Small Particulate Matter Research Articles

An Exploration of Features Impacting Respiratory Diseases in Urban Areas.

Air pollution exposure has become ubiquitous and is increasingly detrimental to human health. Small Particulate matter (PM) is one of the most harmful forms of air pollution. It can easily infiltrate the lungs and trigger several respiratory diseases, especially in vulnerable populations such as children and elderly people. In this work, we start by leveraging a retrospective study of 416 children suffering from respiratory diseases. The study revealed that asthma prevalence was the most common among several respiratory diseases, and that most patients suffering from those diseases live in areas of high traffic, noise, and greenness. This paved the way to the construction of the MOREAIR dataset by combining feature abstraction and micro-level scale data collection. Unlike existing data sets, MOREAIR is rich in context-specific components, as it includes 52 temporal or geographical features, in addition to air-quality measurements. The use of Random Forest uncovered the most important features for the understanding of air-quality distribution in Moroccan urban areas. By linking the medical data and the MOREAIR dataset, we observed that the patients included in the medical study come mostly from neighborhoods that are characterized by either high average or high variations of pollution levels.

Triboelectrification-based particulate matter capture utilizing electrospun ethyl cellulose and PTFE spheres

Air pollution associated with particulate matter (PM) has become one of the most serious environmental problems of the decade. Fibrous filters and electrostatic precipitators are usually employed to the indoor PM removal. In case of fibrous filter, if PM is smaller than the hole of filter, removal efficiency decreases considerably whereas, electrostatic precipitator has fatal drawback of producing unwanted O3. In this study, triboelectric PM capture system was introduced by utilizing integrated mechanical filtration attributed to structural characteristic of electrospun ethylcellulose (EC) and the electrostatic filtration induced by the direct triboelectrification between electrospun EC and polytetrafluoroethylene (PTFE) spheres. The electrospun EC was reinforced by heating above glass transition temperature (Tg) to improve mechanical strength. Further, the triboelectrification between EC and PTFE achieved 100% PM removal efficiency and can eliminate the drawback of mechanical filtration without production of any hazardous substances. The improvement of PM removal efficiency by the triboelectrification were +6.68%, +6.89% and +5.47%, corresponding to PM1, PM2.5 and PM10 respectively. More importantly, it was observed that the triboelectric contribution was much higher for small PM which benefits overall system.

Mitigation of Particulate Matter and Airborne Pathogens in Swine Barn Emissions with Filtration and UV-A Photocatalysis

This study evaluated the use of filtration and UV-A photocatalysis for the reduction of particulate matter (PM) and airborne bacterial pathogens in swine barns. Two MERV filters (8 and 15) were used to mitigate PM concentrations measured at the PM 1, PM 2.5, respirable PM, and PM 10 ranges. Filtration was also used to generate different levels of airborne pathogens to be treated by UV-A. Results show that MERV 8 and 15 filters effectively reduced PM concentrations (96–98%) in air exhausted from a swine barn (p ranged from <0.01 to 0.04). UV-A photocatalysis did not mitigate PM concentrations. UV-A photocatalysis treatment reduced measured colony-forming units (CFUs) by 15–95%. The CFU percent reduction was higher when airborne PM concentration was low. The numeric results suggested a real mitigation effect despite p-values that did not meet the usual statistical cut-off of <0.05 for significance due to the large variability of the CFU control samples. Normalization of measured airborne pathogen concentrations by smaller PM size range concentrations led to emerging significant treatment differences for CFUs. A significant decrease (~51% reduction; p < 0.02) in the concentration of viable airborne bacteria was shown for all PM below the 10 micron range.

Respiratory symptoms, lung function, and fraction of exhaled nitric oxide before and after assignment in a desert environment—a cohort study

BackgroundInhalation of small particulate matter (PM 2.5) may be associated with development of respiratory disease. Increased respiratory symptoms have been reported among military staff after service in countries with recurrent desert storms. ObjectiveThe aim was to investigate whether an assignment in a desert environment and exposure to desert storms are associated with negative effects on respiratory health. MethodsIn two cohorts of Swedish soldiers serving in Mali as part of the United Nations stabilization forces, examination with spirometry, determination of fraction of exhaled nitric oxide (FeNO), and a questionnaire including participant characteristics, symptoms, and exposure was performed before and after service. Ambient air sampling was conducted on-site. Paired t-test was used to compare pre- and post-variables on lung function data, FeNO and symptom level. ResultsMost indoor and outdoor air measurements of dust and silica were within the Swedish occupational exposure limit for PM2.5 and silica (<0.10–2.7 mg/m3 and <0.002–0.40 mg/m3, respectively) as well as for respirable dust and silica (0.056–0.078 mg/m3and 0.0033–0.025 mg/m3, respectively).In the subgroup of participants with reported exposure to desert storms during the stay in Mali, forced expiratory volume in 1 s (FEV1) was significantly lower after exposure than before the mission (mean litres (SD) 4.21 ± 0.66 vs 4.33 ± 0.72, p = 0.021). ConclusionExposure to a desert storm was associated with a decrease in FEV1. Exposure to small particulate matter may contribute to the development of respiratory disease and thus spirometry should be performed after occupational exposure to desert storms.

Urban atmospheric particle size distribution in Santiago, Chile

A monitoring campaign of the atmospheric particulate matter (PM) size distribution (between 0.25 and 10 μm in diameter (Dp)) in an urban area with high levels of air pollution between June 2018 and May, 2019 is presented. The relative contribution of 24 size fractions to the total number and mass concentration of PM was analyzed using an aerosol spectrometer. Local meteorological parameters and their effect on the PM concentrations were also evaluated. The size-fractionated particle mass concentrations showed the accumulation (Dp < 1 μm) and coarse (1 μm < Dp < 10 μm) modes. The highest contribution of the accumulation mode was observed during autumn and winter (reaching 99.7 % and 35.2 % of the total number and mass concentrations, respectively). High relative humidity and low temperatures were strongly correlated with high concentrations for the smaller PM fractions, which can be connected to the increase of residential emissions of PM derived from wood burning sources in winter months. The larger PM fractions showed higher concentrations during the spring and summer months, potentially because of dust resuspension due to the high vehicular traffic in the vicinity. High PM concentrations of the larger fractions were favored by the lack of precipitation events and stronger winds during this time of the year. The results showed the importance of the PM1 fraction to improve the source apportionment studies in urban areas and provide information about the potential health effects associated to high PM concentration events.

Fine Particulate Matter Related to Multiple Sclerosis Relapse in Young Patients.

Objective: Particulate matter (PM) of aerodynamic diameter smaller than 10 μm (PM10) has been associated with multiple sclerosis (MS) relapse. However, the impact of smaller PM with a greater ability to penetrate human organism has never been assessed. We evaluated the impact of PM smaller than 2.5 μm (PM2.5) on the risk of MS relapse.Material and Methods: In a case-crossover study, we included 2,109 consecutive hospitalizations likely due to MS relapse in day hospital in 5 MS centers in the Paris area from January 2009 to December 2013. For each hospitalization, the natural logarithm of the average weekly PM2.5 concentrations (μg/m3) at the patient's residence address during each of the 6 weeks (week[0] to week[−5]) preceding admission was compared with the concentration during the previous week, using a conditional logistic regression adjusted on temperature, flu-like syndrome rate, pollen count, and holiday period.Results: PM2.5 average concentration during week[−3] was significantly associated with the risk of hospitalization for MS relapse [OR = 1.21 (CI 1.01;1.46)]. The association was stronger in patients younger than 30 years [OR=1.77 (CI 1.10; 2.83)].Conclusion: Our study demonstrates an association between exposure to PM2.5 and MS relapse, particularly in young people.

Comparison of childhood asthma incidence in 3 neighbouring cities in southwestern Ontario: a 25-year longitudinal cohort study.

Background:Air pollution is a known trigger for exacerbations among individuals with asthma, but its role in the development of new-onset asthma is unclear. We compared the rate of new asthma cases in Sarnia, a city with high pollution levels, with the rates in 2 neighbouring regions in southwestern Ontario, Canada.Methods:Using a population-based birth cohort design and linked health administrative data, we compared the hazard of incident asthma among children 0 to 10 years of age between those born in Lambton (Sarnia) and those born in Windsor and London–Middlesex, for the period Apr. 1, 1993, to Mar. 31, 2009. We used Cox proportional hazards models to adjust for year of birth and exposure to air pollutants (nitrogen dioxide, sulphur dioxide [SO2], ozone and small particulate matter [PM2.5]), as well as maternal, geographic and socioeconomic factors.Results:Among 114 427 children, the highest incidence of asthma was in Lambton, followed by Windsor and London–Middlesex (30.3, 24.4 and 19.8 per 1000 person-years, respectively; p < 0.001). Relative to Lambton, the hazard of asthma, adjusted for socioeconomic and perinatal factors, was lower in Windsor (hazard ratio [HR] 0.72, 95% confidence interval [CI] 0.67–0.77) and London–Middlesex (HR 0.65, 95% CI 0.61–0.69). Inclusion of air pollutants attenuated this relative difference in both Windsor (HR 0.79, 95% CI 0.62–1.01) and London–Middlesex (HR 0.89, 95% CI 0.64–1.24).InterpretationWe identified a higher incidence of asthma among children born in Lambton (Sarnia) relative to 2 other regions in southwestern Ontario. Higher levels of air pollution (particularly SO2 and PM2.5) in this region, as experienced by children in their first year of life, may be contributory.

The Impact of Bushfire Smoke on Cattle-A Review.

Simple SummaryIn 2019–2020, Australia had a particularly bad bushfire season which resulted in large numbers of people and animals being exposed to smoke haze for several weeks. We conducted a literature review to examine the evidence for effects of prolonged exposure to bushfire smoke on cattle. There was general agreement that small airborne particulate matter in smoke is the substance most likely to cause problems. There was indirect evidence about effects on cattle caused by other types of pollution containing particulate matter. We found little evidence to support severe effects on cattle. This may be because cattle do not tend to suffer from the co-morbidities that, in the human population, seem to be made worse by smoke and pollution. However, small changes to death rates or disease that is not severe may go unreported, so further study is warranted.In 2019–2020, a particularly bad bushfire season in Australia resulted in cattle being exposed to prolonged periods of smoke haze and reduced air quality. Bushfire smoke contains many harmful pollutants, and impacts on regions far from the fire front, with smoke haze persisting for weeks. Particulate matter (PM) is one of the major components of bushfire smoke known to have a negative impact on human health. However, little has been reported about the potential effects that bushfire smoke has on cattle exposed to smoke haze for extended periods. We explored the current literature to investigate evidence for likely effects on cattle from prolonged exposure to smoke generated from bushfires in Australia. We conducted a search for papers related to the impacts of smoke on cattle. Initial searching returned no relevant articles through either CAB Direct or PubMed databases, whilst Google Scholar provided a small number of results. The search was then expanded to look at two sub-questions: the type of pollution that is found in bushfire smoke, and the reported effects of both humans and cattle being exposed to these types of pollutants. The primary mechanism for damage due to bushfire smoke is due to small airborne particulate matter (PM). Although evidence demonstrates that PM from bushfire smoke has a measurable impact on both human mortality and cardiorespiratory morbidities, there is little evidence regarding the impact of chronic bushfire smoke exposure in cattle. We hypothesize that cattle are not severely affected by chronic exposure to smoke haze, as evidenced by the lack of reports. This may be because cattle do not tend to suffer from the co-morbidities that, in the human population, seem to be made worse by smoke and pollution. Further, small changes to background mortality rates or transient morbidity may also go unreported.

TRP Channels as Cellular Targets of Particulate Matter.

Particulate matter (PM) is constituted by particles with sizes in the nanometer to micrometer scales. PM can be generated from natural sources such as sandstorms and wildfires, and from human activities, including combustion of fuels, manufacturing and construction or specially engineered for applications in biotechnology, food industry, cosmetics, electronics, etc. Due to their small size PM can penetrate biological tissues, interact with cellular components and induce noxious effects such as disruptions of the cytoskeleton and membranes and the generation of reactive oxygen species. Here, we provide an overview on the actions of PM on transient receptor potential (TRP) proteins, a superfamily of cation-permeable channels with crucial roles in cell signaling. Their expression in epithelial cells and sensory innervation and their high sensitivity to chemical, thermal and mechanical stimuli makes TRP channels prime targets in the major entry routes of noxious PM, which may result in respiratory, metabolic and cardiovascular disorders. On the other hand, the interactions between TRP channel and engineered nanoparticles may be used for targeted drug delivery. We emphasize in that much further research is required to fully characterize the mechanisms underlying PM-TRP channel interactions and their relevance for PM toxicology and biomedical applications.

Association of Air Pollutant Exposure and Sinonasal Histopathology Findings in Chronic Rhinosinusitis.

Ambient air pollution is well known to cause inflammatory change in respiratory epithelium and is associated with exacerbations of inflammatory conditions such as asthma and chronic obstructive pulmonary disease. However, limited work has been done on the impact of air pollution on pathogenesis of chronic rhinosinusitis and there are no reports in the literature of how pollutant exposure may impact sinonasal histopathology in patients with chronic rhinosinusitis. This study aims to identify associations between certain histopathologic characteristics seen in sinus tissue of patients with chronic rhinosinusitis (CRS) and levels of particulate air pollution (PM2.5) and ground-level ozone in their place of residence. A structured histopathology report was created to characterize the tissues of CRS patients undergoing sinus surgery. An estimate for each patient's exposure to air pollutants including small particulate matter (PM2.5) and ground-level ozone was obtained using the Environmental Protection Agency's (EPA) Environmental Justice Screening and Mapping Tool (EJSCREEN). Mean pollutant exposures for patients whose tissues exhibited varying histopathologic features were compared using logistic regression models. Data from 291 CRS patients were analyzed. Higher degree of inflammation was significantly associated with increased ozone exposure (p = 0.031). Amongst the patients with CRSwNP (n=131), presence of eosinophilic aggregates (p = 0.018) and Charcot-Leyden crystals (p = 0.036) was associated with increased ozone exposure. Exposure to ambient air pollutants may contribute to pathogenesis of CRS. Increasing ozone exposure was linked to both higher tissue inflammation and presence of eosinophilic aggregates and Charcot-Leyden crystals in CRSwNP patients.

Ambient particulate matter (PM1, PM2.5, PM10) and childhood pneumonia: The smaller particle, the greater short-term impact?

BackgroundSmaller sizes of ambient particulate matter (PM) can be more toxic and can be breathed into lower lobes of a lung. Children are particularly vulnerable to PM air pollution because of their adverse effects on both lung functions and lung development. However, it remains unknown whether a smaller PM has a greater short-term impact on childhood pneumonia. AimsWe compared the short-term effects on childhood pneumonia from PM with aerodynamic diameters ≤1 μm (PM1), ≤2.5 μm (PM2.5), and ≤10 μm (PM10), respectively. MethodsDaily time-series data (2016–2018) on pneumonia hospitalizations in children aged 0–17 years, records of air pollution (PM1, PM2.5, PM10, and gaseous pollutants), and weather conditions were obtained for Hefei, China. Effects of different PM were quantified using a quasi-Poisson generalized additive model after controlling for day of the week, holiday, seasonality and long-term time trend, and weather variables. Stratified analyses (gender, age, and season) were also performed. ResultsFor each 10 μg/m3 increase in PM1, PM2.5, and PM10 concentrations over the past three days (lag 0–2), the risk of pneumonia hospitalizations increased by 10.28% (95%CI: 5.88%–14.87%), 1.21% (95%CI: 0.34%–2.09%), and 1.10% (95%CI: 0.44%–1.76%), respectively. Additionally, both boys and girls were at risk of PM1 effects, while PM2.5 and PM10 effects were only seen in boys. Children aged ≤12 months and 1–4 years were affected by PM1, but PM2.5 and PM10 were only associated with children aged 1–4 years. Furthermore, PM1 effects were greater in autumn and winter, while greater PM2.5 and PM10 effects were evident only in autumn. ConclusionThis study suggests a greater short-term impact on childhood pneumonia from PM1 in comparison to PM2.5 and PM10. Given the serious PM pollution in China and other rapid developing countries due to various combustions and emissions, more investigations are needed to determine the impact of different PM on childhood respiratory health.

English

AbstractCherax quadricarinatus (redclaw) aquaculture has not achieved the industry growth that had been predicted in the early days of development. Provision of quality juvenile crayfish seed stock has been identified as a critical factor in overcoming industry development inertia. Hatchery technology has been developed to produce independent craylings and a nursery phase is now being developed to nurture the delicate craylings to a more advanced and robust juvenile stage, suitable for pond stocking. As part of the nursery development, clear definitions of the successive stages from egg through the first several instars, are required. Although some morphological descriptions of the early stages of redclaw have been made, the characteristics and nomenclature for stages from egg through to an advanced juvenile need clarification. A naming system is proposed (Egg, L1, L2, J1, J2 and J3) for the first six instars from egg, based on gross morphology and allometric relationships. Egg volume, wet weight and ocular carapace length (OCL) were analysed through linear regression. Based on these variables, the size of each instar is defined. Descriptions and photographs of the six instars provide a visual reference for identification. Five of the six instars had a significant relationship between wet weight and OCL. Both significantly increased for each successive instar. Lyophilized (dry) weight was not significantly different between stages until after instar J1, where endogenous feeding begins. The growth of the first four instars, in terms of wet weight and OCL but not dry weight, suggests an extra endogenous source of nutrition in addition to the yolk supply. Branchial water uptake during ecdysis has been proposed as a route for dissolved organic matter or small particulate matter to be acquired by the crayfish during the lecithotrophic, nonexogenous feeding stages, as an additional food source that might further enhance growth and survival.

Characterization of cultivable airborne bacteria and their antimicrobial resistance pattern in French milking parlour.

The main goal of this preliminary study was to quantify airborne particles and characterize the dominant cultivable bacterial species as well as some Gram-positive species, and their antibiotic resistance pattern, from environmental samples taken inside and outside of a dairy milking parlour. Sampling was performed over 2days, in different seasons. The small viable particulate matter <10μm (bioaerosols) and cultivable bacteria reached their highest concentrations in the milking parlour. The majority of airborne bacteria in the milking parlour belonged to the genera Staphylococcus (41.9%) and Bacillus (20.9%). A total of 32 different bacterial species of Staphylococcus, Aerococcus, Bacillus, Pseudomonas, Serratia and Acinetobacter were identified. Many of these bacteria may be opportunistic pathogens, causing disease in humans or animals. We found low levels of acquired resistance to the antibiotics commonly used in human or animal infections caused by these opportunistic bacteria. More specifically, resistance to tetracyclines (13.4%), penicillin G (13.4%) and macrolides (7.5%) was identified in Staphylococcus sp. as was a methicillin-resistant S. hominis and resistance to spiramycin (n = 1), lincomycin (n = 1) and streptomycin (n = 2) in Aerococcus sp. An assessment of the occupational risk run by dairy farmers for contracting infections after long- or short-term exposure to micro-organisms requires further studies on the concentration of opportunistic pathogenic bacteria in dairy farm environments.

A Semi-portable Enclosure to Measure Emission Rates from Small Fugitive Sources: Leaf Blower Dust Example

Small fugitive particulate matter (PM) sources may make significant impacts to urban air pollution. The PM emission rates for most of these have not been measured due to the difficulty involved. The EPA addresses some fugitive emission rates in their AP-42 document and these generally were developed from upwind-downwind sampling. A semi-portable enclosure was designed and evaluated for determining PM emission rates from landscape cleaning operations such as leaf blowing, raking, and sweeping. The method consisted of an enclosure to confine PM emissions while performing these activities on actual in-use surfaces while making measurements using real-time PM analyzers. In this enclosure the cleaning equipment could be operated in the same way as normally done. To evaluate the enclosure’s mixing and exchange rates, propene gas was released and used as a tracer. PM emission rates were then calculated from measured concentrations, the dimensions of the enclosure, and area over which the cleaning operation was performed. To evaluate this method, cleaning operations were performed after the pavement floor was vacuumed and then spiked with surrogate debris. To make actual emission rate measurements, the enclosure was placed over landscape with debris from normal grounds maintenance activities. Emission rates were determined as a function of surface type and cleaning tool used. The method would be appropriate for many types of small fugitive dust sources.

Air Pollution and Innovation

Existing estimates of the economic costs of air pollution do not account for its effect on inventive output. Using two weather phenomena as instruments, we estimate this effect in a sample of 1,288 European regions. A decrease in exposure to small particulate matter of 0.17 micro-gram/m3 -- the average yearly reduction in Europe -- leads to 1.7% more patented inventions. After ruling out reallocation of human capital, inventor mortality and R&D expenditures as drivers of the effect, we conclude that air pollution's harm to economic output increases by at least 10% when accounting for innovation.

Expansion of a size disaggregation profile library for particulate matter emissions processing from three generic profiles to 36 source-type-specific profiles

ABSTRACT This study describes a significant upgrade to the particulate matter (PM) size disaggregation profile library used for preparing emissions files for the GEM-MACH (Global Environmental Multiscale-Modelling Air-quality and CHemistry) chemical transport model (CTM). This model uses a sectional (bin) approach to represent the PM size distribution, where one configuration employs 12 size bins to disaggregate PM2.5 and PM10 inventory emissions into the first 10 bins ranging from 0.01 to 10.24 μm in diameter. For the size disaggregation step, a small library of three generic PM size disaggregation profiles is currently applied for three broad source categories (area, mobile, and point). However, as might be expected, these generic profiles are not always representative: for example, emissions from two very different area sources ‒ paved road dust and residential wood combustion ‒ are disaggregated using the same generic size distribution profile. In order to improve the current small PM size disaggregation profile library, a comprehensive literature review was conducted: over 100 relevant publications were identified and PM size distribution profiles for 36 different emission source types were selected and compiled. These 36 source-type-specific PM size distribution profiles were then combined based on process type with corresponding PM speciation profiles to create a library of chemically speciated and size-resolved PM disaggregation profiles. This library can now be used by the SMOKE (Sparse Matrix Operator Kernel Emissions) emissions processing system for the 12-bin version of GEM-MACH to perform PM chemical speciation and size allocation in one step. The size-profile data collected and compiled in this study may also be used for emissions processing for other CTMs with a size-resolved representation of PM. Details of the compilation of the 36 PM size disaggregation profiles are discussed, and the differences in processed PM emissions based on the current and updated PM size disaggregation profile libraries are shown. Implications: A new and expanded particulate matter (PM) size disaggregation profile library covering 36 emission source types has been developed based on an extensive literature review. Its use can produce significant changes in the size allocation of bulk PM inventory emissions processed for input to size-resolved PM chemical transport models. Such models are used to predict atmospheric visibility and to simulate the interactions of aerosol particles with atmospheric radiation and with clouds. The use of more accurate, size-resolved primary PM emissions by these models should improve their predictive skill for atmospheric PM processes affecting air quality, meteorology, and climate.

Effect of Relative Humidity and Temperature on PM2.5 Concentrations in Kampala, Uganda

Background Scientific evidence reveals that exposure to small particulate matter of 2.5 microns or less in diameter (PM2.5) is very detrimental to health thus resulting in increased risks of cardiovascular and respiratory disease, and cancers. There are three factors that have important effect on PM2.5 mass concentration: domestic pollutant emission sources, external sources outside of the country, and the meteorological conditions. We aimed assessing the effect of relative humidity and temperature on PM2.5 concentrations from 2018 to 2019 using the Beta Attenuation monitor 1022. Methods We measured the relative humidity, temperature, ambient PM2.5 concentrations prospectively from October 2017 to December 2019 using the Beta Attenuation Monitor (BAM) 1022 (Met One Instruments, Inc) at the Eastern Africa GEOHealth Hub air quality monitoring station, that installed at Makerere University School of Public Health Roof top building at height of 15 metres above the ground level, Kampala Uganda. Results The findings showed that annual averages of PM2.5, Ambient Temperature (AT) and Relative Humidity (RH) in 2018 was 41.3 µg/m3, 23.10C and 72.0% and in 2019 was 38.5 µg/m3, 23.80C and 71.9% respectively. The results showed that the annual averages for PM2.5, Ambient Temperature (AT) and Relative Humidity (RH) in 2018 and 2019 was about the same. The findings also revealed that every unit increase in relative humidity increased PM2.5 concentrations by 29.3% and every unit increase in ambient temperature reduced PM2.5 concentrations by 2.14). Notably also in 2018 and 2019 the daily PM2.5 average concentrations decreased when RH reached high a threshold 80%. Conclusion The daily PM2.5 average concentrations decreased when the relative humidity reached a high threshold of 80% in 2018 and 2019 in Kampala Uganda. Funding Sources: NIH Fogarty International Center, NIEHS, CDC/NIOSH, Canada’s IDRC, GACC Grant # 5R24 TW009552 [AAU]; 5R24 TW009548 [USC]; 1U01TW010094 [AAU]; 1U2RTW010125 [USC]

Room-scale analysis of spatial and human factors affecting indoor environmental quality in Porto residential flats

Residential indoor environment quality (IEQ) is not fully known, particularly in Southern European countries. In this study, a room-level analysis was performed in forty-two rooms of twelve flats, selected from six buildings located in Porto, Portugal. Each room was monitored for approximately three weeks during the spring. The average monitored values in terms of temperature (T), water vapour pressure excess (ΔP), carbon dioxide (CO2), small particulate matter (PM2.5), the ratio between the indoor and outdoor PM2.5 (PM2.5 I/O), and total volatile organic compounds (TVOC) were 21.7 °C, 175 Pa, 781 ppm (1287 ppm considering only night occupancy periods), 12.2 μg/m3, 3.3 and 345 ppb, respectively. The CO2 concentrations and PM2.5 I/O values were higher than those obtained from the literature, indicating poorly ventilated rooms. A knowledge discovery methodology was used to search for behavioural patterns. Four groups were formed based on a cluster analysis that was qualitatively classified in terms of IEQ. Decision trees were created to evaluate the spatial and human factors affecting these cluster associations. The main factors affecting the IEQ were the presence of smokers, room ventilation ratio, floor area, and number of occupants. The results of this post-occupancy evaluation provide information to optimise the IEQ of the residential sector at the design level and emphasise the existence of a post-occupancy monitoring system that provides occupants with information about IEQ.

Request of hospital care dropped for TIA but remained stable for stroke during COVID-19 pandemic at a large Italian university hospital

Reduced incidence of stroke during COVID-19 pandemic was sometimes reported. While decrease in stroke incidence and fear of patients to go to the hospitals were sometimes invoked to explain this decrease, reduction in urban pollution was also hypothesized as a possible cause. We investigated statistically the incidence of ischemic and hemorrhagic stroke, and of transient ischemic attacks, at a large Italian tertiary stroke center during the pandemic. We analyzed statistically the number of transient ischemic attacks (TIA), ischemic strokes (IS) and hemorrhagic strokes (HS) between March 8 and May 2, 2020, the peak of the COVID-19 epidemic in Italy, and compared them with the identical period of 2019. We also analyzed the concentration of small particulate matter (PM10) in 2019 and 2020, to see if it could account for modified incidence of strokes or TIA. We found a large, significant drop in TIA (− 51%) during the pandemic compared to the same period of 2019. By contrast, the number of HS was identical, and IS showed a not significant − 24% decrease. PM10 concentration, already low in 2019, did not further decrease in 2020. Patients kept seeking hospital care when experiencing permanent neurological symptoms (stroke), but they tended not go to the hospital when their symptoms were transient (TIA). The fact that we did not observe a significant decrease in strokes may be explained by the fact that in our city the concentration of small particulate matter did not change compared to 2019.

Long-Term Exposure to PM10 and in vivo Alzheimer's Disease Pathologies.

Previous studies indicated an association between Alzheimer's disease (AD) dementia and air particulate matter (PM) with aerodynamic diameter <10μm (PM10), as well as smaller PM. Limited information, however, is available for the neuropathological links underlying such association. This study aimed to investigate the relationship between long-term PM10 exposure and in vivo pathologies of AD using multimodal neuroimaging. The study population consisted of 309 older adults without dementia (191 cognitively normal and 118 mild cognitive impairment individuals), who lived in Republic of Korea. Participants underwent comprehensive clinical assessments, 11C-Pittsburg compound B (PiB) positron emission tomography (PET), and magnetic resonance imaging scans. A subset of 78 participants also underwent 18F-AV-1451 tau PET evaluation. The mean concentration of PM with aerodynamic diameter <10μm over the past 5 years (PM10mean) collected from air pollution surveillance stations were matched to each participant's residence. In this non-demented study population, of which 62% were cognitively normal and 38% were in mild cognitive impairment state, exposure to the highest tertile of PM10mean was associated with increased risk of amyloid-β (Aβ) positivity (odds ratio 2.19, 95% confidence interval 1.13 to 4.26) even after controlling all potential confounders. In contrast, there was no significant associations between PM10mean exposure and tau accumulation. AD signature cortical thickness and white matter hyperintensity volume were also not associated with PM10mean exposure. The findings suggest that long-term exposure to PM10 may contribute to pathological Aβ deposition.