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1.
Environ Sci Technol ; 58(12): 5419-5429, 2024 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-38390902

RESUMEN

Traffic emissions are a dominant source of secondary organic aerosol (SOA) in urban environments. Though tailpipe exhaust has drawn extensive attention, the impact of non-tailpipe emissions on atmospheric SOA has not been well studied. Here, a closure study was performed combining urban tunnel experiments and dynamometer tests using an oxidation flow reactor in situ photo-oxidation. Results show a significant gap between field and laboratory research; the average SOA formation potential from real-world fleet is 639 ± 156 mg kg fuel-1, higher than the reconstructed result (188 mg kg fuel-1) based on dynamometer tests coupled with fleet composition inside the tunnel. Considering the minimal variation of SOA/CO in emission standards, we also reconstruct CO and find the critical role of high-emitting events in the real-world SOA burden. Different profiles of organic gases are detected inside the tunnel than tailpipe exhaust, such as more abundant C6-C9 aromatics, C11-C16 species, and benzothiazoles, denoting contributions from non-tailpipe emissions to SOA formation. Using these surrogate chemical compounds, we roughly estimate that high-emitting, evaporative emission, and asphalt-related and tire sublimation share 14, 20, and 10% of the SOA budget, respectively, partially explaining the gap between field and laboratory research. These experimental results highlight the importance of non-tailpipe emissions to atmospheric SOA.


Asunto(s)
Contaminantes Atmosféricos , Emisiones de Vehículos , Emisiones de Vehículos/análisis , Contaminantes Atmosféricos/análisis , Aerosoles/análisis , Oxidación-Reducción
2.
J Environ Manage ; 358: 120798, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38603851

RESUMEN

Adopting energy-saving and noise-reducing technologies in vehicle transportation has the potential to mitigate urban traffic pollution and promote sustainable urban mobility. However, a universal analytical framework for obtaining the combined energy savings and noise reduction patterns in vehicles is still lacking. This study addresses this gap by integrating a fundamental traffic noise model with a vehicle energy conservation equation. A theoretical framework was constructed that establishes the relationship between vehicle noise and energy consumption, with the theoretical origins of this framework explained. By summarizing a substantial body of classical literature, the typical model's properties are analyzed through the principle of optimality, and the noise interval for combined vehicle energy-saving and noise-reducing is determined. Subsequently, a rigorous vehicle experiment was conducted to validate the proposed framework's effectiveness, utilizing synchronized data on energy consumption and noise. The findings indicate that vehicles can achieve unconstrained combined energy-saving and noise-reducing in four driving states and conditional combined energy-saving and noise-reducing in five driving states. The Recall index demonstrates a verification rate exceeding 0.62 for the combined energy-saving and noise-reducing rules. This research provides valuable insights to support energy-saving and noise-reducing measures in urban traffic.


Asunto(s)
Ruido del Transporte , Transportes , Ruido del Transporte/prevención & control , Ruido/prevención & control , Modelos Teóricos , Ciudades , Vehículos a Motor
3.
Artículo en Inglés | MEDLINE | ID: mdl-38658361

RESUMEN

BACKGROUND: With the increasing occurrence of extreme temperature events due to climate change, the attention has been predominantly focused on the effects of heat waves and cold spells on morbidity and mortality. However, the influence of these temperature extremes on blood parameters has been overlooked. METHODS: We conducted a cohort study involving 2,752 adult blood donors in Tianjin, China, between January 18, 2013, and June 25, 2021. The generalized additive mixed model was used to investigate the effects and lagged effects of heat waves and cold spells on six blood parameters of blood donors, including alanine aminotransferase (ALT), white blood cell count (WBC), red blood cell count (RBC), hemoglobin (HB), hematocrit (HCT), and platelet count (PLT). Subgroup analyses were stratified by sex, age, and BMI. RESULTS: Heat waves and cold spells are associated with changes in blood parameters, particularly HB and PLT. Heat waves increased HB and PLT, while cold spells increased HB and decreased PLT. The effect of heat waves is greater than that of cold spells. The largest effect of heat waves on HB and PLT occurred at lag1 with 2.6 g/L (95% CI: 1.76 to 3.45) and lag7 with 9.71 × 10^9/L (95% CI: 6.26 to 13.17), respectively, while the largest effect of cold spells on HB and PLT occurred at lag0 with 1.02 g/L (95% CI: 0.71 to 1.33) and lag2 with -3.85 × 10^9/L (95% CI: -5.00 to -2.70), respectively. In subgroup analysis, the effect of cold spells on ALT was greater in the 40-49 age group. CONCLUSION: We indicated that heat waves and cold spells can impact hemoglobin and platelet counts in the human body. These findings provide evidence linking heat waves or cold spells to diseases and may reduce health risks caused by extreme temperature events.


Asunto(s)
Donantes de Sangre , Frío , Calor , Humanos , Masculino , Femenino , Donantes de Sangre/estadística & datos numéricos , China/epidemiología , Adulto , Persona de Mediana Edad , Estudios de Cohortes , Calor/efectos adversos , Adulto Joven , Hemoglobinas/análisis
4.
Artículo en Inglés | MEDLINE | ID: mdl-36631073

RESUMEN

BACKGROUND: Weather conditions are a possible contributing factor to age-related macular degeneration (AMD), a leading cause of irreversible loss of vision. The present study evaluated the joint effects of meteorological factors and fine particulate matter (PM2.5) on AMD. METHODS: Data was extracted from a national cross-sectional survey conducted across 10 provinces in rural China. A total of 36,081 participants aged 40 and older were recruited. AMD was diagnosed clinically by slit-lamp ophthalmoscopy, fundus photography, and spectral domain optical coherence tomography (OCT). Meteorological data were calculated by European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis and were matched to participants' home addresses by latitude and longitude. Participants' individual PM2.5 exposure concentrations were calculated by a satellite-based model at a 1-km resolution level. Multivariable-adjusted logistic regression models paired with interaction analysis were performed to investigate the joint effects of meteorological factors and PM2.5 on AMD. RESULTS: The prevalence of AMD in the study population was 2.6% (95% CI 2.42-2.76%). The average annual PM2.5 level during the study period was 63.1 ± 15.3 µg/m3. A significant positive association was detected between AMD and PM2.5 level, temperature (T), and relative humidity (RH), in both the independent and the combined effect models. For PM2.5, compared with the lowest quartile, the odds ratios (ORs) with 95% confidence intervals (CIs) across increasing quartiles were 0.828 (0.674,1.018), 1.105 (0.799,1.528), and 2.602 (1.516,4.468). Positive associations were observed between AMD and temperature, with ORs (95% CI) of 1.625 (1.059,2.494), 1.619 (1.026,2.553), and 3.276 (1.841,5.830), across increasing quartiles. In the interaction analysis, the estimated relative excess risk due to interaction (RERI) and the attributable proportion (AP) for combined atmospheric pressure and PM2.5 was 0.864 (0.586,1.141) and 1.180 (0.768,1.592), respectively, indicating a synergistic effect between PM2.5 and atmospheric pressure. CONCLUSIONS: This study is among the first to characterize the coordinated effects of meteorological factors and PM2.5 on AMD. The findings warrant further investigation to elucidate the relationship between ambient environment and AMD.


Asunto(s)
Contaminantes Atmosféricos , Degeneración Macular , Humanos , Adulto , Persona de Mediana Edad , Estudios Transversales , Contaminantes Atmosféricos/análisis , Material Particulado/análisis , China/epidemiología , Degeneración Macular/epidemiología , Degeneración Macular/etiología , Conceptos Meteorológicos
5.
J Appl Toxicol ; 41(5): 668-682, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33263192

RESUMEN

Fine particulate matter ≤2.5 µm (PM2.5 ) air pollution is regarded as one of the prominent risk factors that contributes to morbidity and mortality globally, among which cardiovascular disease (CVD) has been strongly associated with PM2.5 exposure and is a leading cause of death. Atherosclerosis (AS), the common pathological basis of many CVDs, is a progressive syndrome characterized by the accumulation of lipids and fibrous plaque in the arteries. Recent epidemiological and toxicological studies suggest that PM2.5 may also contribute to the development of AS, even at levels below the current air quality standards. In this paper, the complete pathological process of atherosclerotic plaque from occurrence to rupture leading to CVD was elaborated. Then, the growing epidemiological evidence linking PM2.5 to AS in humans was reviewed and summarized. Furthermore, the potential mechanisms of PM2.5 -mediated AS were discussed, including oxidative stress, inflammation, endothelial dysfunction, abnormal lipid metabolism, disturbance of the autonomic nervous system, and abnormal coagulation function. This paper aimed to provide a comprehensive view of the effect of PM2.5 on the occurrence and development of AS for better prevention and mitigation of adverse health impacts due to PM2.5 air pollution.


Asunto(s)
Contaminantes Atmosféricos/toxicidad , Contaminación del Aire/estadística & datos numéricos , Aterosclerosis/epidemiología , Material Particulado/toxicidad , Enfermedades Cardiovasculares/epidemiología , Sistema Cardiovascular/efectos de los fármacos , Humanos , Estrés Oxidativo , Factores de Riesgo
6.
Environ Res ; 188: 109752, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32516633

RESUMEN

Given the inconsistency of epidemiologic evidence for associations between maternal exposures to traffic-related metrics and adverse birth outcomes, this manuscript aims to provide clarity on this topic. Pooled meta-estimates were calculated using random-effects analyses. Subgroup analyses were conducted by study area, study design, and Newcastle-Ottawa quality score (NOS). Funnel plots and Egger's test were conducted to evaluate the publication bias, and Fail-safe Numbers (Fail-safe N) were measured to evaluate the robustness of models. From the initial 740 studies (last search, July 11, 2019), 26 studies were included in our analysis. The pooled odds ratio for the change in small for gestational age associated with per 500 m decrease in the distance to roads was 1.016 (95% CI: 1.004, 1.029). Subgroup analyses revealed significant positive associations between term low birth weight and traffic density in higher-quality literatures with higher NOS [1.060 (95% CI: 1.002, 1.121)], cohort studies [1.020 (95% CI: 1.006, 1.033)], and studies in North America [1.018 (95% CI: 1.005, 1.131)]. The buffer of traffic density made no difference in the effect size. Traffic density seemed to be a better indicator of traffic pollution than the distance to roads.


Asunto(s)
Nacimiento Prematuro , Emisiones de Vehículos , Benchmarking , Femenino , Humanos , Recién Nacido de Bajo Peso , Recién Nacido , Vehículos a Motor , América del Norte , Parto , Embarazo , Nacimiento Prematuro/epidemiología , Emisiones de Vehículos/toxicidad
7.
Ecotoxicol Environ Saf ; 192: 110308, 2020 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-32058168

RESUMEN

PM2.5 particles are regarded as prominent risk factors that contribute to the development of atherosclerosis. However, the composition of PM2.5 is rather complicated. This study aimed to provide a model particle that simulates the behavior of actual PM2.5, for subsequent use in exploring mechanisms and major complications arising from PM2.5. To establish model particles of PM2.5, a series of monodisperse SiO2 microspheres with different average grain diameters were mixed according to the size distribution of actual PM2.5. The organic carbon (OC) was removed from PM2.5 and coated onto the SiO2 model particle, to formulate simulant PM2.5. Results showed that the size distribution of the model particle was highly approximate to that of the PM2.5 core. The polycyclic aromatic hydrocarbon (PAHs) composition profile of the simulated PM2.5 were approximate to PM2.5, and loading efficiency was approximately 80%-120%. Furthermore, compared to the control, SiO2-only model particle had negligible cytotoxicity on cell viability and oxidative stress of HUVECs, and marginal effect on the lipid metabolism and atherosclerotic plaque formation in ApoE-/- mice. In contrast, simulated PM2.5 exhibited similar cytotoxic and detrimental effects on lipid metabolism and atherosclerotic plaque formation with actual PM2.5. Traffic-related PM2.5 had negative effects on endothelial function and led to the formation of atherosclerosis via oxidative stress. The simulated PM2.5 simulated the outcomes of actual PM2.5 exposure. Here, we show that SiO2 particle model cores coated with OC could significantly assist in the evaluation of the effects of specific organic compositions bound on PM2.5, specifically in the context of environmental health and safety.


Asunto(s)
Contaminantes Atmosféricos/toxicidad , Apolipoproteínas E/deficiencia , Material Particulado/química , Placa Aterosclerótica/inducido químicamente , Dióxido de Silicio/química , Contaminantes Atmosféricos/química , Animales , Células Endoteliales de la Vena Umbilical Humana/efectos de los fármacos , Humanos , Metabolismo de los Lípidos/efectos de los fármacos , Ratones , Estrés Oxidativo/efectos de los fármacos , Tamaño de la Partícula , Material Particulado/toxicidad , Hidrocarburos Policíclicos Aromáticos/química , Hidrocarburos Policíclicos Aromáticos/toxicidad , Dióxido de Silicio/toxicidad , Emisiones de Vehículos/toxicidad
8.
J Environ Manage ; 250: 109399, 2019 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-31479935

RESUMEN

The 350 °C and 700 °C corn straw biochars were used to produce solid fuel briquettes. NovoGro (NG), an industrial by-product, were selected as a binder in the briquetting process. The ratios of the raw material to NG was assumed as 100:1 and 50:1 (denoted as 350NB1, 350NB2, 700NB1 and 700NB2, respectively). The physicochemical and morphological properties, combustion characteristics and gas emissions of the four briquettes were investigated. The results revealed that the biochars and the NG binder performed a good combination. The low temperature biochar briquettes, especially 350NB2, had excellent combustion characteristics, including low H/C and O/C ratios (0.17 and 0.82), low gas emissions (104.06 mg/m3 of CO, 157.25 mg/m3 of NOx and 18.92 mg/m3 of SO2), optimal resistance to mechanical shock (~90%) and high calorific values (21.48 MJ/kg). Thus, NG is a good binder for the briquetting of biochar. The low temperature biochar was a good feedstock for solid fuel production in the improvement of the combustion and emission quality.


Asunto(s)
Carbón Orgánico , Zea mays , Temperatura
9.
Ecotoxicol Environ Saf ; 148: 285-292, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29080526

RESUMEN

Two kinds of biochars, one derived from corn straw (CBC) and one from pig manure (PBC), were used as the carriers of a bacterium (B38) to adsorb heavy metals in solution. CBC exhibited high affinity to Hg(II), while PBC showed large adsorption capacity of Pb(II). After loading with B38, the sorption capacity of the co-sorbents were enhanced for Pb(II), but weakened for Hg(II). In a binary system, the overall adsorption capacity to Hg-Pb (CBC+B38, 136.7mg/g; PBC+B38, 181.3mg/g) on co-sorbents was equal to the sum of the single-component values for Hg(II) and Pb(II). Electrostatic interactions and precipitation are the major mechanisms in the adsorption of Hg(II). In contrast, cation-π interactions and precipitation were involved in the sorption process of Pb(II). Moreover, the sorption sites of Hg(II) and Pb(II) partially overlapped on the biochar surface, but were different on co-sorbents. Hence, the co-sorbents have an advantage over the biochar alone in the removal of heavy metal mixtures.


Asunto(s)
Bacillus subtilis/metabolismo , Carbón Orgánico/química , Metales Pesados/metabolismo , Purificación del Agua/métodos , Adsorción , Animales , Plomo/análisis , Plomo/metabolismo , Estiércol , Mercurio/análisis , Mercurio/metabolismo , Metales Pesados/análisis , Porcinos , Zea mays
10.
Environ Sci Pollut Res Int ; 31(15): 22243-22257, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38411910

RESUMEN

Indicators for evaluating road traffic energy consumption are critical parameters in the research field of road traffic energy consumption. Improving the applicability of energy consumption indicators can promote the development of green transportation in cities. However, there is currently a lack of systematic analysis of energy consumption indicators in research. Therefore, based on a comprehensive analysis of relevant literature, this study divides the indicators for evaluating road traffic energy consumption into two categories: macro (aimed at traffic systems or traffic flow) and micro (aimed at vehicles). These indicators are subdivided into four categories according to their application characteristics, including general, specific, predictive, and comprehensive. This paper provides a complete summary of various evaluation indicators, including their scope of application, advantages, and limitations, and highlights the relationships between them. Additionally, recommendations are made for the future development of evaluation indicators. Research has found that micro-level general indicators serve as the fundamental components of the mathematical structure for almost all other indicators. Specialized indicators primarily evaluate energy consumption in different driving states of vehicles. Predictive indicators are mainly used for assessing transportation energy consumption in simulation conditions. Comprehensive indicators are mainly applied to evaluate the life cycle energy consumption of vehicles or transportation systems. In future research, the performance of indicators can be improved through the design of standardized indicators, enhancement of energy consumption prediction accuracy, and integration of traffic flow parameters. The research contributes to upgrading energy-saving technologies in road transportation and developing sustainable urban transportation systems.


Asunto(s)
Monitoreo del Ambiente , Transportes , Monitoreo del Ambiente/métodos , Ciudades , Predicción , Accidentes de Tránsito
11.
Sci Total Environ ; 941: 173390, 2024 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-38815831

RESUMEN

Vehicle exhaust is the primary source of polycyclic aromatic compounds (PACs). Real road tests using a portable vehicle measurement system on light-duty gasoline vehicles and light-duty diesel trucks were conducted to investigate gas- and particle-phase polycyclic aromatic hydrocarbons (PAHs), nitro-PAHs (NPAHs), and oxy-PAHs (OPAHs) in vehicle exhaust with different emission standards, fuel types, and altitudes. The results showed that with the tightening of emission standards, the overall emission factors (EFs) of PACs decreased. Compared with China V diesel vehicles, the emissions of PAHs, OPAHs, and NPAHs from China VI diesel vehicles were 75.1 %, 84.4 %, and 61.2 % lower, respectively. With a ∼100 m increase in altitude, the EFs of PAHs, OPAHs, and NPAHs of diesel vehicles increased 1.88, 1.92, and 1.59 times due to incomplete combustion. In addition, the EFs of PAHs and OPAHs in gasoline vehicles were lower than those in diesel vehicles. In contrast, the proportion of PAHs with highly toxic components, such as dibenzo[a,h]anthracene (DahA) and benzo[a]pyrene (BaP), and the EFs of gas-phase NPAHs in gasoline vehicles were higher than those in diesel vehicles. Furthermore, the emissions of 1,8-DNP from diesel vehicles cannot be disregarded. 1,8-DNP was the main gas-phase NPAHs emitted by China VI and China V diesel vehicles, accounting for 49.3 % and 26.0 %, respectively. Moreover, gas-phase PACs contributed more to the EFs than particle-phase PACs, whereas particle-phase PACs have greater toxic effects. Although the EFs of PAHs are more than 100 times those of NPAHs, the toxic equivalent concentrations (TEQBaP) of PAHs in diesel and gasoline vehicles were approximately 6.5 times and 35 times those of NPAHs. The spatial distribution characteristics revealed that PACs emissions were mainly concentrated in urban areas and highways, and the differences in the toxicity of PACs emissions between different cities depended on the proportion of diesel vehicles. The average TEQBaP of PAHs and NPAHs in Haidong, Haibei, Huangnan, Hainan, Guoluo, and Yushu was 8.42 µg/m3 and 0.36 µg/m3, respectively, while those of Xining and Haixi were 0.24-0.29 µg/m3 and 0.09-0.108 µg/m3 higher, respectively. This study provides a comprehensive understanding of the emission characteristics, health risks, and spatial distribution of PACs from diesel and gasoline vehicle PACs in urban areas.


Asunto(s)
Contaminantes Atmosféricos , Monitoreo del Ambiente , Gasolina , Hidrocarburos Policíclicos Aromáticos , Emisiones de Vehículos , Emisiones de Vehículos/análisis , Hidrocarburos Policíclicos Aromáticos/análisis , Contaminantes Atmosféricos/análisis , Gasolina/análisis , China , Medición de Riesgo , Humanos
12.
Environ Pollut ; 357: 124163, 2024 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-38782165

RESUMEN

By 2020, China has implemented the use of 10% ethanol-blended-gasoline (E10), which is expected to notably impact vehicular volatile organic compounds (VOCs) emissions. The adoption of E10 reduced certain emissions but raised concerns with about more reactive oxygenated volatile organic compounds (OVOCs). This study aimed to evaluate the impact of E10 on the total VOCs emissions from both exhaust and evaporative emissions by conducting tests on the CHINA V (or CHINA VI) light-duty gasoline vehicles (LDGVs) using 0% ethanol blended gasoline (E0) and E10. E10 reduces VOCs emissions in the exhaust, and reduces the ozone and secondary organic aerosol generation potential of VOCs in the exhaust, as evidenced by the lower emission factors (EFs), ozone formation potentials (OFPs) and secondary organic aerosol formation potential (SOAFPs) in the CHINA V LDGVs. Evaporative emissions showed differences in emitted VOCs, with lower EFs, OFPs and SOAFPs for the CHINA V LDGVs fueled with E10. The CHINA VI LDGVs also exhibited reduced EFs, OFPs and SOAFPs. These findings highlight the environmental benefits of E10 in the CHINA VI-compliant LDGVs; however, the effectiveness of the earlier CHINA V standard vehicles requires further evaluation.

13.
Toxics ; 12(4)2024 Apr 19.
Artículo en Inglés | MEDLINE | ID: mdl-38668526

RESUMEN

Limited knowledge exists regarding gasoline and diesel exhaust effects on lipid metabolism. This study collected gasoline and diesel exhaust under actual driving conditions and conducted inhalation exposure on male young and middle-aged C57BL/6J mice for 4 h/day for 5 days to simulate commuting exposure intensity. Additionally, PM2.5 from actual roadways, representing gasoline and diesel vehicles, was generated for exposure to human umbilical vein endothelial cells (HUVECs) and normal liver cells (LO2) for 24, 48, and 72 h to further investigate exhaust particle toxicity. Results showed that diesel exhaust reduced total cholesterol and low-density lipoprotein cholesterol levels in young mice, indicating disrupted lipid metabolism. Aspartate aminotransferase and alanine aminotransferase levels increased by 53.7% and 21.7%, respectively, suggesting potential liver injury. Diesel exhaust exposure decreased superoxide dismutase and increased glutathione peroxidase levels. Cell viability decreased, and reactive oxygen species levels increased in HUVECs and LO2 following exposure to exhaust particles, with dose- and time-dependent effects. Diesel exhaust particles exhibited more severe inhibition of cell proliferation and oxidative damage compared to gasoline exhaust particles. These findings provide novel evidence of the risk of disrupted lipid metabolism due to gasoline and diesel exhaust, emphasizing the toxicity of diesel exhaust.

14.
Huan Jing Ke Xue ; 45(3): 1293-1303, 2024 Mar 08.
Artículo en Zh | MEDLINE | ID: mdl-38471846

RESUMEN

Electrification of bus fleets is an effective approach to reducing transportation-related pollution and carbon emissions. Evaluating the impact of electrification on existing bus fleets can provide valuable insights for promoting full electrification of public transportation in large cities. Utilizing the fuel life cycle method, we analyzed the CO2 and pollutant emissions of Zhengzhou's bus fleet before and after electrification and evaluated emissions under different electrification scenarios. Our results indicated that after electrification, the fuel life cycle CO2 and PM2.5 emissions increased by 32.6% and 42.6%, respectively, whereas CO, NOx, and VOC emissions decreased by 28%, 34%, and 25%, respectively. Optimizing the power generation structure is a critical factor in reducing CO2 and PM2.5 emissions during the electrification process. The best scenario for comprehensive electrification and power generation structure optimization could result in a 38.7% reduction in CO2, as well as reductions of 80.1% in CO, 84.4% in NOx, 92.2% in VOC, and 30.2% in PM2.5. Prioritizing electrification on long-distance routes is recommended during the replacement process. Additionally, replacing plug-in hybrid natural gas vehicles with pure electric vehicles has both advantages and disadvantages in terms of emission reduction. Achieving pollution reduction and carbon synergies requires advancing fleet replacement and power structure adjustments simultaneously.

15.
J Hazard Mater ; 465: 133350, 2024 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-38154178

RESUMEN

Brake wear particles (BWPs) are considered one of the most significant non-exhaust particle emission sources from motor vehicles. Previous studies have primarily focused on BWPs from conventional fuel vehicles (CFVs), with limited research available on BWPs from new energy vehicles (NEVs). We developed an independent BWP emission testing system applicable to NEVs and conducted BWP emission tests on representative NEVs and CFVs under various testing cycles via a chassis dynamometer. The BWP emission characteristics of the NEVs equipped with regenerative braking system significantly differed from those of gasoline vehicles. For transient emission characteristics, gasoline vehicles exhibited higher peak concentrations during brake events than brake drag events, while those with regenerative braking exhibited the opposite feature. Under continuous braking, the concentration of ultrafine particles emitted by NEVs was reduced by more than 3 orders of magnitude compared to gasoline vehicles. In terms of single-particle morphology, BWPs could be mainly divided into three categories: carbonaceous particles, iron-rich particles, and mixed metal particles. We obtained realistic emission characteristics of BWPs from NEVs, which could provide data support and a scientific basis for the formulation of relevant emission standards and control measures in the future.

16.
Sci Total Environ ; 918: 170671, 2024 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-38316305

RESUMEN

This study addresses the literature gap concerning accurately identifying vehicle carbon emission characteristics in high-altitude areas. Utilizing a portable emission measurement system (PEMS) for real-world testing, we quantified the influence of altitude on carbon emissions from light-duty gasoline (LDGV) and diesel vehicles (LDDV). The Random Forest (RF) algorithm was employed to analyze the complex nonlinear relationships between altitude, meteorological conditions, driving patterns, and carbon dioxide (CO2) emissions, enabling predictions across different altitudes. The results showed that CO2 emissions progressively increase with elevation. Furthermore, as altitude increases, combustion efficiency declines, and the overall impact of driving conditions on emission rates diminishes. Altitude and meteorological factors significantly contributed to CO2 emissions, whereas driving conditions and road grades contributed less. Compared with the COPERT model, the RF model demonstrates strong accuracy in predicting carbon emissions at different altitudes. Specifically, the CO2 emission rate nearly triples as altitude increases from 2.0 km to 4.5 km. This research bridges a critical gap in the understanding carbon emissions from high-altitude vehicles, offering insights into policy development for emission reduction strategies in such regions. Future studies should integrate diverse testing methodologies and comprehensive surveys to validate and extend the findings.

17.
Sci Total Environ ; 922: 171128, 2024 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-38395168

RESUMEN

This study comprehensively investigated the impact of dust storms (DSs) on downstream cities, by selecting representative DS events. In this paper, we discussed the characteristics of meteorological conditions, air pollutants, PM2.5 components, and their influence on sulfate formation mechanisms. During DSs, strong winds, reaching speeds of up to 10 m/s, led to significant increases in PM10 and PM2.5, with maximum concentrations of 2684.5 and 429 µg/m3, respectively. Primary gaseous pollutants experienced substantial reductions, with decline rates of 48.1, 34.9, 36.8, and 9.0 % for SO2, NO2, NH3, and CO, respectively. Despite a notable increase in PM2.5 concentrations, only 7.6 % of the total mass of PM2.5 was attributed to ionic and carbonaceous components, a much lower value than observed before the DSs (77.3 %). Concentrations of Fe, Ti, and Mn exhibited increases by factors of 6.5-14.1, 10.4-17.0, and 1.6-4.7, respectively. In contrast to the significant decrease of >76.2 % in nitrogen oxidation ratio (NOR), sulfur oxidation ratio (SOR) remained at a relatively high level, displaying a strong positive correlation with high concentrations of Fe, Mn, and Ti. Quantitative analysis revealed an average increase of 0.187 and 0.045 µg/m3 in sulfate from natural sources and heterogeneous generation, respectively. The heterogeneous reaction on mineral dust was closely linked to atmospheric humidity, radiation intensity, the form of metal existence, and concentrations of it. High concentrations of titanium dioxide and iron­manganese oxides in mineral dust promoted heterogeneous oxidation of SO2 through photocatalysis during the daytime and metal ion catalysis during the nighttime. This study establishes that the metal components in mineral dust promote heterogeneous sulfate formation, quantifies the yield of sulfate generated as a result, and provides possible mechanisms for heterogeneous sulfate formation.

18.
Waste Manag ; 175: 225-234, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38218093

RESUMEN

The arbitrary disposal of used brake pads from motor vehicles has resulted in severe heavy metal pollution and resource wastage, highlighting the urgent need to explore the significant untapped potential of these discarded materials. In this study, The in-situ growth of highly dispersed Fe2O3 nanocrystals was achieved by simple oxidation annealing of brake pad debris(BPD). Interestingly, Cu remained unoxidized and acted as a "valence state transformation bridge of Fe2O3" to construct the "triple Fe-C-Cu sites". The Fenton degradation experiment of pollutants was conducted under constant temperature conditions at 40 °C, a stirring rate of 1300 rpm, a pH value of 3, a catalyst dosage of 0.5 g/L, pollutant dosage ranging from 50 to 400 mg/L, and H2O2 dosage of 0.25 g/L. Experimental results showed that BPD treated at 300 °C for 2 h exhibited optimal Fenton-like oxidation activity, achieving rapid degradation of over 90 % of refractory antibiotics, such as tetracycline and ciprofloxacin, in organic wastewater within 10 min. This remarkable performance was mainly attributed to the synergistic effect of "Fe-C-Cu triple sites", where the electron-donating role of C in the Fe-C and Cu-C interfaces facilitated the conversion of the Fe(III) to Fe(II) and Cu(II) to Cu(I). In addition, the ability of Cu2+ to accept electrons at the Fe-Cu interface promoted the transition from Fe (II) to Fe (III). This "balance of electron gain and loss" accelerated the interfacial electron transfer and the recycle of dual Fenton sites, Fe(II)/Fe(III) and Cu(I)/Cu(II), to generate more ·OH from H2O2. Therefore, this strategy of functionalizing BPD as Fenton-like catalysts without the addition of external Fe provides intriguing prospects for understanding the construction of Fe-based Fenton catalysts and resource utilization of Fe-containing solid waste materials.


Asunto(s)
Contaminantes Ambientales , Hierro , Hierro/química , Peróxido de Hidrógeno/química , Automóviles , Oxidación-Reducción , Compuestos Férricos/química , Compuestos Ferrosos , Catálisis
19.
Environ Pollut ; 332: 121988, 2023 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-37301458

RESUMEN

To study air pollution from aircraft activity at airport and its risks to human health, we conducted an experiment near Tianjin Binhai International Airport from November 11 to November 24, 2017. The characteristics, source apportionment, and health risk of inorganic elements in particles were determined in the airport environment. The mean mass concentrations of inorganic elements in PM10 and PM2.5 were 17.1 and 5.0 µg/m3, accounting for 19.0% of PM10 mass and 12.3% of PM2.5 mass, respectively. Inorganic elements, including arsenic, chromium, lead, zinc, sulphur, cadmium, potassium, sodium, and cobalt, were mainly concentrated in fine particulate matter. The particle number concentration within the 60-170 nm particle size range was significantly higher under polluted than non-polluted conditions. A principal component analysis revealed important contributions of Cr, Fe, K, Mn, Na, Pb, S, and Zn originating from airport activities, including aircraft exhaust, braking, tire wear, ground service equipment, and airport vehicles. Based on analyses of the non-carcinogenic and carcinogenic risks of heavy metal elements in PM10 and PM2.5, there were notable human health impacts, emphasising the importance of relevant research.


Asunto(s)
Contaminantes Atmosféricos , Humanos , Contaminantes Atmosféricos/análisis , Monitoreo del Ambiente , Aeropuertos , Material Particulado/análisis , Emisiones de Vehículos/análisis
20.
Asian J Psychiatr ; 83: 103507, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36796125

RESUMEN

BACKGROUND: Patients with Severe Mental Disorders (SMD) have a higher risk of violent behaviour than the general population. The study aimed to investigate the predictive factors for the occurrence of violent behaviour in community SMD patients. METHODS: The cases and follow-up data were collected from SMD patient Information Management system in Jiangning District, Jiangsu Province. The incidence of violent behaviours was described and analyzed. Logistic regression model was used to examine the influencing factors for violent behaviours in those patients. RESULTS: Among 5277 community patients with SMD in Jiangning District, 42.4% (2236/5277) had violent behaviours. The stepwise logistic regression analysis revealed that the disease-related factors (including disease type, disease course, times of hospitalization, medication adherence, past violent behaviours), the demographic factors (age, male sex, educational level, economic and social living status), and the policy-related factors (like free treatment, annual physical check, disability certificate, family physician services, and community interviews) were significantly related to the violent behaviours in community SMD patients. After gender stratification, we found that male patients with unmarried status and with a longer course of disease were more likely to violent. However, we found that female patients with lower economic status and educational experience were more likely to violent. CONCLUSION: Our results suggest that community SMD patients had a high incidence of violent behaviour. The findings may provide valuable information for policymakers and mental health professionals worldwide taking a number of measures to reduce the incidence of violence in community SMD patients and to better maintain social security.


Asunto(s)
Trastornos Mentales , Humanos , Masculino , Femenino , Estudios Retrospectivos , Trastornos Mentales/epidemiología , Agresión , Violencia , Factores de Riesgo
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