrafine particle exposure and biomarkers of effect on small airways in children.

The small size and large surface area of ultrafine particles (UFP) enhance their ability to deposit in the lung periphery and their reactivity. The Ultrafine Particles from Traffic Emissions and Children's Health (UPTECH) cross-sectional study was conducted in 8-11-year-old schoolchildren attending 25 primary (elementary) schools, randomly selected from the Brisbane Metropolitan Area, Queensland, Australia. Main study findings outlined indirect evidence of distal airway deposition (raised C reactive protein) but as yet, there is no direct evidence in the literature of effects of UFP exposure on peripheral airway function. We present further UPTECH study data from two sensitive peripheral airway function tests, Oscillometry and Multiple Breath Nitrogen Washout (MBNW), performed in 577 and 627 children (88% and 96% of UPTECH study cohort) respectively: mean(SD) age 10.1(0.9) years, 46% male, with 50% atopy and 14% current asthma. Bayesian generalised linear mixed effects regression models were used to estimate the effect of UFP particle number count (PNC) exposure on key oscillometry (airway resistance, (Rrs), and reactance, (Xrs)) and MBNW (lung clearance index, (LCI) and functional residual capacity, (FRC)) indices. We adjusted for age, sex, and height, and potential confounders including socio-economic disadvantage, PM2.5 and NO2 exposure. All models contained an interaction term between UFP PNC exposure and atopy, allowing estimation of the effect of exposure on non-atopic and atopic students. Increasing UFP PNC was associated with greater lung stiffness as evidenced by a decrease in Xrs [mean (95% credible interval) -1.63 (-3.36 to -0.05)%] per 1000#.cm-3]. It was also associated with greater lung stiffness (decrease in Xrs) in atopic subjects across all models [mean change ranging from -2.06 to -2.40% per 1000#.cm-3]. A paradoxical positive effect was observed for Rrs across all models [mean change ranging from -1.55 to -1.70% per 1000#.cm-3] (decreases in Rrs indicating an increase in airway calibre), which was present for both atopic and non-atopic subjects. No effects on MBNW indices were observed. In conclusion, a modest detrimental effect of UFP on peripheral airway function among atopic subjects, as assessed by respiratory system reactance, was observed extending the main UPTECH study findings which reported a positive association with a biomarker for systemic inflammation, C-reactive protein (CRP). Further studies are warranted to explore the pathophysiological mechanisms underlying increased respiratory stiffness, and whether it persists through to adolescence and adulthood.

Ambient Air Pollution and Stillbirths Risk in Sydney, Australia.

We aimed to determine the associations between ambient air pollution, specifically particulate matter less than or equal to 10 microns and 2.5 microns (PM10 and PM2.5 respectively) and ozone (O3), and stillbirths. We analysed all singleton births between 20-42 weeks gestation in metropolitan Sydney, Australia, from 1997 to 2012. We implemented logistic regression to assess the associations between air pollutants and stillbirth for each trimester and for the entire pregnancy. Over the study period, there were 967,694 live births and 4287 stillbirths. Mean levels of PM10, PM2.5 and O3 for the entire pregnancy were 17.9 µg/m3, 7.1 µg/m3 and 3.2 ppb, respectively. Adjusted odds ratios were generally greater than unity for associations between PM and stillbirths, but none were statistically significant. There were no significant associations between O3 and stillbirths. There was potential effect modification of the PM10 and O3 association by maternal age. We did not find consistent evidence of associations between PM and O3 and stillbirths in Sydney, Australia. More high quality birth cohort studies are required to clarify associations between air pollution and stillbirths.

Sub-Clinical Effects of Outdoor Smoke in Affected Communities.

Many Australians are intermittently exposed to landscape fire smoke from wildfires or planned (prescribed) burns. This study aimed to investigate effects of outdoor smoke from planned burns, wildfires and a coal mine fire by assessing biomarkers of inflammation in an exposed and predominantly older population. Participants were recruited from three communities in south-eastern Australia. Concentrations of fine particulate matter (PM2.5) were continuously measured within these communities, with participants performing a range of health measures during and without a smoke event. Changes in biomarkers were examined in response to PM2.5 concentrations from outdoor smoke. Increased levels of FeNO (fractional exhaled nitric oxide) (ß = 0.500 [95%CI 0.192 to 0.808] p < 0.001) at a 4 h lag were associated with a 10 µg/m3 increase in PM2.5 levels from outdoor smoke, with effects also shown for wildfire smoke at 4, 12, 24 and 48-h lag periods and coal mine fire smoke at a 4 h lag. Total white cell (ß = -0.088 [-0.171 to -0.006] p = 0.036) and neutrophil counts (ß = -0.077 [-0.144 to -0.010] p = 0.024) declined in response to a 10 µg/m3 increase in PM2.5. However, exposure to outdoor smoke resulting from wildfires, planned burns and a coal mine fire was not found to affect other blood biomarkers.

Outcomes for patients with COVID-19 admitted to Australian intensive care units during the first four months of the pandemic.

OBJECTIVES: To describe the characteristics and outcomes of patients with COVID-19 admitted to intensive care units (ICUs) during the initial months of the pandemic in Australia. DESIGN, SETTING: Prospective, observational cohort study in 77 ICUs across Australia. PARTICIPANTS: Patients admitted to participating ICUs with laboratory-confirmed COVID-19 during 27 February - 30 June 2020. MAIN OUTCOME MEASURES: ICU mortality and resource use (ICU length of stay, peak bed occupancy). RESULTS: The median age of the 204 patients with COVID-19 admitted to intensive care was 63.5 years (IQR, 53-72 years); 140 were men (69%). The most frequent comorbid conditions were obesity (40% of patients), diabetes (28%), hypertension treated with angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers (24%), and chronic cardiac disease (20%); 73 patients (36%) reported no comorbidity. The most frequent source of infection was overseas travel (114 patients, 56%). Median peak ICU bed occupancy was 14% (IQR, 9-16%). Invasive ventilation was provided for 119 patients (58%). Median length of ICU stay was greater for invasively ventilated patients than for non-ventilated patients (16 days; IQR, 9-28 days v 3 days; IQR, 2-5 days), as was ICU mortality (26 deaths, 22%; 95% CI, 15-31% v four deaths, 5%; 95% CI, 1-12%). Higher Acute Physiology and Chronic Health Evaluation II (APACHE-II) scores on ICU day 1 (adjusted hazard ratio [aHR], 1.15; 95% CI, 1.09-1.21) and chronic cardiac disease (aHR, 3.38; 95% CI, 1.46-7.83) were each associated with higher ICU mortality. CONCLUSION: Until the end of June 2020, mortality among patients with COVID-19 who required invasive ventilation in Australian ICUs was lower and their ICU stay longer than reported overseas. Our findings highlight the importance of ensuring adequate local ICU capacity, particularly as the pandemic has not yet ended.

Lung function over the life course of paediatric and adult patients with cystic fibrosis from a large multi-centre registry.

A key measure of lung function in people with Cystic Fibrosis (CF) is Forced Expiratory Volume in the first second FEV1 percent predicted (FEV1pp). This study aimed to address challenges in identifying predictors of FEV1pp, specifically dealing with non-linearity and the censoring effect of death. Data was obtained from a large multi-centre Australian Cystic Fibrosis Data Registry (ACFDR). A linear mixed model was used to study FEV1pp as the endpoint. There were 3655 patients (52.4% male) included in our study. Restricted cubic splines were used to fit the non-linear relationship between age of visit and FEV1pp. The following predictors were found to be significant in the multivariate model: age of patient at visit, BMI z-score, age interaction with lung transplantation, insulin dependent diabetes, cirrhosis/portal hypertension, pancreatic insufficiency, Pseudomonas aeruginosa infection and baseline variability in FEV1pp. Those with P. aeruginosa infection had a lower mean difference in FEV1pp of 4.7 units, p < 0.001 compared to those who did not have the infection. Joint modelling with mortality outcome did not materially affect our findings. These models will prove useful for to study the impact of CFTR modulator therapies on rate of change of lung function among patients with CF.

Assessing the Effect of Reactive Oxygen Species and Volatile Organic Compound Profiles Coming from Certain Types of Chinese Cooking on the Toxicity of Human Bronchial Epithelial Cells.

The International Agency of Research on Cancer identifies high-temperature frying, which features prominently in Chinese cooking, as producing group 2A carcinogens. This study simultaneously characterized particulate and gaseous-phase cooking emissions, monitored their reactive oxygen species (ROS) concentrations, and evaluated their impact on genetic damage and expression in exposed human bronchial epithelial cells. Five types of edible oil, three kinds of seasonings, and two dishes were assessed. Among tested edible oils, heating of soybean oil released the largest particle number concentration (2.09 × 1013 particles/(g cooking material and oil)·h) and volatile organic compounds (VOCs) emissions (12103.42 µg/(g cooking material and oil)·h). Heating of lard produced the greatest particle mass concentration (0.75 mg/(g cooking material and oil)·h). The main finding was that sunflower and rapeseed oils produced the highest ROS concentrations (80.48 and 71.75 nmol/(g cooking material and oil)·h, respectively). ROS formation most likely occurred during the autoxidation of both polyunsaturated and monounsaturated fatty acids. Among all the tested parameters, only ROS concentrations exhibited consistency with cell viability and showed significant correlations with the expression levels of CYP1A1, HIF-1a, and especially with IL-8 (the marker for oxidative stress within the cell). These findings indicate that ROS concentration is potentially a suitable metric for direct assessment of exposure levels and potential toxicity.

Short-term exposure to ambient fine particulate matter and out-of-hospital cardiac arrest: a nationwide case-crossover study in Japan.

BACKGROUND: PM2·5 is an important but modifiable environmental risk factor, not only for pulmonary diseases and cancers, but for cardiovascular health. However, the evidence regarding the association between air pollution and acute cardiac events, such as out-of-hospital cardiac arrest (OHCA), is inconsistent, especially at concentrations lower than the WHO daily guideline (25 µg/m3). This study aimed to determine the associations between exposure to ambient air pollution and the incidence of OHCA. METHODS: In this nationwide case-crossover study, we linked prospectively collected population-based registry data for OHCA in Japan from Jan 1, 2014, to Dec 31, 2015, with daily PM2·5, carbon monoxide (CO), nitrogen dioxide (NO2), photochemical oxidants (Ox), and sulphur dioxide (SO2) exposure on the day of the arrest (lag 0) or 1-3 days before the arrest (lags 1-3), as well as the moving average across days 0-1 and days 0-3. Daily exposure was calculated by averaging the measurements from all PM2·5 monitoring stations in the same prefecture. The effect of PM2·5 on risk of all-cause or cardiac OHCA was estimated using a time-stratified case-crossover design coupled with conditional logistic regression analysis, adjusted for daily temperature and relative humidity. Single-pollutant models were also investigated for the individual gaseous pollutants (CO, NO2, Ox, and SO2), as well as two-pollutant models for PM2·5 with these gaseous pollutants. Subgroup analyses were done by sex and age. FINDINGS: Over the 2 years, 249 372 OHCAs were identified, with 149 838 (60·1%) presumed of cardiac origin. The median daily PM2·5 was 11·98 µg/m3 (IQR 8·13-17·44). Each 10 µg/m3 increase in PM2·5 was associated with increased risk of all-cause OHCA on the same day (odds ratio [OR] 1·016, 95% CI 1·009-1·023) and at lags of up to 3 days, ranging from OR 1·015 (1·008-1·022) at lag 1 to 1·033 (1·023-1·043) at lag 0-3. Results for cardiac OHCA were similar (ORs ranging from 1·016 [1·007-1·025] at lags 1 and 2 to 1·034 [1·021-1·047] at lag 0-3). Patients older than 65 years were more susceptible to PM2·5 exposure than younger age groups but no sex differences were identified. CO, Ox, and SO2 were also positively associated with OHCA while NO2 was not. However, in two-pollutant models of PM2·5 and gaseous pollutants, only PM2·5 (positive association) and NO2 (negative association) were independently associated with increased risk of OHCA. INTERPRETATION: Short-term exposure to PM2·5 was associated with an increased risk of OHCA even at relatively low concentrations. Regulatory standards and targets need to incorporate the potential health gains from continual air quality improvement even in locations already meeting WHO standards. FUNDING: None.

Associations between long-term exposure to ambient air pollution and Parkinson's disease prevalence: A cross-sectional study.

BACKGROUND: Epidemiological studies have reported contradictory results regarding the effects of ambient air pollution on Parkinson's disease (PD). This study investigated the associations between long-term exposure to particulate matter <2.5 µm in diameter (PM2.5) and nitrogen dioxide (NO2) and PD among participants in the 45 and Up Study, which comprised adults older than 45 years living in New South Wales, Australia. METHODS: We conducted a cross-sectional analysis of long-term exposure to PM2.5 and NO2 concentrations and prevalence of PD using data from around 240,000 cohort members from the 45 and Up Study, NSW. Annual average concentrations of NO2 and PM2.5 were estimated at the participants' residential address using satellite-based land use regression models. Logistic regression was used to quantify the associations between these pollutants and ever physician-diagnosed PD, after adjusting for a range of individual- and area-level covariates. RESULTS: Among the 236,390 participants with complete data, 1,428 (0.6%) reported physician-diagnosed PD. Annual mean PM2.5 and NO2 concentrations for the cohort were 5.8 and 11.9 µg m-3, respectively, and were positively, but not statistically significantly associated with PD. The odds ratio for a 1 µg m-3 increase in PM2.5 was 1.01 (95% confidence interval (CI): 0.98-1.04). The adjusted odds ratio for a 5 µg m-3 increase in NO2 was 1.03 (95% CI: 0.98-1.08). In subgroup analyses, larger associations for NO2 were observed among past smokers (OR 1.11 (95% CI: 1.02-1.20) per 5 µg m-3 increase). CONCLUSIONS: Overall, we found limited evidence of associations between long-term exposure to NO2 or PM2.5 and PD. The associations observed among past smokers require further corroboration.

Measurements of Oxidative Potential of Particulate Matter at Belgrade Tunnel; Comparison of BPEAnit, DTT and DCFH Assays.

To estimate the oxidative potential (OP) of particulate matter (PM), two commonly used cell-free, molecular probes were applied: dithiothreitol (DTT) and dichloro-dihydro-fluorescein diacetate (DCFH-DA), and their performance was compared with 9,10-bis (phenylethynyl) anthracene-nitroxide (BPEAnit). To the best of our knowledge, this is the first study in which the performance of the DTT and DCFH has been compared with the BPEAnit probe. The average concentrations of PM, organic carbon (OC) and elemental carbon (EC) for fine (PM2.5) and coarse (PM10) particles were determined. The results were 44.8 ± 13.7, 9.8 ± 5.1 and 9.3 ± 4.8 µg·m-3 for PM2.5 and 75.5 ± 25.1, 16.3 ± 8.7 and 11.8 ± 5.3 µg·m-3 for PM10, respectively, for PM, OC and EC. The water-soluble organic carbon (WSOC) fraction accounted for 42 ± 14% and 28 ± 9% of organic carbon in PM2.5 and PM10, respectively. The average volume normalized OP values for the three assays depended on both the sampling periods and the PM fractions. The OPBPEAnit had its peak at 2 p.m.; in the afternoon, it was three times higher compared to the morning and late afternoon values. The DCFH and BPEAnit results were correlated (r = 0.64), while there was no good agreement between the BPEAnit and the DTT (r = 0.14). The total organic content of PM does not necessarily represent oxidative capacity and it shows varying correlation with the OP. With respect to the two PM fractions studied, the OP was mostly associated with smaller particles.

All-cause mortality and long-term exposure to low level air pollution in the '45 and up study' cohort, Sydney, Australia, 2006-2015.

BACKGROUND: Epidemiological studies show that long-term exposure to ambient air pollution reduces life expectancy. Most studies have been in environments with relatively high concentrations such as North America, Europe and Asia. Associations at the lower end of the concentration-response function are not well defined. OBJECTIVES: We assessed associations between all-cause mortality and exposure to annual average particulate matter <2.5 µm (PM2.5) and nitrogen dioxide (NO2) in Sydney, Australia, where concentrations are relatively low. METHODS: The '45 and Up Study' comprises a prospective longitudinal cohort from the state of New South Wales, Australia with 266,969 participants linked to death registry data. We analyzed data for the participants who resided in Sydney at baseline questionnaire (n = 75,268). Exposures to long-term pollution were estimated using annual averages from a chemical transport model (PM2.5), and a satellite-based land-use regression model (NO2). Socio-demographic information was extracted from the baseline questionnaire. Cox proportional hazard models were applied to estimate associations, while adjusting for covariates. RESULTS: In our cohort mean annual PM2.5 was 4.5 µg/m3 and mean NO2 was 17.8 µg/m3. The mortality rate was 4.4% over the 7 years of follow up. Models that adjusted for individual-level and area-level risk factors resulted in a detrimental non statistically significant hazard ratio (HR) of 1.05 (95% CI: 0.98-1.12) per 1 µg/m3 increase in PM2.5, and 1.03 (95% CI: 0.98-1.07) per 5 µg/m3 increase in NO2. CONCLUSIONS: We found evidence that low-level air pollution exposure was associated with increased risk of mortality in this cohort of adults aged 45 years and over, even at the relatively low concentrations seen in Sydney. However, a clear determination of the association with mortality is difficult because the results were sensitive to some covariates. Our findings are supportive of emerging evidence that exposure to low levels of air pollution reduces life expectancy.

Ambient Particulate Matter and Paramedic Assessments of Acute Diabetic, Cardiovascular, and Respiratory Conditions.

BACKGROUND: Ambulance data provide a useful source of population-based and spatiotemporally resolved information for assessing health impacts of air pollution in nonhospital settings. We used the clinical records of paramedics to quantify associations between particulate matter (PM2.5) and diabetic, cardiovascular, and respiratory conditions commonly managed by those responding to calls for emergency ambulance services. METHODS: We evaluated 394,217 paramedic assessments from three states in Southeastern Australia (population 13.2 million) and daily PM2.5 concentrations modeled at 5 km resolution from 2009 to 2014. We used a time-stratified, case-crossover analysis adjusted for daily meteorology to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) for each clinical outcome per 10 µg/m increase in daily PM2.5 at lags from 0 to 2 days. RESULTS: Increased PM2.5 was associated with increased odds of paramedic assessments of hypoglycemia (OR = 1.07; 95% CI = 1.02, 1.12, lag 0), arrhythmia (OR = 1.05; 95% CI = 1.02, 1.09, lag 0), heart failure (OR = 1.07; 95% CI = 1.02, 1.12, lag 1), faint (OR = 1.09; 95% CI = 1.04-1.13, lag 0), asthma (OR = 1.06; 95% CI = 1.01, 1.11, lag 1), chronic obstructive pulmonary disease (OR = 1.07; 95% CI = 1.01, 1.13, lag 1), and croup (OR = 1.09; 95% CI = 1.02, 1.17). We did not identify associations with cerebrovascular outcomes. CONCLUSIONS: Ambulance data enable the evaluation of important clinical syndromes that are often initially managed in nonhospital settings. Daily PM2.5 was associated with hypoglycemia, faint, and croup in addition to the respiratory and cardiovascular outcomes that are better established.

Long-term exposure to low concentrations of air pollutants and hospitalisation for respiratory diseases: A prospective cohort study in Australia.

BACKGROUND: Short- and long-term spatiotemporal variation in exposure to air pollution is associated with respiratory morbidity in areas with moderate-to-high level of air pollution, but very few studies have examined whether these associations also exist in areas with low level exposure. OBJECTIVES: We assessed the association between spatial variation in long-term exposure to PM2.5 and NO2 and hospitalisation for all respiratory diseases, asthma, chronic obstructive pulmonary disease (COPD), and pneumonia, in older adults residing in Sydney, Australia, a city with low-level concentrations. METHODS: We recorded data on hospitalisations for 100,084 participants, who were aged >45 years at entry in 2006-2009 until June 2014. Annual NO2 and PM2.5 concentrations were estimated for the participants' residential addresses and Cox proportional hazards regression was used to model the association between exposure to air pollutants and first episode of hospitalisation, controlling for personal and area level covariates. We further investigated the shape of the exposure-response association and potential effect modification by age, sex, education level, smoking status, and BMI. RESULTS: NO2 and PM2.5 annual mean exposure estimates were 17.5 µg·m-3 and 4.5 µg·m-3 respectively. NO2 and PM2.5 was positively, although not significantly, associated with asthma. The adjusted hazard ratio for a 1 µg·m-3 increase in PM2.5 was 1.08, 95% confidence interval 0.89-1.30. The adjusted hazard ratio for a 5 µg·m-3 increase in NO2 was 1.03, 95% confidence interval 0.88-1.19. We found no positive statistically significant associations with hospitalisation for all respiratory diseases, and pneumonia while negative associations were observed with COPD. CONCLUSIONS: We found weak positive associations of exposure to air pollution with hospitalisation for asthma while there was no evidence of an association for all respiratory diseases.

Effects of exposure to ambient ultrafine particles on respiratory health and systemic inflammation in children.

It is known that ultrafine particles (UFP, particles smaller than 0.1 µm) can penetrate deep into the lungs and potentially have adverse health effects. However, epidemiological data on the health effects of UFP is limited. Therefore, our objective was to test the hypothesis that exposure to UFPs is associated with respiratory health status and systemic inflammation among children aged 8 to 11 years. We conducted a cross-sectional study among 655 children (43.3% male) attending 25 primary (elementary) schools in the Brisbane Metropolitan Area, Australia. Ultrafine particle number concentration (PNC) was measured at each school and modelled at homes using Land Use Regression to derive exposure estimates. Health outcomes were respiratory symptoms and diagnoses, measured by parent-completed questionnaire, spirometric lung function, exhaled nitric oxide (FeNO), and serum C reactive protein (CRP). Exposure-response models, adjusted for potential personal and environmental confounders measured at the individual, home and school level, were fitted using Bayesian methods. PNC was not independently associated with respiratory symptoms, asthma diagnosis or spirometric lung function. However, PNC was positively associated with an increase in CRP (1.188-fold change per 1000 UFP cm-3 day/day (95% credible interval 1.077 to 1.299)) and an increase in FeNO among atopic participants (1.054 fold change per 1000 UFP cm-3 day/day (95% CrI 1.005 to 1.106)). UFPs do not affect respiratory health outcomes in children but do have systemic effects, detected here in the form of a positive association with a biomarker for systemic inflammation. This is consistent with the known propensity of UFPs to penetrate deep into the lung and circulatory system.

Role of Chinese cooking emissions on ambient air quality and human health.

Chinese-style cooking often involves volatilization of oils which can potentially produce a large number of pollutants, which have adverse impact on environment and human health. Therefore, we have reviewed 75 published studies associated with research topic among Mainland China, Hong Kong and Taiwan, involving studies on the roles of food ingredients and oil type, cooking style impacting on generated pollutants, and human health. The highest concentration occurred including: 1) when peat, wood, and raw coal were used in stoves; 2) olive oil was adopted; 3) cooking with high temperatures; and 4) without cleaning technology. We conclude that PM concentrations for cooking emissions were between 0.14 and 24.46mg/cm3. VOC concentrations varied from 0.35 to 3.41mg/m3. Barbeque produced the greatest mass concentrations compared to Sichuan cuisine, canteen and other restaurants. The PAHs concentration emitted from the exhaust stacks, dining area and kitchen ranged from 0.0175µg/m3 to 83µg/m3. The largest amount of gaseous pollutants emitted was recorded during incomplete combustion of fuel or when a low combustion efficiency (CO2/ (CO+CO2)<0.5) was observed. The variation range was 6.27-228.89mg/m3, 0.16-0.80mg/m3, 0.69-4.33mg/m3, 0.70-21.70mg/m3 for CO, CO2, NO2 and SO2 respectively. In regards to the toxicity and exposure, current findings concluded that both the dose and exposure time are significant factors to be considered. Scientific research in this area has been mainly driven by comparison among emissions from various ingredients and cooking techniques. There is still a need for more comprehensive studies to fully characterise the cooking emissions including their physical and chemical transformations which is crucial for accurate estimation of their impacts on the environment and human health.

Ambient particulate matter, landscape fire smoke, and emergency ambulance dispatches in Sydney, Australia.

BACKGROUND: Emergency ambulance dispatches (EAD) are a novel outcome for evaluating the public health impacts of air pollution. We assessed the relationships between ambient particulate matter (PM) from all sources, PM from landscape fire smoke (LFS), and EADs likely to be associated with cardiorespiratory problems in the Sydney greater metropolitan region for an 11-year period from 2004 to 2015. METHODS: EAD codes are assigned at the time of the call to emergency services using standard computer assisted algorithms. We assessed EADs coded as: breathing problems, chest pain, stroke or cerebrovascular accident (stroke), cardiac or respiratory arrest and death (arrest), and heart or defibrillator problems (other heart problems). Using a daily times series study design with a generalized linear Poisson regression model we quantified the association between EAD and daily PM2.5 from all sources (PM2.5,all) and PM2.5 primarily due to LFS (PM2.5,LFS). RESULTS: Increases of 10µg·m-3 in PM2.5,all were positively associated with same day EAD for breathing problems (RR=1.03, 95% CI 1.02 to 1.04), arrest (RR=1.03, 95% CI 1.00 to 1.06), and chest pain (RR=1.01 CI 1.00 to 1.02) but not with other outcomes. Increases of 10µg·m-3 PM2.5,LFS were also positively associated with breathing problems on the same day (RR=1.04, 95% CI 1.02 to 1.05) and other heart problems at lag of two days (RR=1.05, 95% CI 1.01 to 1.09). CONCLUSIONS: Emergency dispatches for breathing problems are associated with PM2.5,all and PM2.5,LFS and provide a sensitive end point for continued research and surveillance activities investigating the impacts of daily fluctuations in ambient PM2.5.

Development and Validation of a UAV Based System for Air Pollution Measurements.

Air quality data collection near pollution sources is difficult, particularly when sites are complex, have physical barriers, or are themselves moving. Small Unmanned Aerial Vehicles (UAVs) offer new approaches to air pollution and atmospheric studies. However, there are a number of critical design decisions which need to be made to enable representative data collection, in particular the location of the air sampler or air sensor intake. The aim of this research was to establish the best mounting point for four gas sensors and a Particle Number Concentration (PNC) monitor, onboard a hexacopter, so to develop a UAV system capable of measuring point source emissions. The research included two different tests: (1) evaluate the air flow behavior of a hexacopter, its downwash and upwash effect, by measuring air speed along three axes to determine the location where the sensors should be mounted; (2) evaluate the use of gas sensors for CO2, CO, NO2 and NO, and the PNC monitor (DISCmini) to assess the efficiency and performance of the UAV based system by measuring emissions from a diesel engine. The air speed behavior map produced by test 1 shows the best mounting point for the sensors to be alongside the UAV. This position is less affected by the propeller downwash effect. Test 2 results demonstrated that the UAV propellers cause a dispersion effect shown by the decrease of gas and PN concentration measured in real time. A Linear Regression model was used to estimate how the sensor position, relative to the UAV center, affects pollutant concentration measurements when the propellers are turned on. This research establishes guidelines on how to develop a UAV system to measure point source emissions. Such research should be undertaken before any UAV system is developed for real world data collection.