Spatial-temporal characteristics and influencing factors of carbon emission in Chengdu-Chongqing area: an urban transportation perspective.

The Chengdu-Chongqing twin-city economic circle is a vital growth pole and a new power source for Chinese high-quality development. Studying the spatial-temporal characteristics of carbon emissions and the role of factors affecting them under the transportation perspective is of great significance for this region to realize the carbon peak and carbon neutrality and to formulate carbon emission reduction policies. We use the exploring spatial data analysis (ESDA) and spatial regression model combined with the STIRPAT model, and research finding: (1) The total carbon emissions in the research area gradually increased from 2014 to 2020, but the growth rate showed a significant decline in 2019. (2) There is significant spatial heterogeneity of carbon emissions in the study area; the hotspot areas of total carbon emissions are in Chongqing and Chengdu, forming a high-low aggregation of carbon emissions. Per capita carbon emissions show a high trend in the southwest and a low in the northeast. (3) From the factors of transportation perspective, highway density and private vehicles have a positive impact on carbon emissions, and urban road areas and public transportation have a very significant inhibition of carbon emissions and a spatial spillover effect. (4) Other factors, such as population size, national economic development, urbanization level, and industrial structure, all have a positive effect on carbon emissions, and disposable income has a negative effect on carbon emissions.

A framework for prioritizing urban ecological infrastructure (UEI) implementation tasks based on residents' ecological demands and government policies.

With rapid urbanization, balancing urban ecological infrastructure (UEI) construction and residents' ecological demands (RED) has become an imperative but challenging issue for sustainable development. This study develops an integrated framework to systematically prioritize UEI implementation based on localized RED and government policies. We incorporate the Kano model and quality function deployment (QFD) approach to quantify the complex associations between various resident needs and existing policies. Taking Chengdu City as a case study, resident surveys and policy reviews are conducted to construct the demand-policy linkage matrix and determine the importance of UEI tasks. Results reveal that, (1) flood control capacity is most prioritized by RED, followed by wetland area and less PM2.5, while cultural service demands rank lower; (2) Forest coverage, green space development, wetland construction and park construction emerge as priority UEI implementation tasks that can maximize fulfilling RED. This novel framework enables adaptive customization of UEI planning for different cities through configurable modeling. It provides a valuable decision support tool that enables optimizing or improving the prioritization of UEI implementation tasks based on residents' preferences. The research results have important reference value for the prioritization of UEI implementation tasks.

Changes in wintertime visibility across China over 2013-2019 and the drivers: A comprehensive assessment using machine learning method.

Effective emission reduction measures have largely lowered the particulate concentration in China, but low-visibility events still occur frequently, greatly affecting people's daily life, travel, and health. In the context of carbon neutrality strategy and climate change, the mechanisms governing visibility changes may be undergoing a transformation. To address this critical issue, we have undertaken a comprehensive assessment by employing a novel approach that combines site observations, model-derived datasets, and machine learning techniques. Our analysis of the dataset shows varying degrees of improvement in wintertime visibility in regions such as North China, South China, and the Fenwei Plain over 2013-2019, but an unexpected deterioration (approximately 1 km yr-1) in central and southern China (CSC). We further elucidate key roles of PM2.5 reduction in these regions with visibility improvement; whereas the unsatisfactory visibility trend in CSC was caused by combined effect of relative humidity (RH) increase (47 %), aerosol hygroscopicity (κ) enhancement (9 %), and boundary layer (BLH) reduction (8 %), which greatly overwhelms the effect of PM2.5 reduction recently. Moreover, the study reveals a growing influence of RH on the wintertime visibility, reaching 40 % ± 24 % to the total contribution in 2019, while that of PM2.5 declined to 18 % ± 19 % and is expected to further diminish with emission reduction. Note those often-neglected factors-temperature, wind speed, BLH, and κ, account for over 40 % of the total contribution. Though the importance of aerosol hygroscopic growth to visibility was found decreasing recently, it retains non-negligible impacts on driving inter-annual visibility trends. This study yields innovative insights for air pollution control, underscoring the imperative of region-specific strategies to mitigate low-visibility events.

Ambient Volatile Organic Compound Characterization, Source Apportionment, and Risk Assessment in Three Megacities of China in 2019.

In order to illustrate pollution characterization, source apportionment, and risk assessment of VOCs in Beijing, Baoding, and Shanghai, field observations of CO, NO, NO2, O3, and volatile organic compounds (VOCs) were conducted in 2019. Concentrations of VOCs were the highest in Beijing (105.4 ± 52.1 ppb), followed by Baoding (97.1 ± 47.5 ppb) and Shanghai (91.1 ± 41.3 ppb). Concentrations of VOCs were the highest in winter (120.3 ± 61.5 ppb) among the three seasons tested, followed by summer (98.1 + 50.8 ppb) and autumn (75.5 + 33.4 ppb). Alkenes were the most reactive VOC species in all cities, accounting for 56.0%, 53.7%, and 39.4% of ozone formation potential in Beijing, Baoding, and Shanghai, respectively. Alkenes and aromatics were the reactive species, particularly ethene, propene, 1,3,5-trimethylbenzene, and m/p-xylene. Vehicular exhaust was the principal source in all three cities, accounting for 27.0%, 30.4%, and 23.3% of VOCs in Beijing, Baoding, and Shanghai, respectively. Industrial manufacturing was the second largest source in Baoding (23.6%) and Shanghai (21.3%), and solvent utilization was the second largest source in Beijing (25.1%). The empirical kinetic modeling approach showed that O3 formation was limited by both VOCs and nitric oxides at Fangshan (the suburban site) and by VOCs at Xuhui (the urban site). Acrolein was the only substance with an average hazard quotient greater than 1, indicating significant non-carcinogenic risk. In Beijing, 1,2-dibromoethane had an R-value of 1.1 × 10-4 and posed a definite carcinogenic risk.

Research on the spatial correlation and formation mechanism between traditional villages and rural tourism.

In recent years, the survival and development of traditional villages in China have been serious challenges. Rural tourism is regarded as an important way to solve rural problems, and the combination of rural culture and tourism has become a new power point for rural development. Therefore, it is necessary to explore the spatial distribution structure between traditional villages and rural tourism. In this paper, rural tourism was represented by the rural tourism characteristic village (RTCV), and Henan Province, China, was taken as a study area to analyze the distribution pattern and spatial correlation of rural tourism and traditional village (TV) and discuss the relationship between the spatial correlation and regional natural environment and socioeconomic factors. The results show that the coupling of the spatial correlation between RTCVs and TVs in Henan was clear. They could be divided into 5 regions based on geographical factors. In addition, the research summarized 4 typical spatial structures between TVs and RTCVs in Henan based on the regional symbiosis theory, and the spatial pattern formation mechanism of TVs and RTCVs was discussed based on three driving mechanisms. The spatial structure of the two can provide reference value for other developing countries and regions to achieve sustainable rural development.

Assessment and spatial partitioning of ecosystem services importance in Giant Panda National Park: To provide targeted ecological protection.

Giant Panda National Park is crucial for China's ecological security strategic pattern known as "two screens and three belts." The importance assessment and classification of ecosystem services in giant panda national parks has an important guiding role in the protection of giant panda national park ecosystems. In this study, we examined four indicators of habitat quality: carbon storage, water conservation, and soil and water conservation. Combined with data analysis were used to evaluate and classify the importance of ecosystem services in the study area. The results showed that: (1) the overall habitat quality index in the study area was relatively high, and the index was generally greater than 0.5. The total carbon storage was 60.5 × 106 t, and the highest carbon storage in the region was 16.9533 t. The area with the highest water conservation reached 715.275 mm. The total soil conservation was 2555.7 × 107 t. (2) From the perspective of spatial characteristics, the habitat quality in the study area presented a spatial distribution pattern of high-low from west to east. The carbon storage presented a spatial distribution pattern of high-low from east to west. The soil conservation presented a spatial pattern of decreasing from west to east, and the water conservation increased from west to east. (3) We divided the research into four levels of importance: The area of general importance in the study site accounted for 1017.58 km2 and was distributed in the northwest of the study site. The moderately important areas were distributed in the east of the study site, with an area of 1142.40 km2. The highly important areas were distributed in the west of the study site, totaling 2647.84 km2. Extremely important areas were distributed in the middle, with an area of 1451.32 km2. (4) The grid cell scale of the study area was used as the dataset to determine the weighting. This makes the weighting more objective and ensures that the spatial distribution of areas with different degrees of importance will be more accurate.

Environmental pollution and economic growth: Evidence of SO2 emissions and GDP in China.

This study explores the inherent linkage mechanism between environmental pollution and economic growth using a non-linear MS (M)-VAR (p) model. The results indicate that, first, the growth rates of China's gross domestic product (GDP) and SO2 emissions are in a state of significant inertia. Second, when the system was in a medium-growth regime, the growth rates of SO2 emissions and GDP had a positive correlation, characterized by lower probability and weaker durability. Third, when the system was in a high- or low-growth regime, their growth rates were negatively correlated, characterized by higher probability and stronger durability. Overall, economic growth increases environmental pollution emissions, which intensifies as well as inhibits economic growth. The correlation and sustainability of SO2 emissions and GDP are closely related to the regional status of the entire system. This study is helpful in analyzing the reasons for the nonlinear linkage mechanism between environmental pollution and economic growth.

Chemical characterization, source apportionment, and health risk assessment of PM2.5 in a typical industrial region in North China.

To clarify the chemical characteristics, source contributions, and health risks of pollution events associated with high PM2.5 in typical industrial areas of North China, manual sampling and analysis of PM2.5 were conducted in the spring, summer, autumn, and winter of 2019 in Pingyin County, Jinan City, Shandong Province. The results showed that the total concentration of 29 components in PM2.5 was 53.4 ± 43.9 µg·m-3, including OC/EC, water-soluble ions, inorganic elements, and metal elements. The largest contribution was from the NO3- ion, at 14.6 ± 14.2 µg·m-3, followed by organic carbon (OC), SO42-, and NH4+, with concentrations of 9.3 ± 5.5, 9.1 ± 6.4, and 8.1 ± 6.8 µg·m-3, respectively. The concentrations of OC, NO3-, and SO42- were highest in winter and lowest in summer, whereas the NH4+ concentration was highest in winter and lowest in spring. Typical heavy metals had higher concentrations in autumn and winter, and lower concentrations in spring and summer. The annual average sulfur oxidation rate (SOR) and nitrogen oxidation rate (NOR) were 0.30 ± 0.14 and 0.21 ± 0.12, respectively, with the highest SO2 emission and conversion rates in winter, resulting in the SO42- concentration being highest in winter. The average concentration of secondary organic carbon in 2019 was 2.8 ± 1.9 µg·m-3, and it comprised approximately 30% of total OC. The concentrations of 18 elements including Na, Mg, and Al were between 2.3 ± 1.6 and 888.1 ± 415.2 ng·m-3, with Ni having the lowest concentration and K the highest. The health risk assessment for typical heavy metals showed that Pb poses a potential carcinogenic risk for adults, whereas As may pose a carcinogenic risk for adults, children, and adolescents. The non-carcinogenic risk coefficients for all heavy metals were lower than 1.0, indicating that the non-carcinogenic risk was negligible. Positive matrix factorization analysis indicated that coal-burning emissions contributed the largest fraction of PM2.5, accounting for 35.9% of the total. The contribution of automotive emissions is similar to that of coal, at 32.1%. The third-largest contributor was industrial sources, which accounted for 17.2%. The contributions of dust and other emissions sources to PM2.5 were 8.4% and 6.4%, respectively. This study provides reference data for policymakers to improve the air quality in the NCP.

Optical Genome Mapping for Comprehensive Assessment of Chromosomal Aberrations and Discovery of New Fusion Genes in Pediatric B-Acute Lymphoblastic Leukemia.

PURPOSE: To assess the potential added value of Optical Genomic Mapping (OGM) for identifying chromosomal aberrations. METHODS: We utilized Optical Genomic Mapping (OGM) to determine chromosomal aberrations in 46 children with B-cell Acute lymphoblastic leukemia ALL (B-ALL) and compared the results of OGM with conventional technologies. Partial detection results were verified by WGS and PCR. RESULTS: OGM showed a good concordance with conventional cytogenetic techniques in identifying the reproducible and pathologically significant genomic SVs. Two new fusion genes (LMNB1::PPP2R2B and TMEM272::KDM4B) were identified by OGM and verified by WGS and RT-PCR for the first time. OGM has a greater ability to detect complex chromosomal aberrations, refine complicated karyotypes, and identify more SVs. Several novel fusion genes and single-gene alterations, associated with definite or potential pathologic significance that had not been detected by traditional methods, were also identified. CONCLUSION: OGM addresses some of the limitations associated with conventional cytogenomic testing. This all-in-one process allows the detection of most major genomic risk markers in one test, which may have important meanings for the development of leukemia pathogenesis and targeted drugs.

Assessment of Urban Agglomeration Ecological Sustainability and Identification of Influencing Factors: Based on the 3DEF Model and the Random Forest.

The evaluation of ecological sustainability is significant for high-quality urban development and scientific management and regulation. Taking the Chengdu urban agglomeration (CUA) as the research object, this paper combined the three-dimensional ecological footprint model (3DEF) and random forest to evaluate the ecological sustainability of the study area and identify the influencing factors. The study results indicate that: (1) From 2000 to 2019, the ecological sustainability of Chengdu urban agglomeration was divided into four types, and the overall ecological sustainability of this region showed a downward trend. The areas with higher ecological sustainability were mainly distributed in the northern part of the urban agglomeration (Mianyang City) and the southern part (Leshan City and Ya'an City), while the cities in the central region (Chengdu City, Meishan City, and Ziyang City) had lower ecological sustainability. (2) The main factors affecting the ecological sustainability of urban agglomerations are industrial wastewater discharge, industrial smoke (powder) dust discharge, and green coverage of built-up areas, followed by urbanization and population size. Through this study, we have two meaningful findings: (a) Our research method in this paper provides a new way to study the factors affecting the ecological sustainability of urban agglomerations. (b) The results of the identification of influencing factors might be the reference for urban environmental infrastructure construction and urban planning.

Health Outcomes among Adults Initiating Medical Cannabis for Chronic Pain: A 3-month Prospective Study Incorporating Ecological Momentary Assessment (EMA).

In response to the need of more rigorous data on medical cannabis and chronic pain, we conducted a 3-month prospective study incorporating ecological momentary assessment (EMA) to examine the effects of medical cannabis on pain, anxiety/depression, sleep, and quality of life. Data were collected from 46 adults (Mean age=55.7±11.9, 52.2% male) newly initiating medical cannabis treatment for chronic pain. Participants completed a baseline survey, EMA for approximately 1 week pre- and up to 3 weeks post- medical cannabis treatment, and a 3-month follow-up survey. The self-reported EMA data (2535 random and 705 daily assessments) indicated significant reductions in momentary pain intensity (b = -16.5, p < .001, 16.5 points reduction on 0-100 visual analog) and anxiety (b = -0.89, p < .05), and significant increase in daily sleep duration (b = 0.34, p < .01) and sleep quality (b = 0.32, p <.001) after participants initiated medical cannabis for a few weeks. At 3 months, self-reported survey data showed significantly lower levels of worst pain (t = -2.38, p < .05), pain interference (t = -3.82, p < .05), and depression (t = -3.43, p < .01), as well as increased sleep duration (t = 3.95, p < .001), sleep quality (t = -3.04, p < .01), and quality of life (t = 4.48, p < .001) compared to baseline. In our sample of primarily middle-aged and older adults with chronic pain, medical cannabis was associated with reduced pain intensity/inference, lower anxiety/depression, and improved sleep and quality of life.

The varying driving forces of urban land expansion in China: Insights from a spatial-temporal analysis.

The impacts of socioeconomic development on urban land expansion in China vary across space and time; however, comprehensive investigation of this issue remains scarce in the existing literature. This study used a geographically and temporally weighted regression model (GTWR) to examine the spatiotemporally heterogeneous impacts of socioeconomic factors on urban land expansion in China using a newly available annual urban land-use dataset from 2000 to 2015. We found that although the eastern region has maintained its leading role (53.79%) in terms of urban expansion, the share of the central (20.34%) and western (16.13%) regions is gradually increasing. Cities with a higher administrative status tended to expand more rapidly; however, increasingly expansion has also taken place in the prefecture-level cities in recent years. We further found that Gross domestic product (GDP) growth, population density, and capital investment positively contributed to the expansion, although the directions and strengths of association between these factors and urban expansion varied across space and time. Industrial structure and foreign direct investment (FDI) showed a similar variation change trend, with the number of cities evidencing a negative relationship rapidly expanding and increasingly being seen not just in northwest China but also in the southeast during the study period. We also found that the correlation between public finance expenditure and urban expansion presented significant north-south differentiation. It is worth noting that governmental behavior plays a significant role in driving urban land expansion. Our empirical study confirmed the spatiotemporal heterogeneous effects of socioeconomic factors on urban expansion in China, providing useful insights for city governments and urban planners.

Assessment of Quality Outcomes and Learning Curve for Robot-Assisted Minimally Invasive McKeown Esophagectomy.

BACKGROUND: This study aimed to identify the results of the quality assessment and the learning curve of robot-assisted minimally invasive McKeown esophagectomy (RAMIE-MK). METHODS: The study retrospectively reviewed the data of 400 consecutive patients with esophageal cancer who underwent RAMIE-MK by a single surgeon from November 2015 to March 2019. Cumulative summation analysis of the learning curve was performed. The patients were divided into decile cohorts of 40 cases to minimize demographic deviations and to maximize the power of detecting statistically significant changes in performance. RESULTS: The 90-day mortality rate for all the patients was 0.5% (2 cases). The authors' experience was divided into the ascending phase (40 cases), the plateau phase (175 cases), and the descending phase (185 cases). After 40 cases, significant improvements in operative time (328 vs. 251 min; P = 0.019), estimated blood loss (350 vs. 200 ml; P = 0.031), and conversion rates (12.5% vs. 2.5%; P < 0.001) were observed. After 80 cases, a decrease in the rates of anastomotic leakage (22.5% vs. 8.1%; P = 0.001) and vocal cord palsy (31.3% vs. 18.4%; P = 0.024) was observed. The number of harvested lymph nodes increased after 40 cases (13 vs. 23; P < 0.001), especially for lymph nodes along the recurrent laryngeal nerve (3.0 vs. 6.0; P < 0.001). CONCLUSIONS: The learning phase of RAMIE-MK consists of 40 cases, and quality outcomes can be improved after 80 procedures. Several turning points related to the optimization of surgical outcomes can be used as benchmarks for surgeons performing RAMIE-MK.

How the Daily Smartphone is Associated With Daily Travel, Physical Activity, and Self-Perceived Health: Evidence From 2017 National Household Travel Survey.

Knowledge of how smartphone use in daily life, rather than in the context of intervention, may influence people's behaviors and health is limited and mixed. The 2017 National Household Travel Survey (NHTS) data were used to examine the associations between daily smartphone use and several outcomes, including engaging in vigorous physical activity, self-perceived being healthy, and the adjusted mean differences for total trips and active travels among older adults (≥65 years) as well as among young and middle-aged groups (18-64 years), respectively. The prevalence of daily smartphone use declined with increasing age. Daily smartphone use was associated with increased total trips and active travel, a higher likelihood of engaging in vigorous physical activity, and in self-perceived being healthy status. The associations were stronger among older adults than young and middle-aged adults. More studies are needed to address the complex pathways among daily smartphone use and other outcomes. Daily smartphone use has the potential to address the unmet daily needs of older adults and bridge health disparities for this disadvantaged group.

Spatial differences of ecosystem services and their driving factors: A comparation analysis among three urban agglomerations in China's Yangtze River Economic Belt.

Understanding the spatial distribution characteristics of ecosystem service value (ESV) and their underlying driving factors is critical for ecosystem service management. Using three national-level urban agglomerations in the Yangtze River Economic Belt, Cheng-Yu (CY), Middle-Reach Yangtze River (MRYR), and Yangtze River Delta (YRD), as a case study, this paper quantifies the ESVs and the spatial distribution characteristics, analyzes the driving factors of ESVs using the stochastic impacts by regression on population, affluence, and technology model (STIRPAT). The results specify that: (1) Over the study period 2009-2016, the total ESV of the three urban agglomerations decreases by 5498.70 million USD. The regulating, supporting, and cultural service decrease by 4607.60, 2648.01, and 1182.25 million USD, respectively, while the provisioning service increases by 2795.15 million USD. (2) ESV in MRYR undergoes the largest reduction of 4269.70 million USD, followed by CY and YRD with 1015.66 and 213.35 million USD from 2009 to 2016. (3) In 2016, among the 70 cities at the prefecture level or above, the cities with high total ESV, per unit area ESV, and per capita EVS are mainly distributed to the areas of the south Yangtze River of MRYR and YRD, MRYR, and MRYR and YRD, respectively. (4) In general, land use and cover, population are the main factors affecting ESVs, followed by economic, social and political factors. Among the three urban agglomerations, population, land use and cover basically have the equally important impacts on ESV in CY; land use and cover, especially the proportion of urban construction land has the greatest impact on ESV in MRYR; population, especially the urbanization rate has the greatest impact in YRD. The comparative analysis of the driving factors of ESVs in different regions is helpful to propose differentiated ecological protection policies and promote the increase of ESV accordingly.

Racial Differences in the Oral Microbiome: Data from Low-Income Populations of African Ancestry and European Ancestry.

Increasing evidence indicates the significant racial difference in gut, vaginal, and skin microbiomes. However, little is known regarding the racial difference in the oral microbiome. In this study, deep sequencing of 16S rRNA genes was utilized to assess the oral microbiome in mouth rinse samples of 1,058 African-Americans (AAs) and 558 European-Americans (EAs) from the Southern Community Cohort Study. Generally, AAs had a higher species richness than EAs, with P = 5.28 × 10-14 (Wilcoxon rank sum test) for Faith's phylogenetic diversity index. A significant difference in overall microbiome composition was observed between AAs and EAs, with P = 5.94 × 10-4 (MiRKAT) for the weighted UniFrac distance matrix. We also found 32 bacterial taxa showing a significant differential abundance or prevalence between the two racial groups at a Bonferroni-corrected P < 0.05 in linear or logistic regression analyses. Generally, AAs showed a higher abundance of Bacteroidetes and a lower abundance of Actinobacteria and Firmicutes Interestingly, four periodontal pathogens, Porphyromonas gingivalis, Prevotella intermedia, Treponema denticola, and Filifactor alocis, were more prevalent among AAs than among EAs, with Bonferroni-corrected P values of 5.23 × 10-6, 4.47 × 10-6, 1.08 × 10-3, and 4.49 × 10-5, respectively. In addition, all of these 32 taxa were significantly correlated with the percentage of genetic African ancestry. These findings call for research to understand how the racial difference in oral microbiome influences the health disparity.IMPORTANCE In this systemic investigation of racial differences in the oral microbiome using a large data set, we disclosed the significant differences in the oral microbial richness/evenness, as well as in the overall microbial composition, between African-Americans and European-Americans. We also found multiple oral bacterial taxa, including several preidentified oral pathogens, showing a significant different abundance or prevalence between African-Americans and European-Americans. Furthermore, these taxa were consistently found to be associated with the percentage of genetic African ancestry. Our findings warrant further research to understand how the racial difference in the oral microbiome influences the health disparity.

Cigarette smoking and oral microbiota in low-income and African-American populations.

BACKGROUND: Cigarette smoking is a common risk factor for diseases and cancers. Oral microbiota is also associated with diseases and cancers. However, little is known about the impact of cigarette smoking on the oral microbiota, especially among ethnic minority populations. METHODS: We investigated cigarette smoking in relationship with the oral microbiota in a large population of predominately low-income and African-American participants. Mouth rinse samples were collected from 1616 participants within the Southern Community Cohort Study, including 592 current-smokers, 477 former-smokers and 547 never-smokers. Oral microbiota was profiled by 16S ribosomal RNA gene deep sequencing. RESULTS: Current-smokers showed a different overall microbial composition from former-smokers (p=6.62×10-7) and never-smokers (p=6.00×10-8). The two probiotic genera, Bifidobacterium and Lactobacillus, were enriched among current-smokers when compared with never-smokers, with Bonferroni-corrected p values (PBonferroni ) of 1.28×10-4 and 5.89×10-7, respectively. The phylum Actinobacteria was also enriched in current-smokers when compared with never-smokers, with a median relative abundance of 12.35% versus 9.36%, respectively, and with a PBonferroni =9.11×10-11. In contrast, the phylum Proteobacteria was depleted in current smokers (PBonferroni =5.57×10-13), with the relative abundance being almost three times that of never-smokers (7.22%) when compared with that of current-smokers (2.47%). Multiple taxa within these two phyla showed differences in abundance/prevalence between current-smokers and never-smokers at PBonferroni <0.05. The differences in the overall microbial composition and abundance/prevalence of most taxa were observed among both African-Americans and European-Americans. Meanwhile, such differences were not observed between former-smokers and never-smokers. CONCLUSION: Smoking has strong impacts on oral microbial community, which was recovered after smoking cessation.

Exploring the association between urbanisation and self-rated health of older adults in China: evidence from a national population sample survey.

OBJECTIVES: This study investigated the association between urbanisation and self-rated health of older adults in China, particularly how different dimensions, rate and level of urbanisation are related to older people's health. Additionally, it examined the moderating effect of education on the association between each of the four dimensions of urbanisation and older people's health. DESIGN: The study uses a cross-sectional survey design. PARTICIPANTS: This study analysed 236 030 individuals (aged 60-79 years) nested within 267 prefecture-level cities from 2005 China's 1% population sample survey. OUTCOME MEASURES: Self-rated health was the outcome variable. Four groups of predictors assessed prefectures' level and rate of urbanisation: land-use conversion, economic growth, population concentration and health services. Multilevel logistic regression was used to examine the association between self-rated health and the level and rate of urbanisation, after adjusting for individual-level covariates. Multiplicative interactions explored variations by education. RESULTS: The odd of reporting fair or poor health was negatively associated with the level and rate of population concentration (OR 0.93,95%CI 0.87 to 0.99 and 0.74,95%CI 0.59 to 0.93, respectively) and positively associated with the level of health services (OR 1.12, 95% CI 1.06 to 1.19). Land-use conversion, economic growth and health service improvements (the forms of rate of urbanisation) were not significantly associated with self-rated health. Education had a moderating effect on the association between urbanisation and self-rated health. CONCLUSIONS: Older people living in more densely populated areas and areas undergoing rapid population concentration were less likely to report fair or poor health. This result supports healthy migration and 'salmon bias' hypotheses. No urban health penalty was observed for the older adults in China; therefore, the following pathways linking urbanisation to health are unclear: lifestyle changes, environmental pollution and cultivated land reduction.

Occurrence and ecological risk assessment of disinfection byproducts from chlorination of wastewater effluents in East China.

Effluents containing disinfection byproducts (DBPs) from wastewater treatment plants (WWTPs) may be discharged to the receiving water bodies or reused for irrigation, landscaping, and environmental supplies as well as a source to replenish groundwater. Thus the formation and risk of the DBPs in disinfected wastewater effluents should be concerned. In this study, the occurrence of 44 DBPs including 6 trihalomethanes (THMs), 9 haloaceticacids (HAAs), 2 haloketones (HKs), 9 halonitromethanes (HNMs), 9 haloacetonitriles (HANs) and 9 nitrosamines (NAs) was investigated in 12 chlorinated WWTP effluents from five cities of East China. The contribution of each class of DBPs to the total DBPs concentration and additive toxicity was calculated. The average concentrations of the 6 classes of DBPs were ranked as follows: HAAs (47.0 µg/L) > THMs (28.0 µg/L) > HANs (9.9 µg/L) > HNMs (2.9 µg/L) > HKs (0.79 µg/L) > NAs (0.69 µg/L). The significant positive correlations were observed between the formation of THMs and HAAs, THMs and HANs, as well as HAAs and HANs. The results showed that HAAs and THMs were the dominant DBPs on a mass concentration basis and accounted for 54% and 29%, respectively in the total measured DBPs, but they made a minor contribution to the calculated DBP-associated cytotoxicity. HANs and NAs dominated the DBP-associated cytotoxicity, accounting for 50% and 34% on an additive toxicity basis despite the minor contributions to the mass concentration with 10% and 1%, respectively. The risk quotients for three taxonomic groups (fish, daphnid, and green algae) were calculated to assess the ecological risk of DBPs, and the results demonstrated that both HAAs and HANs had high ecological risk for green algae in chlorinated wastewater effluents.

The Impact of Neighborhood Environment on Women's Willingness to Have a Second Child in China.

In recent years, the Chinese government has changed the one-child policy that was implemented more than 3 decades ago and has began encouraging couples to have 2 children. However, this cannot quickly change people's reproductive concepts after more than 30 years of low fertility rate and birth control. In this context, the aim of our study was to assess the effect of neighborhood environment on Chinese women's fertility-willingness for a second child. Our results show that there is a statistically significant relationship between neighborhood environment and women's fertility-willingness for a second child. Women living in affluent neighborhoods with better living environments have lower fertility-willingness for a second child than those in poor neighborhoods. However, childcare institutions (such as kindergartens) provide shared childcare and improve women's fertility-willingness. We suggest that to encourage more couples to have a second child, it is necessary to increase the number of neighborhood kindergartens. In addition, local governments must improve the social welfare of migrant households and loosen the requirements for migrant households to obtain local hukou, which will allow migrant children to enjoy local public services, especially education services.