Implementation Of Emission Control Measures Research Articles

Joint effects of traffic-related air pollution and hypertensive disorders of pregnancy on maternal postpartum depressive and anxiety symptoms.

Ambient air pollution has been linked to postpartum depression. However, few studies have investigated the effects of traffic-related NOx on postpartum depression and whether any pregnancy-related factors might increase susceptibility. To evaluate the association between traffic-related NOx and postpartum depressive and anxiety symptoms, and effect modification by pregnancy-related hypertension. This study included 453 predominantly low-income Hispanic/Latina women in the MADRES cohort. Daily traffic-related NOx concentrations by road class were estimated using the California LINE-source dispersion model (CALINE4) at participants' residential locations and averaged across pregnancy. Postpartum depressive and anxiety symptoms were evaluated by a validated questionnaire (Postpartum Distress Measure, PDM) at 1, 3, 6 and 12 months postpartum. Multivariate linear regressions were performed to estimate the associations at each timepoint. Interaction terms were added to the linear models to assess effect modification by hypertensive disorders of pregnancy (HDPs). Repeated measurement analyses were conducted by using mixed effect models. We found prenatal traffic-related NOx was associated with increased PDM scores. Specifically, mothers exposed to an IQR (0.22 ppb) increase in NOx from major roads had 3.78% (95% CI: 0.53-7.14%) and 5.27% (95% CI: 0.33-10.45%) significantly higher 3-month and 12-month PDM scores, respectively. Similarly, in repeated measurement analyses, higher NOx from major roads was associated with 3.06% (95% CI: 0.43-5.76%) significantly higher PDM scores across the first year postpartum. Effect modification by HDPs was observed: higher freeway/highway and total NOx among mothers with HDPs were associated with significantly higher PDM scores at 12 months postpartum compared to those without HDPs. This study shows that prenatal traffic-related air pollution was associated with postpartum depressive and anxiety symptoms. The study also found novel evidence of greater susceptibility among women with HDPs, which advances the understanding of the relationships between air pollution, maternal cardiometabolic health during pregnancy and postpartum mental health. Our study has potential implications for clinical intervention to mitigate the effects of traffic-related pollution on postpartum mental health disorders. The findings can also offer valuable insights into urban planning strategies concerning the implementation of emission control measures and the creation of green spaces.

Designing regional joint prevention and control schemes of PM2.5 based on source apportionment of chemical transport model: A case study of a heavy pollution episode

Fine particular matter (PM2.5) pollution still occurs frequently in China. Despite recognizing the importance of regional joint prevention and control (RJPC) for mitigating haze pollution, there is still a limited understanding of scheme design and effectiveness. In this study, with the Fenhe Plain in China serving as the case, the Integrated Source Apportionment Method (ISAM), incorporated into the Community Multiscale Air Quality Modeling System (CMAQ), was used to quantitively identify PM2.5 sources during a typical heavy pollution episode from Jan. 20th to 25th, 2021. Informed by source apportionment, we designed and assessed multiple RJPC scenarios for eliminating heavy pollution, yielding recommended RJPC schemes. Source apportionment results revealed a substantial increase in the contribution percentage of regions within a 350-km radius during the pollution episode compared to the non-polluted period. Sulfate was predominantly contributed from long-distance transport, whereas nitrate was chiefly contributed from closer regions. Ammonium exhibited higher local contributions than nitrate from the Fenhe Plain. Moreover, Taiyuan and Linfen were identified as PM2.5 exporters, whereas Sanmenxia, Jinzhong, and Luliang served as PM2.5 importers, and Yuncheng acted as a comprehensive city. The proposed specific RJPC schemes aimed at eliminating heavy pollution for the Fenhe Plain emphasized the importance of controlling emissions of particulate matter, ammonia, nitrogen oxides, and volatile organic compounds in areas within an approximate 350-km radius outside the Fenhe Plain, in addition to strengthening the local emission control. Nevertheless, only through the comprehensive and in-depth implementation of emission control measures across a larger area can PM2.5 compliance be achieved.

Estimation of winter time NOx emissions in Hefei, a typical inland city of China, using mobile MAX-DOAS observations

In this paper, we present a quantitative determination of the NOx emission in Hefei using mobile Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) measurements. The measurements were carried out during winter time from December 2016 to February 2017. The measured NO2 vertical column densities (VCDs) show a strong spatial gradient with higher values within the city center, indicating the majority of NOx emission sources are located at the city center. A significant “holiday effect” was found by comparing measurements taken during weekdays and weekend. The weekend reduction is more significant in the suburban (∼28%) compared to the city center (∼13%). Mobile measurements of NO2 vertical column densities (VCDs) were analyzed together with meteorological data to determine the NOx emission by applying the loop-integral method. Detailed error analysis of the NOx emission shows the variation of wind field and large measurement gap dominated the total error of NOx emission calculation. The result shows the NOx emission in Hefei during winter time varies in a wide range from 10 × 1024 to 40 × 1024molecs−1 with an average of 18.44 × 1024molecs−1. Our estimation is about 43% lower than the number reported in the previous emission inventory in 2012. The reduction of NOx emission reflects the successful implementation of emission control measures in recent years. Our result also shows about 73% of the total NOx in the city were transported from outside of the city during winter. The impacts of transported NOx are especially large when air masses originated from heavily polluted regions, i.e. North China Plain and Yangtze River Delta. The result presented provides a better understanding of the impacts of local emissions and transportation of pollutants on the local air quality of Hefei.

The blue skies in Beijing during APEC 2014: A quantitative assessment of emission control efficiency and meteorological influence

Most previous studies attributed the alleviation of aerosol pollution to either emission control measures or favorable meteorological conditions. However, our understanding of their quantitative contribution is far from complete. In this study, based on model simulation using the CMA (China Meteorological Administration) Unified Atmospheric Chemistry Environment for aerosols (CUACE/Aero), in combination with simultaneous ground-based hourly PM2.5 observations, we aim to quantify the relative contributions of the emission control measures and meteorology to the blue-skies seen in Beijing during the Asia-Pacific Economic Cooperation (APEC) summit held in November of 2014. A series of model simulations have been performed over Beijing-Tianjin-Hebei (BTH) region by implementing nine different emission control schemes. To investigate the relative contributions of the emission control measures and meteorology, the study period has been divided into five episodes. Overall, the CUACE/Aero model can reasonably well reproduce the temporal and spatial evolution of PM2.5 during APEC 2014, although the model performance varies by different time periods and regions of interest. Model results show the emission control measures on average reduced the PM2.5 concentration by 41.3% in urban areas of Beijing and 39.7% in Huairou district, respectively, indicating emission control plays a significant role for the blue skies observed. Among all the emission control measures under investigation, local emission control in Beijing contributed the largest to the reduction of PM2.5 concentrations with a reduction of 35.5% in urban area of Beijing and 34.8% in Huairou, in contrast with the vehicle emission control in Hebei that contributed the least with a reduction of less than 1%. The emission control efficiency in five episodes has been assessed quantitatively, which falls in the range of 36.2%–41.2% in urban area of Beijing and 34.9%–40.7% in Huairou, indicative of no significant episode and geographic dependence in the emission control efficiency. The emission control measures and meteorology, however, alternated to dominate the absolute reduction of PM2.5 concentrations. When the weather conditions are unfavorable, emission control measures outperformed meteorology with a reduction of 55.3–59.4 μg/m3 in urban area of Beijing and 32.5–33 μg/m3 in Huairou. Conversely, when the northwesterly winds prevailed, meteorology tends to outweigh the role of emission control in accounting for the drop of PM2.5. The atmospheric dilution conditions are determined through the model calculation of the mass inflow of PM2.5 per unit volume near the surface. Our findings have significant implications for effective planning and implementation of emission control measures.

Modelling study of boundary-layer ozone over northern China - Part II: Responses to emission reductions during the Beijing Olympics

The implementation of emission reduction measures during the Olympics provided a valuable opportunity to study regional photochemical pollution over northern China. In this study, the fifth-generation Pennsylvania State University/National Centre for Atmospheric Research Mesoscale Model and Community Multiscale Air Quality model system was applied to conduct two sets of modelling analyses of the period from July 20 to September 20, 2008, to illustrate the influences of emission reduction measures on regional photochemical pollution over northern China during the Beijing Olympics. The results indicated that the implementation of emission control measures decreased the concentrations of ozone (O3) precursors, namely nitrogen oxide (NOx) and volatile organic compounds (VOCs), throughout the boundary layer. The concentrations of these compounds were reduced by 45% in the central urban area of Beijing at the ground level. Although the average O3 concentration in the central urban area increased by more than 8ppbv, the total oxidant concentration decreased significantly by more than 5ppbv. Greater O3 concentrations mainly occurred during periods with weak photochemical reactions. During periods of strong photochemical production, the O3 concentration decreased significantly due to a weakening vertical circulation between the lower and upper boundary layer. Consequently, the number of days when the O3 concentration exceeded 100ppbv decreased by 25% in Beijing. The emission control measures altered the sensitivity of the regional O3 production. The coordinated control region of NOx and VOCs expanded, and the control region of VOCs decreased in size. The reduction of non-point-source emissions, such as fugitive VOCs and vehicles, was more useful for controlling regional photochemical pollution over northern China.

Life Cycle assessment for the implementation of emission control measures for the freight traffic with heavy duty vehicles in germany

This Life Cycle Interpretation Analysis describes the third phase of the Life Cycle Assessment (LCA) for the implementation of emission control measures for the freight traffic with heavy duty vehicles (HDV) in Germany. It is based on the December 1999 edition of ISO/DIS 14043. Special emphasis was placed on the determination of the ecological effectiveness and the ecological category indicator effectiveness for each emission control scenario to compare the overall ecological-economical effect of the emission control measures investigated. Following these steps the main factors influencing the Life Cycle Impact Assessment (LCIA) results were identified. As a result of these analyses only a small number of influencing factors were detected having an influence on the LCIA result of more than 93%. Another result was the determination of the main influence factors from the different phases of the Product Life Cycle (PLC) of the selective catalytic reduction (SCR) system on the total weighting results of the bulk environmental load. The influence of the Life Cycle Inventory Analysis (LCI) results on the final Category Indicator Effectiveness result was analysed. The contribution of the different phases of the PLC of SCR systems on the total result of the LCI with regard to the bulk environmental load was determined. A completeness and sensitivity check was carried out. The results of the study enable plausible conclusions and recommendations, the absolutely essential one being the introduction of an consumption-optimized Diesel engine with SCR systems by the reference year 2005 for ecological and economical reasons.

Life cycle assessment for the implementation of emission control measures for the freight traffic with heavy duty vehicles in Germany

Life cycle assessment for the implementation of emission control measures for the freight traffic with heavy duty vehicles in Germany

Life cycle assessment for the implementation of emission control measures for the freight traffic with heavy duty vehicles in Germany

Life cycle assessment for the implementation of emission control measures for the freight traffic with heavy duty vehicles in Germany