A study on the short-term effect of particulate matter pollution on hospital visits for asthma in children in Shanghai, China.

Recently, particulate matter pollution has been worsening, which has been affecting the asthma visits in children. In this study, we assessed the short-term effects of PM10 and PM2.5 on asthma visits in children in Shanghai, China from January 1, 2009 and December 31, 2010, using a generalized additive model. We controlled the confounding factors, such as long-term trends, week day effect, and weather elements. The lag effects of different age subgroups (≤ 2 yr, 3-5 yr, and 6-18 yr subgroups) were performed. The results showed significant effects of PM10 and PM2.5 on asthma visits in children, though the seasonal lags varied for the three age subgroups. In general, the effect of PM2.5 on asthma visits in children was stronger and more acute than that of PM10. PM2.5 showed the highest relative risk of 1.192 at lag 0 day in summer; and PM10 showed the highest relative risk of 1.073 at lag 3 day in autumn. Overall, particulate matter pollution showed a greater effect on relatively younger children. In particular, the ≤ 2 yr subgroup showed the highest seasonal relative risk of PM10. Especially, seasonal relative risk of PM10 in autumn for the ≤ 2 yr subgroup was much higher than that for the other two subgroups. The 3-5 yr and 6-18 yr subgroups showed the highest seasonal relative risk of PM2.5 in summer and winter, respectively. But the pediatric visits data we obtained cannot reflect the true prevalence of asthma and multiple visits. Thus, selection bias may exist in our analysis.

A review of the impact of outdoor and indoor environmental factors on human health in China.

The Intergovernmental Panel on Climate Change (IPCC) reported that global climate change has led to the increased occurrence of extreme weather events. In the context of global climate change, more evidence indicates that abnormal meteorological conditions could increase the risk of epidemiological mortality and morbidity. In this study, using a systematic review, we evaluated a total of 175 studies (including 158 studies on outdoor environment and 17 studies on indoor environment) to summarize the impact of outdoor and indoor environment on human health in China using the database of PubMed, Web of Science, the Cochrane Library, and Embase. In particular, we focused on studies about cardiovascular and respiratory mortality and morbidity, the prevalence of digestive system diseases, infectious diseases, and preterm birth. Most of the studies we reviewed were conducted in three of the metropolises of China, including Beijing, Guangzhou, and Shanghai. For the outdoor environment, we summarized the effects of climate change-related phenomena on health, including ambient air temperature, diurnal temperature range (DTR), temperature extremes, and so on. Studies on the associations between temperature and human health accounted for 79.7% of the total studies reviewed. We also screened out 19 articles to explore the effect of air temperature on cardiovascular diseases in different cities in the final meta-analysis. Besides, modern lifestyle involves a large amount of time spent indoors; therefore, indoor environment also plays an important role in human health. Nevertheless, studies on the impact of indoor environment on human health are rarely reported in China. According to the limited reports, adverse indoor environment could impose a high health risk on children.

Short-term effect of extreme air temperature on hospital emergency room visits for cardiovascular diseases from 2009 to 2012 in Beijing, China.

Extreme air temperature directly affected human health. However, the short-term effect of extreme air temperature on the incidence of cardiovascular diseases has rarely been reported in China. In this study, we focused on Beijing, China, and assessed the effects of cold/warm days and nights on the number of hospital emergency room (ER) visits for cardiovascular diseases from 2009 to 2012. We used a generalized additive model (GAM) to estimate the association between extreme air temperature and the number of hospital ER visits for cardiovascular diseases. We divided the entire study group into two gender subgroups and three age subgroups. The results showed that the short-term effect of extreme air temperature on hospital ER visits for cardiovascular diseases was more profound in females and the elderly (aged ≥ 75 years). Among all the study subgroups, the highest relative risk (RR) of cardiovascular diseases associated with extremely cold days, warm days, cold nights, and warm nights was 3.0% (95% CI, 1.6%-4.4%), 0.8% (95% CI, - 0.9%-2.6%), 2.8% (95% CI, 1.6%-4.2%), and 1.8% (95% CI, 0.6%-4.3%), respectively. Overall, the effect of extremely low air temperature (during both days and nights) on the incidence of cardiovascular diseases was stronger and more acute than that of extremely high air temperature.

Impact of temperature changes between neighboring days on COPD in a city in Northeast China.

Sudden temperature changes between neighboring days (T24h) have adverse effects on human health. In this study, we used a time series analysis to evaluate the impact of T24h on the number of hospital admissions for chronic obstructive pulmonary disease (COPD) from 2009 to 2012 in Changchun (the capital of Northeast China's Jilin province). We performed the analysis in a generalized additive model (GAM), and the controlling factors included long-term trends, day of the week effect, and the selected weather elements. We divided the entire study group into two gender subgroups (males and females) and two age subgroups (aged < 65 years and aged ≥ 65 years). T24h showed the greatest effect on the entire study group at lag 3 days. In particular, the greatest effect of T24h on females (males) occurred at lag 1 day (lag 3 days); the greatest effect of T24h on the aged ≥ 65 years (aged < 65 years) occurred at lag 1 day (lag 6 days). This indicates that temperature changes between neighboring days have a relatively more acute effect on the elderly and the females than on the younger people and the males. When T24h is less than zero, the highest RR of the number of hospital admissions for COPD occurred at lag 4 days during the warm season (1.025, 95% CI: 0.981, 1.069) and lag 3 days during the cold season (1.019, 95% CI: 0.988, 1.051). When T24h is greater than zero, the highest RR of the number of hospital admissions for COPD occurred at lag 6 days during the warm season (1.026, 95% CI: 0.977, 1.077) and lag 5 days during the cold season (1.021, 95% CI: 0.986, 1.057). The results of this study could be provided to local health authorities as scientific guidelines for controlling and preventing COPD in Changchun, China.

Effect of diurnal temperature range on outpatient visits for common cold in Shanghai, China.

To evaluate the correlations between diurnal temperature range (DTR) and the number of outpatient visits for common cold from Jan. 1, 2008, to Dec. 31, 2010, in the Shanghai metro area; we used a distributed lag non-linear model together with a Poisson regression model. The controlling factors included long-term trends and day of the week in outpatient visits for common cold and the selected weather elements. The entire study group was divided into three different age subgroups, including ≤ 15, 15-65, and ≥ 65 years old. We found some non-linear J-patterns between DTR and daily outpatient visits for common cold. At lag 0 day, the number of outpatient visits for common cold would increase by 11.1% per 1 °C increase in DTR. The greater the DTR, the more it affects outpatient visits for common cold, especially for the ≥ 65 years age group. In addition, DTR plays a more important role in outpatient visits for common cold in spring and winter compared with other seasons of the year. Our study showed that DTR is a risk factor that contributes to common cold. Results in this study can provide scientific evidence for the local authorities in improving preventive measures of the healthcare system.

Short-term effect of PM2.5 on pediatric asthma incidence in Shanghai, China.

Recent epidemiological studies pointed out that air pollution has a significant impact on pediatric asthma. Shanghai is one of the biggest cities in China, and the short-term effect of atmospheric particulate matter on the incidence of pediatric asthma has become a hot topic. From January 1, 2009, to December 31, 2010, we used daily measurements of pollutant concentrations, daily weather data, and daily records of pediatric asthma hospital visits from local authorities to evaluate the short-term effect of air pollution on pediatric asthma incidence in Shanghai, China. We used a generalized additive model (GAM) in the analysis, and the controlled confounding factors include long-term trends, day-of-the-week effects, and weather elements. We divided the entire study group into different age-subgroups. In addition, we took a variety of lag models into consideration. The results showed a strong connection between concentrations of fine particulate matter (PM2.5) and pediatric asthma hospital visits from 2009 to 2010 in Shanghai, China. For the entire study group, the greatest relative risk (RR) of PM2.5 on pediatric asthma hospital visits was 1.060 on a lag of 4 days. As for the three different age-subgroups, the greatest RR of PM2.5 on pediatric asthma hospital visits was 1.061 (at a lag of 5 days), 1.071 (at a lag of 4 days), and 1.052 (at a lag of 2 days), for the under-2-year-olds, 3-to-5-year-olds, and the 6-to-18-year-olds, respectively. The overall short-term effect of PM2.5 on pediatric asthma hospital visits was relatively stronger in younger children. Within the year, we detected the strongest seasonal effect of PM2.5 on pediatric asthma hospital visits in Summer. When adding other air pollutants in the analysis model, RR of PM2.5 on pediatric asthma hospital visits would be increased.

Effects of extreme temperatures on hospital emergency room visits for respiratory diseases in Beijing, China.

Extreme temperature is closely associated with human health, but limited evidence is available for the effects of extreme temperatures on respiratory diseases in China. The goal of this study is to evaluate the effects of extreme temperatures on hospital emergency room (ER) visits for respiratory diseases in Beijing, China. We used a distributed lag non-linear model (DLNM) coupled with a generalized additive model (GAM) to estimate the association between extreme temperatures and hospital ER visits for different age and gender subgroups in Beijing from 2009 to 2012. The results showed that the exposure-response curve between temperature and hospital ER visits was almost W-shaped, with increasing relative risks (RRs) at extremely low temperature. In the whole year period, strong acute hot effects were observed, especially for the elders (age > 65 years). The highest RR associated with the extremely high temperature was 1.36 (95% CI, 0.96-1.92) at lag 0-27. The longer-lasting cold effects were found the strongest at lag 0-27 for children (age ≤ 15 years) and the relative risk was 1.96 (95% CI, 1.70-2.26). We also found that females were more susceptible to extreme temperatures than males.

The relationship between diurnal temperature range and COPD hospital admissions in Changchun, China.

Diurnal temperature range (DTR) has been suggested to be an adverse health factor especially related to respiratory and cardiovascular diseases. In the current study, we investigated the association between DTR and chronic obstructive pulmonary disease (COPD) hospital admissions during 2009 to 2012 in northeast city of Changchun, China. Based on generalized additive model (GAM), the effects were expressed as relative risk (RR) values of COPD with 95% confidence intervals (CIs) with each 1 °C increase in DTR. And they were significantly increased with an increment of 1 °C in DTR, modified by season, age, and sex. The elderly were more vulnerable, with relative risk values of 1.048 (1.029, 1.066) in cold season and 1.037 (1.021, 1.053) in warm season. Regarding the gender, the DTR effect on females was greater during cold season and the RR value was 1.051 (1.033, 1.069) on the current day (lag 0). The greater estimates for males appeared at lag 7 days, with RR of 1.019 (0.998, 1.040). A season-specific effect was detected that the relative risk values with per 1 °C increase in DTR were greater in cold season than in warm season. These findings support the hypothesis of significant relationship between DTR and COPD in Changchun, one northeast city of China.