Particulate Matter Of Different Sizes Research Articles

Ambient particulate matter and in-hospital case fatality of acute myocardial infarction: A multi-province cross-sectional study in China

The acute myocardial infarction (AMI) outcomes have been extensively linked with ambient particulate matter (PM). However, whether a smaller particle has greater impact and the consequent attributable burden associated with PM of different sizes remain unclear. We conducted a multi-province cross-sectional study among AMI patients using the inpatient discharge datasets from four Chinese provinces (Shanxi, Sichuan, Guangxi, and Guangdong) from 2014 to 2019. Ambient PM exposure for each patient was assessed using the ChinaHighAirPollutants dataset. We employed the mixed-effects logistic regression models to evaluate the association of PM of different sizes (PM1, PM2.5, PM10) on in-hospital case fatality. The potential reducible fractions in in-hospital case fatality were estimated through counterfactual analyses. Of 177,749 participants, 125,501 (70.6 %) were male and the in-hospital case fatality rate was 4.9%. For short-term (7-day average) exposure, the odds ratios (ORs) for PM1, PM2.5, and PM10 (per 10 µg/m3) were 1.052 (95 % confidence interval [CI], 1.032–1.071), 1.026 (95 % CI, 1.014–1.037), and 1.016 (95% CI, 1.008–1.024), respectively. The estimated ORs for long-term exposure (annual average) were 1.303 (95 % CI, 1.252–1.356) for PM1, 1.209 (95 % CI, 1.178–1.241) for PM2.5, 1.157 (95 % CI, 1.134–1.181) for PM10. Short-term exposure to PM1 showed the highest potential reducible fraction (8.5 %, 95 % CI, 5.0–11.7 %), followed by PM2.5 and PM10, while the greatest potential reducible fraction of long-term exposure was observed in PM10 (30.9 %, 95 % CI, 27.2–34.4%), followed by PM2.5 and PM1. In summary, PM with smaller size had a more pronounced impact on in-hospital AMI case fatality, with PM1 exhibiting greater effects than PM2.5 and PM10. Substantial health benefits for AMI patients could be achieved by mitigating ambient PM exposure.

Foliar particulate matter retention and toxic trace element accumulation of six roadside plant species in a subtropical city

As a major source of air pollution, particulate matter (PM) and associated toxic trace elements pose potentially serious threats to human health and environmental safety. As is known that plants can reduce air PM pollution. However, the relationship between PM of different sizes and toxic trace elements in foliar PM is still unclear. This study was performed to explore the association between PM of different sizes (PM2.5, PM10, PM>10) and toxic trace elements (As, Al, Cu, Zn, Cd, Fe, Pb) as well as the correlation among toxic trace elements of six roadside plant species (Cinnamomum camphora, Osmanthus fragrans, Magnolia grandiflora, Podocarpus macrophyllus, Loropetalum chinense var. rubrum and Pittosporum tobira) in Changsha, Hunan Province, China. Results showed that P. macrophyllus had the highest ability to retain PM, and C. camphora excelled in retaining PM2.5. The combination of P. macrophyllus and C. camphora was highly recommended to be planted in the subtropical city to effectively reduce PM. The toxic trace elements accumulated in foliar PM varied with plant species and PM size. Two-way ANOVA showed that most of the toxic trace elements were significantly influenced by plant species, PM size, and their interactions (P < 0.05). Additionally, linear regression and correlation analyses further demonstrated the homology of most toxic trace elements in foliar PM, i.e., confirming plants as predictors of PM sources as well as environmental monitoring. These findings contribute to urban air pollution control and landscape configuration optimization.

Association of ambient particulate matter with hospital admissions, length of hospital stay, and hospital costs due to cardiovascular disease: time-series analysis based on data from the Shanghai Medical Insurance System from 2016 to 2019

BackgroundThere is limited evidence supporting a relationship of ambient particulate matter (PM), especially PM1, with hospital admissions, hospital costs, and length of hospital stay (LOS) due to cardiovascular disease (CVD). We used a generalized additive model (GAM) to estimate the associations of these indicators due to CVD for each 10 μg/m3 increase in the level of PM1, PM2.5, and PM10, and the attributable risk caused by PM on CVD was determined using the WHO air quality guidelines from 2005 and 2021.ResultsFor each 10 μg/m3 increase in the level of each PM and for a 0-day lag time, there were significant increases in daily hospital admissions for CVD (PM1: 1.006% [95% CI 0.859, 1.153]; PM2.5: 0.454% [95% CI 0.377, 0.530]; PM10: 0.263% [95% CI 0.206, 0.320]) and greater daily hospital costs for CVD (PM1: 523.135 thousand CNY [95% CI 253.111, 793.158]; PM2.5: 247.051 thousand CNY [95% CI 106.766, 387.336]; PM10: 141.284 thousand CNY [95% CI 36.195, 246.373]). There were no significant associations between PM and daily LOS. Stratified analyses demonstrated stronger effects in young people and males for daily hospital admissions, and stronger effects in the elderly and males for daily hospital costs. Daily hospital admissions increased linearly with PM concentration up to about 30 µg/m3 (PM1), 60 µg/m3 (PM2.5), and 90 µg/m3 (PM10), with slower increases at higher concentrations. Daily hospital costs had an approximately linear increase with PM concentration at all tested concentrations. In general, hospital admissions, hospital costs, and LOS due to CVD were greater for PM2.5 than PM10, and the more stringent 2021 WHO guidelines indicated greater admissions, costs, and LOS due to CVD.ConclusionsShort-term elevation of PM of different sizes was associated with an increased risk of hospital admissions and hospital costs due to CVD. The relationship with hospital admissions was strongest for men and young individuals, and the relationship with hospital costs was strongest for men and the elderly. Smaller PM is associated with greater risk.

Trace element characterization and source identification of particulate matter of different sizes in Hanoi, Vietnam

Particulate matter (PM) with aerodynamic diameters of <1 μm (PM1), 2.5 μm (PM2.5), and 10 μm (PM10) were investigated and analyzed for 15 trace elements in the center of Hanoi, Vietnam during April–September 2018. The mean concentrations were 40 ± 11, 53 ± 17, and 132 ± 39 μg/m3 for PM1, PM2.5, and PM10, respectively, indicating that PM pollution was severe in Hanoi. During the sampling period, the PM concentrations were little affected by local meteorological conditions. The severe PM pollution in Hanoi was significantly influenced by long-range atmospheric transport from northern and northeastern regions, with higher potential source areas for PM1. The total mean concentrations of 15 elements were 1417 ± 141, 1624 ± 159, and 2652 ± 251 ng/m3 in PM1, PM2.5, and PM10, respectively, with Al, Zn, K, Cr, and Ni as the most abundant elements. The particle-size distribution of PM and elements showed a distinct peak in PM1. The metallurgy industry, coal combustion, traffic emission, biomass burning, and soil dust were identified as major contributors of elements in three-size PM. This study implies that PM1 pollution should gain more attention regarding its level and chemical composition.

Self-Powered Air Filter Based on an Electrospun Respiratory Triboelectric Nanogenerator

High-efficiency particulate matter (PM) filtration has been an important effort in air purification; however, conventional physical filtration mechanisms are inefficient in blocking submicron particles, which are extremely hazardous to public health. Here, a self-powered triboelectric air filter (STAF) with high efficiency in filtering PM of different sizes is demonstrated. The STAF consists of conductive sponges (CSs) and electrospun fibers (nanofibrils, NFs), which constitute a respiratory triboelectric nanogenerator (R-TENG) through the coupling of the electrical difference between both materials and the respiratory airflow. It utilizes a reciprocating airflow drive to generate triboelectric charges and improve electrostatic adsorption, especially for fine particles. In the experiment, the STAF can maintain a filtration efficiency of 98% for PM2.5 and up to 91.5% for PM0.5, which clearly exceeds the level of commercial masks. In addition, the STAF maintains a high filtration capacity after one month of storage and has a good performance life. This research is of great importance to effectively improve air purification capacity, protect personal health, and prevent respiratory diseases, and it is also of great value to the development of self-driven wearable applications.

Long-term exposure to fine particulate matter air pollution: An ecological study of its effect on COVID-19 cases and fatality in Germany

BackgroundCOVID-19 is a lung disease, and there is medical evidence that air pollution is one of the external causes of lung diseases. Fine particulate matter is one of the air pollutants that damages pulmonary tissue. The combination of the coronavirus and fine particulate matter air pollution may exacerbate the coronavirus’ effect on human health. Research questionThis paper considers whether the long-term concentration of fine particulate matter of different sizes changes the number of detected coronavirus infections and the number of COVID-19 fatalities in Germany. Study designData from 400 German counties for fine particulate air pollution from 2002 to 2020 are used to measure the long-term impact of air pollution. Kriging interpolation is applied to complement data gaps. With an ecological study, the correlation between average particulate matter air pollution and COVID-19 cases, as well as fatalities, are estimated with OLS regressions. Thereby, socioeconomic and demographic covariates are included. Main findingsAn increase in the average long-term air pollution of 1 μg/m3 particulate matter PM2.5 is correlated with 199.46 (SD = 29.66) more COVID-19 cases per 100,000 inhabitants in Germany. For PM10 the respective increase is 52.38 (SD = 12.99) more cases per 100,000 inhabitants. The number of COVID-19 deaths were also positively correlated with PM2.5 and PM10 (6.18, SD = 1.44, respectively 2.11, SD = 0.71, additional COVID-19 deaths per 100,000 inhabitants). ConclusionLong-term fine particulate air pollution is suspected as causing higher numbers of COVID-19 cases. Higher long-term air pollution may even increase COVID-19 death rates. We find that the results of the correlation analysis without controls are retained in a regression analysis with controls for relevant confounding factors. Nevertheless, additional epidemiological investigations are required to test the causality of particulate matter air pollution for COVID-19 cases and the severity.

A Study on Indoor Particulate Matter Variation in Time Based on Count and Sizes and in Relation to Meteorological Conditions

An important aspect of air pollution analysis consists of the varied presence of particulate matter in analyzed air samples. In this respect, the present work aims to present a case study regarding the evolution in time of quantified particulate matter of different sizes. This study is based on data acquisitioned in an indoor location, already used in a former particulate matter-related article; thus, it can be considered as a continuation of that study, with the general aim to demonstrate the necessity to expand the existing network for pollution monitoring. Besides particle matter quantification, a correlation of the obtained results is also presented against meteorological data acquisitioned by the National Air Quality Monitoring Network. The transformation of quantified PM data in mass per volume and a comparison with other results are also addressed.

Directional Water Transfer Janus Nanofibrous Porous Membranes for Particulate Matter Filtration and Volatile Organic Compound Adsorption.

In order to reduce the possible harm caused by air pollution, excellent personal protective materials are attracting more and more attention. Therefore, the research of multifunctional materials that can filter particulate matter (PM) and volatile organic compounds (VOCs) simultaneously is of great significance. In addition, in cold weather, water vapor in the exhaled gas condenses into small droplets inside the respirator causing uncomfortable feeling of dampness. Herein, we prepared several types of cyclodextrin-containing Janus nanofibrous porous membranes by electrospinning, which can efficiently filter PM of different sizes in the air, effectively adsorb VOCs, and orientate moisture from exhaled gas to the outside of the membranes to provide a dry and comfortable environment. These advantageous features, combined with the cheap price and easy availability of component materials and low respiratory resistance, highlight the great potential of these Janus nanofibrous porous membranes in the development of personal wearable air purifiers.

Effects of Personal Exposures to Micro- and Nano-Particulate Matter, Black Carbon, Particle-Bound Polycyclic Aromatic Hydrocarbons, and Carbon Monoxide on Heart Rate Variability in a Panel of Healthy Older Subjects

As a non-invasive method, heart rate variability (HRV) has been widely used to study cardiovascular autonomous control. Environmental epidemiological studies indicated that the increase in an average concentration of particulate matter (PM) would result in a decrease in HRV, which was related to the increase of cardiovascular mortality in patients with myocardial infarction and the general population. With rapid economic and social development in Asia, how air pollutants, such as PM of different sizes and their components, affect the cardiovascular health of older people, still need to be further explored. The current study includes a 72 h personal exposure monitoring of seven healthy older people who lived in the Taipei metropolitan area. Mobile equipment, a portable electrocardiogram recorder, and the generalized additive mixed model (GAMM) were adopted to evaluate how HRV indices were affected by size-fractionated PM, particle-bound polycyclic aromatic hydrocarbons (p-PAHs), black carbon (BC), and carbon monoxide (CO). Other related confounding factors, such as age, sex, body mass index (BMI), temperature, relative humidity (RH), time, and monitoring week were controlled by fixed effects of the GAMM. Statistical analyses of multi-pollutant models showed that PM2.5–10, PM1, and nanoparticle (NP) could cause heart rate (HR), time-domain indices, and frequency-domain indices to rise; PM1–2.5 and BC would cause the frequency-domain index to rise; p-PAHs would cause HR to rise, and CO would cause time-domain index and frequency-domain index to decline. In addition, the moving average time all fell after one hour and might appear at 8 h in HRVs’ largest percentage change caused by each pollutant, results of which suggested that size-fractionated PM, p-PAHs, BC, and CO exposures have delayed effects on HRVs. In conclusion, the results of the study showed that the increase in personal pollutant exposure would affect cardiac autonomic control function of healthy older residents in metropolitan areas, and the susceptibility of cardiovascular effects was higher than that of healthy young people. Since the small sample size would limit the generalizability of this study, more studies with larger scale are warranted to better understand the HRV effects of simultaneous PM and other pollution exposures for subpopulation groups.

Proteomic changes driven by urban pollution suggest particulate matter as a deregulator of energy metabolism, mitochondrial activity, and oxidative pathways in the rat brain

The adverse effects of air pollution have been long studied in the lung and respiratory systems, but the molecular changes that this causes at the central nervous system level have yet to be fully investigated and understood. To explore the evolution with time of protein expression levels in the brain of rats exposed to particulate matter of different sizes, we carried out two-dimensional gel electrophoresis followed by determination of dysregulated proteins through Coomassie blue staining-based densities (SameSpots software) and subsequent protein identification using MALDI-based mass spectrometry. Expression differences in dysregulated proteins were found to be statistically significant with p-value <0.05. A systems biology-based approach was utilized to determine critical biochemical pathways involved in the rats' brain response. Our results suggest that rats' brains have a particulate matter size dependent-response, being the mitochondrial activity and the astrocyte function severely affected. Our proteomic study confirms the dysregulation of different biochemical pathways involving energy metabolism, mitochondrial activity, and oxidative pathways as some of the main effects of PM exposure on the rat brain. SignificanceRat brains exposed to particulate matter with origin in car engines are affected in two main areas: mitochondrial activity, by the dysregulation of many pathways linked to the respiratory chain, and neuronal and astrocytic function, which stimulates brain changes triggering tumorigenesis and neurodegeneration.

Exposure characteristics of airborne bacteria during a haze pollution event at Qinling Mountain, China

Recently, serious haze pollution events have frequently occurred in many areas of China, but research on other environments, such as the mountains, remains very limited. In this study, airborne microbial samples from Qinling Mountain (34.03° N, 109.02° E, and 969 m above sea level) were collected during a haze pollution event that occurred on January 2017. Plate count method and high-throughput sequencing technology were used to detect the airborne bacteria. Results showed that the mean concentration of airborne culturable bacteria in Qinling Mountain was 3788 ± 1807 CFU m−3, which was higher than the surrounding city, and most of the bacteria were associated with coarse particles (76.9%–84.9%). The coarser particulate matter (PMs) had higher bacterial diversity and abundance than fine PMs. The community structures of airborne bacteria in PMs of different sizes were similar. Source tracking analysis indicated that a small portion of the airborne bacteria could have been from the surrounding environment, while most came from the neighbor cities or other areas that may have aggregated by long-range air masses transport. The results of this work provide an important reference for mountain environmental science and also improved our understanding of the relationship between air pollution and human health.

Bacterial community structure in atmospheric particulate matters of different sizes during the haze days in Xi'an, China

Serious air pollution events have frequently occurred in China associated with the acceleration of urbanization and industrialization in recent years. Exposure to atmospheric particulate matter (PM) of high concentration can lead to adverse effects on human health. Airborne bacteria are important constituents of microbial aerosols and contain lots of pathogens. However, variations in bacterial community structure in atmospheric PM of different sizes (PM2.5, PM10 and TSP) have not yet been explored. In this study, PM samples of different sizes were collected during the hazy days from Jul.2016 to Apr.2017 to determine bacterial diversity and community structure. Samples from soils and leaf surfaces were also collected to determine potential sources of bacterial aerosols. High-throughput sequencing technology was used generate bacterial community profiles, where we determined their diversity and abundances in the samples. Results showed that the dominant bacterial community structures in PM2.5, PM10 and TSP were strongly similar. Compared with non-haze days, the relative abundances of most bacterial pathogens on the haze days did not increase. Meanwhile, temperature, O3 and NO2 had more significant effects on bacterial community than the other environmental factors. Source tracking analysis indicated that the airborne bacteria might be not from local environment. It may come from the entire city or other regions by long distance airflow transport. Results of this study improved our understanding of the influence of bioaerosols on human health and the potential sources of airborne microbes.

Poly(lactic-co-glycolic acid)/Polycaprolactone Nanofibrous Membranes for High-Efficient Capture of Nano- and Microsized Particulate Matter.

The incidence of many diseases is closely related to air pollution. Suspended particulate matter of different sizes represents a major source of environmental pollution. Fine particles, especially ultrafine particles smaller than 2.5 μm, might be more harmful to human health because of their extremely small size, which enables them to penetrate human lungs and bronchi and makes them difficult to filter out. Therefore, the fatal risks associated with PM call for the development of air purification materials with high efficiency and low resistance. In this study, poly(lactic-co-glycolic acid) and polycaprolactone were used to prepare nanofibrous membranes suitable for the efficient capture of particulate matter formed in haze-fog episodes, especially particles smaller than 0.5 μm. The present nanofibrous membranes exhibit superior filtration efficiency for particulate matter, with a much lower pressure drop compared to typical commercial microfiber air filters. Thanks to the combination of small pore size, high porosity, and robust mechanical properties, the poly(lactic-co-glycolic acid)/polycaprolactone (6:4) composite membrane exhibits a high filtration efficiency of 97.81% and a low pressure drop of 181 Pa. These favorable features, combined with the easy availability and biocompatibility of the component materials, highlight the promising potential of the present nanofibrous membranes for the development of personal wearable air purifiers.

Size-fractionated Particulate Matter in Indoor and Outdoor Environments during the 2015 Haze in Singapore: Potential Human Health Risk Assessment

Landscape fires in Indonesia during the 2015 resulted in large-scale emissions of airborne particulate matter (PM) that degraded ambient air quality of several countries in Southeast Asia (SEA) including Singapore. During this transboundary haze episode, the general public was advised to remain indoors as much as possible in order to mitigate their exposure to high concentrations of PM in the outdoor environment. To understand the quantitative relationship between outdoor and indoor air quality, we measured PM2.5 as well as the size-fractionated PM (coarse, accumulation and quasi-ultrafine (q-UF) particles) simultaneously inside and outside a naturally ventilated apartment and studied the potential health risk associated with exposure to PM of different sizes under the three levels of smoke haze (light, moderate and severe). PM mass concentrations increased with a decrease in particle size, and the q-UF particles (diameter ≤ 250 nm) were observed to be as high as 80 to 85 µg m–3 both indoors and outdoors. Estimation of PM deposition patterns along the human respiratory tract revealed that q-UF particles were mainly deposited in the deeper alveolar region, thereby posing severe health threats. Potential human health risk assessment results based on bioavailable concentrations of toxic elements in PM raised further concerns about health impacts of q-UF particles deposited in the alveolar region. Moreover, uncertainty analysis of exposure parameters used in potential carcinogenic health risk assessment model indicated much higher exceedance of potential health risk than the threshold limit for 95th percentile values of the health risk (11.5 times higher for PM2.5) during severe-haze episodes. The potential health risk estimated in this study indicates the need to conduct further studies focused upon mitigation of human exposure to achieve health benefits during haze episodes.

Indoor human exposure to size-fractionated aerosols during the 2015 Southeast Asian smoke haze and assessment of exposure mitigation strategies

The 2015 smoke haze episode was one of the most severe and prolonged transboundary air pollution events ever seen in Southeast Asia (SEA), affecting the air quality of several countries within the region including Indonesia, Malaysia and Singapore. The 24 h mean outdoor PM2.5 (particulate matter (PM) with aerodynamic diameter ≤ 2.5 μm) concentrations ranged from 72–157 μg m−3 in Singapore during this episode, exceeding the WHO 24 h mean PM2.5 guidelines (25 μg m−3) several times over. The smoke haze episode not only affected ambient air quality, but also indoor air quality due to the migration of PM of different sizes from the outdoor to the indoor environment. Despite the frequent occurrence of smoke haze episodes over the years, their potential health impacts on indoor building occupants remain largely unknown in SEA due to the lack of systematic investigations and observational data. The current work was carried out in Singapore to assess human exposure to size-resolved PM during the 2015 smoke haze episode, and to evaluate the effectiveness of exposure mitigation measures in smoke-haze-impacted naturally ventilated indoor environments. The potential health risks associated with exposure to PM2.5 were assessed based on the concentrations of redox active particulate-bound trace elements, which are known to be harmful to human health, with and without exposure mitigation. Overall, it was observed that human health exposure to PM2.5 and its carcinogenic chemical components was reduced substantially by 62% (p < 0.05) while using an air cleaner. However, extremely small hazardous particles were only partially removed by the air cleaner and remain a matter of concern for public health.

Air pollution and inhalation exposure to particulate matter of different sizes in rural households using improved stoves in central China

Household air pollution is considered to be among the top environmental risks in China. To examine the performance of improved stoves for reduction of indoor particulate matter (PM) emission and exposure in rural households, individual inhalation exposure to size-resolved PM was investigated using personal portable samplers carried by residents using wood gasifier stoves or improved coal stoves in a rural county in Central China. Concentrations of PM with different sizes in stationary indoor and outdoor air were also monitored at paired sites. The stationary concentrations of size-resolved PM in indoor air were greater than those in outdoor air, especially finer particles PM0.25. The daily averaged exposure concentrations of PM0.25, PM1.0, PM2.5 and total suspended particle for all the surveyed residents were 74.4±41.1, 159.3±74.3, 176.7±78.1 and 217.9±78.1μg/m3, respectively. Even using the improved stoves, the individual exposure to indoor PM far exceeded the air quality guideline by WHO at 25μg/m3. Submicron particles PM1.0 were the dominant PM fraction for personal exposure and indoor and outdoor air. Personal exposure exhibited a closer correlation with indoor PM concentrations than that for outdoor concentrations. Both inhalation exposure and indoor air PM concentrations in the rural households with gasifier firewood stoves were evidently lower than the reported results using traditional firewood stoves. However, local governments in the studied rural areas should exercise caution when widely and hastily promoting gasifier firewood stoves in place of improved coal stoves, due to the higher PM levels in indoor and outdoor air and personal inhaled exposure.

The fractionation and geochemical characteristics of rare earth elements measured in ambient size-resolved PM in an integrated iron and steelmaking industry zone.

Improved understanding of the fractionation and geochemical characteristic of rare earth elements (REEs) from steel plant emissions is important due to the unclear atmospheric signature of these elements and their adverse impact on human health and the environment. In this study, ambient particulate matter of different sizes was collected from one site in an integrated iron and steelmaking industrial zone (HG) and one urban background site with no direct industrial emissions (ZWY) during a 1-year sampling campaign in China. The total concentrations of REEs for TSP, PM10, and PM2.5 were 27.248, 14.989, 3.542ng/m(3) in HG and 6.326, 5.274, 1.731ng/m(3), respectively, in ZWY, which revealed the local influence of the steelmaking activities to the air quality. With respect to ZWY, the REEs in HG site are obviously fractionated in the coarser fraction, and LREEs account for more than 80% of the total REE burden in all of the samples. Additionally, the REEs in HG and ZWY show a homogeneous trend with successively increased LREE/HREE ratios from the coarse particles to the fine particles. In our samples, La, Ce, Nd, and Sm are the most enriched rare earth elements, especially in the HG site. Moreover, ternary diagrams of LaCeSm indicate that the REEs in HG are potentially contributed by steelworks, carrier vehicles, coal combustion, and road dust re-suspension.

Influence of in-port ships emissions to gaseous atmospheric pollutants and to particulate matter of different sizes in a Mediterranean harbour in Italy

Ship emissions are a growing concern, especially in coastal areas, for potential impacts on human health and climate. International mitigation strategies to curb these emission, based on low-sulphur content fuels, have proven useful to improve local air quality. However, the effect on climate forcing is less obvious. Detailed information on the influence of shipping to particles of different sizes is needed to investigate air quality and climate interaction. In this work, the contributions of maritime emissions to atmospheric concentrations of gaseous pollutants (NO, NO2, SO2, and O3) and of particles (sizes from 0.009 μm to 30 μm) were investigated considering manoeuvring (arrival and departure of ships) and hotelling phases (including loading/unloading activities). Results showed that the size distributions of shipping contributions were different for the two phases and could be efficiently described, using measured data, considering four size-ranges. The largest contribution to particles concentration was observed for Dp < 0.25 μm, however, a secondary maximum was observed at Dp = 0.35 μm. The minimum contribution was observed at Dp around 0.8–0.9 μm with a negligible contribution from hotelling for size range 0.4–1 μm. The comparison of 2012 and 2014 datasets showed no significant changes of gaseous and particulate pollutant emissions and of the contribution to particle mass concentration. However, an increase of the contribution to particle number concentration (PNC) was observed. Results suggested that harbour logistic has a relevant role in determining the total impact of shipping on air quality of the nearby coastal areas. Additionally, future policies should focus on PNC that represents an important fraction of emissions also for low-sulphur fuels. DOAS remote sensing proved a useful tool to directly measure NO2 and SO2 ship emissions giving estimates comparable with those of emission inventory approach.

Gas and particle size distributions of polychlorinated naphthalenes in the atmosphere of Beijing, China

Polychlorinated naphthalenes (PCNs) were listed as persistent organic pollutants in the Stockholm Convention in 2015. Despite numerous studies on PCNs, little is known about their occurrence in atmospheric particulate matter of different sizes. In this study, 49 PCN congeners were investigated for their concentrations and size-specific distributions in an urban atmosphere, and preliminary exposure assessments were conducted. Ambient air samples were collected using a high-volume cascade impactor for division into a gas fraction and four particle size fractions. Samples were collected from October 2013 to June 2014 at an urban site in Beijing, China. The concentration range for PCNs in the atmosphere (gas + particle fractions) was 6.77–25.90 pg/m3 (average 16.28 pg/m3). The particle-bound concentration range was 0.17–2.78 pg/m3 (average 1.73 pg/m3). Therefore, PCNs were mainly found in the gas phase. The concentrations of PCNs in a fraction increased as the particle size decreased (dae > 10 μm, 10 μm ≥ dae > 2.5 μm, 2.5 μm ≥ dae > 1.0 μm and dae ≤ 1.0 μm). Consequently, PCNs were ubiquitous in inhalable fine particles, and the ΣPCNs associated with PM1.0 and PM2.5 reached 68.4% and 84.3%, respectively. Tetra-CNs and penta-CNs (the lower chlorinated homologues) predominated in the atmosphere. The homologue profiles in different size particles were almost similar, but the particulate profiles were different from those in the gas phase. Among the individual PCNs identified, CN38/40, CN52/60 and CN75 were the dominant compounds in the atmosphere. CN66/67 and CN73 collectively accounted for most of the total dioxin-like TEQ concentrations of the PCNs. Exposure to toxic compounds, such as PCNs present in PM1.0 or PM2.5, may affect human health. This work presents the first data on size-specific distributions of PCNs in the atmosphere.

Main components and human health risks assessment of PM10, PM2.5, and PM1 in two areas influenced by cement plants

Particulate matter (PM) is widely recorded as a source of diseases, being more harmful those particles with smaller size. PM is released to the environment as a consequence of different activities, being one of them cement production. The objective of this pilot study was to characterize PM of different sizes around cement facilities to have a preliminary approach of their origin, and evaluate their potential health risks. For that purpose, three fractions of PM (10, 2.5, and 1) were collected in the nearby area of two cement plants with different backgrounds (urban and rural) in different seasons. Subsequently, main components, outdoor and indoor concentrations, exposure, and human health risks were assessed. Greatest levels of PM1, organic matter, and metals were found in urban location, especially in winter. Consequently, environmental exposure and human health risks registered their highest values in the urban plant during wintertime. Exposure was higher for indoor activities, expressing some metals their peak values in the PM1 fraction. Non-carcinogenic risks were below the safety threshold (HQ < 1). Carcinogenic risks for most of the metals were below the limit of 10−5, except for Cr (VI), which exceeded it in both locations, but being in the range considered as assumable (10−6–10−4).