Fine particulate matter, temperature, and lung function in healthy adults: findings from the HVNR study

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.

Concentration-dependent increase in symptoms due to diesel exhaust in a controlled human exposure study

Background

Traffic-related air pollution (TRAP) exposure causes adverse effects on wellbeing and quality of life, which can be studied non-invasively using self-reported symptoms. However, little is known about the effects of different TRAP concentrations on symptoms following controlled exposures, where acute responses can be studied with limited confounding. We investigated the concentration–response relationship between diesel exhaust (DE) exposure, as a model TRAP, and self-reported symptoms.

Methods

We recruited 17 healthy non-smokers into a double-blind crossover study where they were exposed to filtered air (FA) and DE standardized to 20, 50, 150 µg/m3 PM2.5 for 4 h, with a ≥ 4-week washout between exposures. Immediately before, and at 4 h and 24 h from the beginning of the exposure, we administered visual analog scale (VAS) questionnaires and grouped responses into chest, constitutional, eye, neurological, and nasal categories. Additionally, we assessed how the symptom response was related to exposure perception and airway function.

Results

An increase in DE concentration raised total (β ± standard error = 0.05 ± 0.03, P = 0.04), constitutional (0.01 ± 0.01, P = 0.03) and eye (0.02 ± 0.01, P = 0.05) symptoms at 4 h, modified by perception of temperature, noise, and anxiety. These symptoms were also correlated with airway inflammation. Compared to FA, symptoms were significantly increased at 150 µg/m3 for the total (8.45 ± 3.92, P = 0.04) and eye (3.18 ± 1.55, P = 0.05) categories, with trends towards higher values in the constitutional (1.49 ± 0.86, P = 0.09) and nasal (1.71 ± 0.96, P = 0.08) categories.

Conclusion

DE exposure induced a concentration-dependent increase in symptoms, primarily in the eyes and body, that was modified by environmental perception. These observations emphasize the inflammatory and sensory effects of TRAP, with a potential threshold below 150 µg/m3 PM2.5. We demonstrate VAS questionnaires as a useful tool for health monitoring and provide insight into the TRAP concentration–response at exposure levels relevant to public health policy.

Overview of particulate air pollution and human health in China: Evidence, challenges, and opportunities

Ambient particulate matter (PM) pollution in China continues to be a major public health challenge. With the release of the new WHO air quality guidelines in 2021, there is an urgent need for China to contemplate a revision of air quality standards (AQS). In the recent decade, there has been an increase in epidemiological studies on PM in China. A comprehensive evaluation of such epidemiological evidence among the Chinese population is central for revision of the AQS in China and in other developing countries with similar air pollution problems. We thus conducted a systematic review on the epidemiological literature of PM published in the recent decade. In summary, we identified the following: (1) short-term and long-term PM exposure increase mortality and morbidity risk without a discernible threshold, suggesting the necessity for continuous improvement in air quality; (2) the magnitude of long-term associations with mortality observed in China are comparable with those in developed countries, whereas the magnitude of short-term associations are appreciably smaller; (3) governmental clean air policies and personalized mitigation measures are potentially effective in protecting public and individual health, but need to be validated using mortality or morbidity outcomes; (4) particles of smaller size range and those originating from fossil fuel combustion appear to show larger relative health risks; and (5) molecular epidemiological studies provide evidence for the biological plausibility and mechanisms underlying the hazardous effects of PM. This updated review may serve as an epidemiological basis for China’s AQS revision and proposes several perspectives in designing future health studies.

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Acute effects of PM are smaller in China compared with developed countries

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Health effects caused by PM depend on particle composition, source, and size

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There are no thresholds for the health effects of PM

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Mechanistic studies support the biological plausibility of PM’s health effects

Long-term personal PM2.5 exposure and lung function alternation: A longitudinal study in Wuhan urban adults

BACKGROUND

The effect of long-term PM_2.5 exposure on lung function has not been well established.

OBJECTIVES

To investigate the effects of long-term personal PM_2.5 exposure on lung function decline, obstructive, and restrictive ventilatory disorders.

METHOD

Personal PM_2.5 concentrations were evaluated using an estimation model. Lung function parameters including forced vital capacity (FVC), forced expiratory volume in 1 s (FEV₁) and peak expiratory flow (PEF) were measured in 3053 Wuhan participants from the Wuhan-Zhuhai cohort and were repeated every 3 years. Participants were classified into persistently high exposure group, persistently low exposure group and inconsistent exposure group according to the median of PM_2.5 concentration of each visit. Mixed linear models with subject-specific random intercept were used to assess the association of 3-year change of lung function with personal PM_2.5 exposure, and generalized linear models were used to assess the association of 6-year change of lung function with personal PM_2.5 exposure. Cox regression models were applied to assess the associations of PM_2.5 with obstructive and restrictive ventilatory disorders.

RESULTS

The medians of personal PM_2.5 concentrations at baseline and two follow-ups were 153.18, 209.57 and 83.78 μg/m³, respectively. Compared with participants in the persistently low exposure group, participants in the persistently high exposure group showed a 2.99 % (95 % CI: 0.91, 5.08), a 380.15 mL/s (95 % CI: 32.82, 727.48) and a 5.98 % (95 % CI: 0.84, 11.11) additional decline in FEV₁/FVC, PEF and PEFpred after 6 years, respectively. Stratified analyses showed that age, gender, body mass index, smoking status and drinking status had no significant modification effect on the associations. The associations of PM_2.5 exposure with obstructive and restrictive ventilatory disorders were not significant, except for a positive association between persistently high PM_2.5 exposure and restrictive ventilatory disorder among ever drinkers.

CONCLUSION

Long-term high PM_2.5 exposure was associated with FEV₁/FVC, PEF and PEFpred declines.

Acute effects of exposure to fine particulate matter and ozone on lung function, inflammation and oxidative stress in healthy adults

Both fine particulate matter (PM_2.5) and ozone (O₃) may have adverse effects on human health. However, previous studies on the effects of air pollutants mainly have focused on susceptible population, and evidence on healthy young adults is limited. We aimed to examine the associations of the two main air pollutants (PM_2.5 and O₃) with lung function, inflammation and oxidative stress in healthy young adults. We recruited 30 healthy young adults for a longitudinal panel study in Beijing and implemented health examination seven times, including lung function (FEV₁ and PEF) and biomarkers of inflammation and oxidative stress (i.e. C-reactive protein, CRP; interleukin-6, IL-6; malondialdehyde, MDA) from December 2019 to May 2021. Hourly ambient air pollutants data were obtained from the closest air quality monitoring station. Linear mixed-effect model was applied to explore the associations between air pollutants and lung function, inflammation and oxidative stress. We observed higher PM_2.5 exposure was associated with decrement in lung function and increment in CRP and MDA. Each 10 μg/m³ increase in PM_2.5 (lag 2 day) is associated with a 17.06 ml (95% CI: -31.53, -2.58) decrease in FEV₁, 46.34 ml/s (95% CI: -76.41, -16.27) decrease in PEF and increments of 2.86% (95% CI: 1.47%, 4.27%) in CRP, 1.63% (95% CI: 0.14%, 3.14%) in MDA respectively. However, there is no significant association between ozone exposure and health indicators. The study suggested that short-term exposure to PM_2.5 may decrease lung function and induce inflammation and oxidative stress in healthy adults, but there is no association between O₃ and each outcome.

Development of an Air Pollution Risk Perception Questionnaire for Running Race Runners Based on the Health Belief Model

An increasing number of individuals participate in running races worldwide; however, running in the presence of air pollution poses health risks to runners. Therefore, developing a valid and reliable instrument is imperative to assess runners' beliefs and perceptions regarding risks and health behaviors. This study developed a comprehensive questionnaire based on the health behavior model and relevant literature. The questionnaire was tested with 310 responses from individuals with running race experiences in Taiwan. Tests of the measurement model were conducted using reliability and confirmatory factor analysis. The results reveal that the questionnaire consists of eight constructs: perceived susceptibility, perceived severity, perceived benefits, perceived barriers, perceived self-efficacy, cues to action, health behavior intention, and awareness of air quality. The 31 items jointly accounted for 72.71% of the observed variance. All eight factors have good internal consistency, convergent, and discriminant validity with acceptable model fit indexes. Additionally, a valid translated English version of the questionnaire is provided for future research, sports agencies, or governments to explore factors that affect, or interact with, risk while running under air pollution conditions to develop management strategies.

Assessment of Factors Influencing Personal Exposure to Air Pollution on Main Roads in Bogota: A Mixed-Method Study

Background and Objectives: Particulate Matter (PM), particles of variable but small diameter can penetrate the respiratory system via inhalation, causing respiratory and/or cardiovascular diseases. This study aims to evaluate the association of environmental particulate matter (PM_2.5) and black carbon (BC) with respiratory health in users of different transport modes in four roads in Bogotá. Materials and Methods: this was a mixed-method study (including a cross sectional study and a qualitative description of the air quality perception), in 300 healthy participants, based on an exploratory sequential design. The respiratory effect was measured comparing the changes between pre- and post-spirometry. The PM_2.5 and black carbon (BC) concentrations were measured using portable devices. Inhaled doses were also calculated for each participant according to the mode and route. Perception was approached through semi-structured interviews. The analysis included multivariate models and concurrent triangulation. Results: The concentration of matter and black carbon were greater in bus users (median 50.67 µg m^-3; interquartile range (-IR): 306.7). We found greater inhaled dosages of air pollutants among bike users (16.41 µg m^-3). We did not find changes in the spirometry parameter associated with air pollutants or transport modes. The participants reported a major sensory influence at the visual and olfactory level as perception of bad air quality. Conclusions: We observed greater inhaled doses among active transport users. Nevertheless, no pathological changes were identified in the spirometry parameters. People's perceptions are a preponderant element in the assessment of air quality.

Impact of acute temperature and air pollution exposures on adult lung function: A panel study of asthmatics

Background

Individuals with respiratory conditions, such as asthma, are particularly susceptible to adverse health effects associated with higher levels of ambient air pollution and temperature. This study evaluates whether hourly levels of fine particulate matter (PM_2.5) and dry bulb globe temperature (DBGT) are associated with the lung function of adult participants with asthma.

Methods and findings

Global positioning system (GPS) location, respiratory function (measured as forced expiratory volume at 1 second (FEV₁)), and self-reports of asthma medication usage and symptoms were collected as part of the Exposure, Location, and Lung Function (ELF) study. Hourly ambient PM_2.5 and DBGT exposures were estimated by integrating air quality and temperature public records with time-activity patterns using GPS coordinates for each participant (n = 35). The relationships between acute PM_2.5, DBGT, rescue bronchodilator use, and lung function collected in one week periods and over two seasons (summer/winter) were analyzed by multivariate regression, using different exposure time frames.

In separate models, increasing levels in PM_2.5, but not DBGT, were associated with rescue bronchodilator use. Conversely DBGT, but not PM_2.5, had a significant association with FEV₁. When DBGT and PM_2.5 exposures were placed in the same model, the strongest association between cumulative PM_2.5 exposures and the use of rescue bronchodilator was identified at the 0–24 hours (OR = 1.030; 95% CI = 1.012–1.049; p-value = 0.001) and 0–48 hours (OR = 1.030; 95% CI = 1.013–1.057; p-value = 0.001) prior to lung function measure. Conversely, DBGT exposure at 0 hours (β = 3.257; SE = 0.879; p-value>0.001) and 0–6 hours (β = 2.885; SE = 0.903; p-value = 0.001) hours before a reading were associated with FEV₁. No significant interactions between DBGT and PM_2.5 were observed for rescue bronchodilator use or FEV₁.

Conclusions

Short-term increases in PM_2.5 were associated with increased rescue bronchodilator use, while DBGT was associated with higher lung function (i.e. FEV₁). Further studies are needed to continue to elucidate the mechanisms of acute exposure to PM_2.5 and DBGT on lung function in asthmatics.

Life-time summer heat exposure and lung function in young adults: A retrospective cohort study in Shandong China

BACKGROUND

The health impact of short-term heat exposure is well documented. However, limited studies explored the association between life-time summer heat exposure and lung function.

OBJECTIVE

To examine the association between life-time summer heat exposure and lung function among young adults.

METHODS

We conducted a retrospective cohort study among 1928 college students in Shandong, China from September 4, 2020 to November 15, 2020. Life-time summer heat exposure for participants were estimated based on the nearest station meteorological data after the participant's birth date and divided by their learning phases. Lung function indicators included forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1). A multiple linear regression model was conducted to examine the associations between summer heat exposure and lung function. Stratificationanalysis by cooling facilities and respiratory diseases history were also conducted.

RESULTS

The study subjects had a slight majority of women (58.8%), age 19.2 ± 0.6 years. Each 1 °C increase in life-time summer mean temperature was associated with 1.07% [95% confidence interval (CI): -1.95-0.18%] decrease in FVC and 0.88% (95 %CI: -1.71, -0.05%) decrease in FEV1. Participants with respiratory diseases and non-cooling facility users were more susceptible to summer heat exposure. The usage of fan and air condition could effectively reduce the deleterious heat effects on lung function.

CONCLUSION

Life-time summer heat exposure is significantly associated with the reduction of lung function in young adults. Cooling facilities are necessary for pre-school children to reduce heat effects. Fan and air-condition are effective cooling facilities, especially for people with respiratory diseases.

Biomarkers for the adverse effects on respiratory system health associated with atmospheric particulate matter exposure

Large amounts of epidemiological evidence have confirmed the atmospheric particulate matter (PM_2.5) exposure was positively correlated with the morbidity and mortality of respiratory diseases. Nevertheless, its pathogenesis remains incompletely understood, probably resulting from the activation of oxidative stress, inflammation, altered genetic and epigenetic modifications in the lung upon PM_2.5 exposure. Currently, biomarker investigations have been widely used in epidemiological and toxicological studies, which may help in understanding the biologic mechanisms underlying PM_2.5-elicited adverse health outcomes. Here, the emerging biomarkers to indicate PM_2.5-respiratory system interactions were summarized, primarily related to oxidative stress (ROS, MDA, GSH, etc.), inflammation (Interleukins, FE_NO, CC16, etc.), DNA damage (8-OHdG, γH2AX, OGG1) and also epigenetic modulation (DNA methylation, histone modification, microRNAs). The identified biomarkers shed light on PM_2.5-elicited inflammation, fibrogenesis and carcinogenesis, thus may favor more precise interventions in public health. It is worth noting that some inconsistent findings may possibly relate to the inter-study differentials in the airborne PM_2.5 sample, exposure mode and targeted subjects, as well as methodological issues. Further research, particularly by -omics technique to identify novel, specific biomarkers, is warranted to illuminate the causal relationship between PM_2.5 pollution and deleterious lung outcomes.

Hourly concentrations of fine and coarse particulate matter and dynamic pulmonary function measurements among 4992 adult asthmatic patients in 25 Chinese cities

The short-term associations of fine particulate matter (PM_2.5) and coarse particulate matter (PM_2.5-10) with pulmonary function were inconsistent and rarely evaluated by dynamic measurements. Our study aimed to investigate the associations of PM_2.5 and PM_2.5-10 with real-time pulmonary function. We conducted a longitudinal study based on dynamic pulmonary function measurements among adult asthmatic patients in 25 cities of 19 provincial regions of China from 2017 to 2020. Linear mixed-effects models combined with polynomial distributed lag models were used for statistical analysis. A total of 298,396 records among 4,992 asthmatic patients were evaluated. We found generally inverse associations of PM_2.5 and PM_2.5-10 with 16 pulmonary function indicators that were independent of gaseous pollutants. The associations occurred at lag 1 d, became the strongest at lag 4 d, and vanished a week later. PM_2.5-10 had stronger associations than PM_2.5, especially in southern China. Nationally, an interquartile increase in PM_2.5-10 (28.0 μg/m³) was significantly associated with decreases in forced expiratory volume in 1 s (FEV_1, 41.6 mL), the ratio of FEV₁ in forced vital capacity (1.1%), peak expiratory flow (136.9 mL/s), and forced expiratory flow at 25-75% of forced vital capacity (54.3 mL/s). We observed stronger associations in patients of male, BMI ≥ 25 kg/m², age ≥ 45 years old, and during warm seasons. In conclusion, this study provided robust evidence for impaired pulmonary function by short-term exposure to PM_2.5 and PM_2.5-10 in asthmatic patients using the largest dataset of dynamic monitoring. The associations can last for one week and PM_2.5-10 may be more hazardous.

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.

Inhibitory effects of cudratricusxanthone O on particulate matter-induced pulmonary injury

Particulate matter 2.5 (PM_2.5), aerodynamic diameter ≤ 2.5 μm, is the primary air pollutant that plays the key role for lung injury resulted from the loss of vascular barrier integrity. Cudratricusxanthone O (CTXO) is a novel xanthone compound isolated from the root of Cudrania tricuspidata Bureau. Here, we investigated the beneficial effects of CTXO against PM-induced lung endothelial cell (EC) barrier disruption and pulmonary inflammation. Permeability, leukocyte migration, activation of proinflammatory proteins, generation of reactive oxygen species (ROS), and histology were examined in PM_2.5-treated ECs and mice. CTXO significantly scavenged PM_2.5-induced ROS and inhibited the ROS-induced activation of p38 mitogen-activated protein kinase (MAPK). Concurrently, CTXO activated Akt, which helped maintain endothelial integrity. Furthermore, CTXO reduced vascular protein leakage, leukocyte infiltration, and proinflammatory cytokine release in the bronchoalveolar lavage fluid in PM-induced lung tissues. These results indicated that CTXO may exhibit protective effects against PM-induced inflammatory lung injury and vascular hyperpermeability.

What Are the Effects of Meteorological Factors on Exacerbations of Chronic Obstructive Pulmonary Disease?

Chronic obstructive pulmonary disease (COPD) is one of the greatest global public health challenges. Acute exacerbations of COPD lead to the accelerated deterioration of lung function, reduced quality of life, a higher number of hospitalizations, and increased mortality. The factor causing the exacerbation is usually an infectious agent, but the impact of environmental factors is being studied more thoroughly. Among them, meteorological factors are the least examined. Multiple studies have shown that lower temperatures during the cold season, as well as sudden temperature changes regardless of the season, have the most significant negative effect on patients with COPD. However, higher temperatures, especially during summer heatwaves, can also cause COPD exacerbation and it is expected that this will be an even more important health problem in the future considering climate changes. The effects of other meteorological factors on acute exacerbation of COPD, such as atmospheric pressure, solar radiation, rainfall, wind speed, and humidity are far less investigated and opposing results have been obtained in different studies. Thus, there is a need for further research in this area that would result in clinical recommendations and public health interventions that could decrease the global burden of COPD.

Personal PM2.5 exposure and lung function: Potential mediating role of systematic inflammation and oxidative damage in urban adults from the general population

BACKGROUND

Short-term effects of fine particulate matter (PM_2.5) exposure on lung function have been reported. However, few studies have assessed PM_2.5 exposure on the personal level, and the mechanism underlying the effects of PM_2.5 exposure on lung function remains less clear.

OBJECTIVES

To evaluate the association between personal PM_2.5 exposure and lung function alteration in general population and to explore the roles of systematic inflammation and oxidative damage in this association.

METHODS

A total of 7685 lung function tests were completed among 4697 urban adults in Wuhan, China. Plasma C-reactive protein (CRP), urinary 8-iso-prostaglandin-F_2α (8-iso-PGF_2α) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels were measured. Personal PM_2.5 exposure levels were estimated using an estimation model from the actual measurements of individual PM_2.5 levels in 191 participants. Mixed linear models were used to evaluate the association between personal PM_2.5 exposure and lung function. Mediation analyses were conducted to investigate the roles of CRP, 8-iso-PGF_2α and 8-OHdG in above associations.

RESULTS

After adjusting for confounders, each 10 μg/m³ increase in the previous-day personal PM_2.5 exposure was associated with 2.94 mL, 2.02 mL and 16.14 mL/s decreases in forced vital capacity (FVC), forced expiration volume in 1 s (FEV₁) and peak expiratory flow, respectively. The associations were more obvious among never smokers compared with current smokers. Cumulative 7-day exposure to PM_2.5 led to the strongest adverse effects on lung function. Among never smokers with high PM_2.5 exposure levels, a positive relationship was observed between personal PM_2.5 level and urinary 8-iso-PGF_2α, and 8-iso-PGF_2α meditated 4.69% and 12.30% of the association between the 7-day moving PM_2.5 concentration and FVC and FEV₁, respectively. We did not observe a significant positive association between PM_2.5 exposure and plasma CRP or urinary 8-OHdG.

CONCLUSION

Short-term personal exposure to PM_2.5 is associated with reduced pulmonary ventilation function. Urinary 8-iso-PGF_2α partly mediates these associations.

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.

Short-term prediction of urban PM2.5 based on a hybrid modified variational mode decomposition and support vector regression model

PM_2.5 (particulate matter with a size/diameter ≤ 2.5 μm) is an important air pollutant that affects human health, especially in urban environments. However, as time-series data of PM_2.5 are non-linear and non-stationary, it is difficult to predict future PM_2.5 distribution and behavior. Therefore, in this paper, we propose a hybrid short-term urban PM_2.5 prediction model based on variational mode decomposition modified by the correntropy criterion, the state transition simulated annealing (STASA) algorithm, and a support vector regression model to overcome the disadvantages of traditional forecasting techniques which consider different environmental factors. Two experiments were performed with the model to assess its effectiveness and predictive ability: in experiment I, we verified the performance of STASA on benchmark functions, while in experiment II, we used PM_2.5 data from different epochs and regions of Beijing to verify its forecasting performance. The experimental results showed that the proposed model is robust and can achieve satisfactory prediction results under different conditions compared with current forecasting techniques.

Regular running in an air-polluted environment: physiological and anthropometric protocol for a prospective cohort study (Healthy Aging in Industrial Environment Study - Program 4)

INTRODUCTION

Ambient air pollution is a global environmental problem, which causes adverse health effects and premature deaths worldwide. Although regular exercise and physical activity have evident health benefits, the influence of long-term air pollution exposure during regular outdoor running has not been definitively clarified.

METHODS AND ANALYSIS

This study protocol describes the physiological and anthropometric perspectives of the 'Healthy Aging in Industrial Environment' Study - Programme 4 (4HAIE). The 4HAIE research project is intended to be a single-centre, prospective, longitudinal and multidisciplinary cohort study. The presented study protocol describes the cross-sectional measurements and analyses. Overall, 1500 adult participants (age 18-65 years), runners and inactive individuals, living in a high or low air-polluted area of the Czech Republic will be recruited. We will measure and analyse biomarkers of oxidative stress and inflammation in the blood, exercise capacity (graded exercise test and spiroergometry), blood pressure, lung function (spirometry), cardiac autonomic regulation and anthropometry (body composition).

ETHICS AND DISSEMINATION

The 4HAIE study protocol has already been approved by the Ethics Committee of the University of Ostrava (3/2018). A detailed participant information sheet will be provided to each individual prior to obtaining their written informed consent. The study poses little to no risk to participants. The findings of this study will be disseminated at regional and international conferences, in peer-reviewed journals and via social and broadcast media.

Low levels of fine particulate matter increase vascular damage and reduce pulmonary function in young healthy adults

BACKGROUND

Fine particulate matter (PM2.5) related mild inflammation, altered autonomic control of cardiovascular function, and changes to cell function have been observed in controlled human exposure studies.

METHODS

To measure the systemic and cardiopulmonary impacts of low-level PM exposure, we exposed 20 healthy, young volunteers to PM2.5, in the form of concentrated ambient particles (mean: 37.8 μg/m3, SD 6.5), and filtered air (mean: 2.1 μg/m3, SD 2.6). In this double-blind, crossover study the exposure order was randomized. During the 4 h exposure, volunteers (7 females and 13 males) underwent light intensity exercise to regulate ventilation rate. We measured pulmonary, cardiac, and hematologic end points before exposure, 1 h after exposure, and again 20 h after exposure.

RESULTS

Low-level PM2.5 resulted in both pulmonary and extra-pulmonary changes characterized by alterations in systematic inflammation markers, cardiac repolarization, and decreased pulmonary function. A mean increase in PM2.5 concentration (37.8 μg/m3) significantly increased serum amyloid A (SAA), C-reactive protein (CRP), soluble intercellular adhesion molecule-1 (sICAM-1), and soluble vascular cell adhesion molecule-1 (sVCAM-1), 1 h after exposure by 8.7, 9.1, 10.7, and 6.6%, respectively, relative to the filtered air control. SAA remained significantly elevated (34.6%) 20 h after PM2.5 exposure which was accompanied by a 5.7% decrease in percent neutrophils. Decreased pulmonary function was observed 1 h after exposure through a 0.8 and 1.2% decrease in forced expiratory volume in 1 s (FEV1) and FEV1/ forced vital capacity (FEV1/FVC) respectively. Additionally, sex specific changes were observed in repolarization outcomes following PM2.5 exposure. In males, P-wave and QRS complex were increased by 15.4 and 5.4% 1 h after exposure.

CONCLUSIONS

This study is the first controlled human exposure study to demonstrate biological effects in response to exposure to concentrated ambient air PM2.5 particles at levels near the PM2.5 US NAAQS standard.

CLINICAL TRIAL REGISTRATION INFORMATION

clinicaltrials.gov ; Identifier: NCT03232086 . The study was registered retrospectively on July 25, 2017, prior to final data collection on October 25, 2017 and data analysis.

[Evaluation of cyclists exposure to air pollution: a literature review]

OBJECTIVES

To describe and interpret the methodologies and results of the main studies related to the monitoring of exposure of cyclists to air pollution.

METHODS

Research and analysis of national and international research of the last ten years in the Cochrane, Scopus, Embase, Science Direct and Pubmed databases. The search was conducted in August and September 2017 using the following search descriptors for MeSH: air pollution, bicycle riding, environmental exposure, environmental health, exposure by inhalation, environmental pollutants, transportation, public health and toxicology. For DeCS: air Pollution, cycling, exposure to environmental risks, environmental pollutants, inhalation, transportation, public health and toxicology.

RESULTS

Nineteen eligible published articles were identified. Most studies were conducted in Europe and the United States. Four studies have been reported in South America. Other studies seek comparisons on different bicycle routes, compare exposure during variations of the same route, and others determine the distance-exposure relationship. In the same way, variables such as vehicular traffic, distance to the emission sources and the type of bike path, play a fundamental role in the exposure to pollutants in cyclists.

CONCLUSIONS

Several variables were found that influence, directly or indirectly, the cyclists exposure to air pollution, as well as some factors that can reduce this exposure.

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.

Investigating PM2.5 responses to other air pollutants and meteorological factors across multiple temporal scales

It remains unclear on how PM_2.5 interacts with other air pollutants and meteorological factors at different temporal scales, while such knowledge is crucial to address the air pollution issue more effectively. In this study, we explored such interaction at various temporal scales, taking the city of Nanjing, China as a case study. The ensemble empirical mode decomposition (EEMD) method was applied to decompose time series data of PM_2.5, five other air pollutants, and six meteorological factors, as well as their correlations were examined at the daily and monthly scales. The study results show that the original PM_2.5 concentration significantly exhibited non-linear downward trend, while the decomposed time series of PM_2.5 concentration by EEMD followed daily and monthly cycles. The temporal pattern of PM₁₀, SO₂ and NO₂ is synchronous with that of PM_2.5. At both daily and monthly scales, PM_2.5 was positively correlated with CO and negatively correlated with 24-h cumulative precipitation. At the daily scale, PM_2.5 was positively correlated with O₃, daily maximum and minimum temperature, and negatively correlated with atmospheric pressure, while the correlation pattern was opposite at the monthly scale.

Susceptibility of individuals with chronic obstructive pulmonary disease to air pollution exposure in Beijing, China: A case-control panel study (COPDB)

Exposure to air pollution is one of the major risk factors contributing to the occurrence and development of chronic obstructive pulmonary disease (COPD). However, few studies have investigated the susceptibility of patients with COPD to air pollution. Here, we provided a study protocol. A panel study of a total of 480 samples to compare the response to air pollution exposure between 60 patients with COPD and 60 healthy control subjects has been performed in Beijing (the COPDB study) since May 2016. The health assessment and exposure evaluation methods used in this COPDB study are summarized here. Throat, exhaled breath and condensate, urine, serum, plasma, and blood samples, as well as cardiopulmonary function indexes were repeatedly collected over four visits. Indicators of inflammation, oxidative stress, infection, metabolic changes, and genetic differences were then analyzed. Personal and ambient levels of fine particles and their components, as well as gaseous pollutants were monitored during the follow-up period. Linear mixed-effects models were used to evaluate the associations between changes in biomarkers and exposure to air pollution in both patients with COPD and healthy control subjects. Based on the COPDB study, the susceptibility of COPD patients and underlying mechanisms, involving difference in inflammatory, infection, metabolic, and genetic response to different air pollutants, were investigated. Our preliminary result shows that air pollution-associated changes in heart rate were higher in COPD patients than the healthy controls. More investigations of the underlying mechanisms of the susceptibility are ongoing. This study has been registered in ChiCTR with the number of ChiCTR1900023692.

A Hybrid Deep Learning Model to Forecast Particulate Matter Concentration Levels in Seoul, South Korea

Both long- and short-term exposure to high concentrations of airborne particulate matter (PM) severely affect human health. Many countries now regulate PM concentrations. Early-warning systems based on PM concentration levels are urgently required to allow countermeasures to reduce harm and loss. Previous studies sought to establish accurate, efficient predictive models. Many machine-learning methods are used for air pollution forecasting. The long short-term memory and gated recurrent unit methods, typical deep-learning methods, reliably predict PM levels with some limitations. In this paper, the authors proposed novel hybrid models to combine the strength of two types of deep learning methods. Moreover, the authors compare hybrid deep-learning methods (convolutional neural network (CNN)—long short-term memory (LSTM) and CNN—gated recurrent unit (GRU)) with several stand-alone methods (LSTM, GRU) in terms of predicting PM concentrations in 39 stations in Seoul. Hourly air pollution data and meteorological data from January 2015 to December 2018 was used for these training models. The results of the experiment confirmed that the proposed prediction model could predict the PM concentrations for the next 7 days. Hybrid models outperformed single models in five areas selected randomly with the lowest root mean square error (RMSE) and mean absolute error (MAE) values for both PM10 and PM2.5. The error rate for PM10 prediction in Gangnam with RMSE is 1.688, and MAE is 1.161. For hybrid models, the CNN–GRU better-predicted PM10 for all stations selected, while the CNN–LSTM model performed better on predicting PM2.5.

Sex-Dependent Effects of PM2.5 Maternal Exposure and Quercetin Intervention on Offspring's Short Chain Fatty Acids

Short chain fatty acids (SCFAs) are produced by the colonic microbiota through fermentation. Influences of maternal PM2.5 exposure on SCFAs of the offspring have not been well understood. Additionally, studies of dietary intervention have not been carried out yet. Here we performed a study that dams were received PM2.5 and quercetin intervention during gestation and lactation. SCFAs in colon of dams and their offspring (on postnatal day 21 and 35) were analyzed using gas chromatography. For male offspring, when compared with the control group levels of acetic acid, butyric acid, and valeric acid were lower in the PM2.5 group (p < 0.05), however, levels of isobutyric acid and isovaleric acid were higher in the PM2.5 group (p < 0.05). For female offspring, as compared with the control group, propanoic acid was lower in the PM2.5 group, however isovaleric acid was higher in the PM2.5 group (p < 0.05). 100 mg/kg and 200 mg/kg quercetin intervention could inhibit SCFAs production of male offspring, especially in isobutyric acid and isovaleric acid (p < 0.05). 100 mg/kg quercetin intervention could upgrade the level of propanoic acid of female offspring (p < 0.05). Taken together, these results suggest that PM2.5 tracheal exposure during gestation and lactation could influence SCFAs of offspring. Quercetin administration might have the potential to offset the effects of mater PM2.5 exposure on SCFAs in the offspring to some extent. The above effects were showed in a sex-dependent manner.

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.

Inhibitory Effects of Black Ginseng on Particulate Matter-Induced Pulmonary Injury

Inhalation of fine particulate matter (PM2.5) is associated with elevated pulmonary injury caused by the loss of vascular barrier integrity. Black ginseng (BG), steamed and dried ginseng nine times, exhibits various pharmacological activities such as antibacterial, antihyperglycemic, anti-atopic, antibacterial, and anti-inflammatory activities. In this study, we investigated the beneficial effects of black ginseng extract (BGE) against PM-induced lung endothelial cell (EC) barrier disruption and pulmonary inflammation. Permeability, leukocyte migration, activation of proinflammatory proteins, generation of reactive oxygen species (ROS), and histology were examined in PM2.5-treated ECs and mice. BGE significantly scavenged PM2.5-induced ROS and inhibited the ROS-induced activation of p38 mitogen-activated protein kinase (MAPK). Concurrently, BGE activated Akt, which helped maintain endothelial integrity. Furthermore, BGE reduced vascular protein leakage, leukocyte infiltration, and proinflammatory cytokine release in the bronchoalveolar lavage fluid in PM-induced lung tissues. These results indicated that BGE may exhibit protective effects against PM-induced inflammatory lung injury and vascular hyperpermeability.

Inhibitory effects of collismycin C and pyrisulfoxin A on particulate matter-induced pulmonary injury

BACKGROUND

Inhalation of fine particulate matter (PM_2.5) is associated with elevated pulmonary injury caused by the loss of vascular barrier integrity. Marine microbial natural products isolated from microbial culture broths were screened for pulmonary protective effects against PM_2.5. Two 2,2'-bipyridine compounds isolated from a red alga-associated Streptomyces sp. MC025-collismycin C (2) and pyrisulfoxin A (5)-were found to inhibit PM_2.5-mediated vascular barrier disruption.

PURPOSE

To confirm the inhibitory effects of collismycin C and pyrisulfoxin A on PM_2.5-induced pulmonary injury STUDY DESIGN: In this study, we investigated the beneficial effects of collismycin C and pyrisulfoxin A on PM-induced lung endothelial cell (EC) barrier disruption and pulmonary inflammation.

METHODS

Permeability, leukocyte migration, proinflammatory protein activation, reactive oxygen species (ROS) generation, and histology were evaluated in PM_2.5-treated ECs and mice.

RESULTS

Collismycin C and pyrisulfoxin A significantly scavenged PM_2.5-induced ROS and inhibited the ROS-induced activation of p38 mitogen-activated protein kinase as well as activated Akt, which helped in maintaining endothelial integrity, in purified pulmonary endothelial cells. Furthermore, collismycin C and pyrisulfoxin A reduced vascular protein leakage, leukocyte infiltration, and proinflammatory cytokine release in the bronchoalveolar lavage fluid of PM-treated mice.

CONCLUSION

These data suggested that collismycin C and pyrisulfoxin A might exert protective effects on PM-induced inflammatory lung injury and vascular hyperpermeability.

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.

Inhibitory effects of compounds isolated from Dioscorea batatas Decne peel on particulate matter-induced pulmonary injury in mice

Particulate matter 2.5 (PM_2.5), with an aerodynamic diameter of ≤2.5 μm, is the primary air pollutant that plays a key role associated with lung injury produced by loss of vascular barrier integrity. Dioscorea batatas Decne (Chinese yam), a perennial plant belonging to Dioscoreaceae family, is widely cultivated in tropical and subtropical regions across Asia. Both aerial parts and root of D. batatas are consumed for nutritional and medicinal purposes. The aim of this study was to (1) identify the bioactive compounds present in D. batatas peel which may be responsible for inhibition of PM_2.5-induced pulmonary inflammation in mice and (2) examine in vitro mechanisms underlying the observed effects of these compounds on mouse lung microvascular endothelial cells. The measured parameters include permeability, leukocyte migration, proinflammatory protein activation, reactive oxygen species (ROS) generation, and histology. Two phenanthrene compounds, 2,7-dihydroxy-4,6-dimethoxyphenanthrene (1) and 6,7-dihydroxy-2,4-dimethoxyphenanthrene (2) were isolated from D. batatas peels. Both these phenanthrene compounds exhibited significant scavenging activity against PM_2.5-induced ROS and inhibited ROS-induced activation of p38 mitogen-activated protein kinase. In addition, enhancement of Akt pathway, involved in the maintenance of endothelial integrity, was noted. These phenanthrene compounds also reduced vascular protein leakage, leukocyte infiltration, and proinflammatory cytokine release in the bronchoalveolar lavage fluid obtained from PM_2.5-induced lung tissues. Evidence thus indicates that phenanthrene compounds derived from D. batatas may exhibit protective effects against PM_2.5-induced inflammatory lung injury and vascular hyperpermeability in mice.

Stronger association between particulate air pollution and pulmonary function among healthy students in fall than in spring

Previous studies have reported the short-term effects of particulate air pollution on health. However, most of those studies were relatively short in duration, with only a few, in healthy adolescents. We investigated the short-term effects of particulate air pollution on pulmonary function in healthy adolescents over a long period. A panel study was repeatedly conducted twice a year for about one month each, in spring and fall from 2014 to 2016, in an isolated island in the Seto Inland Sea, Japan. Daily measurements of peak expiratory flow (PEF) and forced expiratory volume in 1 s (FEV₁) were performed in a total of 48 healthy college students aged 15-19 years. The ambient concentrations of particulate matter with diameter ≤2.5 μm (PM_2.5) and between 2.5 and 10 μm (PM_10-2.5), and black carbon (BC) were continuously measured. A mixed-effects model was used to investigate the relationships between air pollutants and pulmonary function. In the overall analyses of the six study periods, decreases in the PEF and FEV₁ were significantly associated with increases in the PM_2.5 and BC concentrations. The greatest decrease was found in FEV₁ (-1.97% [95% confidence interval (CI): -2.90, -1.04]), which was associated with an interquartile range (IQR) increase in the 0-72-h average concentrations of PM_2.5 (14.1 μg/m³). Neither PEF nor FEV₁ were associated with PM_10-2.5 concentrations. In the analyses by season, both the PEF and FEV₁ values decreased significantly in relation to increases in the PM_2.5, PM_10-2.5 and BC concentrations in the fall. However, in spring, both PEF and FEV₁ showed weak associations with each of the pollutants. In conclusion, relatively low increases in the ambient particulate matter levels were associated with reduced pulmonary function among healthy adolescents. This association was stronger in fall than in spring.

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.

Inhibitory effects of Kyung-Ok-Ko, traditional herbal prescription, on particulate matter-induced vascular barrier disruptive responses

Inhalation of fine particulate matter (PM_2.5) is associated with elevated pulmonary injury caused by the loss of vascular barrier integrity. A traditional herbal prescription, Kyung-Ok-Ko (KOK), has long been used in Oriental medicine as a tonic for age-related diseases. In this study, we investigated the beneficial effects of KOK on PM-induced lung endothelial cell (EC) barrier disruption and pulmonary inflammation. Permeability, leukocyte migration, activation of proinflammatory proteins, generation of reactive oxygen species (ROS), and histology were examined in PM_2.5-treated EC and mice. KOK significantly scavenged PM_2.5-induced ROS and inhibited the ROS-induced activation of p38 mitogen-activated protein kinase (MAPK). Concurrently, KOK activated Akt, which helped maintain endothelial integrity. Furthermore, KOK reduced vascular protein leakage, leukocyte infiltration, and proinflammatory cytokine release in bronchoalveolar lavage fluids in PM-induced lung tissues. These data suggested that KOK might exhibit protective effects in PM-induced inflammatory lung injury and vascular hyperpermeability.

Inhibitory effects of protopanaxatriol type ginsenoside fraction (Rgx365) on particulate matter-induced pulmonary injury

Inhalation of fine particulate matter (PM_2.5) is associated with elevated pulmonary injury attributed to the loss of vascular barrier integrity. Black ginseng (BG), steamed 9 times and dried ginseng, and its major protopanaxatriol type ginsenosides (ginsenoside Rg4, Rg6, Rh4, Rh1, and Rg2) exhibited various biological activities including anti-septic, anti-diabetic, wound healing, immune-stimulatory, and anti-antioxidant activity. The aim of this study was to investigate the beneficial effects of Rgx365 (a protopanaxatriol type rare ginsenosides fraction) on PM-induced lung endothelial cell (EC) barrier disruption and pulmonary inflammation. Permeability, leukocyte migration, activation of proinflammatory proteins, generation of reactive oxygen species (ROS), and histology were examined in PM_2.5-treated EC and mice. Rgx365 significantly scavenged PM_2.5-induced ROS, inhibited ROS-induced activation of p38 mitogen-activated protein kinase (MAPK), activated Akt in purified pulmonary EC, which helped maintain endothelial integrity. Further, Rgx365 reduced vascular protein leakage, leukocyte infiltration, and proinflammatory cytokine release in bronchoalveolar lavage fluids in PM-induced mouse lung tissues. Data suggested that Rgx365 might exhibit protective effects in PM-induced inflammatory lung injury and vascular hyperpermeability.

Nursing Practice and Particulate Matter Exposure

: Environmental factors underlie more than one-fifth of deaths and disability worldwide. Globally, both indoor and outdoor particulate matter pollution are leading risk factors for reduced quality of life and death. Nurses are in a key position to assess particulate matter exposure and to intervene, providing population, community, family, and individual risk reduction and care. This article presents a case study describing one patient's experiences with asthma and multiple comorbidities, an overview of particulate matter exposure and health, and management strategies for practice.

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 Indoor and Ambient Black Carbon and [Formula: see text] on Pulmonary Function among Individuals with COPD

BACKGROUND

Particulate matter (PM) air pollution has been associated with decreased pulmonary function, but the exposure–response relationship in chronic obstructive pulmonary disease (COPD) patients is uncertain, and most studies have only focused on exposures to ambient pollution.

OBJECTIVES

We aimed to assess associations between pulmonary function and indoor and ambient PM [Formula: see text] ([Formula: see text]) and black carbon (BC).

METHODS

Between November 2012 and December 2014, 125 patients with COPD (mean age, 73.4 y) who were not currently smoking and without known indoor BC sources were recruited. Indoor BC and [Formula: see text] were measured in each home for a week in each season, up to four times a year, followed by in-person spirometry pre- and post-bronchodilator. Ambient exposures were available from a central site monitor. Multivariable adjusted mixed effects regression models were used to assess associations scaled per interquartile range (IQR) of exposure.

RESULTS

There were 367 study visits; the median (IQR) indoor BC and [Formula: see text] were 0.19 (0.22) [Formula: see text] and 6.67 (5.80) [Formula: see text], respectively. Increasing indoor exposures to BC were associated with decreases in pre-bronchodilator forced expiratory volume in 1 s [Formula: see text] and forced vital capacity (FVC), and [Formula: see text]. For example, in multivariable adjusted models, each IQR increase in indoor BC from the weekly integrated filter was associated with a [Formula: see text] [95% confidence interval (CI): [Formula: see text], [Formula: see text]] decrease in pre-bronchodilator [Formula: see text]. Increases in indoor [Formula: see text] were associated with decreases in [Formula: see text] and FVC of smaller magnitude than those for indoor BC; however, the results were less precise. Ambient BC was not associated with pre-bronchodilator pulmonary function, ambient [Formula: see text] was only associated with decreases in FVC and increases in [Formula: see text], and neither indoor nor ambient BC or [Formula: see text] were associated with post-bronchodilator pulmonary function.

CONCLUSIONS

Low-level exposures to indoor BC and [Formula: see text], but not ambient exposures, were consistently associated with decreases in pre-bronchodilator pulmonary function. There was no association between exposures and post-bronchodilator pulmonary function. https://doi.org/10.1289/EHP3668.

Lung function association with outdoor temperature and relative humidity and its interaction with air pollution in the elderly

While the effects of weather variability on cardio-respiratory mortality are well described, research examining the effects on morbidity, especially for vulnerable populations, is warranted. We investigated the associations between lung function and outdoor temperature (T in Celsius degrees (°C)) and relative humidity (RH), in a cohort of elderly men, the Normative Aging Study. Our study included 1103 participants whose forced vital capacity (FVC), forced expiratory volume in one second (FEV₁), and weather exposures were assessed one to five times during the period 1995-2011 (i.e. 3162 observations). Temperature and relative humidity were measured at one location 4 h to 7 days before lung function tests. We used linear mixed-effects models to examine the associations with outdoor T and RH. A 5-degree increase in the 3-day moving average T was associated with a significant 0.7% decrease (95%CI: -1.24, -0.20) in FVC and a 5% increase in the 7-day moving average RH was associated with a significant 0.2% decrease (95%CI: -0.40, -0.02) in FVC and FEV₁. The associations with T were greater when combined with higher exposures of black carbon with a 1.6% decrease (95%CI -2.2; -0.9) in FVC and a 1% decrease (95%CI -1.7; -0.4) in FEV₁. The relationships between T and RH and lung function were linear. No synergistic effect of T and RH was found. Heat and lung function are two predictors of mortality. Our findings suggest that increases in temperature and relative humidity are related to decreases in lung function, and such observations might be amplified by high black carbon levels.

The burden of ambient temperature on years of life lost: A multi-community analysis in Hubei, China

BACKGROUND

Compared with death rates, years of life lost (YLL) has been widely used as a more informative indicator to quantify the burden of premature death. In the context of global climate change, existing evidence linking ambient temperatures and YLL was very scarce across the globe.

METHODS

Daily mortality and meteorological data during 2009-2012 were obtained from 12 communities across Hubei Province in central China. A two-stage approach was used for statistical analysis. At the first stage, a generalized linear regression combined with distributed lag non-linear model was applied to estimate community-specific temperature-YLL associations. A second-stage multivariable meta-analysis was then conducted to pool the community-specific estimates of temperature-related effects on YLL.

RESULTS

A pooled J- or U-shaped association was observed between ambient temperature and YLL due to different mortality categories. Heat effects occurred immediately and only persisted for several days, whereas cold effects were delayed and much longer-lasting. At the provincial level, heat effect (per 1°C increase from 75th to 99th percentile of temperature) at lag 0-2days and cold effect (per 1°C decrease from 25th to 1st percentile of temperature) at lag 0-21days was associated with an increase of 1.91% (95% CI: 0.83, 3.00) and 5.09% (2.79, 7.40) in YLL due to non-accidental deaths, respectively. Much greater effect estimates of cold than heat were also observed for other mortality-specific YLLs (except for respiratory mortality). Heat effects on YLL were higher for males and the youth, while cold effects were greater for females and the elderly. Additionally, relatively stronger associations between heat, cold and YLL were consistently observed in low-educated persons.

CONCLUSIONS

This multi-community study strengthened the evidence that both cold and hot temperatures were associated with increased years of life lost. Our findings may have important implications for better understanding the burden of premature death related to temperature extremes.

High molecular weight hyaluronan attenuates fine particulate matter-induced acute lung injury through inhibition of ROS-ASK1-p38/JNK-mediated epithelial apoptosis

Inhalation of fine particulate matter (PM_2.5) is asscoiated with lung injury. High molecular weight hyaluronan (HMW-HA) is an essential constituent of extracellular matrix (ECM), exhibiting anti-oxidative and anti-inflammatory properties when administered by injection, inhalation, nebulization or gene delivery of HA synthases. The aim of the present study is to determine whether HMW-HA alleviates PM_2.5-induced acute lung injury (ALI) and investigate the underlying mechanisms. We observed that HMW-HA suppressed pathological injury, inflammation, oxidative stress, edema and epithelial damage caused by PM_2.5 in the lungs of the rats. The protective mechanism of HMW-HA was further explored in vitro. The results elucidated that reactive oxygen species (ROS) was involved in PM_2.5-induced cell apoptosis, and HMW-HA mitigated the oxidative potential of PM_2.5, subsequently inhibiting phosphorylation of ASK1 at Thr845, downstream phosphorylation of p38 and JNK, and eventual apoptosis. Our study indicates that HMW-HA is a promising strategy in the prevention of PM_2.5-induced pulmonary damage.

Estimated individual inhaled dose of fine particles and indicators of lung function: A pilot study among Chinese young adults

Fine particle (PM_2.5)-related lung damage has been reported in most studies regarding environmental or personal PM_2.5 concentrations. To assess effects of personal PM_2.5 exposures on lung function, we recruited 20 postgraduate students and estimated the individual doses of inhaled PM_2.5 based on their microenvironmetal PM_2.5 concentrations, time-activity patterns and refereed inhalation rates. During the period of seven consecutive days in each of the four seasons, we repeatedly measured the daily lung function parameters and airway inflammation makers such as fractional exhaled nitric oxide (FeNO) as well as systemic inflammation markers including interleukin-1β on the final day. The high individual dose (median (IQR)) of inhaled PM_2.5 was 957 (948) μg/day. We observed a maximum FeNO increase (9.1% (95%CI: 2.2-15.5)) at lag 0 day, a maximum decrease of maximum voluntary ventilation (11.8% (95% CI: 4.6-19.0)) at lag 5 day and a maximum interleukin-1β increase (103% (95% CI: 47-159)) at lag 2 day for an interquartile range increase in the individual dose of inhaled PM_2.5 during the four seasons. Short-term exposure to PM_2.5 assessed by the individual dose of inhaled PM_2.5 was associated with higher airway and systemic inflammation and reduced lung function. Further studies are needed to understand better underlying mechanisms of lung damage following acute exposure to PM_2.5.

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.

PM2.5 Induced the Expression of Fibrogenic Mediators via HMGB1-RAGE Signaling in Human Airway Epithelial Cells

Background

The aim of the present study was to test whether fine particulate matter (PM2.5) induces the expression of platelet-derived growth factor-AB (PDGF-AB), PDGF-BB, and transforming growth factor-β1 (TGF-β1) in human bronchial epithelial cells (HBECs) in vitro via high-mobility group box 1 (HMGB1) receptor for advanced glycation end products (RAGE) signaling.

Methods

Sprague-Dawley rats were exposed to motor vehicle exhaust (MVE) or clean air. HBECs were either transfected with a small interfering RNA (siRNA) targeting HMGB1 or incubated with anti-RAGE antibodies and subsequently stimulated with PM2.5.

Results

The expression of HMGB1 and RAGE was elevated in MVE-treated rats compared with untreated rats, and PM2.5 increased the secretion of HMGB1 and upregulated RAGE expression and the translocation of nuclear factor κB (NF-κB) into the nucleus of HBECs. This activation was accompanied by an increase in the expression of PDGF-AB, PDGF-BB, and TGF-β1. The HMGB1 siRNA prevented these effects. Anti-RAGE antibodies attenuated the activation of NF-κB and decreased the secretion of TGF-β1, PDGF-AB, and PDGF-BB from HBECs.

Conclusion

PM2.5 induces the expression of TGF-β1, PDGF-AB, and PDGF-BB in vitro via HMGB1-RAGE signaling, suggesting that this pathway may contribute to the airway remodeling observed in patients with COPD.

Geographic variation in Chinese children' forced vital capacity and its association with long-term exposure to local PM10: a national cross-sectional study

The purpose of this study was to estimate the association between Chinese children's forced vital capacity (FVC) and particulate matter with aerodynamic diameter ≤10 μm (PM₁₀). The FVC data of 71,763 children aged 7 to 18 was collected from 2010 Chinese National Survey on Students' Construction and Health (CNSSCH). The local annual average concentration of PM₁₀, relative humidity, ambient temperature, and other air pollutant data of 30 cities was collected from China Meteorological Administration and Ministry of Environment Protection of China. Then, we used generalized additive model (GAM) to estimate the association between children's FVC and PM₁₀. The obvious geographic variation in FVC was found in children of 30 Chinese cities ranging from 1647 ml in Xining to 2571 ml in Beijing. The annual average concentration of PM₁₀ was also different, ranging from 40 μg/m³ in Haikou to 155 μg/m³ in Lanzhou. After adjusted individual characteristics, socioeconomic conditions, ambient temperature, relative humidity, and other air pollutants (e.g., NO₂ and SO₂) in the generalized additive model, we found that the increase of PM₁₀ was associated with decrease of FVC in Chinese children. A 10-μg/m³ increase of PM₁₀ was associated with 1.33-ml decrease in FVC (95% confidence interval: -2.18 to -0.47). We also found a larger effect estimate of PM₁₀ on FVC in boys than that in girls. Consistent associations were found in both physically inactive and active children. The increase of PM₁₀ was associated with decrease of children's FVC. We should develop proper public health policy to protect children's respiratory health during growth and development in polluted areas.

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.

Effects of particulate matter on respiratory disease and the impact of meteorological factors in Busan, Korea

BACKGROUND

Both air pollution and weather impact hospitalization for respiratory diseases. However, few studies have investigated the contribution of weather to hospitalization related to the adverse effects of air pollution. This study analyzed the effects of particulate matter (PM) on daily respiratory-related hospital admissions, taking into account meteorological factors.

METHODS

Daily hospital admissions for respiratory diseases (acute bronchitis, allergic rhinitis, and asthma) between 2007 and 2010 were extracted from the National Health Insurance Corporation, Korea. Patients were divided into three age-based groups (0-15, 16-64, and ≥65 years). PM levels were obtained from 19 monitoring stations in Busan.

RESULTS

The mean number of patients admitted for acute bronchitis, allergic rhinitis, and asthma was 5.8 ± 11.9, 4.4 ± 6.1, and 3.3 ± 3.3, respectively. During that time, the daily mean PM₁₀ and PM_2.5 concentrations were 49.6 ± 20.5 and 24.2 ± 10.9 μg/m³, respectively. The mean temperature anomaly was 7.0 ± 2.3 °C; the relative humidity was 62.0 ± 18.0%. Hospital admission rates for respiratory diseases increased with increasing PM and temperature, and with decreasing relative humidity. A multivariate analysis including PM, temperature anomaly, relative humidity, and age showed a significant increase in respiratory-related admissions with increasing PM levels and a decreasing relative humidity. Higher PM_2.5 levels had a greater effect on respiratory-related hospital admission than did PM₁₀ levels. Children and the elderly were the most susceptible to hospital admission for respiratory disease.

CONCLUSIONS

PM levels and meteorological factors impacted hospitalization for respiratory diseases, especially in children and the elderly. The effect of PM on respiratory diseases increased as the relative humidity decreased.