Urban Area Of Shanghai Research Articles

Analysis of the spatial distribution of Aedes albopictus in an urban area of Shanghai, China

BackgroundAedes albopictus is a vector of major arboviral diseases and a primary pest in tropical and temperate regions of China. In most cities of China, the current monitoring system for the spread of Ae. albopictus is based on the subdistrict scale and does not consider spatial distribution for analysis of species density. Thus, the system is not sufficiently accurate for epidemic investigations, especially in large cities.MethodsThis study used an improved surveillance program, with the mosquito oviposition trap (MOT) method, integrating the actual monitoring locations to investigate the temporal and spatial distribution of Ae. albopictus abundance in an urban area of Shanghai, China from 2018 to 2019. A total of 133 monitoring units were selected for surveillance of Ae. albopictus density in the study area, which was composed of 14 subdistricts. The vector abundance and spatial structure of Ae. albopictus were predicted using a binomial areal kriging model based on eight MOTs in each unit. Results were compared to the light trap (LT) method of the traditional monitoring scheme.ResultsA total of 8,192 MOTs were placed in the study area in 2018, and 7917 (96.6%) were retrieved, with a positive rate of 6.45%. In 2019, 22,715 (97.0%) of 23,408 MOTs were recovered, with a positive rate of 5.44%. Using the LT method, 273 (93.5%) and 312 (94.5%) adult female Ae. albopictus were gathered in 2018 and 2019, respectively. The Ae. albopictus populations increased slowly from May, reached a peak in July, and declined gradually from September. The MOT positivity index (MPI) showed significant positive spatial autocorrelation across the study area, whereas LT collections indicated a nonsignificant spatial autocorrelation. The MPI was suitable for spatial interpolation using the binomial areal kriging model and showed different hot spots in different years.ConclusionsThe improved surveillance system integrated with a geographical information system (GIS) can improve our understanding of the spatial and temporal distribution of Ae. albopictus in urban areas and provide a practical method for decision-makers to implement vector control and mosquito management.Graphical abstract

Atmospheric black carbon in urban and traffic areas in Shanghai: Temporal variations, source characteristics, and population exposure

Black carbon (BC) measurements were performed at Pudong (PD) urban supersite and Gonghexin (GH) roadside station from December 1, 2017 to August 10, 2020 to investigate the variations, source characteristics, and population exposure levels of BC in traffic and urban areas in Shanghai, China. The BC median concentration at GH was more than two-fold that at PD. Absorption Ångström exponent (AAE) values were 1.27 ± 0.17 and 1.31 ± 0.17 at PD and GH, respectively, suggesting the dominance of liquid fossil fuel combustion sources (i.e., traffic exhaust) at these stations. The higher BC and AAE values in winter at PD indicated the relatively increasing contribution of solid fuels (i.e., biomass burning) to BC concentration in urban Shanghai. The diurnal variation in BC showed similar twin-peak patterns at PD and GH, implying that traffic emission mainly contributed to ambient BC concentration in urban Shanghai. The estimated daily intakes (EDIs) of BC were generally higher in males than in females at both PD and GH. The highest BC EDIs at PD were found in age subgroups 1–<2 and 2–<3 years. In contrast, the BC EDIs at GH were observed in age subgroups 6–<9, 12–<15, and 15–<18 years, which were higher than those determined at PD, indicating that more attention must be paid to BC exposure of the population in these age subgroups. These results provide scientific insights into variations, source characteristics, and population exposure levels of BC in urban and traffic areas and could help in the development of BC control strategies in Shanghai.

Estimating the Cooling Effect of Pocket Green Space in High Density Urban Areas in Shanghai, China

Recently, pocket green spaces (PGS), i.e., small green spaces, have attracted growing attention for their various ecological and social services. As a crucial part of urban green spaces in high-density urban areas, PGS facilitates recreation and relaxation for neighborhoods and thus improves the livability of cities at the local scale. However, whether and how the PGS cools the urban heat island effect is still unclear. This research was performed in the highly developed areas of the city of Shanghai during hot summer daytime. We applied a set of cooling effect indicators to estimate the cooling extent, cooling intensity, and cooling efficiency of PGS. We further examined whether and how landscape features within and surrounding the PGS influence its cooling effects. The results showed that 90% of PGS are cooler than their surroundings. Among the landscape features, the land surface temperature of PGS logarithmically decreased with its area, and the maximum local cool island intensity and maximum cooling area logarithmically increased with the area of PGS. The vegetation types and their composition within the PGS also influenced their surface temperature and the cooling effect. The PGS dominated by tree-shrub-grass showed the highest cooling efficiency. The surrounding landscape patterns, especially the patch density and the landscape shape index, influence the cooling effect of PGS at both class and landscape levels. These findings add new knowledge on factors influencing the cooling effect of PGS, and provide the biophysical theoretical basis for developing nature-based cooling strategies for urban landscape designers and planners.

Epidemiological changes in mumps infections between 1990 and 2017 in urban area of Shanghai, China

ABSTRACT 2-dose measles-mumps-rubella (MMR) vaccine was recommended for children in Shanghai in November 1996 and incorporated into Shanghai immunization program in December 2008. We described the mumps epidemiology and assessed impact of the 2-dose MMR vaccination in Changning district, Shanghai, 1990–2017. We obtained the MMR vaccination coverage for children born during 1995–2015 and examined the incidence and disease characteristics of mumps during 1990–2017. The 1st dose MMR coverage had maintained above 95% since 1999 birth cohort. The 2nd dose MMR coverage reached above 90% since 2006 birth cohort. A total of 13,388 cases were reported during 1990–2017. The incidence decreased from 315.2 per 100,000 population in 1990 to 8.8 per 100,000 population in 2017. Of the 13,388 cases, 7585 (56.7%) were male and 91.7% were 1–14 years of age and 86.8% were children in kindergartens and students in schools. Compared with 1990–1996, the incidence had a significant decrease in 0–4 and ≥15 years in 1997–2008 and in all age groups in 2009–2017. A later birth cohort was associated with a lower incidence in children covered by MMR vaccination. In Conclusions, the incidence of mumps has dramatically declined with high coverage of 2-dose MMR in Changning district, Shanghai. Children in kindergartens and schools are still the most affected populations. An increase in incidence in adults has not occurred after 20 years of MMR vaccination. Long-term surveillance is needed to fully evaluate the impact of MMR vaccination policy.

Comparison of Three Receptor Models for Source Apportionment of PM2.5 in Shanghai: Using Hourly Resolved PM2.5 Chemical Composition Data

Continuous measurements of PM2.5 and its chemical composition, including inorganic ions, carbon components, and inorganic elements, were conducted in the urban area of Shanghai from November 2 to 24, 2014. The chemical characteristics and sources of PM2.5 were discussed. The average mass concentration of PM2.5 was (64±33) μg·m-3 (ranging from 12 to 181 μg·m-3). Organic matter contributed the most to the PM2.5 chemical components, accounting for about 28.1% of total PM2.5, followed by NO3-, SO42-, and NH4+, which accounted for 17.4%, 12.4%, and 10.7%, respectively. Meanwhile, three receptor models, including positive matrix factorization (PMF), chemical mass balance (CMB), and multilinear engine 2 (ME2), were applied to apportion the PM2.5 sources based on these online data. The results showed that eight sources were identified, including secondary nitrate, secondary sulfate, secondary organic carbon, heavy fuel oil burning, industry, mobile vehicle exhaust, dust, and power plants. The secondary sources (44.9%-64.8%), including secondary nitrate, secondary sulfate, and secondary organic carbon, were found to be the important contributors to PM2.5. The other two main sources were mobile vehicle exhaust (16.8%-24.8%) and power plants (5.6%-14.9%), whereas other sources were slightly lower contributors. To better verify the accuracy of the PMF, CMB, and ME2 models, the profiles, temporal patterns, and concentrations of different sources obtained by the three models were discussed. Similar source profiles and contributions of secondary nitrate, secondary sulfate, secondary organic carbon, and mobile vehicle exhaust were derived from the PMF, CMB, and ME2, indicating that the results of the three models were reasonable. The ME2 and PMF models simulate better results for power plants and dust sources than CMB, whereas CMB obtained better results for industrial sources.

Association between Active Travel to School and Depressive Symptoms among Early Adolescents.

Background: Although much evidence has demonstrated the positive relationship of active school travel (AST) and physical health, little is known about the relationship of AST and mental health indicators among early adolescents, especially in Chinese populations. Thus, this study aimed to investigate the relationship of AST with depressive symptoms and its sex as well as age difference among early adolescents from Shanghai urban areas, China. Methods: 6478 adolescents (mean age = 13.6) in urban area were recruited, of whom boys accounted for 46.2%. A self-reported questionnaire in Chinese was used to collect data on AST and depressive symptoms, and other control variables. Multivariable logistic regression analyses were used to explore the relationships of AST with depressive symptoms. Results: Of all included participants, 53.2% of adolescents reported being active in AST without sex difference. The prevalence of depressive symptoms was 19.2% without sex difference. AST was associated with reporting no depressive symptoms in adolescents (adjusted OR = 1.20, 95%CI: 1.06–1.36). However, the relationship was significant in boys (adjusted OR = 1.34, 95%CI: 1.11–1.60), in those who were grade 8 (adjusted OR = 1.25, 95%CI: 1.01–1.55) and 9 (adjusted OR = 1.29, 95%CI: 1.01–1.65) adolescents. Conclusions: AST may play an important role in preventing depressive symptoms among early adolescents. However, the relationship of AST with depressive symptoms differed by sex and age. More research is encouraged to explore the mechanism linking AST and depressive symptoms among adolescents, especially in different contexts.

An alternative semi-quantitative GC/MS method to estimate levels of airborne intermediate volatile organic compounds (IVOCs) in ambient air

Abstract Intermediate volatile organic compounds (IVOCs) have attracted much attention due to their contributions to the formation of secondary organic aerosol (SOA) in ambient air. Determination of total IVOCs in ambient air is therefore important for assessing their roles in air pollution. Currently, concentrations of IVOCs are estimated using a previously published semi-quantitative method. In this paper we propose an alternative method for the determination of IVOCs concentrations, in which speciated IVOCs of n-alkanes, polycyclic aromatic hydrocarbons (PAHs) and phthalates are treated as speciated IVOCs and quantified using their respective standards. The ion signal attributed to the speciated IVOCs is then subtracted from the total ion chromatogram (TIC) and the remaining peak area is used to semi-quantitatively estimate the remaining mass regarded as unspeciated complex mixture (UCM) IVOCs. The TIC peak area of speciated IVOCs in ambient air samples is reconstructed based on the peak area ratio of extracted ion chromatogram (EIC) of the quantifying ion and the TIC from their respective standards. The total IVOCs is then calculated as the sum of the speciated IVOCs and the UCM IVOCs. Twenty-one ambient air samples, collected from November 7 to December 12, 2018 in the urban area of Shanghai, were used to compare our method with the previously published method. Although the overall differences in UCM IVOCs and total IVOCs values were small between the two methods, different values of UCM IVOCs and total IVOCs in several sections of the chromatogram that contain phthalates were observed. Analysis of the ambient air samples also revealed that levels of IVOCs were significantly correlated with atmospheric PM2.5. Our method has the advantage that more accurate results in the determination of total IVOCs can be achieved when more compounds are identified and added to the list of speciated IVOCs.

Urban-Rural Differences in Bone Mineral Density and its Association with Reproductive and Menstrual Factors Among Older Women.

This study aimed to compare the bone mineral density (BMD) of older women living in rural and urban areas, and evaluate the potential factors affecting the risk of osteoporosis. We recruited 574 women aged 65years or older from rural areas and 496 from urban areas in Shanghai, China. The BMD values of the lumbar vertebrae and total left hip were measured by a dual energy X-ray absorptiometry densitometer. We also recorded information about education level, family income, medications, reproductive and menstrual history, diet, smoking, and alcohol consumption. Women in urban areas had significantly higher BMD in their lumbar spine, and there was a dramatic increase in the proportion of women with osteoporosis in rural areas. The age at menarche was significantly higher among women living in rural areas, and there were more years from menarche to menopause among urban women. Rural women had significantly higher numbers of both pregnancies and parity, and a significantly lower age at first parity. In multiple linear regression analyses, years from menarche to menopause was independently related to high lumbar spine BMD, while age at menarche and parity was independently related to low lumbar spine BMD. More older women in rural areas had osteoporosis. Later menarche, less years from menarche to menopause and higher parity might partially contribute to decreased BMD among women in rural areas. More attention should be paid to women in rural areas to prevent bone loss and further bone and health impairment.

Dynamic Analysis and Prediction of Food Nitrogen Footprint of Urban and Rural Residents in Shanghai.

The food nitrogen (N) footprint reflects the amount of reactive N emission and its impact on the environment as a result of food production and consumption to satisfy the basic food demands of an urban population. The N-Calculator model was used to estimate the food N footprint and its dynamic changes in Shanghai from 2000 to 2017, and the auto regressive integrated moving average (ARIMA) time series model was used to predict the food N footprint in Shanghai from 2018 to 2027. The results show that the food N footprint was higher in urban areas (15.3–18.8 kg N/capita/yr) than rural areas (12.6–17.4 kg N/capita/yr) of Shanghai from 2000 to 2017. The change in the food N footprint was consistent with changes in food consumption in urban and rural areas, and the total food N footprint of urban and rural residents was positively correlated with the per capita disposable income and population whereas it was negatively correlated with the Engel’s Coefficient and price index. It was predicted that the per capita food N footprint will gradually decrease in 2018–2027 in urban areas of Shanghai, but it will generally increase in the rural areas. This study will help to initiate policy interventions for sustainable N management and contribute to the achievement of key sustainable development goals (SDGs).

Relationship Between AST/ALT Ratio and Peripheral Nerve Function in Type 2 Diabetes Mellitus

Background: The aspartate aminotransferase (AST)/alanine aminotransferase (ALT) ratio is suggested to be related to the increased risks of many metabolic diseases, whereas its association with neurological function in type 2 diabetes mellitus (T2DM) has not been understood. In this study, we aim to investigate the relationships between serum liver enzymes (ALT, AST, the AST/ALT ratio, gamma-glutamyl transferase (GGT)) and peripheral nerve function in patients with T2DM. Methods: In Group 1, we analyzed the associations between parameters of nerve function and liver enzymes in 460 T2DM patients from rural area of Shanghai. Besides, the same methods were applied to another group of 828 T2DM subjects from urban area of Shanghai. Results: In Group 1, the AST/ALT ratio was significantly higher in patients with abnormal nerve conduction [Formula: see text]. The peripheral nerve function significantly declined with increasing tertiles of AST/ALT ratio ([Formula: see text]). After adjustment for all potential confounders, the ratio of AST/ALT was still negatively correlated with the composite Z-scores of conduction velocity (CV). In Group 2, similar significant associations were found between the AST/ALT ratio and peripheral nerve function after adjustment for covariates. Conclusions: In two independent T2DM populations, the AST/ALT ratio was independently and consistently related to peripheral nerve function. The AST/ALT ratio might be helpful to highlight T2DM patients at high risk for diabetic peripheral neuropathy.

Effect of ambient air pollution exposure on renal dysfunction among hospitalized patients in Shanghai, China

ObjectivesWe investigated whether long-term ambient air pollutants (AAP) exposure was associated with estimated glomerular filtration rate (eGFR) among hospitalized patients living in urban areas of Shanghai, China. Study designThis was a cross-sectional observational study. MethodsA total of 3622 newly hospitalized inpatients were investigated from October 2014 to May 2015. The prior year's average exposure to particulate matter (PM) of each participant was estimated using the Kriging interpolation method of ArcGIS. The estimated eGFR was calculated according to the chronic kidney disease epidemiology collaboration (CKD-EPI) equation. Both generalized linear and logistic regression models were applied to assess the associations between AAP and renal function. ResultsOne-year PM10 exposure was associated with lower eGFR; each standard deviation (SD) increase in PM10 was significantly associated with the increased prevalence of CKD [adjusted odds ratio (OR) 1.11; 95% confidence interval (CI): 1.02, 1.21], and lower eGFR by −0.40 (95%CI: −0.80, −0.01) ml/min/1.73 m2. Moreover, the effect of PM10 was significantly greater in people over 65 years old. ConclusionOur results supported that exposure to ambient PM10 increased the risk of CKD and negatively affected renal function among Chinese adults.

Multi-scenario simulation of urban land change in Shanghai by random forest and CA-Markov model

The multi-scenario simulation of urban land can effectively reveal the characteristics and trends of changes in urban space and the contradictions of land use in urban sustainable development. By designing a model based on the random forest algorithm and CA-Markov model, we simulated the evolution of urban space in Shanghai from 2015 to 2030 under two distinct scenarios — unconstrained development and development with planning intervention. Results of model validation indicate that the model accurately simulates urban land in 2015. In Shanghai, important factors affecting urban development are population, GDP and distance to subways. Under the unconstrained scenario, urban areas in Shanghai are predicted to increase by 157.79 km2 between 2015 and 2030, and the spatial expansion of urban areas follows a concentric pattern. Meanwhile, under the scenario with planning intervention, urban expansion is at a lower speed, and more compact because of constraints of ecological, cultivated and cultural protection, and urban areas are predicted to increase by 95.46 km2 in 2030 compared with 2015. We observe a similar concentric pattern, although significantly smaller in magnitude, in spatial expansion under this scenario. The results show that urban development will be more sustainable under the constraints of ecological and cultivated protection.

Changes in daily and cumulative volumetric rainfall at various intensity levels due to urban surface expansion over China

Urban surface expansion affects land–atmosphere interactions as well as rainfall. Both the subregional area-averaged daily (DRAIN) and the subregional cumulative volumetric (VRAIN) rainfall amounts are important in this context for hydrological applications and management. Conducted at the city (Beijing, Shanghai, and Guangzhou), city cluster (Beijing–Tianjin–Hebei (BTH), the Yangtze River Delta (YRD), and the Pearl River Delta (PRD)), and national levels in China, numerical experiments were performed in this study using a regional climate model. The analysis revealed that urban-related changes in rainfall variability were more distinct for stronger rainfall among rainfalls of various intensity levels whereas changes in rainfall intensity were more pronounced for weaker rainfall. Furthermore, urban-induced changes in heavy storm rain were more prominent among rainfalls of various intensity levels, for which changes in the variability in DRAIN and VRAIN were more distinct than changes in their intensities, and exhibited marked subregional characteristics. The risk of heavy storm rain increased because of strengthened urban-induced DRAIN and VRAIN variability over Beijing, and urban areas of the YRD and China. However, the risk of heavy storm rain decreased because of decreased DRAIN and VRAIN variability and the reduced intensity of DRAIN over urban areas of Shanghai, nonurban areas of BTH, and nonurban and the entire areas of Guangzhou, the YRD, and the PRD. The urban-induced drying tendency in the lower troposphere and wetting tendency in the low–middle troposphere, and enhanced vertical motions played an important role in determining the changes in DRAIN and VRAIN in case of storm rain and heavy storm rain.

Sex differences in the application of WHO standards to Shanghai infants from birth to 18 months

BackgroundThe number of obese children in Shanghai has increased annually. Shanghai growth standards are higher than the World Health Organization's (WHO's) growth standards, which may influence caregiver feeding practices and enhance the risk of overweight in infants. MethodA cluster-randomized controlled trial analysed 15,019 infants (healthy newborns, ≥3 clinical consultations in one year) from 19 community health service centers in two urban areas in Shanghai. Randomization was performed at the community level. A total of 8510 infants in the S-group were assessed with the Shanghai growth standards, and 6509 infants in the W-group were assessed by the WHO growth standards. Follow-up data were collected at 1, 2, 4, 6, 9, 12 and 18 months. Changes in the weight-for-age z score (WAZ), length-for-age z score (LAZ), and weight-for length z score (WLZ) were assessed using mixed regression models. Sex differences were compared between groups at all follow-up periods. ResultsCompared to the S-group, the percent of overweight in boys in the W-group significantly decreased starting at 9 months (4.9% vs 3.3%, P = 0.011 at 9 months, 4.5% vs 2.5%, P < 0.001 at 12 months and 3.1% vs 0.8%, P < 0.001 at 18 months), and the percent of overweight in girls in the W-group significantly decreased starting at 12 months (3.0% vs 1.8%, P = 0.009 at 12 months and 1.7% vs 0.6%, P = 0.039 at 18 months). A decreased weight in boys (from 4 months to 18 months, P < 0.05) and an increased length in girls (from 6 months to 18 months, P < 0.05) were the key reasons for the decreased overweight percentage in the W-group. ConclusionThe adoption of the WHO growth standards could result in markedly decreased weight gain in boys and increased length gain in girls beyond the age of 18 months among urban Shanghai infants. Trial registration numberChiCTR1800015371

Seasonal distribution, gas\u2013particle partitioning and inhalation exposure of brominated flame retardants (BFRs) in gas and particle phases

BackgroundAtmosphere is one of the sources and sinks to gas- and particle-bound brominated flame retardants (BFRs). Therefore, BFRs can enter human body via inhalation. In the present study, 79 of gas- and particle-phase samples (TSP, PM10 and PM2.5) were collected during 2015–2016 in urban area of Shanghai, China to investigate the occurrence of 25 polybrominated diphenyl ether (PBDEs) congeners, hexabromobenzene (HBB) and 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE).ResultsThe total concentrations of BFRs ranged from 0.66 to 13.7 pg/m3, 25.82 to 376.27 pg/m3, 14.58 to 365.49 pg/m3 and 15.17 to 304.89 pg/m3 in gas, TSP, PM10 and PM2.5, respectively. HBB was the main compound in gas phase; while BDE-209 was the dominant congener in particle phase. Atmospheric BFRs in winter was much lower than in summer, while particle phase showed opposite seasonal tendency.ConclusionsClausius–Clapeyron equation suggested that BTBPE, BDE-28, -66, -99, -100, and -154 were more driven by temperature and evaporated from local contamination. Higher-brominated congeners tended to be absorbed in particle phase, while low-brominated compounds partitioned in both gas and particle phases. Gas/particle partitioning results showed that absorption into the aerosol organic matter was the dominant process for BFRs. The inhalation health risk assessment demonstrated that the hazard quotient (HQs) for most PBDEs in winter was higher than in summer.

AUTOMATIC ROAD STRUCTURE DETECTION AND VECTORIZATION USING MLS POINT CLOUDS

Abstract. Accurate three-dimensional road structures and models are of great significance to intelligent transportation applications, such as vehicle navigation, inventory evaluation, construction quality control, self-driving vehicles and so on. This paper proposes an efficient and robust method to automatically extract structured road curbs from mobile laser scanning (MLS) data. The proposed method mainly consists of three steps: efficient supervoxel generation, road curbs detection and driving free space estimation. First, supervoxels are generated by assigning ground points with similar geometrical characteristics into the same group. Second, supervoxels with higher local projection density and height difference are identified and clustered as initial road curbs, which are continuous vertical curb facets. The continuous facades consisting of lots of scanned points on the road shoulder can be modeled as multi-dimensional boundary models depending on the requirements of the application, such as vector lines with or without height, micro-facades, etc. Finally, driving free space is obtained due to the road limits can be defined by road boundary in most scenarios. The proposed method is tested on two complex datasets acquired by an Alpha3D mobile laser scanning system from the urban area of Shanghai, China. Experimental results show that the road boundaries and driving free space can be accurately and efficiently extracted, which also demonstrates the superiority of the proposed method.

White Matter Hyperintensities Predict Cognitive Decline: A Community-Based Study.

White matter hyperintensities (WMHs) were commonly seen in brain magnetic resonance imaging (MRI) of the elderly. Many studies found that WMHs were associated with cognitive decline and dementia. However, the association between WMHs in different brain regions and cognitive decline remains debated. We explored the association of the severity of WMHs and cognitive decline in 115 non-demented elderly (≥50 years old) sampled from the Wuliqiao Community located in urban area of Shanghai. MRI scans were done during 2009-2011 at the beginning of the study. Severity of WMHs in different brain regions was scored by Improved Scheltens Scale and Cholinergic Pathways Hyperintensities Scale (CHIPS). Cognitive function was evaluated by Mini-Mental State Examination (MMSE) every 2 to 4 years during 2009-2018. After adjusting for confounding factors including age, gender, education level, smoking status, alcohol consumption, depression, hypertension, diabetes, hyperlipidemia, brain infarcts, brain atrophy, apoE4 status, and baseline MMSE score, periventricular and subcortical WMH lesions as well as WMHs in cholinergic pathways were significantly associated with annual MMSE decline ( p &lt; 0.05), in which the severity of periventricular WMHs predicted a faster MMSE decline (-0.187 points/year, 95% confidence interval: -0.349, -0.026, p = 0.024). The severity of WMHs at baseline was associated with cognitive decline in the non-demented elderly over time. Interventions on WMH lesions may offer some benefits for cognitive deterioration.

Comparison and Source Apportionment of PAHs Pollution of Runoff from Roads in Suburb and Urban Areas of Shanghai

Rapid urbanization has driven surface runoff pollution in urban areas to a serious state. In particular, polycyclic aromatic hydrocarbons(PAHs)from road surface runoff has attracted wide attention. Two traffic roads in Shanghai (Caobao Road in an urban central area, and Jiajin Expressway in the suburbs) were identified as research objects. Runoff samples from these two traffic roads were collected for 7 rainfall events between 2007 and 2018. Then, the concentration characteristics and composition ratio of PAHs were analyzed. The differences in pollution sources of runoff PAHs from two types of traffic roads were identified based on characteristic ratio method and positive matrix factorization(PMF). The results showed that the geometric mean value (5539.2 ng·L-1) of 16 PAHs of runoff from Jiajin Expressway in the suburbs was 10 times greater than that from Caobao Road (548.1 ng·L-1), which was related to a higher truck traffic and a lower cleaning frequency on Jiajin Expressway. The benzo(a)pyrene(BaP)concentration on both roads exceeded the national emission standard, and the amount in the Jiajin Expressway was up to 21 times higher than the standard. There was no significant difference in the composition of PAHs of runoff between Caobao Road and Jiading Expressway, and 4-6 ring were dominant and responsible for 80% of total PAHs loads in both sites. Based on the analysis of the characteristic ratio method, the PAHs of runoff from Caobao Road mostly came from coal-fired sources and traffic sources, while that from Jiajin Expressway were mostly from fossil fuels, coal, and other traffic sources. Quantitative source analysis through PMF method showed that the primary sources of PAHs were gas and coal, accounting for 48.6%, followed by traffic emission sources (29.8%), and oil sources (21.7%). The contribution ratios of PAHs sources of runoff from Jiajin Expressway, sorted in descending order, are:traffic emission sources (38.5%), coal-fired sources (34.6%), oil sources (14.6%), and coking sources (12.6%). PAHs sources and contribution rates between urban and suburban roads are completely different. Gas and coal were the main sources of PAHs of runoff from Caobao Road, which was related to the high population density and relatively large gas consumption in the Xuhui District. Traffic emission was the main source of PAHs from surface runoff on Jiajin Expressway, which was related to the massive flow of coaches and trucks, and their higher PAHs emission compared to small cars. In addition, there are still coking sources of PAHs of runoff from Jiajin Expressway, which can be related to the massive industrial coal consumption in the Qingpu District.

Distribution characteristics and health risk assessment of heavy metals and PAHs in the soils of green spaces in Shanghai, China.

The environmental sustainability of megacities is a global problem, and megacities are experiencing increasing pressure and challenges with regard to providing a suitable living environment for people. Urban green space plays a crucial role in protecting urban ecological environments and in maintaining the physical and mental health of residents. In this study, a total of 94 soil samples from green spaces in Shanghai, including park green spaces and road green spaces in the eight central urban districts, were collected, and the contents of heavy metals and polycyclic aromatic hydrocarbons (PAHs) were analyzed to determine the distribution characteristics and influencing factors and to assess the associated health risks. The accumulation of heavy metals was greater in park green space soils than in road green space soils, although the variation coefficient of the former was lower than that of the latter. Conversely, the accumulation of PAHs was lower in park green space soils than that in road green space soils, although the variation coefficient of the former was higher than that of the latter. In particular, Cu, Zn, Pb, Cd, As, and PAHs have accumulated in Shanghai green space soils. With increasing soil depth (0-2cm, 2-5cm, 5-10cm, and 10-30cm), the PAH content increased in the park green space soils but decreased in the road green space soils. According to the "Technical guidelines for risk assessment of contaminated sites (MEP of China 2014)," the overall health risk posed by green space soils in urban areas in Shanghai can be considered safe, except at individual sampling sites. The PAH, Cu, and Zn contents of park green space soils might be related to the application of organic materials and to traffic and industry emissions. However, the soil pollutants in road green spaces are predominantly related to traffic and industrial emissions. Therefore, the monitoring and management of soil environmental quality must be strengthened.

Can increased outdoor CO2 concentrations impact on the ventilation and energy in buildings? A case study in Shanghai, China

This study presents that increases in atmospheric CO2 levels impact the ventilation and energy in buildings. The most significant impact of ventilation occurs during use, because of the indoor air quality. According to the 2014 IPCC report, observed atmospheric CO2 levels increased at a rate of 1.9–2.1 ppm per year. This study measured CO2 levels in a building in an urban area in Shanghai, China, and analyzed existing ventilation performance and energy simulation in relation to the impact of increased atmospheric CO2 concentrations. As long as the atmospheric CO2 level increased, the outdoor airflow rate had to increase also to maintain an acceptable indoor CO2 level. The ventilation rate was also considered in relation to the surrounding environment. In Shanghai, the average value of CO2 concentrations on an auto road was 550 ± 20 ppm and the average value on a pedestrian road was 435 ± 15 ppm. A building that was surrounded by high traffic roads needed 20–30% more outdoor airflow rate than a building surrounded by pedestrian roads. Accordingly, energy loads in buildings, for heating and cooling were also affected. In order to dilute indoor CO2 level, the thermal ventilation energy and the ventilation energy uniformly provided a 20% energy load increase during the 12 months, while each monthly energy load varied, depending on the season and/or month. By analyzing indoor CO2 levels and the rise in atmospheric CO2 levels, this study determined how these rises impacted the energy consumption of the building, and how to design a new outdoor airflow supply rate to adapt to a changed environmental condition.