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1.
J Biomech Eng ; 144(2)2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-34467371

RESUMO

In this work, consideration is given to an aerodynamic concept to boost the filtration in face masks of airborne hygroscopic particles such as those caused by an infected person when coughs or sneezes. Nowadays, increasing the filtration efficiency of face masks implies either increasing the number of crisscrossing fiber layers or decreasing the equivalent hydraulic diameter of the pore, however, both measures are in clear detriment of its breathability. Here, a novel strategy is proposed in which the filtration of an airborne particle is boosted by increasing its diameter. We called properly this concept as the aerodynamic barrier layer. In this concept, a traditional crisscrossing fiber layer is replaced by a parallel rearranged of the fibers in the direction of the flow. This rearrangement will promote central lift forces which will push the particles toward the center of the channel where after clustering they will coalesce resulting in a bigger particle that can be now easily captured by a conventional fiber crisscrossing layer. Utilizing a simplified geometrical model, an expression for the required length of the aerodynamic barrier layer was derived. It is shown that an aerodynamic barrier layer with a length of only a few millimeters can aerodynamically focus water droplets around 1 µm-diameter and the penetration of airborne particles can be reduced up to 55%.


Assuntos
Filtração/instrumentação , Máscaras , Material Particulado/isolamento & purificação , Desenho de Equipamento , Tamanho da Partícula
2.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 29(5): 1478-1484, 2021 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-34627427

RESUMO

OBJECTIVE: To investigate the toxic damage and possible mechanism of chronic exposure of ambient particulate matter (PM2.5) to the marrow micro-environment of the mice, and the protective effect of chitooligosaccharides. METHODS: Mice were treated with different doses (150, 300, 600 mg/kg) of chitosan after exposure to PM2.5, and then the mice were divided into: high dose group, medium dose group, low dose group according to the given dose, and the model group and the drug group were set as well. The productions of inflammatory cytokines IL-2, IL-8, TPO and VCAM-1 in marrow tissues were detected by ELISA, the expression of CXCL12 and CXCR4 protein in bone marrow tissues were measured by Western blot. RESULTS: Compared with the mice in control group, IL-2 secretion and CXCL12 expression were decreased in the bone marrow of PM2.5 infected mice, while the secretion of IL-8, TPO and VCAM-1 were significantly increased, and CXCR4 expression was significantly up-regulated (P<0.05). Compared with the mice in control group, drug group and other dose groups, IL-2 secretion in the bone marrow of the mice in high-dose group was significantly increased, and IL-8, TPO and VCAM-1 secretion were significantly decreased (P<0.05). CONCLUSION: Chronic exposure of PM2.5 shows some toxicity effect on marrow micro-environment. Chitosan oligosaccharide can reduce the pathologic damage of bone marrow and the toxicity to bone marrow microenvironment caused by PM2.5 at a certain extent.


Assuntos
Quitosana , Transplante de Células-Tronco Hematopoéticas , Sistema Hematopoético , Animais , Medula Óssea , Camundongos , Material Particulado/toxicidade
3.
Environ Monit Assess ; 193(11): 707, 2021 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-34623523

RESUMO

Today, environmental pollution, air pollution in particular, is among the most important problems in the world. Air pollution, which has become a global issue, is estimated to cause the death of around 1 in 8 people worldwide. Due to the significance of air pollution, all components of air pollution are of great importance for human health, and thus the studies on air pollution are highly important, especially in areas with high population density. In this study, it was aimed to determine the regional and periodic change of CO2 and particulate matter pollution in the city of Misurata, one of the important cities of Libya. The study was conducted in the city centre of Misurata, and the measurements were made once in every three days between November and February at 7 different locations selected in the city centre. As a result of the measurements made, the changes in the pollution parameters were evaluated on the basis of zones and months. As a result of the study, the cleanest areas were found to be the industrial area (B3) located in the east of the city and the zone (B4), where the Al-Swehli farm was located, while the dirtiest areas were found to be the main street (B1 and B2) in the city centre and the city centre, in general. In terms of months, the lowest CO2 values were obtained in January, and the highest value was in February, whereas the lowest particulate matter values were obtained in January and the highest values in December.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Dióxido de Carbono , Monitoramento Ambiental , Humanos , Material Particulado/análise
4.
Environ Monit Assess ; 193(10): 682, 2021 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-34595610

RESUMO

Local primary emissions of air pollutants are responsible for public health, decreasing productivity, and cultural activities in local residential areas. In this study, an integrated air quality observation and modeling system with a geographical information system (GIS) was developed to characterize the air pollution caused by local primary emission sources. This integrated system could provide air quality monitoring, data analysis, and visualization results that reflect air pollutant concentration data in a study area containing a local rural village (LRV) and an asphalt manufacturing facility (AMF). Additionally, the model was used to estimate the contributions of air quality from an emission source at the receptor and determine the control factor for the emission rate or meteorological changes. From the forward and backward modeling results, we found that the concentrations of particulate matter smaller than 2.5 µm (PM2.5) concentrations in the village were affected by the unique meteorological and emission conditions. The PM2.5 concentration was significantly increased for the cases with a slow wind speed of 1 m/s or high wind speed of 3 m/s, with an emission rate of 10 g/s. The contribution of AMF emissions was explained by contribution factor analysis. During the study period of December 2014-December 2015, the incoming contribution of PM2.5 at the LRV measurement station was approximately 47.6%. These results suggest that the proposed method can be useful for understanding adverse air quality conditions and estimating the emissions of air pollutants from primary sources for local environmental and public health authorities.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Monitoramento Ambiental , Sistemas de Informação Geográfica , Material Particulado/análise
5.
J Environ Sci (China) ; 109: 45-56, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34607673

RESUMO

Stringent quarantine measures during the Coronavirus Disease 2019 (COVID-19) lockdown period (January 23, 2020 to March 15, 2020) have resulted in a distinct decrease in anthropogenic source emissions in North China Plain compared to the paralleled period of 2019. Particularly, 22.7% decrease in NO2 and 3.0% increase of O3 was observed in Tianjin, nonlinear relationship between O3 generation and NO2 implied that synergetic control of NOx and VOCs is needed. Deteriorating meteorological condition during the COVID-19 lockdown obscured the actual PM2.5 reduction. Fireworks transport in 2020 Spring Festival (SF) triggered regional haze pollution. PM2.5 during the COVID-19 lockdown only reduced by 5.6% in Tianjin. Here we used the dispersion coefficient to normalize the measured PM2.5 (DN-PM2.5), aiming to eliminate the adverse meteorological impact and roughly estimate the actual PM2.5 reduction, which reduced by 17.7% during the COVID-19 lockdown. In terms of PM2.5 chemical composition, significant NO3- increase was observed during the COVID-19 lockdown. However, as a tracer of atmospheric oxidation capacity, odd oxygen (Ox = NO2 + O3) was observed to reduce during the COVID-19 lockdown, whereas relative humidity (RH), specific humidity and aerosol liquid water content (ALWC) were observed with noticeable enhancement. Nitrogen oxidation rate (NOR) was observed to increase at higher specific humidity and ALWC, especially in the haze episode occurred during 2020SF, high air humidity and obvious nitrate generation was observed. Anomalously enhanced air humidity may response for the nitrate increase during the COVID-19 lockdown period.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , COVID-19 , Poluentes Atmosféricos/análise , Poluição do Ar/análise , China , Controle de Doenças Transmissíveis , Monitoramento Ambiental , Humanos , Material Particulado/análise , SARS-CoV-2
6.
J Environ Sci (China) ; 109: 66-76, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34607675

RESUMO

Crop residue open burning is an important emission source of ambient particles in China. This study analyzed the particle emission characteristics of crop residue open burning through combustion experiments with a novel open combustion simulation device using three typical crop straws in north China (corn, wheat, and rice). Particle samples size ranging from 0.006-9.890 µm were collected by an Electrical Low Pressure Impactor plus, a high size-resolution instrument capable of dividing particles into 14 size stages. The size distributions of organic carbon (OC), elemental carbon (EC), water-soluble ions, and elements were analyzed, and source chemical profiles were constructed for PM0.1, PM1, PM2.5, and PM10. The number concentration of particles was concentrated in the Aiken nuclei mode (0.006-0.054 µm), accounting for 75% of the total number, whereas the mass concentration was concentrated in the accumulation mode (0.054-0.949 µm), accounting for 85.43% of the mass loading. OC, EC, Cl-, and K(include total K and water-soluble K) were the major chemical components of the particles, whose mass percentage distributions differed from those of other components. These five main components exhibited a bell-shaped size distribution in the 0.006-9.890 µm range, whereas the other components exhibited a U-shaped distribution. Among the chemical profiles for PM0.1-PM10, OC was the most important component at 10-30%, followed by EC at 2%-8%. The proportions of K+, Cl-, and K varied substantially in different experimental groups, ranging from 0-15%, and K+ and Cl- were significantly correlated (r = 0.878, α = 0.000).


Assuntos
Poluentes Atmosféricos , Material Particulado , Aerossóis/análise , Poluentes Atmosféricos/análise , Carbono/análise , China , Monitoramento Ambiental , Tamanho da Partícula , Material Particulado/análise , Estações do Ano
7.
J Environ Sci (China) ; 109: 77-87, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34607676

RESUMO

Ten nitrated polycyclic aromatic hydrocarbons (nPAHs) and 4 oxygenated polycyclic aromatic hydrocarbons (oPAHs) in fine particulate matter (PM2.5) samples from Mount Tai were analyzed during summer (June to August), 2015. During the observation campaign, the mean concentration of total nPAHs and oPAHs was 31.62 pg/m3 and 0.15 ng/m3, respectively. Two of the monitored compounds, namely 9-nitro-anthracene (9N-ANT) (6.86 pg/m3) and 9-fluorenone (9FO) (0.05 ng/m3) were the predominant compounds of nPAHs and oPAHs, respectively. The potential source and long-range transportation of nPAHs and oPAHs were investigated by the positive matrix factorization (PMF) method and the potential source contribution function (PSCF) methods. The results revealed that biomass/coal burning, gasoline vehicle emission, diesel vehicle emission and secondary formation were the dominant sources of nPAHs and oPAHs, which were mainly from Henan province and Beijing-Tianjin-Hebei region and Bohai sea. The incremental life cancer risk (ILCR) values were calculated to evaluate the exposure risk of nPAHs and oPAHs for three group people (infant, children and adult), and the values of ILCR were 7.02 × 10-10, 3.49 × 10-9 and 1.41 × 10-8 for infant, children and adults, respectively. All these values were lower than the standard of EPA (Environmental Protection Agency) (<10-6), indicating acceptable health risk of nPAHs and oPAHs.


Assuntos
Poluentes Atmosféricos , Hidrocarbonetos Policíclicos Aromáticos , Adulto , Poluentes Atmosféricos/análise , Criança , China , Monitoramento Ambiental , Humanos , Material Particulado/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Medição de Risco
8.
Environ Monit Assess ; 193(11): 716, 2021 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-34637007

RESUMO

In Pretoria South Africa, we looked into the origins of fine particulate matter (PM2.5), based on 1-year sampling campaign carried out between April 18, 2017, and April 17, 2018. The average PM2.5 concentration was 21.1 ± 15.0 µg/m3 (range 0.7-66.8 µg/m3), with winter being the highest and summer being the lowest. The XEPOS 5 energy dispersive X-ray fluorescence (EDXRF) spectroscopy was used for elemental analysis, and the US EPA PMF 5.0 program was used for source apportionment. The sources identified include fossil fuel combustion, soil dust, secondary sulphur, vehicle exhaust, road traffic, base metal/pyrometallurgical, and coal burning. Coal burning and secondary sulphur were significantly higher in winter and contributed more than 50% of PM2.5 sources. The HYSPLIT model was used to calculate the air mass trajectories (version 4.9). During the 1-year research cycle, five transportation clusters were established: North Limpopo (NLP), Eastern Inland (EI), Short-Indian Ocean (SIO), Long-Indian Ocean (LIO), and South Westerly-Atlantic Ocean (SWA). Local and transboundary origin accounted for 85%, while 15% were long-range transport. Due to various anthropogenic activities such as biomass burning and coal mining, NLP clusters were the key source of emissions adding to the city's PM rate. In Pretoria, the main possible source regions of PM2.5 were discovered to be NLP and EI. Effective control strategies designed at reducing secondary sulphur, coal burning, and fossil fuel combustion emissions at Southern African level and local combustion sources would be an important measure to combat the reduction of ambient PM2.5 pollution in Pretoria.


Assuntos
Poluentes Atmosféricos , Poluentes Atmosféricos/análise , Monitoramento Ambiental , Material Particulado/análise , África do Sul , Emissões de Veículos/análise
9.
Sensors (Basel) ; 21(19)2021 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-34640662

RESUMO

Over the past few decades, the concentrating photovoltaic systems, a source of clean and renewable energy, often fully integrated into the roof structure, have been commonly installed on private houses and public buildings. The purpose of those panels is to transform the incoming solar radiation into electricity thanks to the photovoltaic effect. The produced electric power is affected, in the first instance, by the solar panel efficiency and its technical characteristics, but it is also strictly dependent on site elevation, the meteorological conditions and on the presence of the atmospheric constituents, i.e., clouds, hydrometeors, gas molecules and sub-micron-sized particles suspended in the atmosphere that can scatter and absorb the incoming shortwave solar radiation. The Aerosol Optical Depth (AOD) is an adimensional wavelength-dependent atmospheric column variable that accounts for aerosol concentration. AOD can be used as a proxy to evaluate the concentration of surface particulate matter and atmospheric column turbidity, which in turn affects the solar panel energy production. In this manuscript, a new technique is developed to retrieve the AOD at 550 nm through an iterative process: the atmospheric optical depth, incremented in steps of 0.01, is used as input together with the direct and diffuse radiation fluxes computed by Fu-Liou-Gu Radiative Transfer Model, to forecast the produced electric energy by a photovoltaic panel through a simple model. The process will stop at that AOD value (at 550 nm), for which the forecast electric power will match the real produced electric power by the photovoltaic panel within a previously defined threshold. This proof of concept is the first step of a wider project that aims to develop a user-friendly smartphone application where photovoltaic panel owners, once downloaded it on a voluntary basis, can turn their photovoltaic system into a sunphotometer to continuously retrieve the AOD, and more importantly, to monitor the air quality and detect strong air pollution episodes that pose a threat for population health.


Assuntos
Poluição do Ar , Energia Solar , Aerossóis , Poluição do Ar/análise , Atmosfera , Material Particulado
10.
Environ Monit Assess ; 193(10): 622, 2021 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-34477984

RESUMO

In this study, monthly particulate matter (PM2.5) of Paris for the period between January 2000 and December 2019 is investigated by utilizing a periodogram-based time series methodology. The main contribution of the study is modeling the PM2.5 of Paris by extracting the information purely from the examined time series data, where proposed model implicitly captures the effects of other factors, as all their periodic and seasonal effects reside in the air pollution data. Periodicity can be defined as the patterns embedded in the data other than seasonality, and it is crucial to understand the underlying periodic dynamics of air pollutants to better fight pollution. The method we use successfully captures and accounts for the periodicities, which could otherwise be mixed with seasonality under an alternative methodology. Upon the unit root test based on periodograms, it is revealed that the investigated data has periodicities of 1 year and 20 years, so harmonic regression is utilized as an alternative to Box-Jenkins methodology. As the harmonic regression displayed a better performance both in and out-of-sample forecasts, it can be considered as a powerful alternative to model and forecast time series with a periodic structure.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Monitoramento Ambiental , Previsões , Material Particulado/análise
11.
Environ Monit Assess ; 193(10): 637, 2021 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-34499227

RESUMO

Air pollution has negative effects on human health, visibility, materials, plants, and animal health. Particulate matters are one of the most important air pollutants that may create a risk for human health. Especially particulate matters, which are composed of heavy metals and cancer-causing chemicals such as PAH, dioxin, furan, can cause serious reactions in the respiratory tract. Heavy metals are so important because of their capability of accumulation in human tissues. Almost 0.01-3% of heavy metal content may be found in particulate matter. Coarse particulate matters (PM10) which have smaller diameters than 10 microns may enter from the respiratory system and reach the lungs. In this study, PM10 concentrations and heavy metal content (Lead, Nickel, Arsenic, Cadmium) of the samples were measured and evaluated concerning present regulations and limit values for different points in Konya Province, Turkey. The samples were taken at different seasons such as winter, summer, and spring for 16 days. According to the results of this study, in the winter season, PM10 concentration of the measurement point (Directorate Building) located at the settlement area was found the highest. In the summer season, PM10 concentration of the measurement point (Sille Junction) located at crossroads was found the highest. In spring season, maximum PM10 concentration was detected on the measurement point (KOS base station) located in the industrial area. Moreover, daily average nickel (Ni) concentration measured at KOS base station was found the highest and some other station located close to the industrial area and settlement areas were detected higher than average annual limit values in the winter period. Daily average lead (Pb) value was found at least 67% and maximum 98% higher at Sille and Besyol Junctions, but below the annual average limits. Daily average cadmium (Cd) value was mostly calculated in the Directorate Building winter measurement, but it did not exceed the limit value during the measurement periods. Daily average arsenic (As) values at Directorate Building and Karkent measurement points in the winter period were found higher than the annual average limit values. Only daily average nickel concentrations were detected higher than the annual average limits for the summer and spring period at the KOS base station measurement point.


Assuntos
Poluentes Atmosféricos , Metais Pesados , Poluentes Atmosféricos/análise , Monitoramento Ambiental , Humanos , Metais Pesados/análise , Material Particulado/análise , Estações do Ano , Turquia
12.
Sensors (Basel) ; 21(17)2021 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-34502737

RESUMO

This paper presents a calibration system for low-cost suspended particulate matter (PM) sensors, consisting of reference instruments, enclosed space in a metal pipe (volume 0.145 m3), a duct fan, a controller and automated control software. The described system is capable of generating stable and repeatable concentrations of suspended PM in the air duct. In this paper, as the final result, we presented the process and effects of calibration of two low-cost air pollution stations-university measuring stations (UMS)-developed and used in the scientific project known as Storm&DustNet, implemented at the Jagiellonian University in Kraków (Poland), for the concentration range of PM from a few up to 240 µg·m-3. Finally, we postulate that a device of this type should be available for every system composed of a large number of low-cost PM sensors.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Calibragem , Monitoramento Ambiental , Humanos , Umidade , Material Particulado/análise , Temperatura
13.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 43(4): 521-530, 2021 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-34494521

RESUMO

Objective To quantitatively evaluate the associations of PM2.5,PM10,NO2,and SO2 concentrations with the outpatient visits for atopic dermatitis in Lanzhou. Methods The data of outpatient visits,together with meteorological data and air pollutant data,from January 2013 to December 2017 were collected.The generalized additive model based on Poisson distribution was employed to study the lag effects of PM2.5,PM10,NO2,and SO2 concentrations on the visits of outpatients,with the seasonal and long-term trends and day-of-the-week effect controlled. Results The results of the single pollutant model showed that PM2.5 and PM10 had the most obvious while still insignificant impact on the outpatient visits for atopic dermatitis on the current day(lag0).NO2 also had the most obvious impact in the case of lag0 and showed a lag effect.For each 10 µg/m3 increase in NO2 concentration,the excess risk(ER)of outpatient visits for atopic dermatitis was 1.95%(95% CI=1.09%-2.82%,P=0.01).SO2 had the most significant effect on lag6,and the outpatient visits increased by 1.55%(95% CI=0.48%-2.54%)for every 10 µg/m3 rise in SO2 concentration(P=0.02).Females were more sensitive to PM10 and SO2 than males.For every 10 µg/m3 increase in PM10 and SO2,the female outpatient visits increased by 0.02% and 2.47%,respectively.Males were sensitive to PM2.5 and NO2,and the every 10 µg/m3 rise in PM2.5 and NO2 increased male outpatient visits by 0.47% and 1.78%,respectively.Gaseous pollutants(NO2 and SO2)had more significant effect on people ≤2 years old than on those of other ages.Every 10 µg/m3 rise in NO2 and SO2 would increase the ≤2-year-old outpatient visits by 2.35% and 1.57%,respectively(P=0.02).People of 13-59 years old were sensitive to NO2 concentration,and every 10 µg/m3 rise in NO2 concentration increased their visits by 1.39%.NO2 affected the outpatient visits during the cold and warm seasons,with the ER values of 2.35% and 1.89%,respectively(P=0.01).Particulate matter(PM2.5 and PM10)had the most obvious yet insignificant association with the outpatient visits in winter.The interactions between PM2.5 and NO2,between PM10 and NO2,and between SO2 and NO2 affected the total outpatient visits for atopic dermatitis.The results of double pollutant model showed that in the presence of PM2.5,PM10,or SO2,the effect of NO2 on the outpatient visits for atopic dermatitis enhanced compared with that predicted by single pollutant model(P=0.01). Conclusion The air pollutants(PM2.5,PM10,NO2,and SO2)in Lanzhou were closely related to the outpatient visits for atopic dermatitis,and the increased concentrations of NO2 and SO2 was more likely to increase the risk of atopic dermatitis.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Dermatite Atópica , Poluentes Atmosféricos/análise , Poluentes Atmosféricos/toxicidade , Poluição do Ar/efeitos adversos , Pré-Escolar , China , Dermatite Atópica/epidemiologia , Feminino , Humanos , Masculino , Pacientes Ambulatoriais , Material Particulado/efeitos adversos , Material Particulado/análise
14.
Environ Monit Assess ; 193(10): 663, 2021 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-34537887

RESUMO

Many toxicological studies revealed the deleterious effects on human health induced by trace metals in ambient particulate matter (PM). This study reports the season-dependent water-soluble and total metal mass in PM10 collected simultaneously over five microenvironments in a semi-arid urban region, Ahmedabad, located in western India. The mineral dust fraction in PM10 over Bapunagar, Narol, Paldi, Income Tax, and Science City was estimated to be around 39, 45, 47, 44, and 31% during summer (May-June 2017) and 24, 55, 28, 27, and 28% during winter (December 2017-January 2018), respectively, corroborating mineral dust is perennial in the air over Ahmedabad. The PM2.5/PM10 mass ratios over all the sites were higher during winter (40-60%) as compared to those during summer (30-40%), indicating the contribution from the anthropogenic sources to PM mass. Among the metals monitored, the estimated considerable amount of high masses of Zn, Cu, Ni, Cd, and Sb during winter can be ascribed to the anthropogenic inputs based on the estimated enrichment factors (EF). In contrast to the crustal source, these metals might have been possibly emitted from several other man-made sources, which were found to be more water-soluble during both seasons. As per the standards of incremental excess lifetime cancer risk (IELCR), it is estimated that the atmospheric mass concentration of carcinogenic metals such as Cr, Co, and As was higher in all these sites, whereas the metals such as Pb, Ni, and Cd are also found over the industrial site (Narol) in addition to the above-said metals. Notably, people are highly susceptible to these metals, leading to the potential risk of cancer during both seasons.


Assuntos
Poluentes Atmosféricos , Metais Pesados , Poluentes Atmosféricos/análise , Monitoramento Ambiental , Avaliação do Impacto na Saúde , Humanos , Índia , Material Particulado/análise , Estações do Ano
15.
Environ Monit Assess ; 193(9): 618, 2021 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-34476627

RESUMO

Recent studies concluded that air quality has improved due to the enforcement of lockdown in the wake of COVID-19. However, they mostly concentrated on the changes during the lockdown period, and the studies considering the consequences of de-escalation of lockdown are inadequate. Therefore, we investigated the changes in fine particulate matter (PM2.5) during the pre-lockdown, strict lockdown, unlocking, and post-lockdown scenarios. In addition, we assessed the influence of meteorology, mobility, air mass transport, and biomass burning on PM2.5 using Google's mobility data, back trajectory model, and satellite-based fire incident data. Average PM2.5 concentrations in Ghaziabad, Noida, and Faridabad decreased by 60.70%, 63.27%, and 60.40%, respectively, during the lockdown. When compared with the preceding year (2019), the reductions during the shutdown period (25 March-31 May) were within the range of 36.34-44.55%. However, considering the entire year, this reduction in PM2.5 is momentary, and a steady increase in traffic density and industrial operations within cities during post-lockdown reflects a potent recovery of aerosol level, during which the average mass of PM2.5 three- to four-folds higher than the lockdown period. Back trajectories and fire activity results showed that biomass burning in the nearby states (Haryana and Punjab) influence aerosol load. We conclude that a partial lockdown in the event of a sudden surge in pollution would be a beneficial approach. However, reducing fossil fuel consumption and switching to more environmentally friendly energy sources, developing green transport networks, and circumventing biomass burning are efficient ways to improve air quality in the long term.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , COVID-19 , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Biomassa , Cidades , Controle de Doenças Transmissíveis , Monitoramento Ambiental , Humanos , Meteorologia , Material Particulado/análise , SARS-CoV-2
16.
Environ Sci Technol ; 55(17): 11795-11804, 2021 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-34488352

RESUMO

Wildland firefighters are exposed to smoke-containing particulate matter (PM) and volatile organic compounds (VOCs) while suppressing wildfires. From 2015 to 2017, the U.S. Forest Service conducted a field study collecting breathing zone measurements of PM4 (particulate matter with aerodynamic diameter ≤4 µm) on wildland firefighters from different crew types and while performing various fire suppression tasks on wildfires. Emission ratios of VOC (parts per billion; ppb): PM1 (particulate matter with aerodynamic diameter ≤1 µm; mg/m3) were calculated using data from a separate field study conducted in summer 2018, the Western Wildfire Experiment for Cloud Chemistry, Aerosol Absorption, and Nitrogen (WE-CAN) Campaign. These emission ratios were used to estimate wildland firefighter exposure to acrolein, benzene, and formaldehyde. Results of this field sampling campaign reported that exposure to PM4 and VOC varied across wildland firefighter crew type and job task. Type 1 crews had greater exposures to both PM4 and VOCs than type 2 or type 2 initial attack crews, and wildland firefighters performing direct suppression had statistically higher exposures than those performing staging and other tasks (mean differences = 0.82 and 0.75 mg/m3; 95% confidence intervals = 0.38-1.26 and 0.41-1.08 mg/m3, respectively). Of the 81 personal exposure samples collected, 19% of measured PM4 exposures exceeded the recommended National Wildland Fire Coordinating Group occupational exposure limit (0.7 mg/m3). Wildland fire management should continue to find strategies to reduce smoke exposures for wildland firefighters.


Assuntos
Bombeiros , Incêndios , Exposição Ocupacional , Compostos Orgânicos Voláteis , Humanos , Material Particulado/análise , Fumaça/análise , Compostos Orgânicos Voláteis/análise
17.
Sci Total Environ ; 792: 148393, 2021 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-34465048

RESUMO

The ambient atmospheric PM2.5 concentrations in Anhui Province, China, which links the Yangtze River Delta region, China's fastest growing economy area, with the Beijing-Tianjin-Hebei (BTH) region, China's most polluted region, are influenced not only by local emissions, but also by changes in regional circulation. During the period 2013-2017, when China adopted a series of pollution abatement measures, there were still occasional pollution episodes with significant increases in PM2.5 concentrations. PM2.5 rise instead during the period 2013-2017 in Anhui (the Center of the Yangtze-Huaihe, YH), when pollution emissions continued to decrease? What is the controlling mechanism behind these? By analyzing elements such as ground-based PM2.5 concentration and the planetary boundary layer (PBL) structure affecting it as well as larger scale circulation, combined with the analysis of a parameterized index, one can find that aerosol pollution in the YH region can usually be classified into three types. (1) There is a short-term transport stage (TS) in the initial stage of pollution, then as the pollutant concentrations increase, the PBL height decreases, the temperature inversion is gradually formed or strengthened, the wind speed decreases and the relative humidity of the lower layer increases, forming a two-way feedback mechanism in the cumulative stage (CS). (2) Pollutant concentrations will not drop rapidly in the later stage of CS, while a short-term TS will occur again. (3) The explosive rise (ER) events are mainly affected by transportation in the YH. The first of these types tends to be accompanied by the emergence and maintenance of heavy pollution periods (HPEs), and some phases is accompanied by explosive rises (ERs) in PM2.5 that at least double in a short period of time. To sum up, deterioration of meteorological conditions explaining approximately 68% to the increase in PM2.5 in the ER.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Poluentes Atmosféricos/análise , Poluição do Ar/análise , China , Monitoramento Ambiental , Material Particulado/análise , Tempo (Meteorologia)
18.
J Environ Sci (China) ; 108: 1-7, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34465424

RESUMO

The distribution and chemical speciation of arsenic (As) in different sized atmospheric particulate matters (PMs), including total suspended particles (TSP), PM10, and PM2.5, collected from Baoding, China were analyzed. The average total mass concentrations of As in TSP, PM10, and PM2.5 were 31.5, 35.3, and 54.1 µg/g, respectively, with an order of PM2.5 >PM 10 > TSP, revealing that As is prone to accumulate on fine particles. Due to the divergent toxicities of different As species, speciation analysis of As in PMs is further conducted. Most of previous studies mainly focused on inorganic arsenite (iAsIII), inorganic arsenate (iAsV), monomethylarsonate (MMA), and dimethylarsinate (DMA) in PMs, while the identification and sensitive quantification of trimethylarsine oxide (TMAO) were rarely reported. In this study, a high-performance liquid chromatography coupled to inductively coupled plasma mass spectrometry system was optimized for As speciation including TMAO in PMs. An anion exchange column was used to separate MMA, DMA and iAsV, while a cation exchange column to separate TMAO and iAsIII. Results showed that iAsV was the dominate component in all the samples, corresponding to a portion of 79.2% ± 9.3% of the total extractable species, while iAsIII, TMAO and DMA made up the remaining 21%. Our study demonstrated that iAsIII accounted for about 14.4% ± 11.4% of the total extracted species, with an average concentration of 1.7 ± 1.6 ng/m3. It is worth noting that TMAO was widely present in the samples (84 out of 97 samples), which supported the assumption that TMAO was ubiquitous in atmospheric particles.


Assuntos
Arsênio , Arsenicais , Arsênio/análise , Arsenicais/análise , Ácido Cacodílico , China , Cromatografia Líquida de Alta Pressão , Material Particulado/análise
19.
Environ Health ; 20(1): 101, 2021 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-34488764

RESUMO

BACKGROUND: The outbreak of coronavirus disease (COVID-19) began in Wuhan, China in December 2019 and was declared a global pandemic on 11 March 2020. This study aimed to assess the effects of temperature and long-term exposure to air pollution on the COVID-19 mortality rate at the sub-national level in France. METHODS: This cross-sectional study considered different periods of the COVID-19 pandemic from May to December 2020. It included 96 departments (or NUTS 3) in mainland France. Data on long-term exposure to particulate matter (PM2.5), annual mean temperature, health services, health risk, and socio-spatial factors were used as covariates in negative binomial regression analysis to assess their influence on the COVID-19 mortality rate. All data were obtained from open-access sources. RESULTS: The cumulative COVID-19 mortality rate by department increased during the study period in metropolitan France-from 19.8/100,000 inhabitants (standard deviation (SD): 20.1) on 1 May 2020, to 65.4/100,000 inhabitants (SD: 39.4) on 31 December 2020. The rate was the highest in the departments where the annual average of long-term exposure to PM2.5 was high. The negative binomial regression models showed that a 1 µg/m3 increase in the annual average PM2.5 concentration was associated with a statistically significant increase in the COVID-19 mortality rate, corresponding to 24.4%, 25.8%, 26.4%, 26.7%, 27.1%, 25.8%, and 15.1% in May, June, July, August, September, October, and November, respectively. This association was no longer significant on 1 and 31 December 2020. The association between temperature and the COVID-19 mortality rate was only significant on 1 November, 1 December, and 31 December 2020. An increase of 1 °C in the average temperature was associated with a decrease in the COVID-19-mortality rate, corresponding to 9.7%, 13.3%, and 14.5% on 1 November, 1 December, and 31 December 2020, respectively. CONCLUSION: This study found significant associations between the COVID-19 mortality rate and long-term exposure to air pollution and temperature. However, these associations tended to decrease with the persistence of the pandemic and massive spread of the disease across the entire country.


Assuntos
Poluentes Atmosféricos/efeitos adversos , COVID-19/mortalidade , Exposição Ambiental/efeitos adversos , Material Particulado/efeitos adversos , Estudos Transversais , Exposição Ambiental/estatística & dados numéricos , França/epidemiologia , Humanos , Modelos Estatísticos , SARS-CoV-2 , Temperatura
20.
J Hazard Mater ; 416: 125833, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34492791

RESUMO

Aerosol emissions from wastewater treatment plants (WWTPs) have been associated with health reverberation but studies about characteristics of size-segregated aerosol particulate matter (PM) are scarce. In this study, the measurement of particulate number size distribution in the range of < 10 µm, and the collection of PM10-2.5, PM2.5-1.0 and PM1.0, were conducted from an aerobic moving bed biofilm reactor (MBBR) at a full-scale WWTP. MBBR aerosols showed a unimodal number size distribution, with the majority of particles (>94%) in the ultrafine size range (<100 nm). For toxic metal(loid)s or potential pathogens, significant differences were found within MBBR aerosols (PM10-2.5, PM2.5-1.0, and PM1.0), and also between MBBR aerosols and wastewater. Both wastewater and ambient air had important source contributions for MBBR aerosols. The compositions of toxic metal(loid)s in PM1.0, and the populations of potential bacterial or fungal pathogens in PM10-2.5 and PM2.5-1.0, were dominated by that from wastewater. Compared to PM10-2.5 and PM2.5-1.0, PM1.0 had the highest aerosolization potential for the toxic metal(loid)s of As, Cd, Co, Cr, Li, Mn, Ni, U, and Zn, and the genera of Acinetobacter, Pseudomonas and Fusarium. Due to the size-segregated specialty, targeted measures should be employed to reduce the health risks. CAPSULE: The compositions of toxic metal(loid)s in PM1.0, and the populations of potential pathogens in PM10-2.5 and PM2.5-1.0, were dominated by that from wastewater.


Assuntos
Biofilmes , Purificação da Água , Aerossóis/análise , Reatores Biológicos , Material Particulado
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