Short-Term Effects of Fine Particulate Matter and Temperature on Lung Function among Healthy College Students in Wuhan, China

Higher temperature and humidity exacerbate pollutant-associated lung dysfunction in the elderly

RATIONALE

Air pollution and extreme temperature and humidity are risk factors for lung dysfunction, but their interactions are not clearly understood.

OBJECTIVES

To assess the impact of exposure to air pollutants and meteorological factors on lung function, and the contribution of their interaction to the overall effect.

METHODS

The peak expiratory flow rates of 135 participants were repeatedly measured during up to four visits. Two weeks before each visit, the concentrations of gaseous pollutants and 19 fine particle components, and the temperature and relative humidity, were continuously monitored in the community where they lived. A Bayesian Kernel machine regression model was used to explore the non-linear exposure-response relationships of the peak expiratory flow rate with pollutant exposure and meteorological factors, and their interactions.

MEASUREMENTS AND MAIN RESULTS

Increased temperature and relative humidity could exacerbate pollutant-associated decline in the peak expiratory flow rate, although their associations with lung dysfunction disappeared after adjustment for pollutant exposure. For example, declines of peak expiratory flow rate associated with interquartile range increase of 3-day cadmium exposure were -0.03 and -0.07 units, when temperature was at 0.1 and 19.5 °C, respectively. Decreased temperature were associated with declines of peak expiratory flow rate after adjustment for pollutant exposure, and had interaction with pollutant exposure on lung dysfunction.

CONCLUSIONS

High temperature, low temperature, and high humidity were all high-risk factors for lung dysfunction, and their interactions with pollutant levels contributed greatly to the overall effects.

Does Psychological crisis matter for college students: Role of digitalization and employment

This paper aims to describe the psychological crisis's impact on college students in China. The present study has investigated the impact of the usage of digitalization, psychological crisis, employment and age on the college student in China. The study used annual time series data from 2005 to 2020 from provinces in China. This study adopts the Cup-FM test to estimate the long-term association between the variables. The study applied Cup-BC and by-FM estimations to calculate robust and reliable outcomes. The findings show that usage of digitalization and psychological crisis negatively impact college students, whereas employment and age positively impact the college student. Moreover, the result of the interaction term psychological crisis on the usage of digitalization, employment and age has positively impacted college students. The estimated results also provide important policy implications for the China region in designing an appropriate way forward for college students.

The impact of ambient air pollution on lung function and respiratory symptoms in elite athletes

BACKGROUND

Air pollution has become a significant public health concern. During exercise, many physiological factors are thought to increase the effects of air pollution. Air pollution most affects lung function and respiratory symptoms. We investigated the association between lung function, respiratory symptoms, and air pollutant concentration with meteorological factors in elite sports athletes.

METHODS

A total of 59 elite sports athletes from the Korea National Sports University participated in this prospective, observational study from September 2019 to June 2020. At ten visits, lung function and respiratory symptoms were obtained after a training session. We measured six air pollutants, including SO₂, CO, O₃, NO₂, PM₁₀, and PM_2.5, and two meteorological factors, including humidity and temperature. Air pollutants and meteorological factors were measured by two nearest depositories of the national air pollution information system in Korea.

RESULTS

In a single-pollutant model, PM_2.5, PM₁₀, NO₂, and CO were inversely associated with both FEV₁ and FEV₆, 10 μg/m³ in PM_2.5 was associated with a 32.31 mL decrease in FEV₁ and a 36.93 mL decrease in FEV₆. Meanwhile, O₃ and temperature had positive associations with both FEV₁ (13.00 and 3.15 mL) and FEV₆ (16.91 and 4.76 mL) and humidity with FEV₆ (11.98 mL). In the multi-pollutant model at lag 0, FEV₁ was associated negatively with O₃ and NO₂ (-50.68 and -6.87 mL) and positively with SO₂ and temperature (65.76 and 8.08 mL). In the multi-pollutant model at lag 6, temperature was associated with FEV₁ and FEV₆ (6.01 and 8.89 mL). PM_2.5, PM₁₀, NO₂, CO, and temperature were significantly associated with FEV₁ and FEV₆ through lag 0-6.

CONCLUSIONS

Air pollutants and meteorological factors are associated with lung function and respiratory symptoms and have cumulative effects among elite athletes. In the multi-pollutant model, temperature has the most significant effect on lung function.

Joint exposure to air pollution, ambient temperature and residential greenness and their association with metabolic syndrome (MetS): A large population-based study among Chinese adults

Previous studies assessing adverse health have traditionally focused on a single environmental exposure, failing to reflect the reality of various exposures present simultaneously. Air pollution, ambient temperature and greenness have been proposed as critical environmental factors associated with metabolic syndrome (MetS). However, evidence exploring their joint relationships with MetS is needed for identifying interactive factors and developing more targeted public health interventions. The baseline data was obtained from China Multi-Ethnic Cohort (CMEC). Environmental data of air pollutants (PM_2.5, O₃) and NDVI for greenness was calculated from satellites data. Ambient temperature data were obtained from European Center for Medium-Range Weather Forecasts (ECMWF). MetS was classified based on National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) using anthropometric measures and biomarkers. Logistic regression models were utilized to examine the combined relationship of MetS with three-year exposure to air pollutants, temperature and NDVI. Relative excess risk due to interaction (RERI) was calculated to evaluate interaction on an additive scale. We found associations between prevalent MetS and interquartile range (IQR) increases in PM_2.5 (OR: 1.38; 95% confidence interval [95% CI]: 1.23, 1.55) and O₃ (OR: 1.15; 95% CI: 1.09, 1.22). Additive and multiplicative interactions were observed between air pollutants and temperature exposure. Compared to low-temperature level, the relationship between PM_2.5 and MetS attenuated (RERI: 0.22, 95% CI: 0.44, -0.04) at high-temperature level, while the relationship between O₃ and MetS enhanced (RERI: 0.05, 95% CI: 0.02, 0.11). At low NDVI 250 m, the association between PM_2.5 and MetS was stronger (RERI: 0.13, 95% CI: 0.05, 0.19) with high NDVI 250 m as the reference group. Our findings showed that ambient temperature and residential greenness could affect the relationship between air pollutants and MetS.

Human Health, Environmental Quality and Governance Quality: Novel Findings and Implications From Human Health Perspective

Human health and wellbeing are intimately linked to the state of the environment. The current study emphasizes the role of environmental quality, government policies, and human health. This paper provides a detailed literature review of existing findings regarding our key variables of interest. The results argue that the implications of poor government policies and environmental pollution for rising economic development have led to poor environmental quality and health issues for humans. Based on earlier investigations, the present study reviewed the state-of-the-art review and determined innovative insights for outdoor and indoor environment difficulties. This study provides a detailed review of human health, environmental quality, and governance quality. In addition, the study conducts an empirical analysis using the annual data of low-income countries from 1996 to 2020. Government actions and health systems must be modified immediately to address these rising concerns successfully. The report offers policy recommendations for addressing health, governance, and environmental change mitigation issues, all of which are directly or indirectly related to the study. This article presents an overview of environmental change's health impacts and explores how health hazards may be reduced or eliminated through effective adaptation strategies.

Non-optimum ambient temperature may decrease pulmonary function: A longitudinal study with intensively repeated measurements among asthmatic adult patients in 25 Chinese cities

BACKGROUND

Non-optimum ambient temperature has not been widely perceived as an important environmental risk factor for asthma, and the association between ambient temperature and pulmonary function is rarely explored. Our study aimed to investigate the associations between non-optimum ambient temperature and pulmonary function among asthmatic adult patients.

METHODS

We performed a longitudinal study among 4,992 eligible adult asthmatic patients in 25 cities of China from 2017 to 2020. The patients were required to complete pulmonary function test every day in the morning and evening. Linear mixed-effects models and distributed lag non-linear models were used to evaluate the associations between ambient temperature and pulmonary function.

RESULTS

We evaluated 298,396 records of pulmonary function tests. We found inversely J-shaped exposure-response relationship curves for ambient temperature and pulmonary function. The effects of extreme low temperature occurred at lag 0 h and vanished at lag 72 h (almost 3 days). Compared with referent temperature (29.5 °C), extreme low temperature (-9.4 °C) was associated with decreases of 60.4 mL in FEV₁, 299.7 mL/s in PEF, and 101.5 mL in FVC. Extreme high temperature (34.2 °C) was associated with decreases of 26.0 mL in FEV₁, 35.8 mL/s in PEF, and 23.4 mL in FVC. Patients of male, overweight, and elder ages were vulnerable populations, and cold effects were more prominent in the south and in areas without central heating.

CONCLUSIONS

Both extreme low and high ambient temperatures were associated with decreased pulmonary function in adult asthmatic patients. The effect could last for almost 3 days and low temperature was more harmful.

Analysis of the Diurnal Changes in the Water-Soluble Ion Concentration in Wuhan between 2016 and 2019

This study uses online monitoring data from the Hubei Environmental Monitoring Center’s Atmospheric Compound Pollution Automatic Monitoring Station from 2016 to 2019 to analyze the diurnal changes in the concentration of water-soluble ions in particulate matter in Wuhan. During the study period, the concentrations of SO2, NO3−, and SO42− changed significantly, while those of NH4+, NH3, and Ca2+ exhibited minimal differences. SO2 and NO3− showed an annually increasing trend, while NH4+ and SO42− exhibited an annually decreasing trend. The ion concentration was generally higher in the winter and spring and lower in the summer and autumn. The concentration of water-soluble ions was generally higher during the day than at night. However, the “weekend effect” on the change in ion concentrations was substantial and higher during the day than at night. This effect was the strongest for NO3− and the weakest for NH3. These changes in the weekend effect of water-soluble ions in particulate matter clearly revealed the impact of periodic human activities on atmospheric pollution. Taken together, the results of this novel study reveal the diurnal pollution characteristics and “weekend effect” of water-soluble ions with high concentrations in atmospheric aerosols in Wuhan over a four-year period, thus providing relevant insights for Wuhan’s atmospheric mitigation plan.

Understanding the heterogeneity of COVID-19 deaths and contagions: The role of air pollution and lockdown decisions

The uneven geographical distribution of the novel coronavirus epidemic (COVID-19) in Italy is a puzzle given the intense flow of movements among the different geographical areas before lockdown decisions. To shed light on it, we test the effect of the quality of air (as measured by particulate matter and nitrogen dioxide) and lockdown restrictions on daily adverse COVID-19 outcomes during the first pandemic wave in the country. We find that air pollution is positively correlated with adverse outcomes of the pandemic, with lockdown being strongly significant and more effective in reducing deceases in more polluted areas. Results are robust to different methods including cross-section, pooled and fixed-effect panel regressions (controlling for spatial correlation), instrumental variable regressions, and difference-in-differences estimates of lockdown decisions through predicted counterfactual trends. They are consistent with the consolidated body of literature in previous medical studies suggesting that poor quality of air creates chronic exposure to adverse outcomes from respiratory diseases. The estimated correlation does not change when accounting for other factors such as temperature, commuting flows, quality of regional health systems, share of public transport users, population density, the presence of Chinese community, and proxies for industry breakdown such as the share of small (artisan) firms. Our findings provide suggestions for investigating uneven geographical distribution patterns in other countries, and have implications for environmental and lockdown policies.

Fine Particulate Matter and Lung Function among Burning-Exposed Deepwater Horizon Oil Spill Workers

BACKGROUND

During the 2010 Deepwater Horizon (DWH) disaster, controlled burning was conducted to remove oil from the water. Workers near combustion sites were potentially exposed to increased fine particulate matter [with aerodynamic diameter ≤2.5μm (PM2.5)] levels. Exposure to PM2.5 has been linked to decreased lung function, but to our knowledge, no study has examined exposure encountered in an oil spill cleanup.

OBJECTIVE

We investigated the association between estimated PM2.5 only from burning/flaring of oil/gas and lung function measured 1-3 y after the DWH disaster.

METHODS

We included workers who participated in response and cleanup activities on the water during the DWH disaster and had lung function measured at a subsequent home visit (n=2,316). PM2.5 concentrations were estimated using a Gaussian plume dispersion model and linked to work histories via a job-exposure matrix. We evaluated forced expiratory volume in 1 s (FEV1; milliliters), forced vital capacity (FVC; milliliters), and their ratio (FEV1/FVC; %) in relation to average and cumulative daily maximum exposures using multivariable linear regressions.

RESULTS

We observed significant exposure-response trends associating higher cumulative daily maximum PM2.5 exposure with lower FEV1 (p-trend=0.04) and FEV1/FVC (p-trend=0.01). In comparison with the referent group (workers not involved in or near the burning), those with higher cumulative exposures had lower FEV1 [-166.8mL, 95% confidence interval (CI): -337.3, 3.7] and FEV1/FVC (-1.7, 95% CI: -3.6, 0.2). We also saw nonsignificant reductions in FVC (high vs. referent: -120.9, 95% CI: -319.4, 77.6; p-trend=0.36). Similar associations were seen for average daily maximum PM2.5 exposure. Inverse associations were also observed in analyses stratified by smoking and time from exposure to spirometry and when we restricted to workers without prespill lung disease.

CONCLUSIONS

Among oil spill workers, exposure to PM2.5 specifically from controlled burning of oil/gas was associated with significantly lower FEV1 and FEV1/FVC when compared with workers not involved in burning. https://doi.org/10.1289/EHP8930.

Short-term effects of real-time individual fine particulate matter exposure on lung function: a panel study in Zhuhai, China

Fine particulate matter (PM_2.5) is still the primary air pollutant in most Chinese cities and its adverse effects on lung function have been widely reported. However, short-term effects of individual exposure to PM_2.5 on pulmonary expiration flow indices remain largely unknown. In this study, we examined the short-term effects of real-time individual exposure to PM_2.5 on lung function in a panel of 115 healthy adults. We measured individual real-time PM_2.5 exposure and lung function. Environmental PM_2.5 concentrations in the same period were collected from the nearest monitoring station. Generalized linear model was used to assess the effects of individual PM_2.5 exposure on lung function after adjusting for potential confounders. Individual PM_2.5 exposure ranged from 18.5 to 42.4 μg/m³ with fluctuations over time and ambient PM_2.5 concentrations presented a moderate trend of fluctuation at the same day. Except forced expiratory volume in 1 s (FEV₁) decline related to 2-h moving average PM_2.5 exposure, no significant associations between individual PM_2.5 exposure and other volume indices including forced vital capacity (FVC) and FEV₁/FVC ratio were observed. The adverse effects of individual PM_2.5 exposure on pulmonary expiration flow indices including peak expiratory flow (PEF), maximal mid-expiratory flow (MMF) and forced expiratory flow at 50%, and 75% of vital capacity (FEF_50% and FEF_75%) were observed to be strongest at 2 moving average hours and could last for 24 h. Stratified analysis showed greater and longer effects among participants who were aged over 40 years, males, or smokers. These findings suggested that individual PM_2.5 exposure was significantly associated with altered lung function, especially with pulmonary expiration flow indices decline, which was strongest at 2 moving average hours and could last for 24 h.

Particulate matter pollution and emergency room visits for respiratory diseases in a valley Basin city of Northwest China

Epidemiological studies have suggested that particulate matter (PM) pollution seriously affects human health, particularly it is closely associated with respiratory diseases. The aim of this study is to quantitatively evaluate the effect of PMs (PM₁₀ and PM_2.5) on emergency room (ER) visits for respiratory diseases in Lanzhou, a valley basin city in northwest China. Based on the data of the ER visits, daily concentration of particulate matters and daily meteorological elements from January 1, 2013, to July 31, 2017, we used a generalized additive model (GAM) of time series to evaluate the exposure-response relationship between PMs and respiratory ER visits. Seasonal modified effects of PM_2.5 and PM₁₀ on different age and gender groups were also performed. Results showed that the highest incidence of respiratory diseases occurred in winter. Respiratory ER visits for the total were significantly associated with PM_2.5 (at lag 0 day) and PM₁₀ (at lag 3 days), with relative risks (RRs) of 1.042 (95%CI: 1.036 -1.047) and 1.013 (95%CI: 1.011-1.016), respectively. Effects of PM pollutants on respiratory diseases are different among different age and gender groups. Children under 15 years and the elders over 60 years were the most sensitive to PM pollution, and males were more sensitive than females. The results obtained in the current study would provide a scientific evidence for local government to make policy decision for prevention of respiratory diseases.

Exploring short term spatio-temporal pattern of PM2.5 and PM10 and their relationship with meteorological parameters during COVID-19 in Delhi

Present study aims to examine the impact of lockdown on spatio-temporal concentration of PM2.5 and PM10 - categorized and recorded based on its levels during pre-lockdown, lockdown and unlock phases while noting the relationship of these levels with meteorological parameters (temperature, wind speed, relative humidity, rainfall, pressure, sun hour and cloud cover) in Delhi. To aid the study, a comparison was made with the last two years (2018 to 2019), covering the same periods of pre-lockdown, lockdown and unlock phases of 2020. Correlation analysis, linear regression (LR) was used to examine the impact of meteorological parameters on particulate matter (PM) concentrations in Delhi, India. The findings showed that (i) substantial decline of PM concentration in Delhi during lockdown period, (ii) there were substantial seasonal variation of particulate matter concentration in city and (iii) meteorological parameters have close associations with PM concentrations. The findings will help planners and policy makers to understand the impact of air pollutants and meteorological parameters on infectious disease and to adopt effective strategies for future.

Indoor air quality of 5,000 households and its determinants. Part A: Particulate matter (PM2.5 and PM10-2.5) concentrations in the Japan Environment and Children's Study

Exposure to particulate matter (PM) is one of the important risk factors for morbidity and mortality. Although PM concentrations have been assessed using air quality monitoring stations or modelling, few studies have measured indoor PM in large-scale birth cohorts. The Japan Environment and Children's Study (JECS) measured indoor and outdoor air quality in approximately 5000 households when the participating children were aged 1.5 and 3 years. PM was collected using portable pumps for 7 days (total of 24 h), inside and outside each home. Prediction models for indoor PM concentrations were built using data collected at age 1.5 years and post-validated against data collected at age 3 years. Median indoor/outdoor PM_2.5 and PM_10-2.5 concentrations at age 1.5 years [3 years] were 12.9/12.7 [12.5/11.3] μg/m³ and 5.0/6.3 [5.1/6.1] μg/m³, respectively. Random forest regression analysis found that the major predictors of indoor PM_2.5 were indoor PM_10-2.5, outdoor PM_2.5, indoor smoking, observable smoke and indoor/outdoor temperature. Indoor PM_2.5, outdoor PM_10-2.5, indoor humidity and opening room windows were important predictors of indoor PM_10-2.5 concentrations. Indoor benzene, acetaldehyde, ozone and nitrogen dioxide concentrations were also found to predict indoor PM_2.5 and PM_10-2.5 concentrations, possibly due to the formation of secondary organic aerosols. These findings demonstrate the importance of reducing outdoor PM concentrations, avoiding indoor smoking, using air cleaner in applicable and diminishing sources of VOCs that could form secondary organic aerosols, and the resulting models can be used to predict indoor PM concentrations for the rest of the JECS cohort.

Childhood co-exposure of cold stress and PM2.5 aggravates the susceptibility and severity of asthma in adulthood of mice

Both cold stress and ambient fine particle particulate matter (PM_2.5 ) has been reported to aggravate and induce respiratory problems like asthma, but the mechanism involved in that has not been fully understood. Therefore, the present study is to explore the mechanism involved in the increased susceptibility and severity of asthma caused by cold stress and PM_2.5 exposure. Urban PM_2.5 of Shanghai was concentrated to simulate a PM_2.5 -polluted environment with an average concentration of 400 μg/m³ , where 1-month young C57BL/6J mice were exposed for 2 months under cold stress (2°C). Co-exposure of cold stress and PM_2.5 in childhood of mice led to significant infiltration of inflammatory cells in the peribronchial region or airspaces and the thickening or fibrosis of alveolar septum, increased OVA-specific IgE in serum and total cells, eosinophil cells, and the levels of inflammatory cytokines including IL-4, IL-8, IL-1β, IL-5, IL-13, and IFN-γ in bronchoalveolar lavage fluid (BALF) of asthma mice. Moreover, mice in co-exposure group presented a significantly high cough feature, reduced catalase (CAT), glutathione (GSH), superoxide dismutase (SOD), and elevated malonaldehyde (MDA) elevated in BALF; increased ratio of Th2/Th1 and the markable inhibition of Th17 differentiation toward Treg cells in the adulthood of asthma mice. Cold stress and PM_2.5 co-exposure in childhood may promote the deterioration of asthma symptoms in adulthood of mice by increasing inflammatory cytokines, ROS formation, Th2/Th1 imbalance, and suppressing the differentiation of Th17 toward Treg cells, which will help to provide experimental references when making some therapeutic strategies in allergic diseases through focusing on some natural solutions.

Air quality and COVID-19 adverse outcomes: Divergent views and experimental findings

BACKGROUND

The questioned link between air pollution and coronavirus disease 2019 (COVID-19) spreading or related mortality represents a hot topic that has immediately been regarded in the light of divergent views. A first "school of thought" advocates that what matters are only standard epidemiological variables (i.e. frequency of interactions in proportion of the viral charge). A second school of thought argues that co-factors such as quality of air play an important role too.

METHODS

We analyzed available literature concerning the link between air quality, as measured by different pollutants and a number of COVID-19 outcomes, such as number of positive cases, deaths, and excess mortality rates. We reviewed several studies conducted worldwide and discussing many different methodological approaches aimed at investigating causality associations.

RESULTS

Our paper reviewed the most recent empirical researches documenting the existence of a huge evidence produced worldwide concerning the role played by air pollution on health in general and on COVID-19 outcomes in particular. These results support both research hypotheses, i.e. long-term exposure effects and short-term consequences (including the hypothesis of particulate matter acting as viral "carrier") according to the two schools of thought, respectively.

CONCLUSIONS

The link between air pollution and COVID-19 outcomes is strong and robust as resulting from many different research methodologies. Policy implications should be drawn from a "rational" assessment of these findings as "not taking any action" represents an action itself.

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.

Long-term exposure to PM2.5 and Children's lung function: a dose-based association analysis

Background

The current literature is still not consist regarding the effect of long-term exposure to PM2.5 and children’s lung function, partly due to inadequate or inaccurate exposure assessment. In this study, we aim to investigate the associations between long-term exposure to PM2.5, estimated as average daily dose (ADD), and lung function in school-age children.

Methods

We recruited 684 participants of 7–12 years old from the city of Lanzhou located in northwestern China. Participants underwent spirometric tests for lung function and responded to a questionnaire survey. Detailed information about individual air exposure and personal information were collected, including length of school hours, home address, age, gender, etc. Combining the spatial distribution of PM2.5 concentrations in the past 5 years and individual time-activity data, we estimated annual ADD for 5 years preceding the lung function tests and 5-year average ADD, respectively. We used multiple linear regression models to examine the associations between ADD values and lung function, controlling for a range of individual-level covariates.

Results

The 5-year average ADD among all the participants was 50.5 µg/kg-d, with higher values estimated for children living in the urban area than the suburban area, for boys than girls, and for children whose parents received a lower education attainment. We found that a 1 μg/kg-d increment in ADD of PM2.5 was associated with a 10.49 mL (95% CI: −20.47, −0.50) decrease in forced vital capacity (FVC) and a 7.68 mL (95% CI: −15.80, −0.44) decrease in forced exploratory volume in 1 second (FEV₁). Among the annual ADDs estimated for the preceding 5 years, the immediate past year prior to lung function measurement had the greatest effect on lung function. The effect was greater in girls than in boys. We found no associations between annual exposure of PM2.5 (instead of ADD) and lung function when defined concentration was used as an exposure variable.

Conclusions

Long-term PM2.5 exposure, when estimated as exposure dose averaged over a year or longer, was associated with statistically significant reductions in FVC and FEV1 in children of elementary-school age. Future studies may consider the use of individual-level dose estimates (as opposed to exposure concentrations) to improve the dose-response assessment.

Associations of long-term exposure to ambient fine particulate matter and nitrogen dioxide with lung function: A cross-sectional study in China

BACKGROUND

Few studies have evaluated the effects of ambient air pollution exposure on lung function, especially in areas with high air pollution levels.

OBJECTIVES

To investigate the associations of annual concentrations of particulate matter with diameters < 2.5 μm (PM_2.5) and nitrogen dioxide (NO₂) with adult lung function in Shanghai, China.

METHODS

We included 5276 permanent residents aged ≥ 20 years. Annual residential exposure to PM_2.5 and NO₂ was estimated by validated satellite-based and land use regression models, respectively. The effects of PM_2.5 and NO₂ on lung function were estimated separately using multivariable linear regression, adjusting for potential confounders.

RESULTS

Higher exposure to PM_2.5 and NO₂ was significantly associated with lower forced vital capacity (FVC), inspiration capacity (IC), and vital capacity (VC). An increase of 10 μg/m³ in the annual average PM_2.5 exposure was associated with a 45.83 ml (95% CI: -82.59, -9.07) lower FVC, 1.36 (95% CI: -2.42, -0.29) lower FVC of % predicted (FVC_%pred), 121.98 ml (95% CI: -164.38, -79.57) lower IC, and 89.12 ml (95% CI -124.94, -53.3) lower VC. For NO₂, an increase of 10 μg/m³ in the annual average concentration was associated with 26.65 ml (95% CI: -46.29, -7.00) lower FVC, 0.70 (95% CI: -1.27, 0.13) lower FVC_%pred, 65.26 ml (95% CI: -87.76, -42.76) lower IC, and 45.88 ml (95% CI: -65.03, -26.73) lower VC. The estimated effects on FEV1 were -10.25 ml (95% CI: -40.92, 20.42) and -0.29% (95% CI: -1.40, 0.82) per 10 μg/m³ increase in PM_2.5 and -0.74 ml (95% CI: -17.13, 15.65) and 0.01% (95% CI: -0.58, 0.61) per 10 μg/m³ increase in NO₂, which were not statistically significant. Stratified analysis showed that the estimated effects of PM_2.5 were greater in the healthy subgroup than the COPD patients. Obese individuals were more susceptible to adverse effects of PM_2.5 and NO₂ on lung function. Education level showed no or only weak evidence of modification of the associations between air pollution and lung function.

CONCLUSION

In this study, long-term exposure to ambient air pollutants was significantly associated with impaired lung function, presenting as restrictive ventilatory patterns.

Effects of meteorological conditions and air pollution on COVID-19 transmission: Evidence from 219 Chinese cities

The spatial distribution of the COVID-19 infection in China cannot be explained solely by geographical distance and regulatory stringency. In this research we investigate how meteorological conditions and air pollution, as concurring factors, impact COVID-19 transmission, using data on new confirmed cases from 219 prefecture cities from January 24 to February 29, 2020. Results revealed a kind of nonlinear dose-response relationship between temperature and coronavirus transmission. We also found that air pollution indicators are positively correlated with new confirmed cases, and the coronavirus further spreads by 5-7% as the AQI increases by 10 units. Further analysis based on regional divisions revealed that in northern China the negative effects of rising temperature on COVID-19 is counteracted by aggravated air pollution. In the southern cities, the ambient temperature and air pollution have a negative interactive effect on COVID-19 transmission, implying that rising temperature restrains the facilitating effects of air pollution and that they jointly lead to a decrease in new confirmed cases. These results provide implications for the control and prevention of this disease and for the anticipation of another possible pandemic.

The association between ambient temperature and sperm quality in Wuhan, China

BACKGROUND

Few epidemiological investigations have focused on the influence of environmental temperature on human sperm quality. Here, we evaluated the potential association between ambient temperature and human sperm quality in Wuhan, China, and examined the interactive effect of particulate matter (PM_2.5) and temperature.

METHODS

1780 males who had been living in Wuhan for no less than three months and received semen analysis at the Department of Reproductive Medicine in Renmin Hospital of Wuhan University between April 8, 2013 and June 30, 2015 were recruited. Daily mean meteorological data and air pollution data (PM_2.5, O₃ and NO₂) in Wuhan between 2013 and 2015 were collected. A generalized linear model was used to explore the associations between ambient temperature and sperm quality (including sperm concentration, percentage of normal sperm morphology, and progressive motility) at 0-9, 10-14, 15-69, 70-90, and 0-90 days before semen examination, and the interaction between temperature and PM_2.5.

RESULTS

The associations between ambient temperature and sperm quality were an inverted U-shape at five exposure windows, except for a lag of 0-9 days for sperm concentration. A 1 °C increase in ambient temperature above the thresholds was associated with a 2.038 (1.292 ~ 2.783), 1.814 (1.217 ~ 2.411), 1.458 (1.138 ~ 1.777), 0.934(0.617 ~ 1.251) and 1.604 (1.258 ~ 1.951) decrease in the percentage of normal sperm morphology at lag 0-9, lag 10-14, lag 15-69, lag 70-90, and lag 0-90 days, respectively. The interaction p-values of PM_2.5 and temperature were mostly less than 0.05 at five exposure windows. When ambient temperature exposure levels were above the thresholds, a 0.979 (0.659-1.299) and 3.559 (0.251 ~ 6.867) decrease in percentage of normal sperm morphology per 1 °C increase in temperature at lag 0-90 days was observed in the PM_2.5 ≤ P₅₀ group and PM_2.5 > P₅₀ group, respectively.

CONCLUSIONS

Our results indicate that exposure to ambient temperature has a threshold effect on sperm quality, and PM_2.5 enhances the effect of temperature on sperm quality when temperatures are above the threshold.

Acute effects of ambient PM2.5 on lung function among schoolchildren

Previous studies have found that fine particulate matter (PM_2.5) air pollution is associated with decreased lung function. However, most current research focuses on children with asthma, leading to small sample sizes and limited generalization of results. The current study aimed to measure the short-term and lag effects of PM_2.5 among school-aged children using repeated measurements of lung function.This prospective panel study included 848 schoolchildren in Zhejiang Province, China. Each year from 2014–2017, two lung function tests were conducted from November 15^th to December 31^st. Daily air pollution data were derived from the monitoring stations nearest to the schools. A mixed-effects regression model was used to investigate the relationship between PM_2.5 and lung function. The effect of PM_2.5 on lung function reached its greatest at 1-day moving average PM_2.5 exposure. For every 10 μg/m³ increase in the 1-day moving average PM_2.5 concentration, Forced Vital Capacity (FVC) of children decreased by 33.74 mL (95% CI: 22.52, 44.96), 1-s Forced Expiratory Volume (FEV₁) decreased by 32.56 mL (95% CI: 21.41, 43.70), and Peak Expiratory Flow (PEF) decreased by 67.45 mL/s (95% CI: 45.64, 89.25). Stronger associations were found in children living in homes with smokers. Short-term exposure to PM_2.5 was associated with reductions in schoolchildren’s lung function. This finding indicates that short-term exposure to PM_2.5 is harmful to children’s respiratory health, and appropriate protective measures should be taken to reduce the adverse effects of air pollution on children’s health.

Viruses and non-allergen environmental triggers in asthma

Asthma is a complex inflammatory disease with many triggers. The best understood asthma inflammatory pathways involve signals characterized by peripheral eosinophilia and elevated immunoglobulin E levels (called T2-high or allergic asthma), though other asthma phenotypes exist (eg, T2-low or non-allergic asthma, eosinophilic or neutrophilic-predominant). Common triggers that lead to poor asthma control and exacerbations include respiratory viruses, aeroallergens, house dust, molds, and other organic and inorganic substances. Increasingly recognized non-allergen triggers include tobacco smoke, small particulate matter (eg, PM2.5), and volatile organic compounds. The interaction between respiratory viruses and non-allergen asthma triggers is not well understood, though it is likely a connection exists which may lead to asthma development and/or exacerbations. In this paper we describe common respiratory viruses and non-allergen triggers associated with asthma. In addition, we aim to show the possible interactions, and potential synergy, between viruses and non-allergen triggers. Finally, we introduce a new clinical approach that collects exhaled breath condensates to identify metabolomics associated with viruses and non-allergen triggers that may promote the early management of asthma symptoms.

Short-Term Effects of Carbonaceous Components in PM2.5 on Pulmonary Function: A Panel Study of 37 Chinese Healthy Adults

OBJECTIVES

To explore the health effects of indoor/outdoor carbonaceous compositions in PM_2.5 on pulmonary function among healthy students living in the local university campus.

METHODS

Daily peak expiratory flow (PEF) and forced expiratory volume in 1 second (FEV₁) were measured among 37 healthy students in the morning and evening for four two-week periods. Concurrent concentrations of indoor and outdoor PM_2.5 (particulate matter with an aerodynamic diameter ≤ 2.5μm), carbonaceous components in PM_2.5, ambient temperature, and relative humidity in the study area were also obtained. Mixed-effects model was applied to evaluate the associations between carbonaceous components and lung function. Different lags for the carbonaceous components were investigated.

RESULTS

In single-pollutant model, a 10 μg/m³ increase of indoor and outdoor EC (elemental carbon) associated with -3.93 (95%CI: -6.89, -0.97) L/min and -3.21 (95%CI: -5.67, -0.75) L/min change in evening PEF at lag 0 day, respectively. Also, a 10 μg/m³ increase of indoor and outdoor POC (primary organic carbon) concentration was significantly associated with -5.82 (95%CI: -10.82, -0.81) L/min and -7.32 (95%CI: -12.93, -1.71) L/min change of evening PEF at lag 0 day. After adjusting total mass of PM_2.5, indoor EC consistently had a significant adverse impact on evening PEF and FEV₁ at lag3 day and a cumulative effect at lag0-3 day.

CONCLUSIONS

This study suggests that carbonaceous components in PM_2.5 indeed have impacts on pulmonary function among healthy young adults especially on evening PEF. Thus, the local mitigation strategies on pollution are needed.

Cold stress provokes lung injury in rats co-exposed to fine particulate matter and lipopolysaccharide

Cold exposure aggravates respiratory diseases, which are also influenced by the exposures to particulate matter and endotoxin in the air. The aim of this study was to investigate the potential interactions among cold stress, fine particulate matter (PM_2.5, particles with aerodynamic diameter of 2.5 µm or less) and lipopolysaccharide (LPS, pure chemical form of endotoxin) on rat lung and to explore the related possible mechanisms of the interactions. Wistar rats were randomly grouped to be exposed to, 1) normal saline (0.9% NaCl), 2) PM_2.5, 3) LPS, and 4) PM_2.5 and LPS (PM_2.5 + LPS) through intratracheal instillation under cold stress (0 °C) and normal temperature (20 °C). Lung function, lung tissue histology, inflammatory response and oxidative stress levels were measured to examine the lung injury and to investigate the potential mechanisms. Exposure to PM_2.5 or LPS substantially changed pulmonary function [indicated by peak inspiratory flow (PIF) and peak expiratory flow (PEF)], inflammatory cytokine levels [indicated by interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α)] and lung histology, compared to the non-exposed groups. Exposure to PM_2.5 + LPS under cold stress induced the most significant changes, including the increases of IL-6, TNF-α and thiobarbituric acid-reactive substances (TBARS), the decreases of PIF and PEF and more severe lung injury, among all exposure scenarios. Glutathione peroxidase activity and, nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) were found to be suppressed under cold stress, whereas Nrf2 and HO-1 levels were observed to be upregulated by exposure to PM_2.5 or LPS under normal temperature. In conclusion, cold stress may aggravate the lung injury in rats induced by simultaneous exposure to PM_2.5 and LPS. The progress may involve the suppressing of Nrf2/HO-1 signal pathway.

Association of outdoor temperature with lung function in a temperate climate

Acute exposure to cold dry air is a trigger of bronchoconstriction, but little is known about how daily outdoor temperature influences lung function.We investigated associations of temperature from a model using satellite remote sensing data with repeated measures of lung function among 5896 participants of the Framingham Heart Study Offspring and Third Generation cohorts residing in the Northeastern US. We further tested if temperature modified previously reported associations between pollution and lung function. We constructed linear mixed-effects models, and assessed departures from linearity using penalised splines.In fully adjusted linear models, 1-, 2- and 7-day average temperatures were all associated with lower lung function: each 5°C higher previous-week temperature was associated with a 20 mL lower (95% CI -34---6) forced expiratory volume in 1 s. There was significant effect modification by season: negative associations of temperature and lung function were present in winter and spring only. Negative associations between previous-day fine particulate matter and lung function were present during unseasonably warm but not unseasonably cool days, with a similar pattern for other pollutants.We speculate that temperature-related differences in lung function may be explained by behavioural changes on relatively warm days, which may increase outdoor exposures.

Effects of ambient temperature on lung function in patients with chronic obstructive pulmonary disease: A time-series panel study

BACKGROUND

Limited evidence concerns the associations between ambient temperature and lung function and the results are mixed.

OBJECTIVE

To evaluate the associations between temperature variations and daily fluctuations in pulmonary function in chronic obstructive pulmonary disease (COPD) patients.

METHODS

We designed a time-series panel study of 28 male urban COPD patients with repeated daily lung function measurements from December 2012 to May 2013 in Shanghai, China. We used a linear mixed-effect model combined with a distributed lag model to estimate the cumulative effects of temperature on morning/evening pulmonary function tests (PFTs), including peak expiratory flow (PEF) and forced expiratory volume in 1-s (FEV₁), while adjusting for within-subject correlations, individual characteristics, time trends and air pollution levels.

RESULTS

We obtained a total of 8618 pairs of morning PFTs and 8528 pairs of evening PFTs. The associations between daily mean temperature and PEF were inverted U-shaped with both low and high temperatures significantly reducing morning and evening PEF. Compared with the referent temperature (16°C), the low temperature (1st percentile, -1°C) would result in cumulative decreases of 32.20L/min in morning PEF and 21.15L/min in evening PEF over lags of two weeks. The corresponding decrements at the same lag associated with high temperature (99th percentile, 25°C) were 38.10L/min in morning PEF and 27.08L/min in evening PEF. There were no statistically significant changes in morning or evening FEV₁.

CONCLUSIONS

This time-series panel study provided robust evidence that both low and high temperatures were significantly associated with decrements in pulmonary function, particularly in PEF.

Association between body mass index (BMI) and vital capacity of college students of Zhuang nationality in China: a cross-section study

Objective

Our study is to evaluate the association between body mass index (BMI) and vital capacity of college students of Zhuang Nationality in China.

Methods

463 college students of Zhuang Nationality from Guangxi Medical University were selected. Basic information, body composition and vital capacity of college students were measured. According to the level of BMI, college students were divided into four groups (BMI<18.5, 18.5≤BMI<23.9, 23.9≤BMI<27.9 and BMI≥27.9). Multivariate logistic regression analysis was performed to assess the association between BMI and vital capacity.

Results

In male college students, there was no significant difference in vital capacity between the four groups (3029.54±869.25, 3347.06±784.54, 3540.00±805.35 and 3966.50±350.2, P=0.0727, respectively). Multivariate regression analysis showed that after adjusting for confounding factors, no significant association was observed between BMI and vital capacity (OR=115.02, 95% CI: -555.58∼785.63; OR=-166.58, 95% CI: -1684.56∼1351.41; OR=-484.01, 95% CI:-3504.53, 2536.51, respectively. BMI<18.5 group served as reference group). In female college students, there was also no significant difference in vital capacity between the four groups (2455.15±574.4, 2555.06±637.03, 2750.33±1224.05 and 2473.00±159.06, P=0.4011, respectively). Multivariate regression analysis showed that after adjusting for confounding factors, no significant association was observed between BMI and vital capacity (OR=-88.88, 95% CI: -333.59∼155.84; OR=20.00, 95% CI: -694.39∼734.39; OR=2.86, 95% CI: -1830.58, 1836.3, respectively. BMI<18.5 group served as reference group).

Conclusion

There was no evidence that BMI is associated with vital capacity in college students of Zhuang Nationality.

Personal exposure to fine particulate matter, lung function and serum club cell secretory protein (Clara)

BACKGROUND

The underlying mechanisms about the association between ambient fine particulate matter (PM_2.5) and lung function were unclear. Few epidemiological studies have evaluated the potential mediating effects of serum club cell secretory protein (Clara) (CC16), a biomarker of pulmonary epithelium integrity.

OBJECTIVES

To evaluate the short-term effect of personal PM_2.5 exposure on lung function and to explore the potential mediating role of CC16 in this effect.

METHODS

We enrolled 36 healthy, nonsmoking college students for a panel study in Shanghai, China from December 17, 2014 to July 11, 2015. We measured personal and real-time exposure to PM_2.5 for 72 h preceding each of four rounds of health examinations, including lung function test and serum CC16 measurement. We used linear mixed-effect models to examine the effects of PM_2.5 on lung function and CC16 over various lag times. Furthermore, we analyzed the mediating effect of CC16 in the association between PM_2.5 and lung function.

RESULTS

Average PM_2.5 exposure ranged from 36 to 52 μg/m3 across different lag periods. PM_2.5 exposure was negatively associated with lung function and positively associated with serum CC16 concentration. The effect of PM_2.5 on CC16 occurred earlier than that on lung function. For instance, an interquartile range (IQR) increase in 0-2 h average exposure to PM_2.5 was significantly associated with a 4.84% increase in serum CC16; and an IQR increase in 3-6 h average exposure to PM_2.5 was significantly associated with a 1.08% decrease in 1-sec forced expiratory volume. These effects lasted up to 24 h after exposure. Increased serum CC16 contributed 3.9%-36.3% of the association between PM_2.5 and impaired lung function.

CONCLUSIONS

Acute exposure to PM_2.5 might induce an immediate decrease in lung function by virtue of the loss of pulmonary epithelium integrity.

Polydatin protects the respiratory system from PM2.5 exposure

Atmospheric particle is one of the risk factors for respiratory disease; however, their injury mechanisms are poorly understood, and prevention methods are highly desirable. We constructed artificial PM_2.5 (aPM_2.5) particles according to the size and composition of actual PM_2.5 collected in Beijing. Using these artificial particles, we created an inhalation-injury animal model. These aPM_2.5 particles simulate the physical and chemical characteristics of the actual PM_2.5, and inhalation of the aPM_2.5 in rat results in a time-dependent change in lung suggesting a declined lung function, injury from oxidative stress and inflammation in lung. Thus, this aPM_2.5-caused injury animal model may mimic that of the pulmonary injury in human exposed to airborne particles. In addition, polydatin (PD), a resveratrol glucoside that is rich in grapes and red wine, was found to significantly decrease the oxidative potential (OP) of aPM_2.5in vitro. Treating the model rats with PD prevented the lung function decline caused by aPM_2.5, and reduced the level of oxidative damage in aPM_2.5-exposed rats. Moreover, PD inhibited aPM_2.5-induced inflammation response, as evidenced by downregulation of white blood cells in bronchoalveolar lavage fluid (BALF), inflammation-related lipids and proinflammation cytokines in lung. These results provide a practical means for self-protection against particulate air pollution.

Short-term Effects of Outdoor Air Pollution on Lung Function among Female Non-smokers in China

Short-term exposures to outdoor air pollutants have been associated with lower lung function, but the results are inconsistence. The effects of different pollutant levels on lung function changes are still unclear. We quantified the effects of outdoor air pollution exposure (NO₂, PM₁₀, O₃, and PM_2.5) on lung function among 1,694 female non-smokers from the Wuhan-Zhuhai Cohort in China by using linear mixed model. We further investigated the associations in the two cities with different air quality levels separately to quantify the effects of different pollutant level exposure on lung function. We found the moving averages of NO₂, PM₁₀, and PM_2.5 concentrations were significantly associated with reduced FVC. In city at high pollutant level, the moving average of NO₂, PM₁₀, O₃, and PM_2.5 exposures were significantly associated with both FVC and FEV₁ reductions. In the low-level air pollution city, PM₁₀ (Lag03-Lag05) and O₃ concentrations (Lag01-Lag03) were significantly associated with reduced FVC, while PM₁₀ (Lag03-Lag05), O₃ (Lag0-Lag03), and PM_2.5 (Lag04-Lag06) exposure were significantly associated with reduced FEV₁. Our results suggest that outdoor air pollution is associated with short-term adverse effects on lung function among female non-smokers. The adverse effects may persist for longer durations within 7 days at higher air pollutant levels.

Indoor and Outdoor Air Pollution- related Health Problem in Ethiopia: Review of Related Literature

BACKGROUND

The health effects of air pollution are generally global problems, but they have, since recently become issues of particular concern for developing countries. This review assessed the situation of air pollution and related health effects in the context of Ethiopia.

METHODS

The materials reviewed in this publication are published scientific papers from online search engines, unpublished government reports and academic theses/dissertations. In addition, interview data obtained from authorities and experts involved in the management of air quality were analyzed, interpreted and reported in the article.

RESULTS

Review of the few studies conducted in Ethiopia showed that average concentrations of PM2.5 reached as high as 280 µg/m3 for 24-hour measurements (range: 2,417-12,739 µg/m3). Indoor carbon monoxide (CO) levels were universally higher than regulatory limits for the United States and were found to be much higher among households using traditional stoves and solid biomass fuels. The use of traditional stoves and solid biomass fuels was reported in >95% of the households considered. High average levels of NO2 (97 ppb) were reported in a large longitudinal study. The ambient PM10 level was below the WHO guideline values in the majority of the samples. About 50% of the on-road CO samples taken from traffic roads in Addis Ababa were found to be less than the guideline values while the number of motor vehicles in Ethiopia is reported to be increasing by more than 9% per annum. There is a very limited air quality monitoring capacity in the country. The co-ordination between stakeholders in this regard is also inadequate. The limited evidence available on health effects of air pollution indicates that the prevalence of acute respiratory illness among children living in households using crude biomass fuels is significantly higher than the national average figures.

CONCLUSION

The limited evidence reviewed and reported in this article indicates high levels of indoor air pollution and trends of worsening outdoor air pollution. This tentative conclusion carries with it the urgent need for more evidence-based research and capacity building in the areas of indoor and outdoor air pollution.