Size-fractionated Particulate Matter Research Articles

Seasonal and Spatial Variations of PM10 and PM2.5 Oxidative Potential in Five Urban and Rural Sites across Lombardia Region, Italy.

Oxidative potential (OP) of particulate matter (PM) is gaining strong interest as a promising health exposure metric. This study investigated OP of a large set of PM10 and PM2.5 samples collected at five urban and background sites near Milan (Italy), one of the largest and most polluted urban areas in Europe, afflicted with high particle levels. OP responses from two acellular assays, based on ascorbic acid (AA) and dithiothreitol (DTT), were combined with atmospheric detailed composition to examine any possible feature in OP with PM size fraction, spatial and seasonal variations. A general association of volume-normalized OP with PM mass was found; this association may be related to the clear seasonality observed, whereby there was higher OP activity in wintertime at all investigated sites. Univariate correlations were used to link OP with the concentrations of the major chemical markers of vehicular and biomass burning emissions. Of the two assays, AA was particularly sensitive towards transition metals in coarse particles released from vehicular traffic. The results obtained confirm that the responses from the two assays and their relationship with atmospheric pollutants are assay- and location-dependent, and that their combination is therefore helpful to singling out the PM redox-active compounds driving its oxidative properties.

Analysis of Pollutant Emission in Poland From Road Vehicles of the Generalised Category in Accordance With the Vehicle Application Criterion

Abstract This paper presents the results of analyses that were focused on pollutant emissions from road vehicles classified into the generalised categories with respect to vehicle use. The analyses were performed using the authorised results of Poland's pollutant emission inventory, carried out in 1990–2020 by the National Centre for Emissions Management (KOBiZE) at the Institute of Environmental Protection – National Research Institute (IOŚ-PIB) in order to meet requirements for the national emissions reporting under EU legislation and the UNECE Convention on Long-range Transboundary Air Pollution. The following road vehicle categories were analysed: passenger cars, light duty vehicles, heavy-duty trucks, buses (urban buses and coaches) and L category (motorcycles, mopeds, quads, microcars). The emissions of selected pollutants that are harmful to the health of living beings were studied, i.e. nitrogen oxides, non-methane volatile organic compounds, sulfur compounds, particulate matter size fractions, carbon monoxide and lead compounds. The shares of national annual pollutant emissions from each studied vehicle category of the total pollutant emissions from road transport were determined. With the aim to assess trends in improving environmental properties of road vehicles, there were determined changes of the energy emission factors for individual pollutants in all the vehicle categories under the study. The results obtained showed dynamic decreases in the energy emission factors for nitrogen oxides, non-methane volatile organic compounds and carbon monoxide. In the case of particulate matter emission, the improvement was not as pronounced. The evident reduction in the emissions of sulfur and lead compounds in the 21st century was confirmed to be a consequence of practical elimination of these compounds from road vehicle fuels.

Characteristics and Source Apportionment of Size-Fractionated Particulate Matter at Ground and above the Urban Canopy (380 m) in Nanjing, China

In this study, the concentrations and chemical components of size-fractionated particulate matter (PM) in Nanjing at the ground (Gulou, 20 m) and above the urban canopy (Zifeng, 380 m) were sampled and analyzed from 16 November to 12 December in 2016. Higher concentrations of PM10, PM10-2.1, and PM2.1 (108.3 ± 23.4 μg m−3, 47.3 ± 10.6 μg m−3, and 61.0 ± 18.8 μg m−3) were measured at Gulou than those (88.1 ± 21.1 μg m−3, 31.4 ± 6.7 μg m−3, and 56.7 ± 18.6 μg m−3) at Zifeng. The most abundant chemical components for size-fractionated PM were SO42−, NO3−, organic carbon (OC), NH4+, elemental carbon (EC), and crustal elements such as Al, Ca, Fe, and Mg, varying significantly on different particulate sizes. The concentrations of OC and EC were 7.46–19.60 μg m−3 and 3.44–5.96 μg m−3 at Gulou and were 8.34–18.62 μg m−3 and 2.86–4.11 μg m−3 at Zifeng, showing an equal importance in both fine and coarse particles. Nitrate, sulfate, and ammonium were more concentrated in PM2.1, contributing 11.30–13.76 μg m−3, 8.91–9.40 μg m−3, and 5.78–6.81 μg m−3, which was more than in PM10-2.1, which contributed 2.73–5.06 μg m−3, 2.16–3.81 μg m−3, and 0.85–0.87 μg m−3. In contrast, the crustal elements were larger in coarse particles and at the ground level, accounting for 18.6% and 15.3% of the total PM at Gulou and Zifeng. Source apportionment using the chemical mass balance (CMB) model EPA showed that the dominant three sources were secondary nitrate (18.2–24.9%), secondary sulfate (14.5–20.4%), and secondary organic aerosols (15.5–19.6%) for PM10, PM2.1, and PM1.1 at both Gulou and Zifeng during the entire sampling period. However, for PM10-2.1, the largest three contributors were secondary organic aerosols (18.3%), the coal-fired power plant (15.6%), and fugitive dust (14.4%), indicating dusts including construction dust, fugitive dust, and soil dust would contribute more at the ground. The results also showed that the concentrations of PM10, PM2.1, and PM1.1 were lower than the work carried out in the winter of 2010 at the same sampling site by 41.4%, 26.3%, and 24.8%, confirming the improvement of the air quality and the efficient control of PM pollutants.

Joint effect of indoor size-fractioned particulate matters and black carbon on cardiopulmonary function and relevant metabolic mechanism: A panel study among school children

Indoor particulate matter (PM) and black carbon (BC) are associated with adverse cardiopulmonary effect. However, the cumulative and interactive effects of the mixture of size-fractioned PMs and BC on cardiopulmonary function are not well understood, and the underlying biological mechanisms remain unclear. This repeated-measure study was conducted to assess the joint cardiopulmonary effect and metabolic mechanisms of multiple-size particles and BC among 46 children. PM0.5, PM1, PM2.5, PM5, PM10 and BC were monitored for 5 weekdays. Cardiorespiratory function measurements and urine samples collection were conducted three times. Untargeted-metabolomics and meet-in-metabolite approach were applied to mechanism investigation. Bayesian machine kernel regression was adopted to analyze associations among PMs, cardiopulmonary function and metabolites. Lung function and heart rate variability significantly decreased with the increased PMs and BC co-exposure (p < 0.05). The effective particles were BC, PM1-2.5 and PM0.5 in turn. No interaction effects of different particles on cardiopulmonary function were observed at different lag days. BC-related glucose and fatty acid increase, and PM1-2.5-related branched-chain amino acid degradation were primarily observed. Other metabolisms were successively disturbed. The greatest joint effects of PMs and BC on metabolism were mainly at lag0 and lag01 day. They occurred earlier than the strongest effects on cardiopulmonary function, which were at lag01 and lag02 day. BC, PM1-2.5 and PM0.5 were mainly associated with cardiorespiratory indices by disturbing amino acids, glucose, lipid, isoflavone and purine metabolism. Mitochondrial productivity and antioxidation reduction are pivotal to the relevant metabolic alterations. More attention should be paid to BC and smaller-size PMs to control indoor PM pollution and its adverse effect on children.

A Real-Time Comparison of Four Particulate Matter Size Fractions in the Personal Breathing Zone of Paris Subway Workers: A Six-Week Prospective Study

We developed a Bayesian spline model for real-time mass concentrations of particulate matter (PM10, PM2.5, PM1, and PM0.3) measured simultaneously in the personal breathing zone of Parisian subway workers. The measurements were performed by GRIMM, a gravimetric method, and DiSCmini during the workers’ work shifts over two consecutive weeks. The measured PM concentrations were analyzed with respect to the working environment, the underground station, and any specific events that occurred during the work shift. Overall, PM0.3 concentrations were more than an order of magnitude lower compared to the other PM concentrations and showed the highest temporal variation. The PM2.5 levels raised the highest exposure concern: 15 stations out of 37 had higher mass concentrations compared to the reference. Station PM levels were not correlated with the annual number of passengers entering the station, the year of station opening or renovation, or the number of platforms and tracks. The correlation with the number of station entrances was consistently negative for all PM sizes, whereas the number of correspondence concourses was negatively correlated with PM0.3 and PM10 levels and positively correlated with PM1 and PM2.5 levels. The highest PM10 exposure was observed for the station platform, followed by the subway cabin and train, while ticket counters had the highest PM0.3, PM1, and PM2.5 mass concentrations. We further found that compared to gravimetric and DiSCmini measurements, GRIMM results showed some discrepancies, with an underestimation of exposure levels. Therefore, we suggest using GRIMM, calibrated by gravimetric methods, for PM sizes above 1μm, and DiSCmini for sizes below 700 nm.

Personal Exposure and Inhaled Dose Estimation of Air Pollutants during Travel between Albany, NY and Boston, MA

Out of eight deaths caused worldwide, one death is caused due to air pollution exposure, making it one of the top global killers. Personal exposure measurement for real-time monitoring has been used for inhaled dose estimation during various modes of workplace commuting. However, dose-exposure studies during long commutes are scarce and more information on inhaled doses is needed. This study focuses on personal exposures to size-fractionated particulate matter (PM1, PM2.5, PM4, PM7, PM10, TSP) and black carbon (BC) inside a bus traveling more than 270 kms on a highway between Albany, NY and Boston, MA. Measurements were also made indoors, outdoors, and while walking in each city. Mean PM (PM1, PM2.5, PM4, PM7, PM10, TSP) and mean BC concentrations were calculated to estimate the inhaled exposure dose. The highest average PM2.5 and PM10 exposures concentrations were 30 ± 12 and 111 ± 193 µg/m3, respectively, during Boston to Albany. Notably, personal exposure to BC on a bus from Albany to Boston (5483 ± 2099 ng/m3) was the highest measured during any commute. The average inhaled dose for PM2.5 during commutes ranged from 0.018 µg/km to 0.371 µg/km. Exposure concentrations in indoor settings (average PM2.5 = 37 ± 55 µg/m3, PM10 = 78 ± 82 µg/m3, BC = 5695 ± 1774 ng/m3) were higher than those in outdoor environments. Carpeted flooring, cooking, and vacuuming all tended to increase the indoor particulate level. A high BC concentration (1583 ± 1004 ng/m3) was measured during walking. Typical concentration profiles in long-haul journeys are presented.

Association of Exposure to Particulate Matter Air Pollution With Semen Quality Among Men in China

The health effects of exposure to particulate matter (PM) on male fertility remain unclear. Although PM exposure has been linked with semen quality, the results were inconsistent. To examine the association of different size fractions of PM (<2.5 μm [PM2.5], 2.5-10 μm [PM2.5-10], and ≤10 μm [PM10]) exposure with semen quality in China. This retrospective cohort study was conducted using data on men whose wives underwent assisted reproductive technology procedures in a tertiary hospital in Shanghai, China, from January 1, 2013, to December 31, 2019. Participants were from 340 prefecture-level cities of China and were followed up from the date of their first visit until December 31, 2019. Data were analyzed from December 1, 2020, to May 15, 2021. Exposure to PM2.5, PM2.5-10, and PM10 during the entire period (0-90 days before semen ejaculation) and key periods of sperm development (0-9, 10-14, and 70-90 days before semen ejaculation). Semen quality, including sperm count, concentration, and motility. A total of 33 876 men were included in the final analysis, with a mean (SD) age of 34.1 (5.7) years and large variation of PM exposure. For example, the median exposure to PM2.5 during the entire period of sperm development was 46.05 (IQR, 34.38-61.65) μg/m3. During the entire period of sperm development, exposures to higher levels of PM were significantly associated with lower total and progressive sperm motility. For total sperm motility, an IQR increase in PM2.5 exposure was associated with an estimated effect decrease of -3.60% (95% CI, -3.93% to -3.26%); an increase in PM2.5-10 exposure, with an estimated effect decrease of -0.45% (95% CI, -0.76% to -0.14%); and an increase in PM10 exposure, with an estimated effect decrease of -2.44% (95% CI, -2.91% to -1.96%). Similar results were observed for progressive motility. An IQR increase in PM2.5 or PM10 exposures was associated with an estimated effect decrease on sperm progressive motility of -1.87% (95% CI, -2.37% to -1.36%) and -1.05% (95% CI, -1.45% to -0.64%), respectively. However, no significant associations were observed between PM exposure during the entire period of sperm development and sperm count or concentration. These findings suggest that PM exposure may adversely affect sperm motility and highlight the need to reduce ambient particulate air pollution exposure for reproductive-aged men.

The Nature and Size Fractions of Particulate Matter Deposited on Leaves of Four Tree Species in Beijing, China

Particulate matter (PM) in different size fractions (PM0.1–2.5, PM2.5–10 and PM&gt;10) accumulation on four tree species (Populus tomentosa, Platanus acerifolia, Fraxinus chinensis, and Ginkgo biloba) at two sites with different pollution levels was examined in Beijing, China. Among the tested tree species, P. acerifolia was the most efficient species in capturing PM, followed by F. chinensis, G. biloba, and P. tomentosa. The heavily polluted site had higher PM accumulation on foliage and a higher percentage of PM0.1–2.5 and PM2.5–10. Encapsulation of PM within cuticles was observed on leaves of F. chinensis and G. biloba, which was further dominated by PM2.5. Leaf surface structure explains the considerable differences in PM accumulation among tree species. The amounts of accumulated PM (PM0.1–2.5, PM2.5–10, and PM&gt;10) increased with the increase of stomatal aperture, stomatal width, leaf length, leaf width, and stomatal density, but decreases with contact angle. Considering PM accumulation ability, leaf area index, and tolerance to pollutants in urban areas, we suggest P. acerifolia should be used more frequently in urban areas, especially in “hotspots” in city centers (e.g., roads/streets with heavy traffic loads). However, G. biloba and P. tomentosa should be installed in less polluted areas.

The botanical biofiltration of volatile organic compounds and particulate matter derived from cigarette smoke

Despite the growing use of control measures, environmental tobacco smoke (ETS) remains a significant pollutant source in indoor air in many areas of the world. Current control methods for reducing ETS exposure are inadequate to protect public health in environments where cigarettes are smoked. An alternative solution is botanical biofiltration which has previously been shown to lower concentrations of volatile organic compounds (VOCs) and particulate matter (PM) from a range of polluted air streams. This study is the first to assess the potential of a botanical biofilter with the species Spathiphyllum wallisii (Peace Lily) for the removal of cigarette-derived VOCs and all size fractions of PM. Single pass removal efficiencies of 43.26% for total VOCs and 34.37% for total suspended particles were achieved. The botanical biofilter reduced the concentrations of a range of harmful ETS chemicals including nicotine, limonene, and toluene. Evaluation of the re-emission of ETS constituents filtered by the botanical biofilter revealed no particle resuspension or off gassing. The results demonstrate the potential of botanical biofilters to reduce public ETS exposure, although further research is needed to improve upon and ensure the efficiency of these systems for practical applications.

Children's exposure to size-fractioned particulate matter: Chemical composition and internal dose

The health effects of the particulate matter (PM) depend not only on its aerodynamic diameter (AD) and chemical composition, but also on the time activity pattern of the individuals and on their age. The main objective of this work was to assess the exposure of children to aerosol particles by using personal instruments, to study the particle size and composition of the inhaled PM, and to estimate their transport and deposition into the human respiratory tract (HRT). The average daily PM2.5 exposure was 19 μg/m3 and the size fractions with the greatest contribution to PM2.5 concentrations were 1 < AD <2.5 μm and AD <0.25 μm. Results indicated a contribution of 9% from the mineral aerosol, 7.2% from anthropogenic sulphate, 6.7% from black carbon and 5% from anthropogenic trace elements to the daily exposure to PM2.5. The levels of mineral and marine elements increased with increasing particle size, while anthropogenic elements were present in higher concentrations in the finest particles. Particle size has been shown to influence the variability of daily dose deposited between the extrathoracic and alveolar-interstitial zones. On average, 3% of the PM deposited in the bronchial region, whereas 5% to 8% were found in the bronchiolar region. The level of physical activity had a significant contribution to the total daily dose.

Seasonal variation of size-fractionated particulate matter in residential houses in urban area in Vietnam: relationship of indoor and outdoor particulate matter and mass size distribution

The study aims to determine the concentration, size distribution and analyze the relationship of indoor and outdoor particles in urban area, in Vietnam. One thousand two hundred daily samples of PM0.1, PM0.1-0.5, PM0.5-1, PM1-2.5, PM2.5-10, PM&gt;10 were taken simultaneously at four residential houses in summer and winter by nano sampler (Model 3182, Kinomax). The average concentrations of indoor PM0.1, PM0.5, PM1, PM2.5 and PM10 were in range of 5.3-8.9 μg/m3; 10.8-20.1μg/m3; 20.5-47.6 μg/m3; 33.7-105.9 μg/m3 and 44.7-135.0 μg/m3 among four houses, respectively. The concentrations of outdoor PM2.5, PM10 were considerately higher than those of indoor PM, whereas negligible differences on concentrations of PM0.1, PM0.5 and PM1 were observed. The significantly seasonal variation was observed for indoor PM1, PM2.5 and PM10, but not for PM0.1 and PM0.5. Majority of indoor fractions were origin from outdoor sources. Unimodal distributions of indoor particles determined the super-micron size (1 to 2.5 μm) with highest concentration and PM&lt;0.5 and PM&gt;10 with lowest concentration. Fine particles with interval sizes (PM0.5-1 and PM1-2.5) contributed to the predominance to coarse particles in both indoors and outdoors, suggesting serious threat on human health.

Size-fractionated PM-bound PAHs in urban and rural atmospheres of northern Thailand for respiratory health risk assessment

Size-fractionated particulate matters (SPMs) in a range of 9.0 to 0.43 μm, classified based on aerodynamic diameter (dae) as fine PMs (0.43 μm ≤ dae < 2.1 μm) and coarse PMs (2.1 μm ≤ dae < 9.0 μm) were collected by cascade impactors (7 fractions) during smoke haze (SH) and non-smoke haze (NSH) seasons in urban and rural areas of Chiang Mai, Thailand. Their polycyclic aromatic hydrocarbons (PAHs) compositions were determined for respiratory health risk assessment. During SH episode, concentrations of SPMs and PAHs in the rural area were approximately two times higher than in the urban area and about 62–68% of the SPMs were fine particles. Conversely, during NSH season the concentrations in the urban area were higher due to traffic emission. The finest particle sizes (0.65–0.43 μm) contained the highest PAHs concentrations among the other PM sizes. Benzo[b]fluoranthene was a main PAH component found during SH season suggesting biomass burning is a major pollutant source. High molecular weight (5–6 rings) PAHs with high carcinogenicity were likely to concentrate in fine particles. Distribution patterns of SPMs and PAHs during SH season were bimodal with the highest peak at a fine size range (0.65–0.43 μm) and a small peak at a coarse size range (5.8–4.7 μm). Respiratory health risk was estimated based on toxicity equivalent concentrations of PAHs bound-SPMs and inhalation cancer risk (ICR). Relatively high ICR values (1.14 × 10−4 (rural) and 6.80 × 10−5 (urban)) were found during SH season in both areas, in which fine particles played an important role. It revealed that high concentration of fine particles in ambient air is related to high respiratory health risk due to high content of carcinogenic substances.

The unique opportunities and obstacles when integrating personal air pollution monitoring into studies of human fertility

BACKGROUND AND AIM: Exposure to air pollution has been associated with increased risk of infertility and pregnancy loss; however, the majority of research to date has relied on indirect measurements of air pollution which may have significant limitations due to the temporal and spatial variability of outdoor air pollution and the limited time that people spend outdoors. Directly measuring personal exposure to air pollution is a growing topic of interest, particularly in reproductive epidemiology, given the relatively short time windows of exposure susceptibility. METHODS: The Air Pollution, In Vitro Fertilization (IVF), and Reproductive Outcomes (AIR) Study recruited women undergoing a fresh, autogulous IVF cycle at the Massachusetts General Hospital Fertility Center. On the first day of ovarian stimulation, women were instructed to wear a personal particulate matter (PM) air pollution monitor (AirBeam2©), which measures three size fractions of particulate matter (PM1, PM2.5, and PM10), temperature, humidity, and GPS location, and complete a time-activity diary for the following 72-hour period. RESULTS:Between September 2018 and November 2019, 14 (out of 31 eligible) women enrolled in the AIR Study. The majority (71%) of women who did not enroll began ovarian stimulation on the weekend, when study staff were not regularly in clinic. 10 women successfully collected air pollution data for a median (minimum, maximum) of 41.5 (8.4, 64.5) hours during ovarian stimulation. The median (interquartile range) exposure to PM1, PM2.5, and PM10 was 0.7 (4.1), 2.1 (5.5), 3.2 (8.3) μg/m3, respectively. During this 72-hour window, women spent the majority of their time (72%) inside at home. Among the 4 women who were unsuccessful with the air monitors, limited battery life and frequent connection issues were cited as the main issues. CONCLUSIONS:Personal air pollution monitors can be utilized to characterize short-term exposure and, when applied appropriately, may greatly enhance our understanding of how air pollution affects human reproduction. KEYWORDS: air pollution, particulate matter, reproductive outcomes, short-term exposure, exposure assessment

Personal exposure to particulate matter air pollution and outcomes of ovarian stimulation: a pilot study in Massachusetts, US

BACKGROUND AND AIM: Higher exposure to ambient air pollution has been associated with lower fertility in women including specific adverse effects on ovarian steroidogenesis and folliculogenesis; however, no previous studies have measured personal exposure to air pollution which quantifies a woman’s real exposure levels. METHODS: We enrolled nine women undergoing a fresh, autologous assisted reproductive technology (ART) cycle at the Massachusetts General Hospital Fertility Center 2018-2019. At the woman’s baseline ultrasound appointment (cycle day 3), they were given an AirBeam2 monitor, which measures three size fractions of particulate matter (PM1, PM₂.₅, and PM10), a smartphone, and a 3-day activity diary. Women collected exposure data for the following 72 hours. Between cycle day 11 and 16, women underwent oocyte retrieval and information was collected on number of total and mature oocytes retrieved. Multivariable generalized linear models were used to evaluate associations between personal PM exposures and ovarian stimulation outcomes. RESULTS:Women collected PM data for an average (minimum, maximum) of 33.7 (8.4, 64.4) hours during ovarian stimulation. Their median (interquartile range [IQR]) exposure to PM1, PM₂.₅, and PM10 was 0.4 (4.1), 2.3 (5.5), 3.7 (8.3) μg/m³, respectively. After adjusting for age, stimulation protocol, infertility diagnosis, and average temperature exposure, an IQR increase in average exposure to PM1, PM₂.₅, and PM10 during cycle days 3 to 5 was associated with -26.8% (95% CI -37.6, -14.2%), -47.9% (95% CI -61.6, -29.1%), and -43.8% (95% CI -57.3, -26.0%) fewer oocytes retrieved, respectively. An IQR increase in PM1, PM₂.₅, and PM10 exposure was also associated with -18.4% (95% CI -33.9, 0.6%), -38.2% (95% CI -58.5 -8.1%), and -34.0% (95% CI -53.8, -5.6%) fewer mature oocytes retrieved, respectively. CONCLUSIONS:In this small pilot study of women undergoing ART in Massachusetts, higher personal exposure to PM during ovarian stimulation was associated with poorer oocyte yield. KEYWORDS: Air pollution, Particulate matter, Reproductive Outcomes, Short-term exposure, Environmental epidemiology

Interrelationship of Indoor Particulate Matter and Respiratory Dust Depositions of Women in the Residence of Dhanbad City, India.

Women spend relatively more time in indoor environments in developing countries. Exposure to various indoor air pollutants leads them to higher health risks according to household air quality in which they reside. Particulate matter (PM) exposure with their exposure duration inside the household plays a significant role in women's respiratory problems. This studymeasured size-segregated particulate matter concentrations in 63 residences at different locations. Respiratory dust depositions (RDDs) for 118 women in their different respiratory regions like head airway (HD), tracheobronchial (TB), and alveolar (AL) regions for the three PM size fractions (PM10, PM2.5, and PM1) were investigated. For different positions like light exercise and the sitting condition, RDDs values found for AL region were 0.091 μgmin-1 (SD: 0.067, 0.012-0.408) and 0.028 μgmin-1 (SD: 0.021, 0.003-0.126) for PM10, 0.325 μgmin-1 (SD: 0.254, 0.053-1.521) and 0.183 μgmin-1 (SD: 0.143, 0.031-0.857) for PM2.5, 0.257 μgmin-1 (SD: 0.197, 0.043-1.04) and 0.057 μgmin-1 (SD: 0.044, 0.009-0.233) respectively for PM1 to females. RDDs values in the AL region significantly increase as PM10 (11%), PM2.5 (68%), and PM1 (21%), confirming that for women, the AL region is the most prominent affected zone by fine particles (PM2.5).

Controlling flour dust exposure by an intervention focused on working methods in Finnish bakeries: a case study in two bakeries

Objectives. The purpose of this study was to examine the effectiveness of intervention strategies to control mass concentrations and peak exposures of flour dust in two Finnish bakeries. The effect of the intervention on the proportion of various particle size fractions of the total particulate matter was also investigated. Methods. Mass concentrations of flour dust were measured during three working days in a pre-intervention and post-intervention study in both an industrial and a traditional bakery. Gravimetric sampling and real-time measurements were performed. Relevant intervention strategies focused on working methods were planned in collaboration with the managers of the bakeries. Results. The average mass concentration of inhalable flour dust reduced in most of the stationary locations post intervention. The reductions in exposure levels were between 39 and 45%. However, the exposure levels increased 28–55% in the breathing zone. Real-time measurements showed reductions in the peak mass concentrations in the traditional bakery post intervention. In both bakeries, the total particulate matter size fraction consisted predominantly of particles with an aerodynamic diameter lower than 1 µm and greater than 10 µm. Conclusion. Further studies are needed to plan more effective intervention measures supplemented by technical control methods in both bakeries.

Evaluating size-fractioned indoor particulate matter in an urban hospital in Iran.

Hospitals host vulnerable people with potentially enhanced sensitivity to air pollutants. We measured particulate matter (PM) including PM1, PM2.5, and PM10 with a portable device in a hospital, a nearby reference building, and ambient air in Shiraz, Iran. Indoor/outdoor (I/O) ratio values were calculated to infer on the origin of size-fractioned PM. The mean hospital indoor concentrations of PM2.5 and PM10 (4.7 and 38.7μg/m3, respectively) but not PM1 were higher than in the reference building and lower than in ambient air. The highest hospital PM10 mean concentrations were found in the radiotherapy ward (77.5μg/m3) and radiology ward (70.4μg/m3) while the lowest were found in the bone marrow transplantation (BMT) ward (18.5μg/m3) and cardiac surgery ward (19.8μg/m3). The highest PM2.5 concentrations were found in the radiology (8.7μg/m3) and orthopaedic wards (7.7μg/m3) while the lowest were found in the BMT ward (2.8μg/m3) and cardiac surgery ward (2.8μg/m3). The I/O ratios and the timing of peak concentrations during the day (7 a.m. to 4 p.m.) indicated the main roles of outdoor air and human activity on the indoor levels. These suggest the need for mechanical ventilation with PM control for a better indoor air quality (IAQ) in the hospital.

Commuting by car, public transport, and bike: Exposure assessment and estimation of the inhaled dose of multiple airborne pollutants

It is known that air pollution affects human health and commuting environments are significant contributors to the total daily personal exposure to air pollution. With this study we aim at assessing and comparing personal exposure to traffic-related air pollution and related estimated inhaled dose of different typical commuter profiles in real-world scenarios focusing on multimodal commuting and different transport microenvironments. A car driver and two multimodal commuters (cyclist/public transport and pedestrian/public transport commuters), which reached the same destination in the city center, leaving from the same starting point in the metropolitan area of the city, were investigated in the metropolitan area of Milan, Italy. Real-time monitors for the measurement of size-fractionated particulate matter (PM - Aerocet 831-Met One Instrument Inc., Grant Pass, Oregon, USA), equivalent Black Carbon (eBC - Aethlabs, San Francisco, CA, USA), and NO2 (CairClip NO2, Cairpol; La Roche Blanche, France) and time-integrated samplers for the measurement of NO2 and benzene were used. Inhaled dose was estimated as well by applying estimated pulmonary ventilation rates to 1-min exposure measures. The Bootstrapping method was used to resample data and perform more robust comparisons among commuters and microenvironments (MEs). Results of the study could be summarized as follows: (i) travel times of the cyclist were the shortest; (ii) the highest concentrations and estimated inhaled doses were found during morning rush hour; (iii) the cyclist and the car commuter were exposed to the highest overall median values of fractionated PM and benzene, respectively; (iv) cycling MEs presented the highest median concentrations of PM, while the overall median concentration of eBC was higher commuting by car than walking and cycling; (v) the cyclist was the commuter with the highest overall median estimated inhaled dose for fractionated PM, while benzene was the highest for the car driver, and NO2 for the pedestrian; (vi) exposure differences both among microenvironments and commuters diverged comparing morning and evening commuting. Our results suggest that a multi-pollutant approach is necessary to better represent the complexity of personal exposure to traffic-related air pollution in multimodal mobility studies. Moreover, shifting from car driving to multimodal mobility is already a valuable choice for the metropolitan area of Milan considering both exposure and commuting time. However, to further reduce personal exposure and especially estimated inhaled dose of multimodal and active commuters, exposure mitigation interventions in selected MEs, traffic calming, and innovative mobility policies are still needed.

Risks of hospital outpatient visits for overall and cause-specific respiratory disease associated with particulate matter pollution in Lanzhou, China

Until now, few epidemiological studies have focused on the association between ambient particulate matter (PM) pollution and hospital outpatient visits for overall and cause-specific respiratory disease, especially in Lanzhou. This study aimed to evaluate the short-term effects of PM2.5, PMC, and PM10 on hospital outpatient visits for overall and subtypes of respiratory disease in Lanzhou, China, during 2007–2017, using a generalized additive model (GAM). We further assessed the impact of ambient size-fractioned PM on daily total and cause-specific respiratory morbidity, following a series of air quality improvement action in the area with overall and period-specific analyses. Positive associations were identified between PM2.5, PMC, and PM10 and daily morbidity rates from overall respiratory diseases, upper respiratory tract infection, lower respiratory tract infection, pneumonia, and COPD at different lag pattern. Each 10 μg/m3 increase in PM2.5 at lag07, PMC at lag03, and PM10 at lag06 corresponded to an increase of 1.353% (95% CI: 1.249%, 1.457%), 0.052% (95%CI: 0.015%, 0.089%), and 0.201% (95% CI: 0.165%, 0.236%) in daily hospital outpatient visits for total respiratory, respectively. We did not find significant effects of PM2.5, PMC, and PM10 on asthma. For specific subtypes of respiratory diseases, the effects of PM were strongest on pneumonia morbidity, with an increase of 3.712% (95% CI: 3.308%, 4.117%), 0.874% (95% CI: 0.698%, 1.051%), and 0.967% (95% CI: 0.836%, 1.099%) per 10 μg/m3 increment in PM2.5, PMC, and PM10, respectively. The exposure-response association was non-linear across the full range of exposures. With drastic reductions in annual PM levels, the three size-specific PM associate and respiratory morbidity risk showed decreasing trend over time. This study suggests that PM could exert adverse influences on the outcomes of all-cause and cause-specific respiratory outpatient visits in Lanzhou, China. PM2.5 would have significant effects on pneumonia and RTI. Strategies should be considered to further reduce levels of ambient PM2.5.

Mobile Monitoring of Air Pollution Reveals Spatial and Temporal Variation in an Urban Landscape

Urban air pollution poses a major threat to human health. Understanding where and when urban air pollutant concentrations peak is essential for effective air quality management and sustainable urban development. To this end, we implement a mobile monitoring methodology to determine the spatiotemporal distribution of particulate matter (PM) and black carbon (BC) throughout Philadelphia, Pennsylvania and use hot spot analysis and heatmaps to determine times and locations where pollutant concentrations are highest. Over the course of 12 days between June 27 and July 29, 2019, we measured air pollution concentrations continuously across two 150 mile (241.4 km) long routes. Average daily mean concentrations were 11.55 ± 5.34 μg/m3 (PM1), 13.48 ± 5.59 μg/m3 (PM2.5), 16.13 ± 5.80 μg/m3 (PM10), and 1.56 ± 0.39 μg/m3 (BC). We find that fine PM size fractions (PM2.5) constitute approximately 84% of PM10 and that BC comprises 11.6% of observed PM2.5. Air pollution hotspots across three size fractions of PM (PM1, PM2.5, and PM10) and BC had similar distributions throughout Philadelphia, but were most prevalent in the North Delaware, River Wards, and North planning districts. A plurality of detected hotspots found throughout the data collection period (30.19%) occurred between the hours of 8:00 AM–9:00 AM.