Effects of Transcutaneous Neuromuscular Electrical Stimulation on Swallowing Disorders: A Systematic Review and Meta-Analysis.

OBJECTIVE: The aim of the study was to evaluate the efficacy of transcutaneous neuromuscular electrical stimulation on swallowing disorders. DESIGN: MEDLINE/PubMed, Embase, CENTRAL, Web of science, and PEDro were searched from their earliest record to August 1, 2019. All randomized controlled trials and quasi-randomized controlled trial were identified, which compared the efficacy of neuromuscular electrical stimulation plus traditional therapy with traditional therapy in swallowing function. The Grading of Recommendations Assessment, Development and Evaluation approach was applied to evaluate the quality of evidence. RESULTS: Eight randomized controlled trials and three quasi-randomized controlled trials were included. These studies demonstrated a significant, moderate pooled effect size (standard mean difference = 0.62; 95% confidence interval = 0.06 to 1.17). Studies stimulating suprahyoid muscle groups revealed a negative standard mean difference of 0.17 (95% confidence interval = -0.42, 0.08), whereas large effect size was observed in studies stimulating the infrahyoid muscle groups (standard mean difference = 0.89; 95% confidence interval = 0.47 to 1.30) and stimulating the suprahyoid and infrahyoid muscle groups (standard mean difference = 1.4; 95% confidence interval = 1.07 to 1.74). Stimulation lasting 45 mins or less showed a large, significant pooled effect size (standard mean difference = 0.89; 95% confidence interval = 0.58 to 1.20). The quality of evidences was rated as low to very low. CONCLUSIONS: There is no firm evidence to conclude on the efficacy of neuromuscular electrical stimulation on swallowing disorders. Larger-scale and well-designed randomized controlled trials are needed to reach robust conclusions.

Circular RNA circ_0003204 inhibits proliferation, migration and tube formation of endothelial cell in atherosclerosis via miR-370-3p/TGFßR2/phosph-SMAD3 axis.

BACKGROUND: Circular RNAs (circRNAs) represent a class of non-coding RNAs (ncRNAs) which are widely expressed in mammals and tissue-specific, of which some could act as critical regulators in the atherogenesis of cerebrovascular disease. However, the underlying mechanisms by which circRNA regulates the ectopic phenotype of endothelial cells (ECs) in atherosclerosis remain largely elusive. METHODS: CCK-8, transwell, wound healing and Matrigel assays were used to assess cell viability, migration and tube formation. QRT-qPCR and Immunoblotting were used to examine targeted gene expression in different groups. The binding sites of miR-370-3p (miR-370) with TGFßR2 or hsa_circ_0003204 (circ_0003204) were predicted using a series of bioinformatic tools, and validated using dual luciferase assay and RNA immunoprecipitation (RIP) assay. The localization of circ_0003204 and miR-370 in ECs were investigated by fluorescence in situ hybridization (FISH). Gene function and pathways were enriched through Metascape and gene set enrichment analysis (GSEA). The association of circ_0003204 and miR-370 in extracellular vesicles (EVs) with clinical characteristics of patients were investigated using multiple statistical analysis. RESULTS: Circ_0003204, mainly located in the cytoplasm of human aorta endothelial cells (HAECs), was upregulated in the ox-LDL-induced HAECs. Functionally, the ectopic expression of circ_0003204 inhibited proliferation, migration and tube formation of HAECs exposed to ox-LDL. Mechanically, circ_0003204 could promote protein expression of TGFßR2 and its downstream phosph-SMAD3 through sponging miR-370, and miR-370 targeted the 3' untranslated region (UTR) of TGFßR2. Furthermore, the expression of circ_0003204 in plasma EVs was upregulated in the patients with cerebral atherosclerosis, and represented a potential biomarker for diangnosis and prognosis of cerebrovascular atherogenesis. CONCLUSIONS: Circ_0003204 could act as a novel stimulator for ectopic endothelial inactivation in atherosclerosis and a potential biomarker for cerebral atherosclerosis.

Identification of disrupted pathways in ulcerative colitis-related colorectal carcinoma by systematic tracking the dysregulated modules.

PURPOSE: The aim of this study was to identify the altered biological pathways associated with ulcerative colitis (UC)-related colorectal carcinoma (CRC) by systematic tracking the dysregulated modules from re-weighted protein- protein interaction (PPI) networks based on the expression profiles from normal, UC and various stages of CRC. METHODS: We firstly recruited the UC- and CRC-related microarray data from ArrayExpress database, and obtained 8 expression profiles which contained 5 conditions (normal, UC, early stage CRC, stage II CRC and stage III CRC). Then, the PPI networks of normal and different disease stages were constructed and re-weighted using Pearson correlation coefficient (PCC). Next, the condition-specific modules were extracted from 5 PPI networks via clique-merging algorithm, and altered modules were captured on the basis of module correlation density (MCD). Subsequently, the gene compositions of altered modules and gene differential expressions in different disease stages were identified to screen the dysregulated genes. Finally, pathways enrichment analyses for the genes in altered modules and differentially expressed genes (DEGs) were implemented. RESULTS: The extensive changes of gene correlations existed in 5 condition-specific PPI networks, which made different MCDs among different disease stages. The same number of modules (N=1952) were explored in 5 PPI networks. By comparing with normal condition, there were 463, 791, 1060 and 345 altered modules in UC, early stage CRC, stage II and III CRC, respectively. Overall, 77, 110, 170 and 110 common genes were identified between genes of altered modules and DEGs in UC, early stage CRC, stage II CRC and stage III CRC, respectively. Functional enrichment analyses indicated that cell cycle and oocyte meiosis were the common and most significant pathways in colonic diseases. CONCLUSIONS: Tracking the altered modules from PPI networks is useful to uncover disrupted pathways in colonic diseases. Cell cycle and oocyte meiosis might be associated with the pathophysiological background of colonic diseases.

Epidemiological evidence on association between ambient air pollution and stroke mortality.

BACKGROUND: Inconsistent results have been found on the association between air pollution and stroke mortality. Additionally, evidence on people who are potentially sensitive to air pollution-associated stroke mortality is limited. METHODS: Daily stroke mortality of adults aged over 65 between 2003 and 2008 in Shanghai, China were collected. The time-stratified case-crossover approach was used to assess the association between daily concentrations of air pollutants including particles with size <10 µm, sulfur dioxide (SO2) and nitrogen dioxide (NO2) and stroke mortality. RESULTS: Both total-stroke and ischaemic-stroke mortalities were found to be significantly associated with all three air pollutants. Haemorrhagic stroke was significantly associated with SO2 and NO2 only. Substantial differences were observed for effect estimates of ischaemic-stroke mortality in relation to NO2 among people with cardiac diseases compared with those without; for an increase of 10 µg/m(3) in NO2, the increase in ischaemic-stroke mortality was 7.05% (95% CI 1.92% to 12.17%) for people with comorbid cardiac diseases versus 0.60% (95% CI -0.49% to 1.68%) for those without. We did not find evidence of effect modification by hypertension and diabetes. CONCLUSIONS: This study provides new evidence for the association between exposure to ambient air pollution and stroke mortality. Our results also suggest that underlying cardiac disorder may increase the risk for ischaemic-stroke mortality in relation to air pollution exposure, especially NO2. .

Using a generalized additive model with autoregressive terms to study the effects of daily temperature on mortality.

BACKGROUND: Generalized Additive Model (GAM) provides a flexible and effective technique for modelling nonlinear time-series in studies of the health effects of environmental factors. However, GAM assumes that errors are mutually independent, while time series can be correlated in adjacent time points. Here, a GAM with Autoregressive terms (GAMAR) is introduced to fill this gap. METHODS: Parameters in GAMAR are estimated by maximum partial likelihood using modified Newton's method, and the difference between GAM and GAMAR is demonstrated using two simulation studies and a real data example. GAMM is also compared to GAMAR in simulation study 1. RESULTS: In the simulation studies, the bias of the mean estimates from GAM and GAMAR are similar but GAMAR has better coverage and smaller relative error. While the results from GAMM are similar to GAMAR, the estimation procedure of GAMM is much slower than GAMAR. In the case study, the Pearson residuals from the GAM are correlated, while those from GAMAR are quite close to white noise. In addition, the estimates of the temperature effects are different between GAM and GAMAR. CONCLUSIONS: GAMAR incorporates both explanatory variables and AR terms so it can quantify the nonlinear impact of environmental factors on health outcome as well as the serial correlation between the observations. It can be a useful tool in environmental epidemiological studies.

Association of particulate air pollution with daily mortality: the China Air Pollution and Health Effects Study.

China is one of the few countries with some of the highest particulate matter levels in the world. However, only a small number of particulate matter health studies have been conducted in China. The study objective was to examine the association of particulate matter with an aerodynamic diameter of less than 10 µm (PM(10)) with daily mortality in 16 Chinese cities between 1996 and 2008. Two-stage Bayesian hierarchical models were applied to obtain city-specific and national average estimates. Poisson regression models incorporating natural spline smoothing functions were used to adjust for long-term and seasonal trends of mortality, as well as other time-varying covariates. The averaged daily concentrations of PM(10) in the 16 Chinese cities ranged from 52 µg/m(3) to 156 µg/m(3). The 16-city combined analysis showed significant associations of PM(10) with mortality: A 10-µg/m(3) increase in 2-day moving-average PM(10) was associated with a 0.35% (95% posterior interval (PI): 0.18, 0.52) increase of total mortality, 0.44% (95% PI: 0.23, 0.64) increase of cardiovascular mortality, and 0.56% (95% PI: 0.31, 0.81) increase of respiratory mortality. Females, older people, and residents with low educational attainment appeared to be more vulnerable to PM(10) exposure. Conclusively, this largest epidemiologic study of particulate air pollution in China suggests that short-term exposure to PM(10) is associated with increased mortality risk.

Stock volatility as a risk factor for coronary heart disease death.

AIMS: The volatility of financial markets may cause substantial emotional and physical stress among investors. We hypothesize that this may have adverse effects on cardiovascular health. The Chinese stock markets were extremely volatile between 2006 and 2008. We, therefore, examined the relationship between daily change of the Shanghai Stock Exchange (SSE) Composite Index (referred as the Index) and coronary heart disease (CHD) deaths from 1 January 2006 to 31 December 2008 in Shanghai, the financial capital of China. METHODS AND RESULTS: Daily death and stock performance data were collected from the Shanghai Center for Disease Control and Prevention and SSE, respectively. Data were analysed with over-dispersed generalized linear Poisson models, controlling for long-term and seasonal trends of CHD mortality, day of the week, Index closing value, weather conditions, and air pollution levels. We observed a U-shaped relationship between the Index change and CHD deaths: both rising and falling of the Index were associated with more deaths and the fewest deaths coincided with little or no change of the index. We also examined the absolute daily change of the Index in relation to CHD deaths: in a 1-day lag model, each 100-point change of the Index corresponded to 5.17% (95% confidence interval: 1.71, 8.63%) increase in CHD deaths. Further analysis showed that the association was stronger for out-of-hospital CHD death than for in-hospital death. CONCLUSION: We found that CHD deaths fluctuated with daily stock changes in Shanghai, suggesting that stock volatility may adversely affect cardiovascular health.

Part 1. A time-series study of ambient air pollution and daily mortality in Shanghai, China.

Although the relation between outdoor air pollution and daily mortality has been examined in several Chinese cities, there are still a number of key scientific issues to be addressed concerning the health effects of air pollution in China. Given the changes over the past decade in concentrations and sources of air pollution (e.g., the change from one predominant source [coal combustion], which was typical of the twentieth century, to a mix of sources [coal combustion and motor-vehicle emissions]) and transition in China, it is worthwhile to investigate the acute effects of outdoor air pollution on mortality outcomes in the country. We conducted a time-series study to investigate the relation between outdoor air pollution and daily mortality in Shanghai using four years of daily data (2001-2004). This study is a part of the Public Health and Air Pollution in Asia (PAPA) program supported by the Health Effects Institute (HEI). We collected data on daily mortality, air pollution, and weather from the Shanghai Municipal Center of Disease Control and Prevention (SMCDCP), Shanghai Environmental Monitoring Center, and Shanghai Meteorologic Bureau. An independent auditing team assigned by HEI validated all the data. Our statistical analysis followed the Common Protocol of the PAPA program (found at the end of this volume). Briefly, a natural-spline model was used to analyze the mortality, air pollution, and covariate data. We first constructed the basic models for various mortality outcomes excluding variables for air pollution, and used the partial autocorrelation function of the residuals to guide the selection of degrees of freedom for time trend and lag days for the autoregression terms. Thereafter, we introduced the pollutant variables and analyzed their effects on mortality outcomes, including both mortality due to all natural (nonaccidental) causes and cause-specific mortality. We fitted single- and multipollutant models to assess the stability of the effects of the pollutants. For mortality due to all natural causes, we also examined the associations stratified by sex and age. Stratified analyses by education level, used as a measure of socioeconomic status, were conducted as well. In addition to an analysis of the entire study period, the effects of air pollution in just the warm season (from April to September) and cool season (from October to March) were analyzed. We also examined the effects of alternative model specifications--such as lag effects of pollutants and temperature, degrees of freedom for time trend and weather conditions, statistical approaches, and averaging methods for pollutant concentrations-on the estimated effects of air pollution. We found significant associations between the air pollutants--particulate matter 10 pm or less in aerodynamic diameter (PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2), and ozone (O3) -and daily mortality from all natural causes and from cardiopulmonary diseases. The increased mortality risks found in the data from Shanghai were generally similar in magnitude, per concentration of pollutant, to the risks found in research from other parts of the world. An increase of 10 microg/m3 in 2-day moving average concentrations of PM10, SO2, NO2, and O3 corresponded to 0.26% (95% confidence interval [CI], 0.14-0.37), 0.95% (95% CI, 0.62-1.28), 0.97% (95% CI, 0.66-1.27), and 0.31% (95% CI, 0.04-0.58) increases, respectively, in mortality due to all natural causes. Sensitivity analyses suggested that our findings were generally insensitive to alternative model specifications. We found significant effects of the gaseous pollutants SO2 and NO2 on daily mortality after adjustment for PM10. Our analysis also provided preliminary, but not conclusive, evidence that women, older people, and people with a low level of education might be more vulnerable to air pollution than men, younger people, and people with a high level of education. In addition, the associations between air pollution and daily mortality appeared to be more pronounced in the cool season than in the warm. We concluded that short-term exposure to outdoor air pollution (PM10, SO2, NO2, and O3) was associated with daily mortality in Shanghai and that gaseous pollutants might have independent health effects in the city. Overall, the results of the study appeared largely consistent with those reported in other locations worldwide. Further research will be needed to disentangle the effects of the various pollutants and to gain more conclusive insights into the influence of various sociodemographic characteristics (e.g., sex, age, and socioeconomic status) and of season on the associations between air pollution and daily mortality.

The urban heat island and its impact on heat waves and human health in Shanghai.

With global warming forecast to continue into the foreseeable future, heat waves are very likely to increase in both frequency and intensity. In urban regions, these future heat waves will be exacerbated by the urban heat island effect, and will have the potential to negatively influence the health and welfare of urban residents. In order to investigate the health effects of the urban heat island (UHI) in Shanghai, China, 30 years of meteorological records (1975-2004) were examined for 11 first- and second-order weather stations in and around Shanghai. Additionally, automatic weather observation data recorded in recent years as well as daily all-cause summer mortality counts in 11 urban, suburban, and exurban regions (1998-2004) in Shanghai have been used. The results show that different sites (city center or surroundings) have experienced different degrees of warming as a result of increasing urbanization. In turn, this has resulted in a more extensive urban heat island effect, causing additional hot days and heat waves in urban regions compared to rural locales. An examination of summer mortality rates in and around Shanghai yields heightened heat-related mortality in urban regions, and we conclude that the UHI is directly responsible, acting to worsen the adverse health effects from exposure to extreme thermal conditions.

Visibility, air quality and daily mortality in Shanghai, China.

This study was designed to assess the association between visibility and air quality, and to determine whether the variations in daily mortality were associated with fluctuations in visibility levels in Shanghai, China. Mortality data were extracted from the death certificates, provided by Shanghai Municipal Center of Disease Control and Prevention, and visibility data were obtained from Shanghai Municipal Bureau of Meteorology. Air quality data (PM(10), PM(2.5), PM(10-2.5), SO(2), NO(2) and O(3)) were obtained from Shanghai Environmental Monitoring Center. Generalized additive model (GAM) with penalized splines was used to analyze the mortality, visibility, air pollution, and covariate data. Among various pollutants, PM(2.5) showed strongest correlation with visibility. Visibility, together with humidity, was found appropriate in predicting PM(2.5) (R-squared: 0.64) and PM(10) (R-squared: 0.62). Decreased visibility was significantly associated with elevated death rates from all causes and from cardiovascular disease in Shanghai; one inter-quartile range (8 km) decrease in visibility corresponded to 2.17% (95%CI: 0.46%, 3.85%), 3.36% (95%CI: 0.96%, 5.70%), and 3.02% (95%CI: -1.32%, 7.17%) increase of total, cardiovascular and respiratory mortality, respectively. The effect estimates using predicted PM(2.5) and PM(10) concentrations were similar to those assessed using actual concentrations. This is the first study in Mainland China assessing the association between visibility and adverse health outcomes. Our findings suggest the possibility of using visibility as a surrogate of air quality in health research in developing countries where air pollution data might be scarce and not routinely monitored.

Diurnal temperature range as a novel risk factor for COPD death.

BACKGROUND AND OBJECTIVE: Although the relationship between day-to-day temperature changes and COPD mortality is well established, it is not known whether temperature variation within one day, that is diurnal temperature range (DTR), is a risk factor for acute COPD death, independent of the absolute temperature level. METHODS: In a time-series study, the relationship between DTR and daily COPD mortality between 2001 and 2004 in Shanghai, China was assessed. A semi-parametric generalized additive model was used to allow for long-term and seasonable trends in COPD mortality, as well as variation in air pollution and weather. RESULTS: There was a significant association between DTR and daily COPD mortality. A 1 degrees C increase in the 4-day moving average for DTR corresponded to a 1.25% (95% confidence interval: 0.35-2.15) increase in COPD mortality. CONCLUSION: These findings suggest that DTR is a novel risk factor for acute COPD death.

Season, sex, age, and education as modifiers of the effects of outdoor air pollution on daily mortality in Shanghai, China: The Public Health and Air Pollution in Asia (PAPA) Study.

BACKGROUND: Various factors can modify the health effects of outdoor air pollution. Prior findings about modifiers are inconsistent, and most of these studies were conducted in developed countries. OBJECTIVES: We conducted a time-series analysis to examine the modifying effect of season, sex, age, and education on the association between outdoor air pollutants [particulate matter < 10 microm in aerodynamic diameter (PM(10)), sulfur dioxide, nitrogen dioxide, and ozone] and daily mortality in Shanghai, China, using 4 years of daily data (2001-2004). METHODS: Using a natural spline model to analyze the data, we examined effects of air pollution for the warm season (April-September) and cool season (October-March) separately. For total mortality, we examined the association stratified by sex and age. Stratified analysis by educational attainment was conducted for total, cardiovascular, and respiratory mortality. RESULTS: Outdoor air pollution was associated with mortality from all causes and from cardiorespiratory diseases in Shanghai. An increase of 10 mug/m(3) in a 2-day average concentration of PM(10), SO(2), NO(2), and O(3) corresponds to increases in all-cause mortality of 0.25% [95% confidence interval (CI), 0.14-0.37), 0.95% (95% CI, 0.62-1.28), 0.97% (95% CI, 0.66-1.27), and 0.31% (95% CI, 0.04-0.58), respectively. The effects of air pollutants were more evident in the cool season than in the warm season, and females and the elderly were more vulnerable to outdoor air pollution. Effects of air pollution were generally greater in residents with low educational attainment (illiterate or primary school) compared with those with high educational attainment (middle school or above). CONCLUSIONS: Season, sex, age, and education may modify the health effects of outdoor air pollution in Shanghai. These findings provide new information about the effects of modifiers on the relationship between daily mortality and air pollution in developing countries and may have implications for local environmental and social policies.

Short-term effects of ambient gaseous pollutants and particulate matter on daily mortality in Shanghai, China.

Identification of the specific pollutants contributing most to the health hazard of the air pollution mixture may have important implications for environmental and social policies. In the current study, we conducted a time-series analysis to examine the specific effects of major air pollutants [particulate matter less than 10 microns in diameter (PM(10)), sulfur dioxide (SO(2)), and nitrogen dioxides (NO(2))] on daily mortality in Shanghai, China, using both single-pollutant and multiple-pollutant models. In the single-pollutant models, PM(10), SO(2), and NO(2) were found to be associated with mortality from both all non-accidental causes and from cardiopulmonary diseases. Unlike some prior studies in North America, we found a significant effect of gaseous pollutants (SO(2) and NO(2)) on daily mortality even after adjustment for PM(10) in the multiple-pollutant models. Our findings, combined with previous Chinese studies showing a consistent, significant effect of gaseous pollutants on mortality, suggest that the role of outdoor exposure to SO(2) and NO(2) should be investigated further in China.

Diurnal temperature range and daily mortality in Shanghai, China.

Although the relationship between temperature level and mortality outcomes has been well established, it is still unknown whether within-day variation in temperature, e.g. diurnal temperature range (DTR), is a risk factor for death independent of the corresponding temperature. Moreover, DTR is a meteorological indicator associated with global climate change which may be related to a variety of health outcomes. We hypothesized that large diurnal temperature change might be a source of additional environmental stress and therefore a risk factor for death. We used daily weather and mortality data from Shanghai, China to test this hypothesis. We conducted a time-series study to examine the association between DTR and mortality outcomes from 2001 to 2004. A semi-parametric generalized additive model (GAM) was used to assess the acute effect of DTR on mortality after controlling for covariates including time trend, day of the week (DOW), temperature, humidity, and outdoor air pollution. We found a strong association between DTR and daily mortality after adjustment for those potential confounders. A 1 degrees C increment of the 3-day moving average of DTR corresponded to a 1.37% (95% CI 1.08-1.65%) increase in total non-accidental mortality, a 1.86% (95% CI 1.40-2.32%) increase in cardiovascular mortality, and a 1.29% (95% CI 0.49-2.09%) increase in respiratory mortality. The effects of DTR on total non-accidental and cardiovascular mortality were significant on both "cold" (below 23 degrees C) and "warm" (at least 23 degrees C) days, although respiratory mortality was only significantly associated with DTR on "cold" days. This study suggests within-day variation in temperature may be a novel risk factor for death.

Differentiating the effects of fine and coarse particles on daily mortality in Shanghai, China.

The findings on health effects of ambient fine particles (PM2.5) and coarse particles (PM10-2.5) remain inconsistent. In China, PM2.5 and PM10-2.5 are not the criteria air pollutants, and their monitoring data are scarce. There have been no epidemiological studies of health effects of PM2.5 and PM10-2.5 simultaneously in China. We conducted a time series study to examine the acute effects of PM2.5 and PM10-2.5 on daily mortality in Shanghai, China from Mar. 4, 2004 to Dec. 31, 2005. We used the generalized additive model (GAM) with penalized splines to analyze the mortality, air pollution and covariate data. The average concentrations of PM2.5 and PM10-2.5 were 56.4 microg/m3 and 52.3 microg/m3 in our study period, and PM2.5 constituted around 53.0% of the PM10 mass. Compared with the Global Air Quality Guidelines set by World Health Organization (10 microg/m3 for annual mean) and U.S. National Ambient Air Quality Standards (15 microg/m3 for annual mean), the PM2.5 level in Shanghai was much higher. We found that PM2.5 was associated with the death rates from all causes and from cardiorespiratory diseases in Shanghai. We did not find a significant effect of PM10-2.5 on mortality outcomes. A10 microg/m3 increase in the 2-day moving average (lag01) concentration of PM2.5 corresponded to 0.36% (95% CI 0.11%, 0.61%), 0.41% (95% CI 0.01%, 0.82%) and 0.95% (95% CI 0.16%, 1.73%) increase of total, cardiovascular and respiratory mortality. For PM10-2.5, the effects were attenuated and less precise. Our analyses provide the first statistically significant evidence in China that PM2.5 has an adverse effect on population health and strengthen the rationale for further limiting levels of PM2.5 in outdoor air in Shanghai.

Heat wave impacts on mortality in Shanghai, 1998 and 2003.

A variety of research has linked extreme heat to heightened levels of daily mortality and, not surprisingly, heat waves both in 1998 and in 2003 all led to elevated mortality in Shanghai, China. While the heat waves in the two years were similar in meteorological character, elevated mortality was much more pronounced during the 1998 event, but it remains unclear why the human response was so varied. In order to explain the differences in human mortality between the two years' heat waves, and to better understand how heat impacts human health, we examine a wide range of meteorological, pollution, and social variables in Shanghai during the summers (15 June to 15 September) of 1998 and 2003. Thus, the goal of this study is to determine what was responsible for the varying human health response during the two heat events. A multivariate analysis is used to investigate the relationships between mortality and heat wave intensity, duration, and timing within the summer season, along with levels of air pollution. It was found that for heat waves in both summers, mortality was strongly associated with the duration of the heat wave. In addition, while slightly higher than average, the air pollution levels for the two heat waves were similar and cannot fully explain the observed differences in human mortality. Finally, since the meteorological conditions and pollution levels for the two heat waves were alike, we conclude that improvements in living conditions in Shanghai, such as increased use of air conditioning, larger living areas, and increased urban green space, along with higher levels of heat awareness and the implementation of a heat warning system, were responsible for the lower levels of human mortality in 2003 compared to 1998.

A time series analysis of outdoor air pollution and preterm birth in Shanghai, China.

OBJECTIVE: To investigate the relation between air pollution exposure and preterm birth in Shanghai, China. METHODS: We examined the effect of ambient air pollution on preterm birth using time-series approach in Shanghai in 2004. This method can eliminate potential confounding by individual risk factors that do not change over a short period of time. Daily numbers of preterm births were obtained from the live birth database maintained by Shanghai Municipal Center of Disease Control and Prevention. We used the generalized additive model (GAM) with penalized splines to analyze the relation between preterm birth, air pollution, and covariates. RESULTS: We observed a significant effect of outdoor air pollution only with 8-week exposure before preterm births. An increase of 10 microg/m3 of 8-week average PM10, SO2, NO2, and O3 corresponded to 4.42% (95%CI 1.60%, 7.25%), 11.89% (95%CI 6.69%, 17.09%), 5.43% (95%CI 1.78%, 9.08%), and 4.63% (95%CI 0.35%, 8.91%) increase of preterm birth. We did not find any significant acute effect of outdoor air pollution on preterm birth in the week before birth. CONCLUSION: Ambient air pollution may contribute to the risk of preterm birth in Shanghai. Our analyses also strengthen the rationale for further limiting air pollution level in the city.

Interaction between ambient particles and ozone and its effect on daily mortality.

OBJECTIVE: To examine the effect of particulate matter (PM) less than 10 microns in diameter (PM10) and ozone (O3) on daily mortality in Shanghai, China. METHODS: A generalized additive model with penalized spline function was used to observe the acute effect of PM10 and O3 on daily mortality. RESULTS: Higher PM10 significantly increased the effect of O3 on total mortality, and O3 also increased the effect of PM10 although the estimated increment was statistically insignificant. CONCLUSION: Our findings provide further evidence for the effect of PM10 and O3 on daily mortality.