Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 50.004
Filtrar
1.
J Hazard Mater ; 421: 126732, 2022 01 05.
Artículo en Inglés | MEDLINE | ID: mdl-34332475

RESUMEN

Bio-heavy oil (BHO) is a renewable fuel, but its efficient use is problematic because its combustion may emit hazardous air pollutants (e.g., polycyclic aromatic hydrocarbon (PAH) compounds, NOx, and SOx). Herein, catalytic fast pyrolysis over HZSM-5 zeolite was applied to upgrading BHO to drop-in fuel-range hydrocarbons with reduced contents of hazardous species such as PAH compounds and N- and S-containing species (NOx and SOx precursors). The effects of HZSM-5 desilication and linear low-density polyethylene (LLDPE) addition to the feedstock on hydrocarbon production were explored. The apparent activation energy for the thermal decomposition of BHO was up to 37.5% lowered by desilicated HZSM-5 (DeHZSM-5) compared with HZSM-5. Co-pyrolyzing LLDPE with BHO increased the content of drop-in fuel-range hydrocarbons and decreased the content of PAH compounds. The DeHZSM-5 was effective in producing drop-in fuel-range hydrocarbons from a mixture of BHO and LLDPE and suppressing the formation of N- and S-containing species and PAH compounds. The DeHZSM-5 enhanced the hydrocarbon production by up to 58.5% because of its enhanced porosity and high acid site density compared to its parent HZSM-5. This study experimentally validated that BHO can be upgraded to less hazardous fuel via catalytic fast co-pyrolysis with LLDPE over DeHZSM-5.


Asunto(s)
Contaminación del Aire , Biocombustibles , Biomasa , Catálisis , Sustancias Peligrosas , Calor
2.
J Hazard Mater ; 421: 126766, 2022 01 05.
Artículo en Inglés | MEDLINE | ID: mdl-34396962

RESUMEN

Photocatalytic oxidation (PCO)-based air filters are gaining attention owing to their capacity for indoor pollutant removal. This review summarized the application of ultraviolet-photocatalytic oxidation (UV-PCO) in heating, ventilation, and air conditioning (HVAC) systems, including the modeling studies, reactor designs, the influence of operational conditions, with emphasis on the common issue of byproduct generation, and the resulting indoor byproduct exposure levels. As a result, the concentrations of the typical byproducts for the most challenging pollutants were relatively low, except for the PCO of ethanol. Hence, UV-PCO is not recommended for buildings with high ethanol concentrations. Based on the formation of the formaldehyde, a new exposure-based evaluation standard for UV-PCO was developed to evaluate the feasibility of integrating UV-PCO reactors into an HVAC system. Then, applying the newly developed evaluation standard on a developed database (data size: 174) from the literature, 32.5% of the cases were identified as suitable for HVAC system applications in residential and commercial buildings, and all cases could be used for industrial buildings. Finally, a case study was conducted to develop a support vector machine (SVM) classification model with good accuracy, and challenging compound types, inlet concentrations, and air velocity were found to be the main parameters affecting the applicability of UV-PCO.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire Interior , Compuestos Orgánicos Volátiles , Contaminación del Aire Interior/análisis , Catálisis , Fotoquímica , Tecnología
3.
J Environ Manage ; 301: 113829, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-34592669

RESUMEN

The increasing carbon dioxide level in the earth's atmosphere and continuously changing climate creates a significant challenge to sustainability in the world. It is not easy to control pollution due to carbon dioxide emissions from coal-fired power plants into the atmosphere. However, carbon capture technology provides an advantage for capturing carbon from power plants. Various researchers suggested the non-linear optimization model with post-combustion carbon capture technology in coal-fired power plants to reduce carbon emission. However, in their research articles, most researchers did not include loss of power due to retrofitting carbon capture technology in power plants and carbon emission from the compensatory power plant. This paper proposes a linear optimization model that minimizes the emission release from the power plant and its compensatory plant by appropriate selection of carbon capture technology. Our proposed model incorporates loss of power due to adopting carbon capture technology and emission release from the power plant and compensatory power plant in the problem formulation. We have also generated the Pareto curve that determines the trade-off solutions between emission release and the overall electricity cost. The applicability of our model is illustrated through power sector data from two Indian states. The net reduction of emissions in the two states are 27.17 % and 26.29 %, achieved by a mixed integer linear programming approach in coal-fired power plants. The model developed is generic and provides a sustainable environment for the generation of electricity.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , Contaminación del Aire/prevención & control , Dióxido de Carbono/análisis , Carbón Mineral/análisis , Técnicas de Apoyo para la Decisión , Electricidad , Centrales Eléctricas
4.
J Environ Manage ; 301: 113861, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-34601351

RESUMEN

Air pollution is commonly disregarded as a source of nutrient loading to impaired surface waters managed under the Clean Water Act per states' 303(d) list programs. The contribution of air pollution to 2017-2018 South Platte River nitrogen (N) loads was estimated from the headwaters to the gage at Weldona, Colorado, USA (100 km downstream of Denver), using data from the National Atmospheric Deposition Program (NADP) and the SPAtially Referenced Regressions On Watershed attributes (SPARROW) model. The NADP offers wet-deposition raster created by spatial interpolation of data collected from regionally representative monitoring sites, excluding the influences from urban site data. For this study, NADP wet-deposition data obtained from sites within the Denver-Boulder, Colorado, urban corridor were included and excluded in new spatial interpolations of wet-deposition raster, which were used as input for SPARROW to model the influence of urban air pollution sources on South Platte River loads. Because urban air pollution is already incorporated into the NADP Total Deposition modeling methodology, dry N deposition was held constant for each SPARROW modeling scenario when dry deposition was included. By including the urban wet-deposition data in the model, estimated N loading to the South Platte River at Denver increased by 9-11 percent. Factoring in dry deposition at a 1:1.8 dry:wet ratio obtained from the results, urban air pollution was estimated to contribute as much as 20 percent of the nitrate Total Maximum Daily Load for Segment 14 of the South Platte River.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Contaminantes Atmosféricos/análisis , Monitoreo del Ambiente , Nitratos/análisis , Nitrógeno/análisis , Ríos
5.
J Environ Manage ; 301: 113860, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-34626947

RESUMEN

Humans face threats from air pollutants present in both indoor and outdoor environments. The emerging role of plants in remediating the atmospheric environment is now being actively investigated as a possible solution for this problem. Foliar surfaces of plants (e.g., the leaves of cotton) can absorb a variety of airborne pollutants (e.g., formaldehyde, benzene, trimethylamine, and xylene), thereby reducing their concentrations in indoor environments. Recently, theoretical and experimental studies have been conducted to offer better insights into the interactions between plants and the surrounding air. In our research, an overview on the role of plants in reducing air pollution (often referred to as phytoremediation) is provided based on a comprehensive literature survey. The major issues for plant-based research for the reduction of air pollution in both outdoor and indoor environments are discussed in depth along with future challenges. Analysis of the existing data confirms the effectiveness of phytoremediation in terms of the absorption and purification of pollutants (e.g., by the leaves and roots of plants and trees), while being controlled by different variables (e.g., pore characteristics and planting patterns). Although most lab-scale studies have shown that plants can effectively absorb pollutants, it is important for such studies to reflect the real-world conditions, especially with the influence of human activities. Under such conditions, pollutants are to be replenished continually while the plant surface area to ambient atmosphere volume ratio vastly decreases (e.g., relative to lab-based experiments). The replication of such experimental conditions is the key challenge in this field of research. This review is expected to offer valuable insights into the innate ability of various plants in removing diverse pollutants (such as formaldehyde, benzene, and particulate matter) under different environmental settings.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire Interior , Contaminación del Aire , Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , Contaminación del Aire/prevención & control , Contaminación del Aire Interior/análisis , Humanos , Material Particulado/análisis , Plantas
6.
Sci Total Environ ; 804: 150091, 2022 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-34517316

RESUMEN

BACKGROUND: Ambient air pollution exposure has been associated with higher mortality risk in numerous studies. We assessed potential variability in the magnitude of this association for non-accidental, cardiovascular disease, respiratory disease, and lung cancer mortality in a country-wide administrative cohort by exposure assessment method and by adjustment for geographic subdivisions. METHODS: We used the Belgian 2001 census linked to population and mortality register including nearly 5.5 million adults aged ≥30 (mean follow-up: 9.97 years). Annual mean concentrations for fine particulate matter (PM2.5), nitrogen dioxide (NO2), black carbon (BC) and ozone (O3) were assessed at baseline residential address using two exposure methods; Europe-wide hybrid land use regression (LUR) models [100x100m], and Belgium-wide interpolation-dispersion (RIO-IFDM) models [25x25m]. We used Cox proportional hazards models with age as the underlying time scale and adjusted for various individual and area-level covariates. We further adjusted main models for two different area-levels following the European Nomenclature of Territorial Units for Statistics (NUTS); NUTS-1 (n = 3), or NUTS-3 (n = 43). RESULTS: We found no consistent differences between both exposure methods. We observed most robust associations with lung cancer mortality. Hazard Ratios (HRs) per 10 µg/m3 increase for NO2 were 1.060 (95%CI 1.042-1.078) [hybrid LUR] and 1.040 (95%CI 1.022-1.058) [RIO-IFDM]. Associations with non-accidental, respiratory disease and cardiovascular disease mortality were generally null in main models but were enhanced after further adjustment for NUTS-1 or NUTS-3. HRs for non-accidental mortality per 5 µg/m3 increase for PM2.5 for the main model using hybrid LUR exposure were 1.023 (95%CI 1.011-1.035). After including random effects HRs were 1.044 (95%CI 1.033-1.057) [NUTS-1] and 1.076 (95%CI 1.060-1.092) [NUTS-3]. CONCLUSION: Long-term air pollution exposure was associated with higher lung cancer mortality risk but not consistently with the other studied causes. Magnitude of associations varied by adjustment for geographic subdivisions, area-level socio-economic covariates and less by exposure assessment method.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Adulto , Contaminantes Atmosféricos/análisis , Contaminantes Atmosféricos/toxicidad , Contaminación del Aire/análisis , Contaminación del Aire/estadística & datos numéricos , Censos , Estudios de Cohortes , Exposición a Riesgos Ambientales/análisis , Exposición a Riesgos Ambientales/estadística & datos numéricos , Humanos , Material Particulado/análisis , Material Particulado/toxicidad
7.
Handb Exp Pharmacol ; 268: 359-366, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-34159483

RESUMEN

Air pollution is worldwide a major public health problem and affects large part of the population. Air pollution does not only harm the respiratory tract system but also the other organs of the body. The damage may result directly from the pollutants toxicity, because the pollutant enters into the organs through a direct route or indirectly through systemic inflammation. There is accumulating evidence suggesting that ambient air pollution not only affects the human lung and the cardiovascular system, but also has negative effects on allergic diseases. In this regard, it has been shown that exposure increases the risk of allergies and eczema in children and adults. However, the mechanism how ambient air pollution affects the skin is not well investigated up to now and needs further research.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Hipersensibilidad , Adulto , Contaminantes Atmosféricos/efectos adversos , Contaminantes Atmosféricos/análisis , Contaminación del Aire/efectos adversos , Contaminación del Aire/análisis , Niño , Humanos , Hipersensibilidad/epidemiología , Hipersensibilidad/etiología , Pulmón , Factores de Riesgo
8.
Sci Total Environ ; 803: 149747, 2022 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-34487895

RESUMEN

This study estimates exposure and inhaled dose to air pollutants of children residing in a tropical coastal-urban area in Southeast Brazil. For that, twenty-one children filled their time-activities diaries and wore the passive samplers to monitor NO2. The personal exposure was also estimated using data provided by the combination of WRF-Urban/GEOS-Chem/CMAQ models, and the nearby monitoring station. Indoor/outdoor ratios were used to consider the amount of time spent indoors by children in homes and schools. The model's performance was assessed by comparing the modelled data with concentrations measured by urban monitoring stations. A sensitivity analyses was also performed to evaluate the impact of the model's height on the air pollutant concentrations. The results showed that the mean children's personal exposure to NO2 predicted by the model (22.3 µg/m3) was nearly twice to those measured by the passive samplers (12.3 µg/m3). In contrast, the nearest urban monitoring station did not represent the personal exposure to NO2 (9.3 µg/m3), suggesting a bias in the quantification of previous epidemiological studies. The building effect parameterisation (BEP) together with the lowering of the model height enhanced the air pollutant concentrations and the exposure of children to air pollutants. With the use of the CMAQ model, exposure to O3, PM10, PM2.5, and PM1 was also estimated and revealed that the daily children's personal exposure was 13.4, 38.9, 32.9, and 9.6 µg/m3, respectively. Meanwhile, the potential inhalation daily dose was 570-667 µg for PM2.5, 684-789 µg for PM10, and 163-194 µg for PM1, showing to be favourable to cause adverse health effects. The exposure of children to air pollutants estimated by the numerical model in this work was comparable to other studies found in the literature, showing one of the advantages of using the modelling approach since some air pollutants are poorly spatially represented and/or are not routinely monitored by environmental agencies in many regions.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire Interior , Contaminación del Aire , Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , Contaminación del Aire Interior/análisis , Brasil , Niño , Exposición a Riesgos Ambientales/análisis , Monitoreo del Ambiente , Humanos , Material Particulado/análisis , Instituciones Académicas
9.
Sci Total Environ ; 803: 149931, 2022 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-34487903

RESUMEN

Economic and urban development in sub-Saharan Africa (SSA) may be shifting the dominant air pollution sources in cities from biomass to road traffic. Considered as a marker for traffic-related air pollution in cities, we conducted a city-wide measurement of NOx levels in the Accra Metropolis and examined their spatiotemporal patterns in relation to land use and meteorological factors. Between April 2019 to June 2020, we collected weekly integrated NOx (n = 428) and NO2 (n = 472) samples at 10 fixed (year-long) and 124 rotating (week-long) sites. Data from the same time of year were compared to a previous study (2006) to assess changes in NO2 concentrations. NO and NO2 concentrations were highest in commercial/business/industrial (66 and 76 µg/m3, respectively) and high-density residential areas (47 and 59 µg/m3, respectively), compared with peri-urban locations. We observed annual means of 68 and 70 µg/m3 for NO and NO2, and a clear seasonal variation, with the mean NO2 of 63 µg/m3 (non-Harmattan) increased by 25-56% to 87 µg/m3 (Harmattan) across different site types. The NO2/NOx ratio was also elevated by 19-28%. Both NO and NO2 levels were associated with indicators of road traffic emissions (e.g. distance to major roads), but not with community biomass use (e.g. wood and charcoal). We found strong correlations between both NO2 and NO2/NOx and mixing layer depth, incident solar radiation and water vapor mixing ratio. These findings represent an increase of 25-180% when compared to a small study conducted in two high-density residential neighborhoods in Accra in 2006. Road traffic may be replacing community biomass use (major source of fine particulate matter) as the prominent source of air pollution in Accra, with policy implication for growing cities in SSA.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , Monitoreo del Ambiente , Meteorología , Dióxido de Nitrógeno/análisis , Óxidos de Nitrógeno/análisis , Material Particulado/análisis
10.
Sci Total Environ ; 803: 149979, 2022 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-34487906

RESUMEN

PM2.5 is the key pollutant threatening human health and can even cause lung cancer. Pollution is the most serious problem in China with its fast industrialisation, urbanisation and high population density. This pollutant is conveyed through the atmosphere, trade and the embodied emission flow amongst regions. Scientific evaluation of the responsibility for regional lung cancer by considering both internal and external influences seems to be meaningful in addressing regional inequity. This study develops a relatively convenient and practical method to evaluate the regional inequity reflected by lung cancer associated with PM2.5 pollution in China. Results show that PM2.5 emissions and concentrations have similar distribution patterns: high values were predominant in the east and south where has high population density, while the west had low values. The cancer incidence rate showed high values mainly in eastern and central China. At a provincial scale, the lung cancer incidence rate was significantly correlated with PM2.5 concentration levels, and a high correlation was also found between PM2.5 concentration and emissions, indicating that emission reduction is the key to lung cancer prevention. Due to domestic trade, some developed regions more pulled lung cancer in less developed regions, and some less developed regions also have an obvious influence on external regions. Spatially, provinces in northern and central China are always more influenced by external regions. Lung cancer inequity analysis shows that coastline regions are more advantaged, while the reverse applies to inland China. The central government needs to further strengthen regional coordinated development measures, such as economic compensation for medical care and adjustments to industry structure. It should optimise spatial allocation and comprehensively consider regional inequity and character.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Neoplasias Pulmonares , Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , China/epidemiología , Monitoreo del Ambiente , Humanos , Incidencia , Neoplasias Pulmonares/epidemiología , Material Particulado/análisis
11.
Sci Total Environ ; 803: 150007, 2022 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-34492492

RESUMEN

Satellite-based measures of NO2 have become increasingly available for resolving the limitation on insufficient spatial and temporal coverage of ground-level monitoring networks. Oversampled NO2 column density can obtain more detailed features of NO2 column with a spatial resolution as high as 2 km × 2 km, while it is still challenging to identify hotspots of NOx pollution plume in city-scale due to background interference. In this study, we proposed a method for detecting the NOx hotspot grids from oversampled satellite NO2 column based on the image segmentation method, and identifying major source types using Term frequency-inverse document frequency (TF-IDF). A fractal model was used to evaluate and eliminate the background portion of the NO2 column and an adaptive threshold method was adopted to identify the region of interest (ROI) of local hotspot NO2 column. Hot-grid index, counting the frequency of NO2 hotspot ROI in each grid, was conducted to identify the hotspot grids. TF-IDF was used to semantically analyze the major source types of NO2 hotspot grids. Taking Central and Eastern China as the studied domain, the hotspot grids of NO2 and the relevant major source types were identified based on the proposed method. The major non-road mobile sources (such as Beijing Capital International Airport), industrial areas (such as Caofeidian Industrial Park) and urban areas were clearly distinguished. The power plant, Coke and Iron and Steel were identified as major source types in the whole year in the corresponding NOx hotspot grids. Notably, the identification of hotspot grids indicated a higher probability of a local high-intensity NOx pollution plume rather than a quantitative NOx emission; the key source types were the semantic keywords in hotspot grids, which does not mean there were no other exiting emission sources. This proposed method has strong implications on rapidly identifying the NOx hotspot grids based on oversampled TROPOMI NO2 column and the list of industrial enterprises.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , Ciudades , Monitoreo del Ambiente , Dióxido de Nitrógeno/análisis
12.
Chemosphere ; 286(Pt 2): 131833, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34426128

RESUMEN

Due to the poor living and healthcare conditions, preterm birth (PTB) in rural population is a pressing health issue. However, PTB studies in rural population are rare. To explore the effects of air pollutants on PTB in rural population, we collected 697,316 medical records during 2014-2016 based on the National Free Preconception Health Examination Project. Logistic regression models were used to estimate the association between air pollutants and PTB and the modifying effects of demographic characteristics. Relative contribution and principal component analysis-generalized linear model (PCA-GLM) analysis were used to explore the most significant air pollutant and gestational period. Our results demonstrated that PTB risk is positively associated with exposure to air pollutants including PM10, PM2.5, SO2, NO2, and CO, while negatively associated with O3 exposure (P < 0.05). In addition, we found that NO2 was the largest contributor to the risk of PTB caused by air pollutants (26.5%). The third trimester of pregnancy was the most sensitive exposure window. PCA-GLM analysis showed that the first component (a combination of PM, SO2, NO2, and CO) increased the risk of PTB. Moreover, we found that rural women who are younger, had higher educated, multi-parity, or smoke appeared to be more sensitive to the association between air pollutants exposure and PTB (P-interaction<0.05). Our findings suggested that increased air pollutants except O3 were associated with elevated PTB risk, especially among vulnerable mothers. Therefore, the effects of air pollutants exposure on PTB should be mitigated by restricting emission sources of NO2 and SO2 in rural population, especially during the third trimester.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Nacimiento Prematuro , Efectos Tardíos de la Exposición Prenatal , Contaminantes Atmosféricos/análisis , Contaminantes Atmosféricos/toxicidad , Contaminación del Aire/análisis , Contaminación del Aire/estadística & datos numéricos , China/epidemiología , Femenino , Humanos , Recién Nacido , Exposición Materna/estadística & datos numéricos , Material Particulado/análisis , Material Particulado/toxicidad , Embarazo , Nacimiento Prematuro/inducido químicamente , Nacimiento Prematuro/epidemiología , Población Rural
13.
Chemosphere ; 286(Pt 2): 131802, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34426134

RESUMEN

BACKGROUND: Spontaneous abortion (SAB) brings serious physical and psychological sequelae to women and their families. Though a growing body of individual studies have suggested the possible linkage between chronic particulate matter (PM) exposure and risks of SAB, the provided results were rather contradictory. We therefore performed an evidence-based meta-analysis. METHODS: We systematically searched the PubMed, EMBASE and Web of Science databases for available studies published before February 1, 2021 which reported associations between PM exposure and SAB. Corresponding models were applied to combine relative risks (RRs) and their confidence intervals (CIs) from eligible studies according to heterogeneity test. The GRADEpro app was used to evaluate the certainty of evidence. Sensitivity analyses and a publication bias assessment were also utilized to determine the stability of results. RESULTS: Of the initial 2358 citations, 6 papers examining the chronic effects of PM exposure were deemed eligible and a total population of approximately 723,000 was observed. Pooled RR for SAB risks associated with a 10 µg/m3 increase in fine particulate matter (PM2.5) and particulate matter ≤ 10 µm in aerodynamic diameter (PM10) were 1.20 (95%CI: 1.01-1.40) and 1.09 (95%CI: 1.02-1.15), respectively. The GRADE results of PM2.5 and PM10 were both categorized as "moderate" certainty evidence. CONCLUSION: Our findings revealed a significant increase of SAB hazards related with maternal PM exposure, and this study may therefore provide new evidence for personal protection to improve reproductive health.


Asunto(s)
Aborto Espontáneo , Contaminantes Atmosféricos , Contaminación del Aire , Aborto Espontáneo/inducido químicamente , Aborto Espontáneo/epidemiología , Contaminantes Atmosféricos/análisis , Contaminantes Atmosféricos/toxicidad , Contaminación del Aire/análisis , Contaminación del Aire/estadística & datos numéricos , Exposición a Riesgos Ambientales/análisis , Exposición a Riesgos Ambientales/estadística & datos numéricos , Femenino , Humanos , Material Particulado/análisis , Embarazo
14.
Chemosphere ; 286(Pt 1): 131634, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34325266

RESUMEN

One contemporary issue is how environmental pollution and climate can affect the dissemination and severity of COVID-19 in humans. We documented the first case of association between particulate matter ≤2.5 µm (PM2.5) and COVID-19 mortality rates that involved rural and medium-sized municipalities in northwestern Mexico, where direct air quality monitoring is absent. Alternatively, anthropogenic PM2.5 emissions were used to estimate the PM2.5 exposure in each municipality using two scenarios: 1) considering the fraction derived from combustion of vehicle fuel; and 2) the one derived from modeled anthropogenic sources. This study provides insights to better understand and face future pandemics by examining the relation between PM2.5 pollution and COVID-19 mortality considering the population density and the wind speed. The main findings are: (i) municipalities with high PM2.5 emissions and high population density have a higher COVID-19 mortality rate; (ii) the exceptionally high COVID-19 mortality rates of the rural municipalities could be associated to dust events, which are common in these regions where soils without vegetation are dominant; and (iii) the influence of wind speed on COVID-19 mortality rate was evidenced only in municipalities with <100 inhabitants per km2. These results confirm the suggestion that high levels of air pollutants associated with high population density and an elevated frequency of dust events may promote an extended prevalence and severity of viral particles in the polluted air of urban, suburban, and rural communities. This supports an additional means of dissemination of the coronavirus SARS-CoV-2, in addition to the direct human-to-human transmission.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , COVID-19 , Contaminantes Atmosféricos/análisis , Contaminación del Aire/efectos adversos , Contaminación del Aire/análisis , Ciudades , Polvo/análisis , Monitoreo del Ambiente , Humanos , Material Particulado/análisis , Densidad de Población , Población Rural , SARS-CoV-2 , Viento
15.
Chemosphere ; 286(Pt 2): 131703, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34352541

RESUMEN

Exposure to phthalates poses adverse health impacts to human beings. In this study, we analyzed 7 phthalates in dust samples, which were collected with vacuum cleaner from 40 to 31 residences in Beijing in summer and winter, respectively. The major phthalates (median concentration in the summer and winter, respectively) were DiBP (55 and 40 ng/mg), DnBP (99 and 30 ng/mg) and DEHP (795 and 335 ng/mg). The concentrations were significantly influenced by season and residence time of house dust. The concentrations of phthalates in dust on plastic surfaces were highest, followed by those on wooden and fabric surfaces. The dust-air partition coefficients (Kd) were calculated: the median values were 0.13, 0.02 and 5.62 m3/mg in the summer and 0.06, 0.018 and 0.76 m3/mg in the winter for DiBP, DnBP and DEHP, respectively. A comparison with Kd* at equilibrium state suggested that partition between air and dust deviated from equilibrium state in both seasons. The results also revealed that dust-phthalates in the summer may completely originate from source materials via direct transfer and external physical process; while dust-phthalates in the winter may come from both air (via partition) and source material (via direct transfer and external physical process). The influence of temperature on dust-phthalate concentrations differed by season, owing to different origin of dust-phthalates in two seasons. Polar organic components in dust, which are products of reactions between O3 and unsaturated hydrocarbons in dust, likely played an important role in fate and transport of phthalates. The presence of them resulted in the significant associations between dust-phthalate concentrations and air humidity in the summer. Moreover, the impacts of indoor PM2.5 concentrations, traffic conditions surrounding residence, household lifestyle and number of occupants were also observed. The mechanisms behind those observations were discussed.


Asunto(s)
Contaminación del Aire Interior , Ácidos Ftálicos , Contaminación del Aire Interior/análisis , China , Polvo/análisis , Exposición a Riesgos Ambientales/análisis , Humanos , Ácidos Ftálicos/análisis
16.
Chemosphere ; 286(Pt 2): 131807, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34371362

RESUMEN

An online field observation was conducted in Zibo, China from September 1, 2018 to February 28, 2019, covering autumn and winter. Within the investigation period, the mean mass concentrations of PM1, PM2.5, and PM10 were 49.3, 86.1, and 136.5 µg m-3, respectively. OA (organic aerosol) was the most dominant species in PM2.5 (39.7 %), followed by NO3- (26.3 %) and SO42- (17.0 %), indicating the importance of secondary species on PM2.5. Increase of particles were always accompanied increasing relative humidity (RH), slow wind, and increasing precursors, contributing the secondary transition. SO42- was more susceptible to RH, indicating the dominant role of heterogeneous processes in its secondary formation. As RH increased, its strengthening effect on SO42- increased as well. Photochemistry was the main contributor to the secondary formation of NO3-. The morning and evening rush hours determined the peak of absolute NO3- throughout the day. By classifying particles into three bins, we found that smaller particles were the biggest contributors (larger PM1/PM2.5) of slight pollution (35 < PM2.5<115 µg m-3). When severe haze occurred, PM2.5 contributed more than particles of other sizes (PM1 or PM10). Secondary species contributed more to particles within 2.5 µm but less to larger particles. PM1/PM2.5 was high from 9:00 to 15:00, indicating the strong effect of photochemistry on smaller particles. In comparison, larger particles favored more humid conditions. NO3- preferentially existed in larger particles because the hygroscopicity of preexisting species (SO42- and NO3-) promoted partitioning. SO42- appeared a stable diurnal variation, replying its stable contribution to particles of different sizes.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Aerosoles/análisis , Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , China , Monitoreo del Ambiente , Material Particulado/análisis , Estaciones del Año
17.
Chemosphere ; 286(Pt 3): 131963, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34426263

RESUMEN

BACKGROUND: Exposure to air pollution has been linked with altered immune function in adults, but little is known about its effects on early life. This study aimed to investigate the effects of exposure to air pollution during prenatal and postnatal windows on cell-mediated immune function in preschoolers. METHODS: Pre-school aged children (2.9 ± 0.5 y old, n = 391) were recruited from a mother-child cohort study in Wuhan, China. We used a spatial-temporal land use regression (LUR) model to estimate exposures of particulate matter with aerodynamic diameters ≤2.5 µm (PM2.5) and ≤10 µm (PM10), and nitrogen dioxide (NO2) during the specific trimesters of pregnancy and the first two postnatal years. We measured peripheral blood T lymphocyte subsets and plasma cytokines as indicators of cellular immune function. We used multiple informant models to examine the associations of prenatal and postnatal exposures to air pollution with cell-mediated immune function. RESULTS: Prenatal exposures to PM2.5, PM10, and NO2 during early pregnancy were negatively associated with %CD3+ and %CD3+CD8+ cells, and during late pregnancy were positively associated with %CD3+ cells. Postnatal exposures to these air pollutants during 1-y or 2-y childhood were positively associated with IL-4, IL-5, IL-6, and TNF-α. We also observed that the associations of prenatal or postnatal air pollution exposures with cellular immune responses varied by child's sex. CONCLUSIONS: Our results suggest that exposure to air pollution during different critical windows of early life may differentially alter cellular immune responses, and these effects appear to be sex-specific.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Contaminantes Atmosféricos/análisis , Contaminantes Atmosféricos/toxicidad , Contaminación del Aire/efectos adversos , Contaminación del Aire/análisis , Niño , Preescolar , Estudios de Cohortes , Exposición a Riesgos Ambientales/efectos adversos , Exposición a Riesgos Ambientales/análisis , Femenino , Humanos , Inmunidad Celular , Masculino , Dióxido de Nitrógeno/análisis , Dióxido de Nitrógeno/toxicidad , Material Particulado/análisis , Material Particulado/toxicidad , Embarazo
18.
Sci Total Environ ; 803: 150038, 2022 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-34525726

RESUMEN

Despite several national and local policies towards cleaner air in England, many schools in London breach the WHO-recommended concentrations of air pollutants such as NO2 and PM2.5. This is while, previous studies highlight significant adverse health effects of air pollutants on children's health. In this paper we adopted a Bayesian spatial hierarchical model to investigate factors that affect the odds of schools exceeding the WHO-recommended concentration of NO2 (i.e., 40 µg/m3 annual mean) in Greater London (UK). We considered a host of variables including schools' characteristics as well as their neighbourhoods' attributes from household, socioeconomic, transport-related, land use, built and natural environment characteristics perspectives. The results indicated that transport-related factors including the number of traffic lights and bus stops in the immediate vicinity of schools, and borough-level bus fuel consumption are determinant factors that increase the likelihood of non-compliance with the WHO guideline. In contrast, distance from roads, river transport, and underground stations, vehicle speed (an indicator of traffic congestion), the proportion of borough-level green space, and the area of green space at schools reduce the likelihood of exceeding the WHO recommended concentration of NO2. We repeated our analysis under a hypothetical scenario in which the recommended concentration of NO2 is 35 µg/m3 - instead of 40 µg/m3. Our results underscore the importance of adopting clean fuel technologies on buses, installing green barriers, and reducing motorised traffic around schools in reducing exposure to NO2 concentrations in proximity to schools. Also, our findings highlight the presence of environmental inequalities in the Greater London area. This study would be useful for local authority decision making with the aim of improving air quality for school-aged children in urban settings.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , Teorema de Bayes , Niño , Exposición a Riesgos Ambientales/análisis , Monitoreo del Ambiente , Humanos , Londres , Dióxido de Nitrógeno/análisis , Material Particulado/análisis , Instituciones Académicas , Organización Mundial de la Salud
19.
Sci Total Environ ; 803: 150011, 2022 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-34525772

RESUMEN

Emission regulations of the power and industry sectors have been identified as the major driver of PM2.5 mitigation over China during 2013-2017. In this study, we use ground-based observations of four air pollutants (CO, NO2, SO2, and PM2.5) to show that additional stringent emission policies on the industrial, transportation, and residential sectors during the new 3-year protection plan (2018-2020) have accelerated the improvement of China's air quality. Based on regional (North and South China) trends of annual mean measurements, significant reductions are observed for all four pollutants during 2017-2020. These decreasing trends are found to be >30% stronger than 2015-2017 for NO2, CO, and PM2.5. For CO and PM2.5, the acceleration is the strongest in winter and North China, when and where the residential clean-heating actions were implemented. While for NO2, the accelerations are pronounced regardless of region or season, reflecting nationwide measures to reduce NOx emissions from industrial and transportation activities. SO2 concentration reductions that were already substantial before 2017 are maintained but not accelerated, consistent with the dominance of end-of-pipe measures rather than a structural change of energy fuels. Our investigation highlights the value of multi-pollutant analysis to relate emission policies with air quality changes.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , Contaminación del Aire/prevención & control , China , Monitoreo del Ambiente , Material Particulado/análisis
20.
Chemosphere ; 286(Pt 1): 131566, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34293557

RESUMEN

It is well documented that fine particles matter (PM2.5), ozone (O3), and nitrogen dioxide (NO2) are associated with a range of adverse health outcomes. However, most epidemiologic studies have focused on understanding their additive effects, despite that individuals are exposed to multiple air pollutants simultaneously that are likely correlated with each other. Therefore, we applied a novel method - Bayesian Kernel machine regression (BKMR) and conducted a population-based cohort study to assess the individual and joint effect of air pollutant mixtures (PM2.5, O3, and NO2) on all-cause mortality among the Medicare population in 15 cities with 656 different ZIP codes in the southeastern US. The results suggest a strong association between pollutant mixture and all-cause mortality, mainly driven by PM2.5. The positive association of PM2.5 with mortality appears stronger at lower percentiles of other pollutants. An interquartile range change in PM2.5 concentration was associated with a significant increase in mortality of 1.7 (95% CI: 0.5, 2.9), 1.6 (95% CI: 0.4, 2.7) and 1.4 (95% CI: 0.1, 2.6) standard deviations (SD) when O3 and NO2 were set at the 25th, 50th, and 75th percentiles, respectively. BKMR analysis did not identify statistically significant interactions among PM2.5, O3, and NO2. However, since the small sub-population might weaken the study power, additional studies (in larger sample size and other regions in the US) are in need to reinforce the current finding.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Ozono , Anciano , Contaminantes Atmosféricos/análisis , Contaminantes Atmosféricos/toxicidad , Contaminación del Aire/análisis , Contaminación del Aire/estadística & datos numéricos , Teorema de Bayes , Estudios de Cohortes , Exposición a Riesgos Ambientales/análisis , Exposición a Riesgos Ambientales/estadística & datos numéricos , Humanos , Dióxido de Nitrógeno/análisis , Dióxido de Nitrógeno/toxicidad , Ozono/análisis , Ozono/toxicidad , Material Particulado/análisis , Material Particulado/toxicidad
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...