Improving traffic-related air pollution estimates by modelling minor road traffic volumes.

Accurately estimating annual average daily traffic (AADT) on minor roads is essential for assessing traffic-related air pollution (TRAP) exposure, particularly in areas where most people live. Our study assessed the direct and indirect external validity of three methods used to estimate AADT on minor roads in Melbourne, Australia. We estimated the minor road AADT using a fixed-value approach (assuming 600 vehicles/day) and linear and negative binomial (NB) models. The models were generated using road type, road importance index, AADT and distance of the nearest major road, population density, workplace density, and weighted road density. External measurements of traffic counts, as well as black carbon (BC) and ultrafine particles (UFP), were conducted at 201 sites for direct and indirect validation, respectively. Statistical tests included Akaike information criterion (AIC) to compare models' performance, the concordance correlation coefficient (CCC) for direct validation, and Spearman's correlation coefficient for indirect validation. Results show that 88.5% of the roads in Melbourne are minor, yet only 18.9% have AADT. The performance assessment of minor road models indicated comparable performance for both models (AIC of 1,023,686 vs. 1,058,502). In the direct validation with external traffic measurements, there was no difference between the three methods for overall minor roads. However, for minor roads within residential areas, CCC (95% confidence interval [CI]) values were -0.001 (-0.17; 0.18), 0.47 (0.32; 0.60), and 0.29 (0.18; 0.39) for the fixed-value approach, the linear model, and the NB model, respectively. In the indirect validation, we found differences only on UFP where the Spearman's correlation (95% CI) for both models and fixed-value approach were 0.50 (0.37; 0.62) and 0.34 (0.19; 0.48), respectively. In conclusion, our linear model outperformed the fixed-value approach when compared against traffic and TRAP measurements. The methodology followed in this study is relevant to locations with incomplete minor road AADT data.

Associations between Traffic-Related Air Pollution and Cognitive Function in Australian Urban Settings: The Moderating Role of Diabetes Status.

Traffic-related air pollution (TRAP) is associated with lower cognitive function and diabetes in older adults, but little is known about whether diabetes status moderates the impact of TRAP on older adult cognitive function. We analysed cross-sectional data from 4141 adults who participated in the Australian Diabetes, Obesity and Lifestyle (AusDiab) study in 2011-2012. TRAP exposure was estimated using major and minor road density within multiple residential buffers. Cognitive function was assessed with validated psychometric scales, including: California Verbal Learning Test (memory) and Symbol-Digit Modalities Test (processing speed). Diabetes status was measured using oral glucose tolerance tests. We observed positive associations of some total road density measures with memory but not processing speed. Minor road density was not associated with cognitive function, while major road density showed positive associations with memory and processing speed among larger buffers. Within a 300 m buffer, the relationship between TRAP and memory tended to be positive in controls (ß = 0.005; p = 0.062), but negative in people with diabetes (ß = -0.013; p = 0.026) and negatively associated with processing speed in people with diabetes only (ß = -0.047; p = 0.059). Increased TRAP exposure may be positively associated with cognitive function among urban-dwelling people, but this benefit may not extend to those with diabetes.

Differences in psychosocial distress among rural and metropolitan health care workers during the COVID-19 pandemic.

OBJECTIVE: The Australian COVID-19 Frontline Healthcare Workers study examined the prevalence and severity of mental health symptoms during the second wave of the COVID-19 pandemic. This substudy examined the differences in psychological well-being between rural and metropolitan health care workers (HCWs). DESIGN: A nationwide survey conducted between August and October 2020. SETTING AND PARTICIPANTS: Australian HCWs were recruited through multiple strategies. MAIN OUTCOME MEASURES: Demographics, mental health outcomes (anxiety, depression, post-traumatic stress disorder [PTSD] and burnout). RESULTS: Complete responses were included from 7846 participants, with 1473 (18.8%) in regional or remote ('rural') areas and 81.2% in metropolitan areas. Rural participants were older, more likely to work in allied health, nursing or in health administration, and had worked longer in their profession than metropolitan participants. Levels of resilience were similar (p = 0.132), but there was significantly higher prevalence of pre-COVID-19 pandemic mental illness in the rural workforce (p < 0.001). There were high levels of current mental health issues: moderate-severe PTSD (rural 38.0%; metropolitan 41.0% p = 0.031); high depersonalisation (rural 18.1%; metropolitan 20.7% p = 0.047); and high emotional exhaustion (rural 46.5%; metropolitan 43.3% p = 0.002). Among rural participants, mental health symptoms were associated with younger age, worry about being blamed if they contracted COVID-19, fear of transmitting COVID-19 to their family, experiencing worsening relationships and working in primary care or allied health. CONCLUSION: Despite having low COVID-19 case numbers in rural Australian health services compared with metropolitan counterparts over the course of 2020, there were widespread mental health impacts on the workforce. Rural health services need specific and flexible training, education, work policies and practices that support psychological well-being now in preparedness for ongoing or future crises.

Vegetation and vehicle emissions around primary schools across urban Australia: associations with academic performance.

BACKGROUND: Evolving evidence suggests that vegetation surrounding schools is beneficial to children's academic performance, however vehicle emissions are adversely related. Little is known about concurrent impacts of vegetation and vehicle emissions on academic performance. This study examined associations of vegetation and vehicle emissions near urban Australian primary schools with children's academic performance. METHODS: Vegetation within schoolyards and Euclidean buffers (100, 300 and 1000 m) was assessed using the Normalized Difference Vegetation Index (NDVI). Weighted road density (WRD) was computed for each buffer as a vehicle emissions proxy. Cross-sectional associations and mediating pathways between vegetation and vehicle emissions and standardized average academic scores in Literacy (Reading, Writing, Language Conventions) and Mathematics for Grades 3 and 5 attending 3745 primary schools in urban areas (population ≥10,000) of Australia in 2018 were assessed using generalised linear models adjusted for school socio-educational status. RESULTS: Significant positive associations were found between vegetation and Reading in Grades 3 and 5, Mathematics in Grade 3 (all buffers), Writing in Grade 3 (100 and 300 m), and Language Conventions in Grades 3 and 5 (most buffers). Increased vehicle emissions were negatively associated with Reading and Mathematics in Grades 3 and 5 (most buffers), and Language Conventions in Grade 3 (300 and 1000 m) and Grade 5 (100-1000 m). Within 300 m, vehicle emissions partially mediated associations between vegetation with Mathematics in Grade 3 (proportion mediated, 21%), Reading and Language Conventions in Grade 5 (15%, 37% respectively). CONCLUSIONS: Our findings contribute to growing evidence that vegetation around primary schools is associated with higher achievement in Literacy and Mathematics, with partial mediation by vehicle emissions. Future studies should conduct on-site measurement of vehicle emissions and audit vegetation around schools to confirm findings and inform urban/school planners and school leaders on designing and modifying school environments to support learning.

Outdoor particulate matter exposure and upper respiratory tract infections in children and adolescents: A systematic review and meta-analysis.

BACKGROUND: While the relationship between outdoor particulate matter (PM) and lower respiratory tract infections in children and adolescents is accepted, we know little about the impacts of outdoor PM on the risk of developing or aggravating upper respiratory tract infections (URTIs). METHODS: We aimed to review the literature examining the relationship between outdoor PM exposure and URTIs in children and adolescents. A systematic search of EMBASE, MEDLINE, PubMed, Scopus, CINAHL and Web of Science databases was undertaken on April 3, 2020 and October 27, 2021. Comparable short-term studies of time-series or case-crossover designs were pooled in meta-analyses using random-effects models, while the remainder of studies were combined in a narrative analysis. Quality, risk of bias and level of evidence for health effects were appraised using a combination of emerging frameworks in environmental health. RESULTS: Out of 1366 articles identified, 34 were included in the systematic review and 16 of these were included in meta-analyses. Both PM2.5 and PM10 levels were associated with hospital presentations for URTIs (PM2.5: RR = 1.010, 95%CI = 1.007-1.014; PM10: RR = 1.016, 95%CI = 1.011-1.021) in the meta-analyses. Narrative analysis found unequivocally that total suspended particulates were associated with URTIs, but mixed results were found for PM2.5 and PM10 in both younger and older children. CONCLUSION: This study found some evidence of associations between PM and URTIs in children and adolescents, the relationship strength increased with PM10. However, the number of studies was limited and heterogeneity was considerable, thus there is a need for further studies, especially studies assessing long-term exposure and comparing sources.

Urban Neighbourhood Environments, Cardiometabolic Health and Cognitive Function: A National Cross-Sectional Study of Middle-Aged and Older Adults in Australia.

Population ageing and urbanisation are global phenomena that call for an understanding of the impacts of features of the urban environment on older adults' cognitive function. Because neighbourhood characteristics that can potentially have opposite effects on cognitive function are interdependent, they need to be considered in conjunction. Using data from an Australian national sample of 4141 adult urban dwellers, we examined the extent to which the associations of interrelated built and natural environment features and ambient air pollution with cognitive function are explained by cardiometabolic risk factors relevant to cognitive health. All examined environmental features were directly and/or indirectly related to cognitive function via other environmental features and/or cardiometabolic risk factors. Findings suggest that dense, interconnected urban environments with access to parks, blue spaces and low levels of air pollution may benefit cognitive health through cardiometabolic risk factors and other mechanisms not captured in this study. This study also highlights the need for a particularly fine-grained characterisation of the built environment in research on cognitive function, which would enable the differentiation of the positive effects of destination-rich neighbourhoods on cognition via participation in cognition-enhancing activities from the negative effects of air pollutants typically present in dense, destination-rich urban areas.

From urban neighbourhood environments to cognitive health: a cross-sectional analysis of the role of physical activity and sedentary behaviours.

BACKGROUND: There is a dearth of studies on the effects of the neighbourhood environment on adults' cognitive function. We examined how interrelated aspects of the built and natural neighbourhood environment, including air pollution, correlate with adults' cognitive function, and the roles of physical activity and sedentary behaviours in these associations. METHODS: We used data from 4,141 adult urban dwellers who participated in the Australian Diabetes, Obesity and Lifestyle 3 study on socio-demographic characteristics, neighbourhood self-selection, physical activity and sedentary behaviours, and cognitive function. Neighbourhood environmental characteristics included population density, intersection density, non-commercial land use mix, and percentages of commercial land, parkland and blue space, all within 1 km residential buffers. We also calculated annual mean concentrations of NO2 and PM2.5. Generalised additive mixed models informed by directed acyclic graphs were used to estimate the total, direct and indirect effects of environmental attributes on cognitive functions and the joint-significance test was used to examine indirect effects via behaviours. RESULTS: In the total effects models, population density and percentage of parkland were positively associated with cognitive function. A positive association of PM2.5 with memory was also observed. All neighbourhood environmental attributes were directly and/or indirectly related to cognitive functions via other environmental attributes and/or physical activity but not sedentary behaviours. Engagement in transportation walking and gardening frequency partially mediated the positive effects of the neighbourhood environment on cognitive function, while frequency of transportation walking mediated the negative effects. CONCLUSIONS: In the context of a low-density country like Australia, denser urban environments with access to parkland may benefit residents' cognitive health by providing opportunities for participation in a diversity of activities. A more fine-grained characterisation of the neighbourhood environment may be necessary to tease out the negative and positive impacts of inter-related characteristics of urban neighbourhood environments on cognitive function.

Parental Preconception Exposures to Outdoor Neighbourhood Environments and Adverse Birth Outcomes: A Protocol for a Scoping Review and Evidence Map.

Parental preconception exposures to built and natural outdoor environments could influence pregnancy and birth outcomes either directly, or via a range of health-related behaviours and conditions. However, there is no existing review summarising the evidence linking natural and built characteristics, such as air and noise pollution, walkability, greenness with pregnancy and birth outcomes. Therefore, the planned scoping review aims to collate and map the published literature on parental preconception exposures to built and natural outdoor environments and adverse pregnancy and birth outcomes. We will search electronic databases (MEDLINE, EMBASE, Scopus) to identify studies for inclusion. Studies will be included if they empirically assess the relationship between maternal and paternal preconception exposures to physical natural and built environment features that occur outdoors in the residential neighbourhood and adverse pregnancy and birth outcomes. Two reviewers will independently screen titles and abstracts, and then the full text. Data extraction and assessment of study quality will be performed by one researcher and checked by a second researcher. Results will be summarised in a narrative synthesis, with additional summaries presented as tables and figures. The scoping review will be disseminated via a peer-reviewed publication, at academic conferences, and published on a website.

The impact of Traffic-Related air pollution on child and adolescent academic Performance: A systematic review.

BACKGROUND: The negative health impacts of traffic-related air pollution (TRAP) have been investigated for many decades, however, less attention has been paid to the effect of TRAP on children's academic performance. Understanding the TRAP-academic performance relationship will assist in identifying mechanisms for improving students' learning and aid policy makers in developing guidance for protecting children in school environments. METHODS: This systematic review assessed the relationship between TRAP and academic performance. Web of Science, PubMed, CINAHL, Medline, PsycINFO, SPORTDiscus, Scopus and ERIC databases were searched for relevant, peer reviewed, articles published in English. Articles assessing exposure to TRAP pollutants (through direct measurement, local air quality monitoring, modelling, or road proximity/density proxy measures) and academic performance (using standardised tests) in children and adolescents were included. Risk of bias was assessed within and between studies. RESULTS: Of 3519 search results, 10 relevant articles were included. Nine studies reported that increased exposure to some TRAP was associated with poorer student academic performance. Study methodologies were highly heterogeneous and no consistent patterns of association between specific pollutants, age groups, learning domains, exposure windows, and exposure locations were established. There was a serious risk of bias within individual studies and confidence in the body of evidence was low. CONCLUSIONS: This review found evidence suggestive of a negative association between TRAP and academic performance. However, the quality of this evidence was low. The existing body of literature is small, lacks the inclusion of high-quality exposure measures, and presents limitations in reporting. Future research should focus on using valid and reliable exposure measures, individual-level data, consistent controlling for confounders and longitudinal study designs.

Associations of traffic-related air pollution and greenery with academic outcomes among primary schoolchildren.

BACKGROUND: There is preliminary evidence that greenery/greenspace around schools may be positively associated with children's cognitive development and academic outcomes, whereas traffic-related air pollution (TRAP) may have a detrimental effect. Few studies have examined pathways between both exposures and academic outcomes. This study aimed to assess associations between greenery, road traffic density (a proxy for TRAP) surrounding primary (elementary) schools, and academic achievement of primary schoolchildren in Melbourne, Australia. METHODS: This cross-sectional study examined mean academic scores in Years 3 and 5 for primary schools (n = 851) in Greater Melbourne. Scores were from the 2018 'National Assessment Program - Literacy and Numeracy' (NAPLAN) in five domains: 'Reading'; 'Writing'; 'Spelling'; 'Grammar & Punctuation' and 'Numeracy'. Greenery was measured within school boundaries and surrounding Euclidean buffers (100, 300, 1000 and 2000 m) using the Normalized Difference Vegetation Index (NDVI). Measured TRAP proxies were weighted road density (WRD) within the buffers and distance to a major road. Generalised Linear Models were used to examine associations of greenery and TRAP with academic scores (adjusted for school socio-educational status), and to identify mediating pathways. RESULTS: Greenery was positively associated with Reading scores in Year 3 (all buffers except 2000 m) and in Year 5 (all buffers), with Numeracy in Years 3 and 5 (all buffers) and with Grammar & Punctuation in Year 5 (all buffers). WRD was inversely associated with Reading scores in Year 5 (all buffers), with Numeracy in Year 3 (all buffers) and Year 5 (300 and 1000 m buffers), and with Grammar & Punctuation in Year 3 (100 and 300 m buffers) and Year 5 (all buffers). Distance to a major road was not associated with any score. TRAP partially mediated associations of greenery within 300 m with Numeracy in Year 3 and Grammar & Punctuation in Year 5, and within 2000 m for Reading in Year 5. CONCLUSIONS: Preliminary evidence indicated that greenery around primary schools was positively associated with Reading, Numeracy and Grammar & Punctuation scores, with TRAP mediating some associations. Further research is required to improve TRAP exposure assessment around schools to verify these findings and inform town/school planners and educators regarding optimal school locations and environments for promoting learning.

Development of Measures of Perceived Neighborhood Environmental Attributes Influencing, and Perceived Barriers to Engagement in, Healthy Behaviors for Older Chinese Immigrants to Australia.

Environmental correlates, barriers, and facilitators of physical activity, healthy eating, and socializing are understudied in older immigrants to developed countries. This study developed/adapted and validated measures of perceived barriers and neighborhood environmental characteristics related to these health-enhancing behaviors appropriate for older Chinese immigrants to Australia and similar Western countries. Older Chinese immigrants living in Melbourne (Australia) were recruited from neighborhoods varying in walkability and percentage of Chinese residents. Versions of the Neighborhood Environment for Healthy Aging-Chinese Immigrants to Australia (NEHA-CIA) questionnaire (20 subscales) and the Perceived Barriers to Health-Enhancing Behaviors questionnaire (four subscales) were developed from extant validated scales and information collected in formative qualitative research. Thirty-one participants took part in cognitive interviews aimed to pilot-test and refine the questionnaires. The modified questionnaires were administered to 52 participants twice, two weeks apart. Test-retest reliability (intraclass correlation coefficients), internal consistency (Cronbach's α), and construct validity (associations with theoretically-relevant constructs) were examined. Most items and subscales of both questionnaires had good test-retest reliability and internal consistency, while the NEHA-CIA also showed good construct validity. Future studies need to further examine the construct validity of the questionnaire of perceived barriers and determine the factorial validity of both measures on large representative samples.

A systematic review of the evidence of outdoor air pollution on asthma hospital visits in children and adolescents in South Asia - a call for data.

Background: Outdoor air pollution and childhood asthma are increasing problems in South Asian countries. However, little is known about the associations between levels of air pollution and severe childhood asthma requiring hospital treatment in these regions. Methods: We undertook a systematic review to assess the evidence between outdoor air pollution exposure and childhood and adolescent asthma hospitalization in South Asia. MEDLINE, Web of Science, Google Scholar, CINAHL, Embase, Scopus, ProQuest Central databases were searched for peer-reviewed papers, and examination of reference lists was conducted for additional studies. We identified all the literature published in English up to January 2021 for the study population comprised of children aged less than 19 years. The search strategy was designed to identify all the studies and screen them as per the inclusion criteria. The method of qualitative synthesis using the standard tool determined the comprehensiveness of the assessment of bias. Results: Of the original 367 studies screened three studies were ultimately included from India, Pakistan and Sri Lanka and a narrative synthesis was conducted. Although studies reported adverse effects of outdoor pollution on asthma hospitalizations, limitations in exposure assessments, varying definitions of asthma hospitalizations and limited data analysis were identified. Conclusions: There is currently limited evidence that can provide meaningful risk estimates of the impact of outdoor air pollution on asthma hospitalizations during childhood and adolescence. Studies with comparable outcome definitions, appropriate exposure assessments and study designs are needed to inform future public and environmental health policy. PROSPERO registration: CRD42020156714 (28/04/2020).

Is short-term exposure to grass pollen adversely associated with lung function and airway inflammation in the community?

BACKGROUND: The association between grass pollen exposure and early markers of asthma exacerbations such as lung function changes and increase in airway inflammation is limited. We investigated the associations between short-term grass pollen exposure and lung function and airway inflammation in a community-based sample, and whether any such associations were modified by current asthma, current hay fever, pollen sensitization, age, and other environmental factors. METHODS: Cross-sectional and short-term analyses of data from the Melbourne Atopy Cohort Study (MACS) participants (n = 936). Lung function was assessed using spirometry. Airway inflammation was assessed by fractional exhaled nitric oxide (FeNO) and exhaled breath condensate pH and nitrogen oxides (NOx). Daily pollen counts were collected using a volumetric spore trap. The associations were examined by linear regression. RESULTS: Higher ambient levels of grass pollen 2 days before (lag 2) were associated with lower mid-forced expiratory flow (FEF25%-75% ) and FEV1 /FVC ratio (Coef. [95% CI] = -119 [-226, -11] mL/s and -1.0 [-3.0, -0.03] %, respectively) and also 3 days before (lag 3). Increased levels of grass pollen a day before (lag 1) were associated with increased FeNO (4.35 [-0.1, 8.7] ppb) and also at lag 2. Adverse associations between pollen and multiple outcomes were greater in adults with current asthma, hay fever, and pollen sensitization. CONCLUSION: Grass pollen exposure was associated with eosinophilic airway inflammation 1-2 days after exposure and airway obstruction 2-3 days after exposure. Adults and individuals with asthma, hay fever, and pollen sensitization may be at higher risk.

The Role of Traffic-Related Air Pollution on Neurodegenerative Diseases in Older People: An Epidemiological Perspective.

Traffic-related air pollution is ubiquitous and almost impossible to avoid. It is important to understand the role that traffic-related air pollution may play in neurodegenerative diseases, such as dementia, Alzheimer's disease, and Parkinson's disease, particularly among older populations and at-risk groups. There is a growing interest in this area among the environmental epidemiology literature and the body of evidence identifying this role is emerging and strengthening. This review focuses on the principal components of traffic-related air pollutants (particulate matter and nitrogen oxides) and the epidemiological evidence of their contribution to common neurodegenerative diseases. All studies reported are currently observational in nature and there are mixed findings depending on the study design, assessment of traffic-related air pollutant levels, assessment of the neurodegenerative disease outcome, time period of assessment, and the role of confounding environmental factors and at-risk genetic characteristics. All current studies have been conducted in income-rich countries where traffic-related air pollution levels are relatively low. Additional longer-term studies are needed to confirm the levels of risk, consider other contributing environmental factors and to be conducted in settings where air pollution exposures are higher and at-risk populations reside and work. Better understanding of these relationships will help inform the development of preventive measures and reduce chronic cognitive and physical health burdens (cost, quality of life) at personal and societal levels.

International Mind, Activities and Urban Places (iMAP) study: methods of a cohort study on environmental and lifestyle influences on brain and cognitive health.

INTRODUCTION: Numerous studies have found associations between characteristics of urban environments and risk factors for dementia and cognitive decline, such as physical inactivity and obesity. However, the contribution of urban environments to brain and cognitive health has been seldom examined directly. This cohort study investigates the extent to which and how a wide range of characteristics of urban environments influence brain and cognitive health via lifestyle behaviours in mid-aged and older adults in three cities across three continents. METHODS AND ANALYSIS: Participants aged 50-79 years and living in preselected areas stratified by walkability, air pollution and socioeconomic status are being recruited in Melbourne (Australia), Barcelona (Spain) and Hong Kong (China) (n=1800 total; 600 per site). Two assessments taken 24 months apart will capture changes in brain and cognitive health. Cognitive function is gauged with a battery of eight standardised tests. Brain health is assessed using MRI scans in a subset of participants. Information on participants' visited locations is collected via an interactive web-based mapping application and smartphone geolocation data. Environmental characteristics of visited locations, including the built and natural environments and their by-products (e.g., air pollution), are assessed using geographical information systems, online environmental audits and self-reports. Data on travel and lifestyle behaviours (e.g., physical and social activities) and participants' characteristics (e.g., sociodemographics) are collected using objective and/or self-report measures. ETHICS AND DISSEMINATION: The study has been approved by the Human Research Ethics Committee of the Australian Catholic University, the Institutional Review Board of the University of Hong Kong and the Parc de Salut Mar Clinical Research Ethics Committee of the Government of Catalonia. Results will be communicated through standard scientific channels. Methods will be made freely available via a study-dedicated website. TRIAL REGISTRATION NUMBER: ACTRN12619000817145.

Air pollution is associated with depressive symptoms in elderly women with cognitive impairment.

BACKGROUND: Studies on air pollution and depression in the elderly are limited and the results are heterogeneous. OBJECTIVES: We examined the association of ambient air pollution exposure and diagnosis and symptoms of depression in the elderly; and whether any associations were confounded or modified by cognitive decline. METHODS: We enrolled 821 elderly women from the German SALIA cohort (follow-up examination, 2007-2010). Self-reported depressive symptoms and level of cognition were evaluated using the CESD-R Scale and the CERAD-Plus test, respectively. We used two depression endpoints for analyses: self-reported doctor diagnosis of depression and frequency of depressive symptoms (CESD-R score). Long-term concentrations of particulate matter (PM) size fractions and nitrogen oxides (NOx) modeled by land-use regression were assigned to home addresses. Cross-sectional associations were assessed using adjusted logistic and linear regression models. RESULTS: Concentrations of coarse particles (PMcoarse), fine particles (PM2.5 and PM2.5 abs) and NO2 were significantly associated with diagnosis of depression (e.g. for PM2.5 OR = 1.62, 95%CI: 1.06, 2.46 and for NO2 OR = 1.54, 95% CI: 1.08, 2.19). Similarly, an increase of one interquartile range in PM10, PM2.5, NO2 and NOx was associated with depressive symptoms assessed with the CESD-R score (e.g. for PM2.5 16.2% difference in the mean; 95% CI: 5.8%, 26.5% and for NO2 14.5%; 95% CI: 4.8%, 24.2%). These associations were stronger in women with cognitive decline (e.g. Pint for PM2.5:0.022 and NO2:0.017) compared to women with normal cognition. In addition, living less than 100 m distance to major roads was significantly associated with diagnosis (OR = 1.99, 95% CI: 1.14, 3.47) and symptoms (19.7%; 95% CI: 4.3%, 35.1%) of depression. We did not observe any interaction effect of cognition on prior diagnosis of depression. CONCLUSIONS: Exposure to air pollution was associated with diagnosis of depression and depressive symptoms in elderly women. Women with impaired cognition may be at greater risk of depressive symptoms when exposed to air pollution.

Effects of opioid receptor ligands in rats trained to discriminate 22 from 2 hours of food deprivation suggest a lack of opioid involvement in eating for hunger.

It is well accepted that opioids promote feeding for reward. Some studies suggest a potential involvement in hunger-driven intake, but they suffer from the scarcity of methodologies differentiating between factors that intersect eating for pleasure versus energy. Here, we used a unique food deprivation discrimination paradigm to test a hypothesis that, since opioids appear to control feeding reward, injection of opioid agonists would not produce effects akin to 22 h of food deprivation. We trained rats to discriminate between 22 h and 2 h food deprivation in a two-lever, operant discrimination procedure. We tested whether opioid agonists at orexigenic doses produce discriminative stimulus effects similar to 22 h deprivation. We injected DAMGO, DSLET, or orphanin FQ in the paraventricular hypothalamic nucleus (PVN), a site regulating hunger/satiety, and butorphanol subcutaneously (to produce maximum consumption). We assessed the ability of the opioid antagonist, naltrexone, to reduce the discriminative stimulus effects of 22 h deprivation and of the 22 h deprivation-like discriminative stimulus effects of PVN-injected hunger mediator, neuropeptide Y (NPY). In contrast to PVN NPY, centrally or peripherally injected opioid agonists failed to induce discriminative stimuli similar to those of 22 h deprivation. In line with that, naltrexone did not reduce the hunger discriminative stimuli induced by either 22 h deprivation or NPY administration in 2 h food-restricted subjects, even though doses used therein were sufficient to decrease deprivation-induced feeding in a non-operant setting in animals familiar with consequences of 2 h and 22 h deprivation. We conclude that opioids promote feeding for reward rather than in order to replenish lacking energy.

Association between fire smoke fine particulate matter and asthma-related outcomes: Systematic review and meta-analysis.

BACKGROUND: Asthma-related outcomes are regularly used by studies to investigate the association between human exposure to landscape fire smoke and health. Robust summary effect estimates are required to inform health protection policy for fire smoke exposure. OBJECTIVE: To conduct a systematic review and meta-analysis to estimate the association between short-term exposure to landscape fire smoke (LFS) fine particulate matter (PM2.5) and asthma-related outcomes. METHODS: We conducted a systematic review and meta-analysis following PRISMA guidelines. Four databases (PubMed, Medline, EMBASE and Scopus) and reference lists of recent fire smoke and health reviews were searched. The Newcastle-Ottawa Scale was used to evaluate the quality of case-crossover studies, and a previously validated quality assessment framework was used for observational studies lacking control groups. Publication bias was assessed using funnel plots and Egger's Test. The trim and fill method was used when there was evidence of publication bias. Sensitivity and influence analyses were conducted on all endpoints to test the robustness of estimates. Summary estimates were obtained for hospitalisations and emergency department (ED) visits. A descriptive analysis was conducted for physician visits, medication use, and salbutamol dispensations. RESULTS: From an initial 181 articles (after duplicate removal), 20 studies were included for quantitative assessment and descriptive synthesis. LFS PM2.5 levels were positively associated with asthma hospitalisations (RR = 1.06, 95% CI: 1.02-1.09) and emergency department visits (RR = 1.07, 95% CI: 1.04-1.09). Subgroup analyses found that females were more susceptible than males for ED visits, and that there was an increasing association by age groups for hospital admissions and ED visits. High heterogeneity between studies was observed, but results were robust to sensitivity analysis. CONCLUSIONS: Females and all adults aged over 65 years appear to be the population groups most sensitive to asthma-related outcomes when exposed to LFS PM2.5. Overall, results were higher than those obtained for a typical PM2.5 mixture.

Outdoor fungal spores and acute respiratory effects in vulnerable individuals.

BACKGROUND: Many outdoor fungal spores are ubiquitous, respirable and possibly allergenic. They may contribute to asthma symptoms; however, little is known about their effects on respiratory function. OBJECTIVE: To investigate if outdoor fungal spore levels were associated with lung function or airway inflammation, and whether fungal sensitization or current asthma modified any associations. METHODS: Cross-sectional associations between same day (Lag0) and cumulative 3-day lagged (Lag0-3) counts of 12 outdoor fungal spore taxa and pre-bronchodilator spirometry (FEV1, FVC, FEF25%-75%), bronchodilator response (BDR) and airway inflammation (fractional exhaled nitric oxide (FeNO) and exhaled breath condensate (EBC) nitrogen oxides (NOx) and pH were investigated in 936 Melbourne Atopy Cohort Study participants during September 2009 to December 2011. Generalized linear models were used to quantify associations with lung function, FeNO and EBC pH; generalized estimating equations for BDR; and ordinal logistic regression for EBC NOx. Models were adjusted for age, sex, height, temperature, relative humidity, grass pollen and sample storage time. Potential effect modification by fungal sensitization and current asthma were examined using interaction terms. RESULTS: Mixed associations were found. Higher levels of Ustilago/smuts were associated with lower lung function at Lag0 (FEV1: 21ml [95%CI -36, -7]; FEF25%-75%: 39ml [-65, -13]) and Lag0-3 (FEV1: 9ml [-14, -4]; FEF25%-75% -18ml [-27, -9]). Positive BDR was associated with Ustilago/smuts (Lag0 OR = 1.1 [1.04, 1.2]; Lag0-3 OR = 1.04 [1.02, 1.07]), Alternaria (Lag0 OR = 1.3 [1.0, 1.6]) and Drechslera (Lag0 OR = 1.1 [1.03, 1.2]). Higher EBC NOx was associated with Cladosporium (Lag0-3 OR = 1.1 [1.0, 1.2]), Alternaria (Lag0-3 OR = 1.1 [1.0, 1.3]). No associations were found with higher FeNO. In those with fungal sensitization, Ustilago/smuts and Drechslera were associated with lower FEV1 and FVC; Cladosporium was associated with increased FEV1, FVC and FEF25%-75% but also with higher FeNO and lower EBC pH. In those with current asthma, Alternaria, Ustilago/smuts and Drechslera were associated with lower FEV1, FVC, FEF25-75% and EBC pH. CONCLUSION: Exposure to outdoor fungal spores may be associated with lower lung function and increased airway inflammation, particularly in those with fungal sensitization and/or current asthma.