RETRACTED ARTICLE: The Interaction Effects of Temperature and Humidity on Emergency Room Visits for Respiratory Diseases in Beijing, China

Temperature modification of air pollutants and their synergistic effects on respiratory diseases in a semi-arid city in Northwest China

Air pollutants and temperature are significant threats to public health, and the complex linkages between the environmental factors and their interactions harm respiratory diseases. This study is aimed to analyze the impact of air pollutants and meteorological factors on respiratory diseases and their synergistic effects in Dingxi, a city in northwestern China, from 2018 to 2020 using a generalized additive model (GAM). Relative risk (RR) was employed to quantitatively evaluate the temperature modification on the short-term effects of PM2.5 and O3 and the synergistic effects of air pollutants (PM2.5 and O3) and meteorological elements (temperature and relative humidity) on respiratory diseases. The results indicated that the RRs per inter-quatile range (IQR) rise in PM2.5 and O3 concentrations were (1.066, 95% CI: 1.009-1.127, lag2) and (1.037, 95% CI: 0.975-1.102, lag4) for respiratory diseases, respectively. Temperature stratification suggests that the influence of PM2.5 on respiratory diseases was significantly enhanced at low and moderate temperatures, and the risk of respiratory diseases caused by O3 was significantly increased at high temperatures. The synergy analysis demonstrated significant a synergistic effect of PM2.5 with low temperature and high relative humidity and an antagonistic effect of high relative humidity and O3 on respiratory diseases. The findings would provide a scientific basis for the impact of pollutants on respiratory diseases in Northwest China.

Effects of Environmental and Socioeconomic Inequalities on Health Outcomes: A Multi-Region Time-Series Study

The gradual increase in temperatures and changes in relative humidity, added to the aging and socioeconomic conditions of the population, may represent problems for public health, given that future projections predict even more noticeable changes in the climate and the age pyramid, which require analyses at an appropriate spatial scale. To our knowledge, an analysis of the synergic effects of several climatic and socioeconomic conditions on hospital admissions and deaths by cardiorespiratory and mental disorders has not yet been performed in Brazil. Statistical analyses were performed using public time series (1996-2015) of daily health and meteorological data from 16 metropolitan regions (in a subtropical climate zone in South America). Health data were stratified into six groups according to gender and age ranges (40-59; 60-79; and ≥80 years old) for each region. For the regression analysis, two distributions (Poisson and binomial negative) were tested with and without zero adjustments for the complete series and percentiles. Finally, the relative risks were calculated, and the effects based on exposure-response curves were evaluated and compared among regions. The negative binomial distribution fit the data best. High temperatures and low relative humidity were the most relevant risk factors for hospitalizations for cardiovascular diseases (lag = 0), while minimum temperatures were important for respiratory diseases (lag = 2 or 3 days). Temperature extremes, both high and low, were the most important risk factors for mental illnesses at lag 0. Groups with people over 60 years old presented higher risks for cardiovascular and respiratory diseases, while this was observed for the adult group (40-59 years old) in relation to mental disorders. In general, no major differences were found in the results between men and women. However, regions with higher urbanization levels presented risks, mainly for respiratory diseases, while the same was observed for cardiovascular diseases for regions with lower levels of urbanization. The Municipal Human Development Index is an important factor for the occurrence of diseases and deaths for all regions, depending on the evaluated group, representing high risks for health outcomes (the value for hospitalization for cardiovascular diseases was 1.6713 for the female adult group in the metropolitan region Palmas, and the value for hospitalization for respiratory diseases was 1.7274 for the female adult group in the metropolitan region Campo Mourão). In general, less developed regions have less access to adequate health care and better living conditions.

The effect of nitrogen dioxide and atmospheric pressure on hospitalization risk for chronic obstructive pulmonary disease in Guangzhou, China

BACKGROUND

The relationship between air pollution and meteorological factors on diseases has become a research hotspot recently. Nevertheless, few studies have touched the inferences of nitrogen dioxide (NO₂) and atmospheric pressure (AP) on hospitalization risk for chronic obstructive pulmonary disease (COPD).

OBJECTIVES

To investigate the short-term impact of particulate air pollutants and meteorology factors on hospitalizations for COPD and quantify the corresponding risk burden of hospital admission.

METHODS

In our study, COPD cases were collected from Guangzhou Panyu Central Hospital (n = 11,979) from Dec of 2013 to Jun 2019. The 24-h average temperature, relative humidity (RH), wind speed (V), AP and other meteorological data were obtained from Guangzhou Meteorological Bureau. Air pollution data were collected from Guangzhou Air Monitoring Station. The influence of different NO₂ and AP values on COPD risk was quantified by a distributed lag nonlinear model (DLNM) combined with Poisson Regression and Time Series analysis.

RESULTS

We found that NO₂ had a non-linear relationship with the incidence of COPD, with an approximate "M" type, appearing at the peaks of 126 μg/m³ (RR = 1.32, 95%CI, 1.07 to 1.64) and 168 μg/m³ (RR = 1.21, 95%CI, 0.94 to 1.55), respectively. And the association between AP and COPD incidence exhibited an approximate J-shape with a peak occurring at 1035 hPa (RR = 1.16, 95% CI, 1.02 to 1.31).

CONCLUSIONS

The nonlinear relationship of NO₂ and AP on COPD admission risk in different periods of lag can be used to establish an early warning system for diseases and reduce the possible outbreaks and burdens of COPD in a sensitive population.

Effect of urban expansion on atmospheric humidity in Beijing-Tianjin-Hebei urban agglomeration

Accelerated urban expansion has contributed to the urban-rural contrast regarding atmospheric humidity. However, the effect of urban expansion on atmospheric humidity is not understood well in the Beijing-Tianjin-Hebei urban agglomeration (BTHUA). In this study, observations from 133 meteorological stations were used to analyze the long-term trend of atmospheric humidity and the urban expansion effect in the BTHUA during the period 1961-2014. The urban expansion effect on atmospheric humidity was evaluated by calculating the differences in atmospheric humidity trends between urban and rural series based on the dynamic classification method using secular urban impervious data. The results revealed that a drying trend of annual and seasonal average atmospheric humidity was observed in the urban areas of the BTHUA during the period 1961-2014, characterized by decreasing relative humidity (RH), water vapor pressure (E_a), specific humidity (Q) and increasing vapor pressure deficit (VPD). A more prominent drying trend (p < 0.05) appeared in spring and autumn, whereas a relatively weaker trend occurred in summer and winter. The trend of atmospheric humidity was significantly correlated (Spearman correlation coefficients: -0.45, 0.48, -0.29 and -0.32 for RH, VPD, E_a and Q, respectively; p < 0.01) with the urban expansion rate. The effect of urban expansion on the trend of VPD, E_a and Q was the strongest in spring at 0.138 hpa, -0.237 hpa and -0.151 hpa per decade, respectively, while the urban expansion effect on RH was the strongest in winter, reaching -1.159% per decade. This study provides a better understanding of the relationship between variations in atmospheric humidity and urban expansion, as well as scientific support for urban planning.

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.

Morbidity burden of respiratory diseases attributable to ambient temperature: a case study in a subtropical city in China

BACKGROUND

There are significant associations between ambient temperature and respiratory disease mortality. However, few studies have assessed the morbidity burdens of various respiratory diseases that are attributable to different temperature ranges in subtropical regions.

METHODS

Daily outpatient visits, weather variables, and air pollution data were collected from January 2013 to August 2017 in a hospital in Dongguan city. A standard time series quasi-Poisson regression with a distributed lag non-linear model (DLNM) was applied to estimate the associations between daily mean temperature and morbidity for total respiratory diseases, bronchiectasis, chronic obstructive pulmonary disease (COPD), and asthma. Attributable fractions were then calculated to quantify disease burden relative to different temperature components. Finally, we conducted stratified analysis by age group.

RESULTS

Both low and high temperatures were associated with an increased risk of morbidity secondary to respiratory diseases. Compared with the optimum temperature, the accumulated relative risk (RR) during the seven lag days was 1.13 with a 95% confidence interval (CI) of 1.01-1.26 for extreme heat and 1.02 (95% CI: 0.99-1.05) for extreme cold. Heat-related respiratory morbidity risk was higher than cold-related risk for the total population, but an opposite result was observed for the elderly. About 8.4% (95% CI: 2.8-13.3%) of respiratory morbidity was attributable to non-optimal temperatures, and moderate heat was responsible for most of the excess respiratory morbidity (7.5, 95% CI: 2.4-12.2%).

CONCLUSIONS

We found that exposure to non-optimal temperatures increased the risk of respiratory morbidity in subtropical region, and moderate heat contributed to most of the temperature-related respiratory morbidities. This indicates a need for further examination of moderate, rather than extreme, heat in subtropical region.

Different sensitivities to ambient temperature between first- and re-admission childhood asthma cases in Hong Kong - A time series study

OBJECTIVES

Asthma can be triggered by various factors due to different etiologies. Environmental factors remain a common trigger of asthma, especially amongst children, and such ambient exposures can be harder to avoid compared to behavioral triggers. As such, the contribution of environmental factors may be enhanced when considering repeat asthma cases compared to initial presentations. To test this hypothesis, we assessed associations between ambient temperature and hospital admissions for asthma in Hong Kong and stratified admission records into first and repeat asthma hospitalizations.

METHODS

The daily number of asthma hospitalizations among children aged 0-5 years in Hong Kong during 2007-2011 was regressed on daily mean temperature using distributed lagged nonlinear models, with adjustment for seasonal patterns, day-of-week effects, and other meteorological factors and air-pollutants. Analyses were stratified by summer/winter and by type of admission (first admission and repeated admission).

RESULTS

About 33% of the 12284 asthma hospitalizations were repeat admissions. Repeat admissions demonstrated higher sensitivity to high temperature in the summer. During this period, high temperatures were associated with increased risk of repeat admission but not with first admissions: RR (95% CI) comparing 31 °C vs. 29 °C across lags 0-15 days was 3.40 (1.26, 9.18) and 0.74 (0.31, 1.77) for repeat and first admissions respectively. In the cold season, all admissions increased with falls in temperature, with slightly stronger associations apparent for repeat admissions compared to first admission: 1.20 (1.00, 1.44) vs. 1.10 (0.96, 1.26) respectively comparing risk at 15 °C vs. 12 °C across lags 0-5 days.

CONCLUSIONS

To our knowledge, this is the first study to show stronger associations between ambient temperature and repeat asthma admissions compared to first admissions. The higher sensitivity among those experiencing repeat admissions may allow for more personalized disease management. Given the substantial differences in associations by admission type, future studies of ambient exposures on asthma should consider analyzing the two groups separately.

Meteorological factors, air pollutants, and emergency department visits for otitis media: a time series study

AbstractOtitis media (OM) is a very common disease in children, which results in a significant economic burden to the healthcare system for hospital-based outpatient departments, emergency departments (EDs), unscheduled medical examinations, and antibiotic prescriptions. The aim of this retrospective observational study is to investigate the association between climate variables, air pollutants, and OM visits observed in the 2007-2010 period at the ED of Cuneo, Italy. Measures of meteorological parameters (temperature, humidity, atmospheric pressure, wind) and outdoor air pollutants (particulate matter, ozone, nitrous dioxide) were analyzed at two statistical stages and in several specific steps (crude and adjusted models) according to Poisson's regression. Response variables included daily examinations for age groups 0-3, 0-6, and 0-18. Control variables included upper respiratory infections (URI), flu (FLU), and several calendar factors. A statistical procedure was implemented to capture any delayed effects. Results show a moderate association for temperature (T), age 0-3, and 0-6 with P < 0.05, as well as nitrous dioxide (NO₂) with P < 0.005 at age 0-18. Results of subsequent models point out to URI as an important control variable. No statistical association was observed for other pollutants and meteorological variables. The dose-response models (DLNM-final stage) implemented separately on a daily and hourly basis point out to an association between temperature (daily model) and RR 1.44 at age 0-3, CI 1.11-1.88 (lag time 0-1 days) and RR 1.43, CI 1.05-1.94 (lag time 0-3 days). The hourly model confirms a specific dose-response effect for T with RR 1.20, CI 1.04-1.38 (lag time range from 0 to 11 to 0-15 h) and for NO₂ with RR 1.03, CI 1.01-1.05 (lag time range from 0 to 8 to 0-15 h). These results support the hypothesis that the clinical context of URI may be an important risk factor in the onset of OM diagnosed at ED level. The study highlights the relevance of URI as a control variable to be included in the statistical analysis in association with meteorological factors and air pollutants. The study also points out to a moderate association of OM with low temperatures and NO₂, with specific risk factors for this variable early in life. Further studies are needed to confirm these findings, particularly with respect to air pollutants in larger urban environments.

Nonlinear and Interactive Effects of Temperature and Humidity on Childhood Hand, Foot and Mouth Disease in Hefei, China

BACKGROUND

Hand, foot and mouth disease (HFMD) is one of the major infectious diseases among children and remains a health threat, especially among Asian countries. Many epidemiologic studies suggested significant association of air temperature and humidity with childhood HFMD; however, evidence on the temperature effects on childhood HFMD in temperate cities is limited, and the interactive effects of temperature and humidity have not been studied yet.

METHODS

Daily counts of HFMD in children younger than 15 years of age and daily meteorologic variables during 2010 to 2012 were obtained in Hefei, China. A distributed lag nonlinear model was applied to estimate the potential nonlinear association between temperature and childhood HFMD. The interactive effects between temperature and humidity on childhood HFMD were also investigated.

RESULTS

Temperature rise was associated with higher risk of childhood HFMD. Within the incubation period of HFMD, temperature rise appeared to have the acute effects on childhood HFMD, and a 5°C increase of temperature at lag 0-6 days was associated with 24.8% (95% confidence interval: 11.94%-39.10%) increase of childhood HFMD. Females and children of 0-4 years of agewere more vulnerable to temperature rise. Notably, there were obvious combined effects between temperature and humidity on childhood HFMD-the risk of childhood HFMD elevated at higher temperature and humidity level.

CONCLUSIONS

This study provides evidence that temperature and humidity may jointly affect childhood HFMD, and such interactive impact needs to be considered when evaluating the temperature-childhood HFMD relationship.

Impact of meteorological factors on lower respiratory tract infections in children

Objective

To evaluate retrospectively the relationship between meteorological factors in Shenmu County, Yulin City, Shaanxi Province, China and the incidence of lower respiratory tract infections in children.

Methods

Meteorological data (air temperature, atmospheric pressure, rainfall, hours of sunlight, wind speed and relative humidity) for Shenmu County and medical data from hospitalized patients aged ≤16 years were collected between January 2009 and December 2012. The association between meteorological factors and rate of hospitalization due to lower respiratory tract infections was investigated; the total hospitalization rate was compared with the rate of lower respiratory tract disease-related hospitalizations.

Results

The leading bacterial causes of lower respiratory tract infections were Streptococcus pneumoniae and Haemophilus influenzae type B; the main viral cause was respiratory syncytial virus. Lower respiratory tract infection hospitalization rate was significantly correlated with air temperature (R = −0.651), atmospheric pressure (R = 0.560), rainfall (R = −0.614) and relative humidity (R = −0.470), but not with hours of sunlight (R = −0.210) or wind speed (R = 0.258). Using multiple linear regression, lower respiratory tract infection hospitalization rate decreased with a gradual increase in air temperature (F = 38.30) and relative humidity (F = 15.58).

Conclusion

Air temperature and relative humidity were major influencing meteorological factors for hospital admissions in children due to lower respiratory tract infections.