The effects of weather, air pollutants, and Asian dust on hospitalization for asthma in Fukuoka

Association of diurnal temperature range and childhood asthma: a population-based cross-sectional study in a Tropical City, China

BACKGROUND

Climate change has significantly impacted the diurnal temperature range (DTR), particularly in tropical regions of China, where DTR fluctuations are more frequent. While previous studies have primarily focused on the link between short-term DTR exposure and childhood asthma, there is limited information on the long-term effects from large-scale studies.

METHODS

In 2022, a cross-sectional survey involving 9,130 children aged 2-10 years was conducted using stratified cluster random sampling in tropical Sanya, Hainan Province, China. Data on demographics, and asthma symptoms were collected using the validated International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. Temperature, precipitation and Normalized Difference Vegetation Index (NDVI) were obtained from remote sensing satellite. A generalized linear model (GLM) was employed to analyze the association between DTR exposure and asthma, and stratified analyses were conducted based on environmental and lifestyle factors.

RESULTS

The prevalence of childhood asthma was 7.57%, with the annual average DTR ranging from 5.15℃ to 7.26℃. After adjusting for potential confounders, each 1℃ increase in DTR was associated with a 65.9% higher risk of asthma (95% CI: 1.058, 2.602). Stratified analyses indicated that the impact of DTR on asthma risk was stronger among children living in areas with higher temperatures, higher precipitation, lower vegetation coverage (measured by NDVI), as well as those who were not breastfed, exposed to passive smoking, or whose mothers had pets during pregnancy.

CONCLUSIONS

In Sanya, increased annual DTR was significantly associated with a higher odds of childhood asthma, and this effect was influenced by environmental and lifestyle factors. Therefore, public health strategies could mitigate childhood asthma risk associated with DTR through urban greening, advocating for breastfeeding, reducing secondhand smoke, and avoiding pet ownership during pregnancy.

Ambient temperature and hospitalizations of children due to respiratory diseases in Cuiabá-MT, Brazil

This study evaluated the role of temperature and fine particulate matter in hospitalizations of children living in Cuiabá-MT, obtained from DATASUS, between 01/01/2016 and 12/31/2018. Daily concentrations of the pollutant fine particulate matter were estimated using the CAMS mathematical model, made available by CPTEC. Diagnoses of tracheitis and laryngitis, pneumonia, bronchitis, bronchiolitis and asthma were included. INMET provided data on maximum and minimum temperatures and relative humidity. Statistical analysis was performed with three generalized additive Poisson regression models, one of which only included the minimum temperature, another including the pollutant and the last with an interaction variable. There were 1,612 hospitalizations in the period; in the multivariate model, associations were identified between minimum temperature and hospitalizations in lags 1 to 5; the effect of increasing the minimum temperature by 4°C resulted in an increase in the risk of hospitalizations by 18%; 15.2% of hospitalizations are attributed to this increase and an excess of approximately US$ 68,000.00 in expenses for the health system during the period evaluated. In addition to the known effects of exposure to pollutants on health, it was possible to identify that an increase in the minimum daily temperature can cause damage to children's health.

Ambient air pollution sensitivity and severity of pediatric asthma

BACKGROUND

Ambient air pollution exposure increases the incidence and severity of pediatric asthma. Despite this, we lack effective therapies to protect patients from the impact of ambient air pollution exposure. A roadblock is the inability to identify patients that are affected by air pollution.

OBJECTIVE

To examine the association between AAP sensitivity determined by individual exposure prior to asthma exacerbations and the severity of asthma in pediatric patients.

METHODS

We assess the association between spikes in ambient air pollution and asthma exacerbations. Patients were considered sensitive to a specific pollutant if they experienced an asthma exacerbation immediately following a spike in the concentration of that pollutant. Cut off values for these spikes were determined as two standard deviations above the mean concentration two weeks prior and two weeks post the days leading up to an asthma exacerbation.

RESULTS

We included 8129 pediatric patients with over 34,346 associated asthma exacerbations. In a multinomial log-linear logistic regression model comparing patients with mild asthma to patients with moderate or severe asthma, sensitivity to Ozone, SO2, PM2.5 and PM10 was significantly associated to severe as opposed to mild asthma (OR 1.39 with CI 1.08-1.78, 1.58 with CI 1.12-2.23, 1.37 with CI 1.07-1.76, and 1.63 with CI 1.12-2.37 respectively). Furthermore, moderate as opposed to mild asthma was significantly associated with sensitivity to SO2 and PM2.5 (OR 1.24 with CI 1.06-1.44 and 1.26 with CI 1.12-1.43, respectively).

IMPACT STATEMENT

There is a subpopulation of pediatric asthma patients that experience asthma exacerbations just following spikes in ambient air pollution. This subgroup of patients has more severe asthma despite correction for significant confounders. The presented work is the first to reveal the clinically significant impact of variation in ambient air pollution sensitivity in pediatric asthma, highlighting the importance of accounting for variable sensitivity in the study of the effects of ambient air pollution exposure on pediatric asthma.

Airborne Suspended Particulate Matter and the Prevalence of Allergic Conjunctivitis in Japan

Background This study aimed to examine the association of suspended particulate matter (SPM) with outpatient attendance for allergic conjunctivitis. Methodology The information on air pollution, encompassing total hydrocarbons, non-methane hydrocarbons, methane, carbon monoxide, nitrogen oxide, nitric oxide, oxidants, and SPM alongside data concerning daily weather conditions such as temperature, wind speed, and humidity, was gathered. Subsequently, the weekly mean values for outpatient visits, air pollution, and weather parameters were computed. Results The number of outpatient visits for allergic conjunctivitis was significantly associated with SPM levels (r = 0.70, p = 0.0037), oxidant levels (r = 0.70, p = 0.0038), wind speed (r = 0.48, p = 0.0472), and humidity (r = 0.77, p = 0.0009) from January to March, as well as SPM levels (r = 0.53, p = 0.0309) and carbon monoxide (r = 0.56, p = 0.0230) from April to June. Multivariate analysis showed that SPM (odds ratio = 1.37, p = 0.0161) and wind velocity (odds ratio = 1.52, p = 0.0038) were significant predictors of the number of outpatient visits from January to December. Conclusions SPM levels were the only independent predictor of outpatient visits for allergic conjunctivitis, suggesting that SPM contributes to the pathophysiology of this condition.

Effects of Ambient Air Pollutants on Hospital Admissions among Children Due to Asthma and Wheezing-Associated Lower Respiratory Infections in Mysore, India: A Time Series Study

Air pollutants are known to trigger asthma and wheezing-associated lower respiratory infections in children, but evidence regarding their effect on hospital admissions in India is limited. We conducted a time-series study over a period of five years to assess the role of ambient air pollutants in daily asthma-related hospital admissions in children in Mysore, India. Daily asthma and wheeze (associated with lower respiratory infections) admissions were modelled using a generalised additive model (GAM) to examine the non-linear effects and generalised linear models (GLM) for linear effects, if any. Models were adjusted by day of the week and lag days, with smooth terms for time, maximum temperature, and relative humidity, and they were stratified by sex and age group. Of the 362 children admitted, more than 50% were boys, and the mean age was 5.34 years (±4.66). The GAMs showed non-linear associations between NO2, PM2.5, and NH3. For example, a 10 µgm-3 (or 10%) increase in NO2 increased admissions by 2.42. These non-linear effects were more pronounced in boys. A linear effect was detected for PM10 with a relative risk (95% CI) of 1.028, 1.013, and 1.043 with admission. Further research is needed to explore whether these findings can be replicated in different cities in India. Air pollution needs to be controlled, and policies that focus on lower cut-off levels for vulnerable populations are necessary.

Effect of particulate matter (PM2.5 and PM10) on health indicators: climate change scenarios in a Brazilian metropolis

Recife is recognized as the 16th most vulnerable city to climate change in the world. In addition, the city has levels of air pollutants above the new limits proposed by the World Health Organization (WHO) in 2021. In this sense, the present study had two main objectives: (1) To evaluate the health (and economic) benefits related to the reduction in mean annual concentrations of PM₁₀ and PM_2.5 considering the new limits recommended by the WHO: 15 µg/m³ (PM₁₀) and 5 µg/m³ (PM_2.5) and (2) To simulate the behavior of these pollutants in scenarios with increased temperature (2 and 4 °C) using machine learning. The averages of PM_2.5 and PM₁₀ were above the limits recommended by the WHO. The scenario simulating the reduction in these pollutants below the new WHO limits would avoid more than 130 deaths and 84 hospital admissions for respiratory or cardiovascular problems. This represents a gain of 15.2 months in life expectancy and a cost of almost 160 million dollars. Regarding the simulated temperature increase, the most conservative (+ 2 °C) and most drastic (+ 4 °C) scenarios predict an increase of approximately 6.5 and 15%, respectively, in the concentrations of PM_2.5 and PM₁₀, with a progressive increase in deaths attributed to air pollution. The study shows that the increase in temperature will have impacts on air particulate matter and health outcomes. Climate change mitigation and pollution control policies must be implemented for meeting new WHO air quality standards which may have health benefits.

Low temperature reduces occludin expression in bronchial epithelial cells: Implications in cold-induced asthma

BACKGROUND

Cold exposure is a common factor to trigger asthma attacks. However, the underlying mechanism has not been thoroughly elucidated. We aimed to investigate the hypothesis that low temperature reduces occludin expression and compromises epithelial barrier function in airways, which in turn, results in asthma exacerbation.

METHODS

We examined occludin expression in human bronchial epithelial cell line (Beas-2B) cells exposed to either 29 °C or 37 °C. The following drugs were administered prior to cold treatment: MG132 (a proteasome inhibitor), cycloheximide (a protein synthesis inhibitor), HC-067047 plus GSK2193874 (transient receptor potential vanilloid 4 [TRPV4] antagonists), or C4-ceramide (a glucocorticoid-inducible kinase [SGK1] activator). siNedd4-2 was transfected into Beas-2B cells to investigate the role that Nedd4-2 plays in mediating occludin instability induced by cold. In animal experiments, we treated ovalbumin (OVA)-induced asthmatic mice with a thermoneutral temperature of 30 °C or cold exposure (10 °C, 6 h/day) for 2 weeks. GSK2193874 or C4-ceramide was administered during the cold treatment. Occludin expression of the lung, pulmonary permeability, serum IgE levels, and lung inflammation were assessed.

RESULTS

Low temperature treatment (29 °C) significantly reduced the expression of occludin in Beas-2B cells from 1 to 9 h, which was rescued upon treatment with MG132, HC-067047 plus GSK2193874, C4-ceramide, or Nedd4-2 knockdown. Low temperatures affected occludin stability through SGK1/Nedd4-2-dependent proteolysis. In vivo mice data revealed that cold exposure compromised the airway epithelial barrier function, decreased occludin expression, and exacerbated lung inflammation, which was attenuated by the GSK2193874 or C4-ceramide injection.

CONCLUSION

We identified a potential mechanism underlying cold-induced asthma exacerbation involving Nedd4-2-mediated occludin proteolysis and airway epithelial barrier disruption.

Comparison of the Concentration of Suspended Particles and Their Chemical Composition near the Ground Surface and Dust Extinction Coefficient by LIDAR

In many epidemiological studies, the dust extinction coefficient measured by light detection and ranging (LIDAR) is used as an indicator of exposure to Asian dust. However, few reports on the relationship between the distribution of total suspended particles (TSPs) near the ground surface and the dust extinction coefficient exist. In this study, we examined the relationship between the concentrations of TSPs near the ground surface, substances indicative of mineral content, and air pollutants that may be transported with Asian dust and dust extinction coefficients in two regions: Imizu and Yurihama-Matsue, from March to May in 2011 and 2013. In both years, large dust extinction coefficients were observed in Imizu and Matsue on days when the concentrations of TSPs and mineral content indicators were high near the ground surface in Imizu and Yurihama, and Asian dust was expected to be highly suspended. In both regions, the concentrations of TSPs and mineral content indicators were significantly positively correlated with the dust extinction coefficient. The concentrations of all air pollutants analyzed were significantly positively correlated with the dust extinction coefficient in each region in 2013, but not in 2011. These results suggest that the dust extinction coefficient is a useful indicator of Asian dust near the ground surface; however, as harmful air pollutants occasionally move with Asian dust, it is necessary to monitor these pollutants near the ground surface when conducting an epidemiological study on the health effect of airborne particles.

Photochemical oxidants and ambulance dispatches for asthmatic symptoms in Tokyo

While photochemical oxidants (O_x = O₃+ NO₂) are known to increase asthma flare-ups, there is a paucity of studies of the Japanese population, especially for Tokyo residents. We used data on asthma cases (n = 7,455) from ambulance dispatches in Tokyo, 2015-2016. Variables included date and time of incidence, age, sex, occurrence location at the ward (ku) level, and the symptom/cause of dispatch as recorded by paramedics. O_x data were obtained from the nearest air quality monitoring station to the occurrence location, then linked them with the outcomes based on occurrence date. We directly incorporated a distributed lag model into a bi-directional case-crossover study design controlling for ambient temperature and day of week. A 10-ppb increase in O_x for lag days 0-3 was associated with a 5.51% (95% CI: 0.13 to 11.18) increase in ambulance dispatches related to asthma. The association was strongest on lag day 1 (4.67%, 95% CI: 0.51 to 9.00). Exposure to high levels of O_x was associated with increased ambulance dispatches related to asthma exacerbations in Tokyo, Japan.

Cold temperature and sudden temperature drop as novel risk factors of asthma exacerbation: a longitudinal study in 18 Chinese cities

BACKGROUND

Few studies have explored the role of ambient temperature in asthma exacerbation.

OBJECTIVE

We aimed to explore the association of temperature with diurnal peak expiratory flow (PEF) variation and asthma exacerbation.

METHOD

We developed a longitudinal study among asthmatic adults in 18 Chinese cities. Subjects recorded PEF in dynamic pulmonary function monitoring from 2017 to 2020. Linear mixed-effect model and generalized additive model with distributed non-linear models were used to assess the effect of temperature and temperature change between neighboring days (TCN) on diurnal PEF variation and the risk of asthma exacerbation.

RESULT

We evaluated a total of 79,217 daily PEF monitoring records from 4467 adult asthmatic patients. There were significant increase of diurnal PEF variation and higher risk of asthma exacerbation with cold and sudden temperature drop. Compared with the referent temperature (99th percentile, 32 °C), exposure to moderate cold (25th percentile, 3 °C) and extreme cold (2.5th percentile, -7 °C) was associated with elevations of 1.28% and 1.16% in diurnal PEF variation over lag 0-2 days, respectively. The odds ratios of asthma exacerbation (determined by diurnal PEF variation >20%) at the two temperature cutoffs were 1.68 and 1.73. A sudden temperature drop (2.5th percentile of TCN, -5 °C) was associated with 1.13% elevation in diurnal PEF variation, and with increased risk of asthma exacerbation (odd ratio = 1.50) over lag 0-4 days.

CONCLUSION

This large multicenter study provided the first-hand empirical evidence that cold temperature and a temperature drop may increase the risk of asthma exacerbation.

Association of childhood asthma with intra-day and inter-day temperature variability in Shanghai, China

OBJECTIVES

Short-term temperature variability (TV) is associated with the exacerbation of asthma, but little is known about the relative effects of intra- and inter-day TV. We aimed to assess the relative impacts of intra- and inter-day TV on childhood asthma and to explore the modification effects by season.

METHODS

A quasi-Poisson generalized linear regression model combined with a distributed lag nonlinear model was adopted to evaluate the nonlinear and lagged effects of TV on childhood asthma in Shanghai from 2009 to 2017. Intra- and inter-day TV was measured with diurnal temperature range (DTR) and temperature changes between neighboring days (TCN), respectively.

RESULTS

Increased DTR was associated with the elevated relative risk (RR) of daily outpatient visits for childhood asthma (DOVCA) in both the whole year (RR_lag0-14 for the 99th percentile: 1.264, 95% confidence interval (CI): 1.052, 1.518) and cold season (RR_lag0-12 for the 99th percentile: 1.411, 95% CI: 1.053, 1.889). Higher TCN in the warm season was associated with the increased RR of DOVCA (RR_lag0-14 for the 99th percentile: 2.964, 95% CI: 1.636, 5.373). The number and fraction of DOVCA attributed to an interquartile range (IQR) increase of TCN were higher than those attributed to DTR in both the whole year period and warm season. However, the number and fraction of DOVCA attributed to an IQR increase of DTR were greater than those attributed to TCN in the cold season.

CONCLUSIONS

Our results provide novel evidence that both intra- and inter-day TV might be a trigger of childhood asthma. Higher DTR appeared to have greater impacts on childhood asthma in the cold season while an increase in TCN seemed to have bigger effects in the warm season.

Communicating respiratory health risk among children using a global air quality index

Air pollution poses a serious threat to children's respiratory health around the world. Satellite remote-sensing technology and air quality models can provide pollution data on a global scale, necessary for risk communication efforts in regions without ground-based monitoring networks. Several large centers, including NASA, produce global pollution forecasts that may be used alongside air quality indices to communicate local, daily risk information to the public. Here we present a health-based, globally applicable air quality index developed specifically to reflect the respiratory health risks among children exposed to elevated outdoor air pollution. Additive, excess-risk air quality indices were developed using 51 different coefficients derived from time-series health studies evaluating the impacts of ambient fine particulate matter, nitrogen dioxide, and ozone on children's respiratory morbidity outcomes. A total of four indices were created which varied based on whether or not the underlying studies controlled for co-pollutants and in the adjustment of excess risks of individual pollutants. Combined with historical estimates of air pollution provided globally at a 25 × 25 km² spatial resolution from the NASA's Goddard Earth Observing System composition forecast (GEOS-CF) model, each of these indices were examined in a global sample of 664 small and 140 large cities for study year 2017. Adjusted indices presented the most normal distributions of locally-scaled index values, which has been shown to improve associations with health risks, while indices based on coefficients controlling for co-pollutants had little effect on index performance. We provide the steps and resources need to apply our final adjusted index at the local level using freely-available forecasting data from the GEOS-CF model, which can provide risk communication information for cities around the world to better inform individual behavior modification to best protect children's respiratory health.

Outdoor air pollution and the risk of asthma exacerbations in single lag0 and lag1 exposure patterns: a systematic review and meta-analysis

Objective: To synthesize evidence regarding the relationship between outdoor air pollution and risk of asthma exacerbations in single lag0 and lag1 exposure patterns.Methods: We performed a systematic literature search using PubMed, Embase, Cochrane Library, Web of Science, ClinicalTrials, China National Knowledge Internet, Chinese BioMedical, and Wanfang databases. Articles published until August 1, 2020 and the reference lists of the relevant articles were reviewed. Two authors independently evaluated the eligible articles and performed structured extraction of the relevant information. Pooled relative risks (RRs) and 95% confidence intervals (CIs) of lag0 and lag1 exposure patterns were estimated using random-effect models.Results: Eighty-four studies met the eligibility criteria and provided sufficient information for meta-analysis. Outdoor air pollutants were associated with increased risk of asthma exacerbations in both single lag0 and lag1 exposure patterns [lag0: RR (95% CI) (pollutants), 1.057(1.011, 1.103) (air quality index, AQI), 1.007 (1.005, 1.010) (particulate matter of diameter ≤ 2.5 μm, PM_2.5), 1.009 (1.005, 1.012) (particulate matter of diameter, PM₁₀), 1.010 (1.006, 1.014) (NO₂), 1.030 (1.011, 1.048) (CO), 1.005 (1.002, 1.009) (O₃); lag1:1.064(1.022, 1.106) (AQI), 1.005 (1.002, 1.008) (PM_2.5), 1.007 (1.004, 1.011) (PM₁₀), 1.008 (1.004, 1.012) (NO₂), 1.025 (1.007, 1.042) (CO), 1.010 (1.006, 1.013) (O₃)], except SO₂ [lag0: RR (95% CI), 1.004 (1.000, 1.007); lag1: RR (95% CI), 1.003 (0.999, 1.006)]. Subgroup analyses revealed stronger effects in children and asthma exacerbations associated with other events (including symptoms, lung function changes, and medication use).Conclusion: Outdoor air pollution increases the asthma exacerbation risk in single lag0 and lag1 exposure patterns.Trial registration: PROSPERO, CRD42020204097. https://www.crd.york.ac.uk/.Supplemental data for this article is available online at https://doi.org/10.1080/02770903.2021.2008429 .

Impact of the State of Emergency during the COVID-19 Pandemic in 2020 on Asthma Exacerbations among Children in Kobe City, Japan

The coronavirus disease (COVID-19) pandemic altered environmental factors. We studied the impact of these changes on asthma exacerbation (AE) by comparing the AE-related environmental factors between COVID-19 (2020) and pre-COVID-19 (2011–2019) eras. Between 2011 and 2020, 278,465 children (<16 years old) visited our emergency department, and 7476 were diagnosed with AE. The number of patients showed spring and fall peaks in 2011–2019. Multivariate analyses showed significant positive relationships of the number of AE patients with the average temperature among all patients and 0–5-year-olds and with sulfur dioxide (SO₂) levels in 2011–2019 among 0–5-year-olds. Although the spring peak in the number of patients was not observed in 2020 after declaration of a state of emergency, the fall peak was again observed after the state of emergency was lifted. No changes in average temperature were detected, but SO₂ was significantly reduced following declaration of the state of emergency in 2020. Therefore, SO₂ reduction might have contributed to the disappearance of the peak of AE. However, a fall peak was observed again in 2020, although SO₂ levels continued to be low. These data suggest that person to person interaction seems to be associated with AE, presumably due to unknown viral infections.

Associations between Dust Exposure and Hospitalizations in El Paso, Texas, USA

The Southwestern USA has been identified as one of the most persistent dust-producing regions of North America, where exposure to inhalable particulate matter (PM10) originating from desertic landscape during dust events/dust exposures (DEs) can reach hazardous levels. El Paso, Texas’s ambient air has reached hazardous levels of PM10 from dust with near zero visibility due to these natural events originating in the surrounding Chihuahuan Desert. The aim of this study was to investigate whether dust exposures in El Paso (generally acute, short-term exposures from nearby source areas) are associated with significant increases in hospitalizations on the day of the exposure and up to seven days afterwards. Using a Poisson regression, it was found that the relative risks of hospitalizations due to a variety of conditions were associated with dust exposures (through increases of 100 μg/m3 maximum hourly PM10 and/or increases of 4.5 m/s maximum hourly wind speed) in El Paso County, Texas between 2010 and 2014. Valley fever, coronary atherosclerosis, genitourinary diseases, neurodegenerative diseases, injury and poisoning, circulatory system conditions, respiratory system diseases, births, septicemia, Associated Diseases (the aggregation of hospital admissions for all causes, each associated with at least 5% of hospitalizations), and all ICD-9 admissions were significantly positively associated with dust exposures, indicated from higher to lower significant risk, at different lag periods after exposure. These findings, showing that an association does exist between dust exposures and hospitalizations, have important implications for residents of the world’s dryland cities.

Investigating the effects of dust storms on morbidity and mortality due to cardiovascular and respiratory diseases: A systematic review

New epidemiological studies acknowledge the detrimental effects of dust storms on health. The aim of this study was to systematically review the effects of dust storms on the morbidity and mortality rates of cardiovascular and respiratory diseases. The results of this study were obtained based on articles published in English-language journals. For the purpose of this study, all articles published until the end of 2020 based on the search in the "Scopus," "Web of Science," and "PubMed" databases were selected. Articles were searched independently by two trained researchers. Dust storms are the cause of many diseases and health-related complications, of which cardiovascular and respiratory diseases are common. It is necessary to recognize and investigate the harmful effects of dust storms to prevent serious harms to human societies. In the reviewed articles, the impact of dust storms on several diseases, including cardiovascular and respiratory diseases, has been analyzed. Most of these articles acknowledge the effect of dust storms on increasing the incidence and mortality rate of these diseases, although in some articles this effect is not statistically significant. Many studies conducted around the world confirm the harmful effects of dust storms on cardiovascular and respiratory diseases, including increase in the number and duration of hospitalizations, as well as increase in mortality and exacerbation of these diseases. However, some studies do not consider the harmful effects of dust storms on the above diseases to be statistically significant.

Global Health Impacts of Dust Storms: A Systematic Review

BACKGROUND

Dust storms and their impacts on health are becoming a major public health issue. The current study examines the health impacts of dust storms around the world to provide an overview of this issue.

METHOD

In this systematic review, 140 relevant and authoritative English articles on the impacts of dust storms on health (up to September 2019) were identified and extracted from 28 968 articles using valid keywords from various databases (PubMed, WOS, EMBASE, and Scopus) and multiple screening steps. Selected papers were then qualitatively examined and evaluated. Evaluation results were summarized using an Extraction Table.

RESULTS

The results of the study are divided into two parts: short and long-term impacts of dust storms. Short-term impacts include mortality, visitation, emergency medical dispatch, hospitalization, increased symptoms, and decreased pulmonary function. Long-term impacts include pregnancy, cognitive difficulties, and birth problems. Additionally, this study shows that dust storms have devastating impacts on health, affecting cardiovascular and respiratory health in particular.

CONCLUSION

The findings of this study show that dust storms have significant public health impacts. More attention should be paid to these natural hazards to prepare for, respond to, and mitigate these hazardous events to reduce their negative health impacts.Registration: PROSPERO registration number CRD42018093325.

Temperature variability and asthma hospitalisation in Brazil, 2000-2015: a nationwide case-crossover study

BACKGROUND

Both cold and hot temperature have been associated with the onset of asthma, but it remains largely unknown about the risk of asthma hospitalisation associated with short-term temperature fluctuation or temperature variability (TV).

OBJECTIVE

To explore the association between short-term exposure to TV and asthma hospitalisation in Brazil.

METHODS

Data for asthma hospitalisation and weather conditions were collected from 1816 Brazilian cities between 2000 and 2015. TV was calculated as the SD of all daily minimum and maximum temperatures within 0-7 days prior to current day. A time-stratified case-crossover design was performed to quantify the association between TV and hospitalisation for asthma.

RESULTS

A total of 2 818 911 hospitalisations for asthma were identified during the study period. Each 1°C increase in 0-7 days' TV exposure was related to a 1.0% (95% CI 0.7% to 1.4%) increase in asthma hospitalisations. The elderly were more vulnerable to TV than other age groups, while region and season appeared to significantly modify the associations. There were 159 305 (95% CI 55 293 to 2 58 054) hospitalisations, US$48.41 million (95% CI US$16.92 to US$78.30 million) inpatient costs at 2015 price and 450.44 thousand inpatient days (95% CI 156.08 to 729.91 thousand days) associated with TV during the study period. The fraction of asthma hospitalisations attributable to TV increased from 5.32% in 2000 to 5.88% in 2015.

CONCLUSION

TV was significantly associated with asthma hospitalisation and the corresponding substantial health costs in Brazil. Our findings suggest that preventive measures of asthma should take TV into account.

Effect of Asian dust on respiratory symptoms among children with and without asthma, and their sensitivity

There has been little study on the effect of Asian dust exposure on respiratory symptoms among children who are vulnerable to environmental factors. In this panel study, we investigated the effect of Asian dust on respiratory symptoms among children with and without asthma, and their sensitivity. Children attending two elementary schools (137 total), and 23 children with asthma from cooperating medical institutions in Fukuoka prefecture were recruited. Subjects measured peak expiratory flow rate (PEF), and recorded asthma-like symptoms, cough, nasal symptoms and use of medication in a diary from April 1, 2013 to June 30, 2013. To assess exposure to Asian dust, we used Light Detection and Ranging (LIDAR) data. For the analysis of the association between Asian dust and respiratory symptoms, the case-crossover design and generalized estimating equation (GEE) models were used. Taking individual sensitivity to respiratory aggravation into consideration, the subjects were classified into three groups: children without asthma, children with asthma who do not use long-term preventive medication (CA) and children with asthma who use long-term preventive medication (CA-LTM). For CA, Asian dust exposure was significantly associated with asthma-like symptoms, with a hazard ratio of 5.17 (95%CI: 1.02=26.12) at Lag0, and the change in %maxPEF, -1.65% (95%CI:-2.82, -0.48) at Lag0. For children without asthma, a statistically significant association was found between Asian dust exposure and the change in %maxPEF, -0.56% (95%CI: -1.31, -0.08) at Lag1. However, no adverse effects were observed in CA-LTM. Temperature had significant effects on %maxPEF for three groups. Asian dust, photochemical oxidant and pollen caused simultaneously additive adverse effects on nasal symptoms for children without asthma. This study suggests the possibility that long-term preventive medication to manage asthma may suppress aggravation of respiratory symptoms due to Asian dust and may be an effective prevention.

Association between African Dust Transport and Acute Exacerbations of COPD in Miami

Background: Air pollution is increasingly recognized as a risk factor for acute exacerbation of chronic obstructive pulmonary disease (COPD). Changing climate and weather patterns can modify the levels and types of air pollutants. For example, dust outbreaks increase particulate air pollution. Objective: This paper examines the effect of Saharan dust storms on the concentration of coarse particulate matter in Miami, and its association with the risk of acute exacerbation of COPD (AECOPD). Methods: In this prospective cohort study, 296 COPD patients (with 313 events) were followed between 2013 and 2016. We used Light Detection and Ranging (LIDAR) and satellite-based Aerosol Optical Depth (AOD) to identify dust events and quantify particulate matter (PM) exposure, respectively. Exacerbation events were modeled with respect to location- and time-lagged dust and PM exposures, using multivariate logistic regressions. Measurements and main results: Dust duration and intensity increased yearly during the study period. During dust events, AOD increased by 51% and particulate matter ≤2.5 µm in aerodynamic diameter (PM_2.5) increased by 25%. Adjusting for confounders, ambient temperature and local PM_2.5 exposure, one-day lagged dust exposure was associated with 4.9 times higher odds of two or more (2+ hereto after) AECOPD events (odds ratio = 4.9; 95% CI = 1.8–13.4; p < 0.001). Ambient temperature exposure also showed a significant association with 2+ and 3+ AECOPD events. The risk of AECOPD lasted up to 15 days after dust exposure, declining from 10× higher on day 0 to 20% higher on day 15. Conclusions: Saharan dust outbreaks observed in Miami elevate the concentration of PM and increase the risk of AECOPD in COPD patients with recurring exacerbations.

Development of a system for the detection of the inflammatory response induced by airborne fine particulate matter in rat tracheal epithelial cells

•

Atmospheric endotoxin level is related to inflammatory response induction

•

Stable cell lines established to determine the expression of pro-inflammatory genes

•

Our system serves monitoring of inflammatory response to airborne particulate matter

Exposure to airborne particulate matter (PM) is related to the increased risk of several diseases, including chronic and allergic rhinitis. We have previously shown that atmospheric endotoxin level was positively associated with the number of emergency department visits for asthma even after adjusting for meteorological factors, suggestive of the significant association between atmospheric endotoxin level and asthma exacerbation. Whether atmospheric endotoxin level is related to inflammatory response induction is, however, unclear. Here, we established stable cell lines to determine the promoter activity of the genes encoding pro-inflammatory cytokines such as tumor necrosis factor alpha, interleukin 6 (IL6), and IL33 by transfection of each reporter plasmid into rat tracheal epithelial EGV-4 T cells. These cells could measure the inflammatory response induced by endotoxin treatment more easily, rapidly, and sensitively than the conventional system using immunodetection assays. Furthermore, we revealed a relationship between atmospheric endotoxin level and inflammatory response induction. Thus, the system established herein may serve as a promising tool to monitor inflammatory response induced upon PM exposure.

Development of a system for the detection of the inflammatory response induced by airborne fine particulate matter in rat tracheal epithelial cells

Exposure to airborne particulate matter (PM) is related to the increased risk of several diseases, including chronic and allergic rhinitis. We have previously shown that atmospheric endotoxin level was positively associated with the number of emergency department visits for asthma even after adjusting for meteorological factors, suggestive of the significant association between atmospheric endotoxin level and asthma exacerbation. Whether atmospheric endotoxin level is related to inflammatory response induction is, however, unclear. Here, we established stable cell lines to determine the promoter activity of the genes encoding pro-inflammatory cytokines such as tumor necrosis factor alpha, interleukin 6 (IL6), and IL33 by transfection of each reporter plasmid into rat tracheal epithelial EGV-4 T cells. These cells could measure the inflammatory response induced by endotoxin treatment more easily, rapidly, and sensitively than the conventional system using immunodetection assays. Furthermore, we revealed a relationship between atmospheric endotoxin level and inflammatory response induction. Thus, the system established herein may serve as a promising tool to monitor inflammatory response induced upon PM exposure.

Health Effects of Asian Dust: A Systematic Review and Meta-Analysis

BACKGROUND

Potential adverse health effects of Asian dust exposure have been reported, but systematic reviews and quantitative syntheses are lacking.

OBJECTIVE

We reviewed epidemiologic studies that assessed the risk of mortality, hospital admissions, and symptoms/dysfunction associated with exposure to Asian dust.

METHODS

We performed a systematic search of PubMed and Web of Science to identify studies that reported the association between Asian dust exposure and human health outcomes. We conducted separate meta-analyses using a random-effects model for mortality and hospital admissions for a specific health outcome and assessed pooled estimates for each lag when at least three studies were available for a specific lag.

RESULTS

We identified 89 studies that met our inclusion criteria for the systematic review, and 21 studies were included in the meta-analysis. The pooled estimates (percentage changes) of mortality from circulatory and respiratory causes for Asian dust days vs. non-Asian dust days were 2.33% [95% confidence interval (CI): 0.76, 3.93] increase at lag 0 and 3.99% (95% CI: 0.08, 8.06) increase at lag 3, respectively. The increased risk for hospital admissions for respiratory disease, asthma, and pneumonia peaked at lag 3 by 8.85% (95% CI: 0.80, 17.55), 14.55% (95% CI: 6.74, 22.94), and 8.51% (95% CI: 2.89, 14.44), respectively. Seven of 12 studies reported reduced peak expiratory flow, and 16 of 21 studies reported increased respiratory symptoms associated with Asian dust exposure. There were substantial variations between the studies in definitions of Asian dust, study designs, model specifications, and confounder controls.

DISCUSSION

We found evidence of increased mortality and hospital admissions for circulatory and respiratory events. However, the number of studies included in the meta-analysis was not large and further evidences are merited to strengthen our conclusions. Standardized protocols for epidemiological studies would facilitate interstudy comparisons. https://doi.org/10.1289/EHP5312.

Annual changes in the prevalence of asthma may be related to air pollution in Fukuoka: 29 years of observation

The relationship between the annual changes of the prevalence of bronchial asthma (BA) and that of concentrations of air pollutants has not been reported. We studied the annual prevalence of BA, remission of BA, and wheeze in children at the same five elementary schools in Fukuoka city, Japan, in October to November from 1988 to 2016 by the same methods using the same questionnaire. Annual changes in the prevalence of asthma among boys were related to changes in the air concentrations of NO (r=0.708), NO2 (r=0.665) suspended particulate matter (SPM) (r=0.803), and smoking rate (r=0.741), but there were no such relationships among girls. Annual changes in the prevalence of wheeze were related to changes of NO, NO2, SPM, and smoking rate among boys and girls (NO: r=0.650, 0.660; NO2: r=0.556, 0.490; SPM: r=0.582, 0.518; smoking rate: r=0.656, 0.593, respectively) (all of the above are significant with p<0.05). There was no relationship between remission of BA and any of the pollutants. Annual changes in the prevalence of boys' BA and boys' and girls' wheeze among first-grade children (age 6 or 7 years) in Fukuoka were correlated with changes in the concentration of air pollutants (SPM, NO, NO2 or smoking rate). Recent decrease of asthma prevalence in this area might be related to the decreasing tendency of air pollutant concentration. The causal relationship between the two will need to be verified in the future.

Association between Asian dust exposure and respiratory function in children with bronchial asthma in Nagasaki Prefecture, Japan

BACKGROUND

Studies on the adverse effects of Asian dust (AD) on respiratory function in children are scarce. The objective of this study was to examine the association between AD and respiratory function by measuring peak expiratory flow rates (PEFRs) in asthmatic children.

METHODS

The study was carried out from March to May from 2014 through 2016. One hundred ten children with bronchial asthma were recruited from four hospitals in the Goto Islands and south Nagasaki area in Nagasaki prefecture. The parents were asked to record their children's PEFRs every morning/evening and clinical symptoms in an asthma diary. AD was assessed from light detection and ranging data, and a linear mixed-effects model was used to estimate the effects of AD on daily PEFR. Time-stratified case-crossover analyses were performed to examine the association between AD and asthma attacks defined by reduction levels in PEFR.

RESULTS

AD was detected on 11 days in the Goto Islands, and on 23 days in the south Nagasaki area. After adjusting for age, sex, temperature, and daily oxidants, we found a consistent association between AD and a 1.1% to 1.7% decrease in PEFR in the mornings and a 0.7% to 1.3% decrease in the evenings at a lag of 0 to 5 days. AD was not associated with the number of asthma attacks, respiratory symptoms, or other symptoms at any lag days examined.

CONCLUSIONS

Exposure to AD was associated with reduced PEFR, although the effects were not large enough to induce clinically apparent symptoms, in clinically well-controlled asthmatic children.

[Health Effects of Asian Dust Events: A Literature Review Update of Epidemiological Evidence]

Asian dust is a phenomenon involving the long-range transport of atmospheric pollutants originating from the desert areas of China and Mongolia. In recent years, the health effects of Asian dust have raised public concerns. Numerous studies on the health effects of Asian dust have been published since the last review in 2010. Thus, a literature review was conducted to shed light on the latest epidemiologic findings. PubMed and Science Direct databases were used for the review of epidemiologic studies published between June 2009 and April 2018. We identified 53 epidemiologic studies. Mortality, ambulance transportation, hospitalization/medical examination, changes in symptomatic, functional, and examination findings, as well as birth outcomes have been reported as outcomes. When the outcomes were categorized by disease, the effects of Asian dust on respiratory, cardiovascular, and allergic diseases raised concerns. The common evidences of causation between Asian dust and these diseases were the consistency of findings and temporal sequence of association. As results of research on dose-response relationships have become available, and the possibility that the health effects of Asian dust may vary depending on its chemical composition has been pointed out, further research using the exposure level indicators of Asian dust or its chemical composition should be conducted. Furthermore, with focus on the crucial issue of reducing exposure, research related to prevention and raising awareness should be further promoted.

Cardiovascular and respiratory emergency dispatch due to short-term exposure to ambient PM10 in Dezful, Iran

Introduction: This study was conducted to determine the relation between exposure to particulate matter less than 10 microns (PM₁₀) caused by dust storms and the risk of cardiovascular, respiratory and traffic accident missions carried out by Emergency Medical Services (EMS).

Methods: This was a time-series study conducted in Dezful city, Iran. Daily information on the number of missions by the EMS due to cardiovascular, respiratory and crash problems and data on PM₁₀ were inquired from March 2013 until March 2016. A generalized linear model (GLM) with distributed lag models (DLMs) was used to evaluate the relation between the number of EMS missions and the average daily PM₁₀. The latent effects of PM₁₀ were estimated in single and cumulative lags, up to 14 days.

Results: In the adjusted model, for each IQR increase in the average daily PM₁₀ concentration, the risk of EMS missions in the total population in single lags of 2 to 7 days, and the cumulative lags of 0-7 and 0-14 days after exposure had a 0.8, 0.8, 0.8, 0.8, 0.7, 0.6, 6.7 and 1.4% significant increase. Also, for each IQR increase in the daily mean concentration of PM₁₀ in single 1 to 7, and cumulative lags of 0-2, 0-7, and 0-14 days after exposure, respectively, a 2.4, 2.7, 2.8, 2.9, 2.9, 2.7, 2.5, 7.4, 23.5 and 33. 3 % increase was observed in the risk of EMS cardiovascular missions.

Conclusion: Increase in daily PM₁₀ concentrations in Dezful is associated with an increase in the risk of EMS missions in lags up to two weeks after exposure.

Associations of chemical composition and sources of PM2.5 with lung function of severe asthmatic adults in a low air pollution environment of urban Nagasaki, Japan

Previous studies have linked ambient PM_2.5 to decreased pulmonary function, but the influence of specific chemical elements and emission sources on the severe asthmatic is not well understood. We examined the mass, chemical constituents, and sources of PM_2.5 for short-term associations with the pulmonary function of adults with severe asthma in a low air pollution environment in urban Nagasaki, Japan. We recruited 35 asthmatic adults and obtained the daily record of morning peak expiratory flow (PEF) in spring 2014-2016. PM_2.5 filters were extracted from an air quality monitoring station (178 days) and measured for 27 chemical elements. Source apportionment was performed using Positive Matrix Factorization (PMF). We fitted generalized linear model with generalized estimating equation (GEE) method to estimate changes in PEF (from personal monthly maximum) and odds of severe respiratory deterioration (first ≥ 15% PEF reduction within a 1-week interval) associated with mass, constituents, and sources of PM_2.5, with adjustment for temperature and relative humidity. Constituent sulfate (SO₄^2-) and PM_2.5 from oil combustion and traffic were associated with reduced PEF. An interquartile range (IQR) increase in SO₄^2- (3.7 μg/m³, average lags 0-1) was associated with a decrease of 0.38% (95% confidence interval = -0.75% to -0.001%). An IQR increase in oil combustion and traffic-sourced PM_2.5 (2.64 μg/m³, lag 1) was associated with a decrease of 0.33% (-0.62% to -0.002%). We found a larger PEF decrease associated with PM_2.5 from dust/soil on Asian Dust days. There was no evidence linking total mass and metals to reduced pulmonary function. The ventilatory capacity of adults with severe asthma is susceptible to specific constituents/sources of PM_2.5 such as sulfate and oil combustion and traffic despite active self-management of asthma and low air pollution levels in the study location.

Human albumin augmented airway inflammation induced by PM2.5 in NC/Nga mice

The synergic allergic inflammatory effects of particulate matter (PM) 2.5 and human albumin were investigated in NC/Nga mice, which are hypersensitive to mite allergens. PM2.5 or PM2.5 plus human albumin with aluminum oxide was injected twice intraperitoneally for sensitization. After 7 days, PM2.5 or PM2.5 plus human albumin was administered five times intranasally to mice for further sensitization. Subsequently, PM2.5 was administered as a challenge on the 11th day. On the 12th day, mice were examined for airway hyperresponsiveness (AHR), bronchoalveolar lavage fluid (BALF) cell count, mRNA expression of Th₁ , Th₂ cytokines, chemokines, and mucus proteins (MUC5AC and MUC5B) in the lung tissue and histopathology. Although PM2.5 or human albumin alone did not induce allergic airway inflammation, simultaneous inoculation of PM2.5 and human albumin-induced airway inflammation showing increase in AHR, total BALF cell numbers, mRNA levels of IL-13, eotaxin 1, eotaxin 2, and MUC5AC, and anti-IG against human serum albumin. Inflammation was observed around the bronchus in PM2.5 plus human albumin-induced lungs. These results demonstrate that PM2.5 can induce allergic airway inflammation through the synergistic action with human albumin in NC/Nga mice.

Involvement of PM2.5-bound protein and metals in PM2.5-induced allergic airway inflammation in mice

BACKGROUND

The aim of this study was to investigate the protein and trace element components of PM2.5 and their contribution to the allergic airway inflammation in BALB/c mice.

METHODS

PM2.5, treated at high temperature and with a strong acid to hydrolyze any protein content and remove trace elements, was administered to BALB/c mice. Allergic airway inflammation was compared between the three groups (saline, pure PM2.5 and treated PM2.5) by evaluating airway hyperresponsiveness (AHR), bronchoalveolar lavage fluid (BALF) cells, serum IgE, the mRNA of various cytokine (IL-4, IL-5, IL-13, eotaxin-1 and CXCL3), mucus protein mRNA (MUC5ac and MUC5b) and the filtration of inflammatory cells in the lung.

RESULTS

The treatment of PM2.5 with a strong acid at a high temperature attenuated AHR, eosinophil percentage in BALF, mRNA levels of IL-13 and CXCL3 and peribronchial inflammation. On the contrary, the percentage of neutrophils in BALF, mRNA expression of MIP2α, EGFR, Nrf2, and TLR4 and 4-OH-2-nonenal levels in the lung was increased. Moreover, the treatment of the PM2.5 reduced PM2.5-bound proteins as well as the percentages of the trace elements in PM2.5 in the order Zn > Cu >  Pb > P > S > Mn > Fe > Ca > Ni, whereas the percentage of C, Si and Cl increased.

CONCLUSIONS

PM2.5 collected by of the cyclone system induced allergic airway inflammation in mice. PM2.5-bound proteins and acid-soluble metals may be involved in the pathogenesis of PM2.5-induced allergic airway inflammation.

The Short-Term Effects of Ambient Air Pollutants on Childhood Asthma Hospitalization in Taiwan: A National Study

This investigation determined the effects of air pollution on childhood asthma hospitalization in regions with differing air pollution levels in Taiwan over a long time period. Data of childhood hospital admissions for asthma in patients aged 0–18 years and air quality in eight regions for the period 2001–2012 in Taiwan were collected. Poisson generalized linear regression analysis was employed to identify the relative risks of hospitalization due to asthma in children associated with exposure to varying levels of air pollutants with a change in the interquartile range after adjusting for temperature and relative humidity. Particulate matter ≤2.5 μm (PM_2.5), particulate matter ≤10 μm (PM₁₀), ozone (O₃), sulfur dioxide (SO₂), and nitrogen dioxide (NO₂), were positively associated with childhood asthma hospitalization, while O₃ was negatively associated with childhood asthma hospitalization. SO₂ was identified as the most significant risk factor. The relative risks for asthma hospitalization associated with air pollutants were higher among children aged 0–5 years than aged 6–18 years and were higher among males than females. The effects of air pollution on childhood asthma were greater in the higher-level air pollution regions, while no association was observed in the lower-level air pollution regions. These findings may prove important for policymakers involved in implementing policies to reduce air pollution.

The effect of short-term particular matter2.5 exposure on asthma attacks in asthma children in Fukuoka, Japan

We investigated whether asthma attacks in asthmatic children were caused by short-term exposure to particulate matter(PM)2.5. Methods Subjects were 411 patients who received inhalation therapy in National Fukuoka Hospital, from March to May 2013. All subjects were outpatients. We surveyed the air quality measurement results in the stations closest to the address of the patients. Data were used from the City of Fukuoka website data on air pollution. We carried out a case-crossover study and compared PM2.5 concentration between 7 days after asthma attack occurred and the day asthma attack occurred and 1, 2 and 3 days before asthma attack occurred. Results Highest hourly concentration of the day (OR 1.013, 95%CI 1.000-1.025) showed a significant association with 1 day before PM2.5 concentration statistically. And 0-1 year-old infants were more vulnerable to the highest concentration of 1 day before PM2.5 concentration(P &lt; 0.05). Average concentration of NO2 and O3 and asthma attack also showed a significant association. Conclusions Maximal daily PM2.5 concentrations within 24 hours prior to the attack affect asthma exacerbation. 0-1 year-old infants are particularly vulnerable to PM2.5 concentration. Asthma exacerbation is aggravated by NO2 and O3 concentration on the day of the asthma attack.

Enhanced health risks from exposure to environmentally persistent free radicals and the oxidative stress of PM2.5 from Asian dust storms in Erenhot, Zhangbei and Jinan, China

Asian dust storms can increase the level of atmospheric pollution over regions downwind of dust storms and may have adverse health effects on residents along the sandstorm transmission route. This study was the first to report the concentration levels, properties and possible sources of environmentally persistent free radicals (EPFRs) and oxidative potential in atmospheric PM_2.5 at the three sites of Erenhot, Zhangbei, and Jinan along the transport route of Asian dust storms during the occurrence of Asian dust storms in the spring of 2016. Under non-sandstorm weather conditions, the average EPFR concentrations at the three sites were Zhangbei>Jinan>Erenhot, while the PM-induced oxidative potential levels were Erenhot>Jinan>Zhangbei. The PM_2.5 concentration increased significantly during dust storm events, and the total atmospheric concentration of EPFRs (spins/m³) and total oxidation potential (a.u./m³) of PM_2.5 simultaneously increased. However, the EPFR concentration in PM_2.5 (spins/g) and the unit mass of the PM oxidation potential (a.u./g) were significantly reduced. Electron paramagnetic resonance analysis combined with backward trajectory analysis and MODIS products showed that Asian dust storms can carry EPFRs over long distances. Correlation analysis showed that the atmospheric concentrations of EPFRs were positively correlated with elemental carbon (EC) for the Zhangbei and Jinan samples but were not significantly correlated with EC for the Erenhot samples, indicating that combustion may be an important source of EPFRs for the Zhangbei and Jinan samples. In contrast, the EPFRs in the Erenhot samples were more affected by dust/sand. The EPFR concentration levels showed a significant positive correlation with the oxidation potentials for the Erenhot and Zhangbei samples and showed negative correlations for the Jinan samples, suggesting that the EPFRs in the Erenhot and Zhangbei samples may provide an important contribution to the oxidative stress in PM_2.5. In contrast, the oxidation potential for the Jinan samples was mainly caused by substances other than EPFRs. This study presents a basic understanding of the potential health effects of Asian dust storms, and this information can be used to assess the health risks of Asian dust storms in future studies.

Association of airborne particles, protein, and endotoxin with emergency department visits for asthma in Kyoto, Japan

Background

The health effects of biological aerosols on the respiratory system are unclear. The purpose of this study was to clarify the association of airborne particle, protein, and endotoxin with emergency department visits for asthma in Kyoto City, Japan.

Methods

We collected data on emergency department visits at a hospital in Kyoto from September 2014 to May 2016. Fine (aerodynamic diameter ≤ 2.5 μm) and coarse (≥ 2.5 μm) particles were collected in Kyoto, and protein and endotoxin levels were analyzed. The association of the levels of particles, protein, endotoxin, and meteorological factors (temperature, relative humidity, wind speed, and air pressure) with emergency department visits for asthma was estimated.

Results

There were 1 to 15 emergency department visits for asthma per week, and the numbers of visits increased in the autumn and spring, namely many weeks in September, October, and April. Weekly concentration of protein in fine particles was markedly higher than that in coarse particles, and protein concentration in fine particles was high in spring months. Weekly endotoxin concentrations in fine and coarse particles were high in autumn months, including September 2014 and 2015. Even after adjusting for meteorological factors, the concentrations of coarse particles and endotoxin in both particles were significant factors on emergency department visits for asthma.

Conclusions

Our results suggest that atmospheric coarse particles and endotoxin are significantly associated with an increased risk of asthma exacerbation.

Electronic supplementary material

The online version of this article (10.1186/s12199-018-0731-2) contains supplementary material, which is available to authorized users.

Application of a Time-Stratified Case-Crossover Design to Explore the Effects of Air Pollution and Season on Childhood Asthma Hospitalization in Cities of Differing Urban Patterns: Big Data Analytics of Government Open Data

Few studies have assessed the lagged effects of levels of different urban city air pollutants and seasons on asthma hospitalization in children. This study used big data analysis to explore the effects of daily changes in air pollution and season on childhood asthma hospitalization from 2001 to 2010 in Taipei and Kaohsiung City, Taiwan. A time-stratified case-crossover study and conditional logistic regression analysis were employed to identify associations between the risk of hospitalization due to asthma in children and the levels of air pollutants (PM_2.5, PM₁₀, O₃, SO₂, and NO₂) in the days preceding hospitalization. During the study period, 2900 children in Taipei and 1337 in Kaohsiung aged ≤15 years were hospitalized due to asthma for the first time. The results indicated that the levels of air pollutants were significantly associated with the risk of asthma hospitalization in children, and seasonal effects were observed. High levels of air pollution in Kaohsiung had greater effects than in Taipei after adjusting for seasonal variation. The most important factor was O₃ in spring in Taipei. In children aged 0-6 years, asthma was associated with O₃ in Taipei and SO₂ in Kaohsiung, after controlling for the daily mean temperature and relative humidity.

The association between ambient temperature and childhood asthma: a systematic review

The objectives of this study are to review available information on the association between ambient temperature and childhood asthma, and to elucidate the possible underlying mechanisms of this relationship. A systematic review was conducted based on the papers retrieved from four databases, including PubMed, ProQuest, ScienceDirect, and Scopus. Papers examining the association of absolute temperature or temperature variation with childhood asthma published from 1 January 2000 to 31 December 2016 were included. Thirteen papers have quantified the effect of absolute temperature on childhood asthma, and six papers have examined the effect of intra- or inter-day temperature variation on childhood asthma. All studies were conducted in urban areas. Aeroallergen sensitizations were only considered in the analyses of one study. Discrepancy existed in the significance of the relationship between absolute temperature and childhood asthma, and also in the shape of this relationship (i.e. linear or non-linear) and whether temperature effects were lagged. Increasing evidence is suggesting non-linear relationship between absolute temperature and childhood asthma. Future research should investigate the burden of childhood asthma specifically attributable to extreme temperatures and temperature variation using advanced statistical approach, particularly in rural areas, after properly considering aeroallergens and air pollution. Projecting future burden of childhood asthma under climate change scenarios is also warranted.

The association between local meteorological changes and exacerbation of acute wheezing in Kandy, Sri Lanka

BACKGROUND

Severe wheezing is a common medical emergency. Past studies have demonstrated associations between exacerbation of wheezing and meteorological factors and atmospheric pollution. There are no past studies from Sri Lanka that analyzed correlation between daily multiple meteorological variables and exacerbation of wheezing.

OBJECTIVES

To determine the correlations between daily counts of patients nebulized at the Outpatient Department (OPD) of Teaching Hospital - Kandy (THK) and local meteorological variables, and to explore the utility of that information.

DESIGN

We considered daily counts of patients nebulized at the OPD of THK as an indicator of exacerbations of wheezing in the population catered to by this hospital. We determined the correlations between daily counts of patients nebulized at OPD and the following meteorological variables for four years: daily rainfall, minimum temperature, maximum temperature, diurnal temperature range, difference between maximum temperature and the temperature at 1800 hours, daytime humidity, nighttime humidity, barometric pressure and visibility. We utilized wavelet time series method for data analysis.

RESULTS

All nine meteorological parameters studied were correlated with the daily counts of patients nebulized with average lag periods ranging from 5 to 15 days. Peaks of daily rainfall, maximum temperature, diurnal temperature range, difference between maximum temperature and the temperature at 1800 hours and daytime humidity were followed by peaks of counts of patients nebulized (positive correlations). Troughs of minimum temperature, nighttime humidity, barometric pressure and visibility were followed by peaks of patients nebulized (negative correlations).

CONCLUSIONS

The THK shall expect more patients with acute wheezing after extremes of weather. Minimum temperature has been consistently correlated with the exacerbation of respiratory symptoms in the past studies in other countries as well. Hence, prescribing the inhalation of more drugs on unusually cold days (prophylactically) may help prevent acute exacerbation of wheezing in patients on treatment for asthma and COPD.

The Effects of PM2.5 from Asian Dust Storms on Emergency Room Visits for Cardiovascular and Respiratory Diseases

A case-crossover study examined how PM_2.5 from Asian Dust Storms (ADS) affects the number of emergency room (ER) admissions for cardiovascular diseases (CVDs) and respiratory diseases (RDs). Our data indicated that PM_2.5 concentration from ADS was highly correlated with ER visits for CVDs and RDs. The odds ratios (OR) increased by 2.92 (95% CI: 1.22–5.08) and 1.86 (95% CI: 1.30–2.91) per 10 µg/m³ increase in PM_2.5 levels, for CVDs and RDs, respectively. A 10 µg/m³ increase in PM_2.5 from ADSs was significantly associated with an increase in ER visits for CVDs among those 65 years of age and older (an increase of 2.77 in OR) and for females (an increase of 3.09 in OR). In contrast, PM_2.5 levels had a significant impact on RD ER visits among those under 65 years of age (OR = 1.77). The risk of ER visits for CVDs increased on the day when the ADS occurred in Taiwan and the day after (lag 0 and lag 1); the corresponding risk increase for RDs only increased on the fifth day after the ADS (lag 5). In Taiwan’s late winter and spring, the severity of ER visits for CVDs and RDs increases. Environmental protection agencies should employ an early warning system for ADS to reduce high-risk groups’ exposure to PM_2.5.

Association of Asian Dust with daily medical consultations for pollinosis in Fukuoka City, Japan

BACKGROUND

The objective is to examine the association between AD and the daily number of medical consultations for pollinosis in Fukuoka City.

METHODS

We analyzed 65,488 daily medical consultations for pollinosis from 4 clinics in Fukuoka City from February to April, 1989-2012. Time-series analyses were performed to estimate the clinic-specific relative risk (RR) of clinical pollinosis associated with AD, adjusting for airborne pollen, suspended particulate matter (SPM), meteorological and temporal factors. Delayed effects were considered. The association with SPM was also examined given its relationship with AD. The clinic-specific RRs were combined using meta-analytic technique.

RESULTS

AD on the same day (lag 0) and the previous 3 to 5 days (lags 3, 4, and 5) was positively associated with the risk of medical consultations for pollinosis. Clinic visits were 21.5% (95% confidence interval 3.1% - 43.1%) higher when there was an AD event (across lags 0-5). The association with SPM showed comparable lag structure, but with smaller effect estimates. When stratified by the occurrence of AD, the estimated risk increases associated with SPM did not differ between the AD-affected and AD-free days.

CONCLUSION

AD is associated with an increased risk of medical consultations for pollinosis in spring. More research is needed to elucidate the roles of air particles with different sizes.

Effect of outdoor air pollution on asthma exacerbations in children and adults: Systematic review and multilevel meta-analysis

Background

Several observational studies have suggested that outdoor air pollution may induce or aggravate asthma. However, epidemiological results are inconclusive due to the presence of numerous moderators which influence this association. The goal of this study was to assess the relationship between outdoor air pollutants and moderate or severe asthma exacerbations in children and adults through a systematic review and multilevel meta-analysis.

Material and methods

We searched studies published in English on PubMed, Scopus, and Google Scholar between January 2000 and October 2016. Studies following a case-crossover design with records of emergency departments and/or hospital admissions as a surrogate of moderate or severe asthma exacerbations were selected. A multilevel meta-analysis was employed, taking into account the potential clustering effects within studies examining more than one lag. Odds ratios (ORs) and 95% confidence intervals were estimated. A subgroup analysis in children aged 0 to 18 years and a sensitivity analysis based on the quality of the included studies as defined in the Newcastle-Ottawa Scale were performed. Publication bias was evaluated through visual inspection of funnel plots and by a complementary search of grey literature. (Prospero Registration number CRD42015032323).

Results

Database searches retrieved 208 records, and finally 22 studies were selected for quantitative analysis. All pollutants except SO₂ and PM₁₀ showed a significant association with asthma exacerbations (NO₂: 1.024; 95% CI: 1.005,1.043, SO₂: 1.039; 95% CI: 0.988,1.094), PM₁₀: 1.024; 95% CI: 0.995,1.053, PM_2.5: 1.028; 95% CI: 1.009,1.047, CO: 1.045; 95% CI: 1.005,1.086, O₃: 1.032; 95% CI: 1.005,1.060. In children, the association was significant for NO₂, SO₂ and PM_2.5.

Conclusion

This meta-analysis provides evidence of the association between selected air pollutants and asthma exacerbations for different lags.

PM2.5-induced airway inflammation and hyperresponsiveness in NC/Nga mice

The allergic inflammatory effects of particulate matter (PM) 2.5, collected with the cyclone system in Yokohama city in Japan, were investigated in NC/Nga mice, which are hypersensitive to mite allergens. PM2.5 with alum was injected intraperitoneally for sensitization. Five days later, 200 μg of PM2.5 in 25 μL of saline was administered to mice intranasally five times for further sensitization. On the 11th day, PM2.5 was administered as a challenge. On the 12th day, mice were examined for airway hyperresponsiveness (AHR), the bronchoalveolar lavage fluid (BALF) cell count, mRNA expression of Th₁ , Th₂ cytokines, and metallothioneins in lung tissue, and histopathology. PM2.5 increased AHR, total cell numbers including eosinophils in BALF, and mRNA levels of IL-5, IL-22, eotaxin, eotaxin 2, and metallothionein 3. In PM2.5-induced lungs, inflammation was observed around the bronchus. These results demonstrate that PM2.5 alone, collected with the cyclone system in Yokohama city in Japan, induces asthma-like airway inflammation. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1047-1054, 2017.

Effect of exposure to an Asian dust storm on fractional exhaled nitric oxide in adult asthma patients in Western Japan

BACKGROUND

Epidemiological investigations indicate that an Asian dust storm (ADS) can aggravate respiratory disorders. However, the effects of ADS on airway inflammation remain unclear. The aim of this study was to investigate the association of exposure to ADS with airway inflammation.

METHODS

The subjects were 33 adult patients with asthma who measured daily peak flow expiratory (PEF) from March to May 2012. Fractional exhaled nitric oxide (FeNO) was measured before and after ADS.

RESULTS

The FeNO values were 13.8±13.7 ppb before the ADS and 20.3±19.0 ppb after the ADS, with no significant difference. There was also no significant association of PEF with ADS exposure. However, the increase of FeNO after ADS exposure was proportional to the decrease of PEF (R=-0.78, P<0.0001).

CONCLUSION

These results suggest that airway inflammation aggravated by ADS exposure may induce a decrease in pulmonary function in some adult patients with asthma.

Effects of Asian Dust Particles on the Early-Stage Antigen-Induced Immune Response of Asthma in NC/Nga Mice

Asian dust (AD) can aggravate airway inflammation in asthma, but the association between AD and the development of asthma remains unclear. This study aimed to investigate the effects of AD on the early stage of antigen sensitization using a mouse model of asthma, as well as the role of leukotrienes (LTs) in antigen-induced airway inflammation potentiated by AD particles. NC/Nga mice were co-sensitized by intranasal instillation of AD particles and/or Dermatophagoides farinae (Df) for five consecutive days. Df-sensitized mice were stimulated with an intranasal Df challenge at seven days. Mice were treated with the type 1 cysteinyl LT (CysLT₁) receptor antagonist orally 4 h before and 1 h after the allergen challenge. At 24 h post-challenge, the differential leukocyte count, inflammatory cytokines, and LTs in bronchoalveolar lavage fluid were assessed, and airway inflammation was evaluated histopathologically. AD augmented neutrophilic and eosinophilic airway inflammation with increased CysLTs and dihydroxy-LT in a mouse model of asthma. The CysLT₁ receptor antagonist was shown to attenuate both neutrophilic and eosinophilic airway inflammation augmented by AD. Therefore, exposure to AD may be associated with the development of asthma and LTs may play important roles in airway inflammation augmented by AD.

Temperature in summer and children's hospitalizations in two Mediterranean cities

BACKGROUND AND OBJECTIVE

Children are potentially vulnerable to hot ambient temperature. However, the evidence on heat-related children's morbidity is still scarce. Our aim was to examine the association between temperatures in summer (May to September) and children's hospitalizations in two Mediterranean cities, Rome and Valencia, during the period 2001-2010.

METHODS

Quasi-Poisson generalised additive models and distributed lag non-linear models were combined to study the relationship between daily mean temperature and hospital admissions for all natural, respiratory and gastrointestinal diseases in children under 15 years of age. Associations were summarised as the percentage of change (Ch%) in admissions at 50th, 75th, 90th, 95th and 98th percentiles of temperature in summer compared to 1.) the 50th percentile in the whole year (50th(y)) and 2.) the preceding percentile in the previous series. Cumulated risks were obtained for groups of lags showing a similar pattern: 0-1, 2-7, 8-14 and 15-21 days.

RESULTS

Almost whatever increase of temperature from 50th(y) was significantly associated with an increase of paediatric hospitalizations by all natural diseases at short term (lag 0-1), while small increases at high temperatures only had a delayed effect on this outcome. The same pattern was observed in Rome for respiratory admissions, while in Valencia only a delayed association (days 8-14) was observed. The increase of temperature from 50th to 75th percentiles was associated at short time to an increase of gastrointestinal admissions in both cities.

CONCLUSION

Children's hospitalizations rose with heat in Rome and Valencia. Patterns of delays and critical windows of exposure mainly varied according the outcome considered.

Short-term exposure to air pollution and morbidity of COPD and asthma in East Asian area: A systematic review and meta-analysis

BACKGROUND

The association between short-term exposure to air pollution and morbidity of COPD and asthma has been observed in many studies. However, there is a lack of systematic review of the overall risk ratios in East Asian area to provide scientific evidence for health risk assessment.

METHODS

A systematic literature retrieval was conducted in December 2014. The results from eligible studies were stratified by pollutants, diseases, types of hospital utilization, and age groups of the subject. For each pollutant-outcome pair, meta-analysis was conducted to calculate the pooled risk ratios (RR) with 95% confidence intervals for every 10μg/m(3) increase in pollutants (1mg/m(3) in CO). We also performed meta-regression to explore the source of heterogeneity and funnel plots to detect publication bias.

RESULTS

Based on results from 26 studies, statistically significant pooled RRs of different pollutants and age groups ranged from 1.007 (SO2 in all ages) to 1.028 (O3 in all ages) for COPD general hospital admissions, 1.011 (SO2 in all ages) to 1.028 (O3 in all ages) for COPD emergency hospital admissions, 1.013 (PM10 in all ages) to 1.141 (CO in children) for all-type asthma hospital utilization, 1.010 (PM10 in all ages) to 1.141 (CO in children) for asthma general hospital admissions, and 1.009 (SO2 in all ages) to 1.040 (NO2 in children) for asthma emergency hospital admissions. The association between air pollution and asthma morbidity was generally stronger in children, but not significant in people aged 15-64.

CONCLUSIONS

Evidence was found that short-term exposure to air pollution was associated with increasing risk of hospital utilization for COPD and asthma in the whole population, the elderly and children, but not in people aged 15-64. Children tended to be more susceptible to the effect of air pollution on asthma morbidity.

Asian Dust and Pediatric Emergency Department Visits Due to Bronchial Asthma and Respiratory Diseases in Nagasaki, Japan

Background

The adverse health effects of Asian dust (AD) on the respiratory system of children are unclear. We hypothesized that AD events may lead to increased visits by children to emergency medical centers due to bronchial asthma and respiratory diseases, including bronchial asthma.

Methods

We used anonymized data on children receiving primary emergency treatment at Nagasaki Municipal Primary Emergency Medical Center, Japan between March 2010 and September 2013. We used Light Detection and Ranging (LIDAR) data to assess AD exposure and performed time-stratified case-crossover analyses to examine the association between AD exposure and emergency department visits. The main analysis was done with data collected from March through May each year.

Results

The total number of emergency department visits during the study period was 756 for bronchial asthma and 5421 for respiratory diseases, and the number of “AD days” was 47. In school children, AD events at lag day 3 and lag day 4 were associated with increased emergency department visits due to bronchial asthma, with odds ratios of 1.837 (95% confidence interval [CI], 1.212–2.786) and 1.829 (95% CI, 1.179–2.806), respectively. AD events were significantly associated with respiratory diseases among preschool children at lag day 0, lag day 1, and lag day 2, with odds ratios of 1.244 (95% CI, 1.128–1.373), 1.314 (95% CI, 1.189–1.452), and 1.273 (95% CI, 1.152–1.408), respectively. These associations were also significant when the results were adjusted for meteorological variables and other air pollutants.

Conclusions

The study findings suggested that AD exposure increases emergency department visits by children.

Differences in the effects of Asian dust on pulmonary function between adult patients with asthma and those with asthma-chronic obstructive pulmonary disease overlap syndrome

BACKGROUND

Asian dust (AD) exposure exacerbates pulmonary dysfunction in patients with asthma. Asthma-chronic obstructive pulmonary disease overlap syndrome (ACOS), characterized by coexisting symptoms of asthma and chronic obstructive pulmonary disease, is considered a separate disease entity. Previously, we investigated the effects of AD on pulmonary function in adult patients with asthma. Here, we present the findings of our further research on the differences in the effects of AD exposure on pulmonary function between patients with asthma alone and those with ACOS.

METHODS

Between March and May 2012, we conducted a panel study wherein we monitored daily peak expiratory flow (PEF) values in 231 adult patients with asthma. These patients were divided into 190 patients with asthma alone and 41 patients with ACOS in this study. Daily AD particle levels were measured using light detection and ranging systems. Two heavy AD days (April 23 and 24) were determined according to the Japan Meteorological Agency definition. A linear mixed model was used to estimate the association between PEF and AD exposure.

RESULTS

Increments in the interquartile range of AD particles (0.018 km(-1)) led to PEF changes of -0.50 L/min (95% confidence interval, -0.98 to -0.02) in patients with asthma alone and -0.11 L/min (-0.11 to 0.85) in patients with ACOS. The PEF changes after exposure to heavy AD were -2.21 L/min (-4.28 to -0.15) in patients with asthma alone and -2.76 L/min (-6.86 to 1.35) in patients with ACOS. In patients with asthma alone, the highest decrease in PEF values was observed on the heavy AD day, with a subsequent gradual increase over time.

CONCLUSION

Our results suggest that the effects of AD exposure on pulmonary function differ between patients with asthma alone and ACOS, with the former exhibiting a greater likelihood of decreased pulmonary function after AD exposure.

The effect of Asian dust on asthma by socioeconomic status using national health insurance claims data in Korea

CONTEXT

Asian dust events are associated with increased asthma incidence, asthma exacerbation, decreased lung function and increased risk for hospitalization.

OBJECTIVE

The purpose of this study was to evaluate the effect of Asian dust events on asthma exacerbation by socioeconomic status using national health insurance claims data.

MATERIALS AND METHODS

A case-crossover design was used to analyze asthma-related national health insurance claims, air pollutant and climate data from 2007 to 2013 in Seoul and Incheon, Korea. We stratified our analysis by socioeconomic status (health insurance versus medical aid subscribers) and calculated the maximum air pollutant levels and average climate values per day. The number of asthma-related visits to medical institutions per day was compared between "event" and "control" days.

RESULTS

Compared with "control days", the average number of asthma-related visits to medical institutions decreased on "event" days and increased 1-5 d thereafter. The number of visits by health insurance subscribers also decreased on "event" days and increased 1-5 d thereafter, while the number of visits by medical aid subscribers did not change on "event" days but increased 1-4 d thereafter.

DISCUSSION AND CONCLUSION

Our study confirms that Asian dust events result in an increased number of asthma-related visits to medical institutions. This effect differed by socioeconomic status.