Acute respiratory response to individual particle exposure (PM1.0, PM2.5 and PM10) in the elderly with and without chronic respiratory diseases

Numerical analysis on the airflow organization of a blowing suction dust collector

Small sweeper will become a very popular way to clean roads in cities if its dust removal efficiency could be improved by combining the dust collector of blowing-suction type. A new dust collector of blowing-suction type used in urban cleaning vehicle is presented by this article, which is named W-shaped blowing suction dust collector, and its gas-solid two-phase flow field is numerically analyzed by computational fluid dynamics (CFD) method, including effects of its structural parameters and operating parameters on the dust removal efficiency. It has been demonstrated that the flow field characteristics and the overall dust removal efficiency of the blowing-suction dust collector depend on the diameter-width ratio and the inclination angle of the baffle/slot-shaped nozzle, and the air blowing velocity and the sweeper traveling speed. The optimal combination of structural parameters is the diameter-width ratio of 0.25 and the inclination angle of the baffle/slot-shaped air blow of 69.5°, and the ideal operating parameters are an air blowing velocity of 15 m/s at each port and a sweeper-traveling speed of 1.3 m/s. In the conditions mentioned above, the average near ground velocity of the dust collector is greater than the particle start-up speed of 15m/s and the average velocity of the surrounding air inlet surfaces increases significantly. The negative pressure of the dust collection port is relatively high. Meanwhile, the blowing suction dust collector in this study achieved a dust removal efficiency of over 95%. This study will provide a useful reference for its fabrication followed.

Association between respiratory tract deposited dose of size-segregated PM and FeNO based on individual exposure assessment for Korean children

FeNO (fractional exhaled nitric oxide) is a crucial marker to understand children's respiratory diseases such as asthma, and severity may vary depending on PM diameter and respiratory tract region. This study investigates the relationship between size-segregated respiratory deposited PM dose and FeNO for children. Size-segregated PM (PM1.0, PM1.0-2.5, and PM2.5-10.0) and FeNO were measured for eighty children based on individual exposure assessment in five consecutive days. Individual physical activity was measured by an accelerometer device. Accordingly, a dosimetry model estimated the respiratory deposited dose by PM diameter in the extrathoracic (ET), tracheobronchial (TB), and pulmonary (PUL) regions. A linear mixed model (LMM) with distributed lag non-linear model (DLNM) was used for analysis. The effects of home environment and traffic-related factors were also examined for sensitivity analysis. We found that IQR increases of PM2.5-10.0 and PM1.0 were associated with 15.1 % (95 % CI: 3.5, 28.1) and 15.9 % (95 % CI: 2.7, 30.9) FeNO increase in respiratory Total region in 0-12 h lag. In cumulative lag 0-24 h, PM1.0 was only associated with FeNO increase: 16.6 % (95 % CI: 1.5, 34.1) in total region. No association was observed in lag 12-24 h. PM2.5-10.0 was related to short-term airway inflammation in the upper respiratory tract whereas PM1.0 has a cumulative effect on both the upper and lower respiratory tract. In sensitivity analysis, PM2.5-10.0 was associated with a 0-12 h lag, whereas both PM2.5-10.0 and PM1.0 were associated with a cumulative lag of 0-24 h. Both home environment and traffic-related factors showed a synergetic effect with PM1.0 in short-term exposure and an antagonistic effect with PM2.5-10.0 in long-term exposure. This study highlights that airway inflammation depends on PM sizes, exposure durations, and respiratory tract regions.

The Association Between Personal Air Pollution Exposures and Fractional Exhaled Nitric Oxide (FeNO): A Systematic Review

PURPOSE OF REVIEW

Airway inflammation is a common biological response to many types of environmental exposures and can lead to increased nitric oxide (NO) concentrations in exhaled breath. In recent years, several studies have evaluated airway inflammation using fractional exhaled nitric oxide (FeNO) as a biomarker of exposures to a range of air pollutants. This systematic review aims to summarize the studies that collected personal-level air pollution data to assess the air pollution-induced FeNO responses and to determine if utilizing personal-level data resulted in an improved characterization of the relationship between air pollution exposures and FeNO compared to using only ambient air pollution exposure data.

RECENT FINDINGS

Thirty-six eligible studies were identified. Overall, the studies included in this review establish that an increase in personal exposure to particulate and gaseous air pollutants can significantly increase FeNO. Nine out of the 12 studies reported statistically significant FeNO increases with increasing personal PM2.5 exposures, and up to 11.5% increase in FeNO per IQR increase in exposure has also been reported between FeNO and exposure to gas-phase pollutants, such as ozone, NO2, and benzene. Furthermore, factors such as chronic respiratory diseases, allergies, and medication use were found to be effect modifiers for air pollution-induced FeNO responses. About half of the studies that compared the effect estimates using both personal and ambient air pollution exposure methods reported that only personal exposure yielded significant associations with FeNO response. The evidence from the reviewed studies confirms that FeNO is a sensitive biomarker for air pollutant-induced airway inflammation. Personal air pollution exposure assessment is recommended to accurately assess the air pollution-induced FeNO responses. Furthermore, comprehensive adjustments for the potential confounding factors including the personal exposures of the co-pollutants, respiratory disease status, allergy status, and usage of medications for asthma and allergies are recommended while assessing the air pollution-induced FeNO responses.

COPD Exposed to Air Pollution: A Path to Understand and Protect a Susceptible Population

TOPIC IMPORTANCE

Air pollution poses a risk to the respiratory health of individuals with COPD. Long- and short-term exposures to higher levels of particulate-rich air pollution are associated with increased COPD exacerbation, hospitalization, and mortality, collectively implicating air pollution as a cause of adverse COPD-related outcomes.

REVIEW FINDINGS

This review summarizes the evidence for COPD as a phenotype that confers susceptibility for adverse health outcomes in the face of common air pollution. We highlight how typical contributors to compromised urban air quality, including that from traffic, wildfire smoke, and indoor biomass combustion, adversely affect the COPD patient population. Evidence underscoring the burden of ongoing air pollution exposure on patients with COPD is discussed. We then detail the detrimental impact of that exposure on COPD pathophysiology, which in turn increases the patient's susceptibility. We specifically propose that indoor air is a particularly rational target for increased monitoring and remediation to protect patients with COPD. Because COPD is a heterogeneous disease with several endotypes, future intervention studies need to better include control populations, to highlight COPD-specific risks and identify subpopulations within patients with COPD who will benefit the most from improved indoor air quality.

SUMMARY

Regulatory efforts must continue to broadly lower emission standards to protect this susceptible population from the negative health impacts of air pollution.

Medium-term exposure to size-fractioned particulate matter and asthma exacerbations in China: A longitudinal study of asthmatics with poor medication adherence

BACKGROUND

Studies have shown that short- and long-term exposure to particulate matter (PM) can increase the risk of asthma morbidity and mortality. However, the effect of medium-term exposure remains unknown. We aim to examine the effect of medium-term exposure to size-fractioned PM on asthma exacerbations among asthmatics with poor medication adherence.

METHODS

We conducted a longitudinal study in China based on the National Mobile Asthma Management System Project that specifically and routinely followed asthma exacerbations in asthmatics with poor medication adherence from April 2017 to May 2019. High-resolution satellite remote-sensing data were used to estimate each participant's medium-term exposure (on average 90 days) to size-fractioned PM (PM1, PM2.5, and PM10) based on the residential address and the date of the follow-up when asthma exacerbations (e.g., hospitalizations and emergency room visits) occurred or the end of the follow-up. The Cox proportional hazards model was employed to examine the hazard ratio of asthma exacerbations associated with each PM after controlling for sex, age, BMI, education level, geographic region, and temperature.

RESULTS

Modelling results revealed nonlinear exposure-response associations of asthma exacerbations with medium-term exposure to PM1, PM2.5, and PM10. Specifically, for emergency room visits, we found an increased hazard ratio for PM1 above 22.8 µg/m3 (1.060, 95 % CI: 1.025-1.096, per 1 µg/m3 increase), PM2.5 above 38.2 µg/m3 (1.032, 95 % CI: 1.010-1.054), and PM10 above 78.6 µg/m3 (1.019, 95 % CI: 1.006-1.032). For hospitalizations, we also found an increased hazard ratio for PM1 above 20.3 µg/m3 (1.055, 95 % CI: 1.001-1.111) and PM2.5 above 39.2 µg/m3 (1.038, 95 % CI: 1.003-1.074). Furthermore, the effects of PM were greater for a longer exposure window (90-180 days) and among participants with a high BMI.

CONCLUSION

This study suggests that medium-term exposure to PM is associated with an increased risk of asthma exacerbations in asthmatics with poor medication adherence, with a higher risk from smaller PM.

Comparison of static and dynamic exposures to air pollution, noise, and greenness among seniors living in compact-city environments

GPS technology and tracking study designs have gained popularity as a tool to go beyond the limitations of static exposure assessments based on the subject's residence. These dynamic exposure assessment methods offer high potential upside in terms of accuracy but also disadvantages in terms of cost, sample sizes, and types of data generated. Because of that, with our study we aim to understand in which cases researchers need to use GPS-based methods to guarantee the necessary accuracy in exposure assessment. With a sample of 113 seniors living in Barcelona (Spain) we compare their estimated daily exposures to air pollution (PM2.5, PM10, NO2), noise (dB), and greenness (NDVI) using static and dynamic exposure assessment techniques. Results indicate that significant differences between static and dynamic exposure assessments are only present in selected exposures, and would thus suggest that static assessments using the place of residence would provide accurate-enough values across a number of exposures in the case of seniors. Our models for Barcelona's seniors suggest that dynamic exposure would only be required in the case of exposure to smaller particulate matter (PM2.5) and exposure to noise levels. The study signals to the need to consider both the mobility patterns and the built environment context when deciding between static or dynamic measures of exposure assessment.

Causal effect of PM1 on morbidity of cause-specific respiratory diseases based on a negative control exposure

BACKGROUND

Extensive studies have linked PM_2.5 and PM₁₀ with respiratory diseases (RD). However, few is known about causal association between PM₁ and morbidity of RD. We aimed to assess the causal effects of PM₁ on cause-specific RD.

METHODS

Hospital admission data were obtained for RD during 2014 and 2019 in Beijing, China. Negative control exposure and extreme gradient boosting with SHapley Additive exPlanation was used to explore the causality and contribution between PM₁ and RD. Stratified analysis by gender, age, and season was conducted.

RESULTS

A total of 1,183,591 admissions for RD were recorded. Per interquartile range (28 μg/m³) uptick in concentration of PM₁ corresponded to a 3.08% [95% confidence interval (CI): 1.66%-4.52%] increment in morbidity of total RD. And that was 4.47% (95% CI: 2.46%-6.52%) and 0.15% (95% CI: 1.44%-1.78%), for COPD and asthma, respectively. Significantly positive causal associations were observed for PM₁ with total RD and COPD. Females and the elderly had higher effects on total RD, COPD, and asthma only in the warm months (Z = 3.03, P = 0.002; Z = 4.01, P < 0.001; Z = 3.92, P < 0.001; Z = 2.11, P = 0.035; Z = 2.44, P = 0.015). Contribution of PM₁ ranked first, second and second for total RD, COPD, and asthma among air pollutants.

CONCLUSION

PM₁ was causally associated with increased morbidity of total RD and COPD, but not causally associated with asthma. Females and the elderly were more vulnerable to PM₁-associated effects on RD.

Lung function decline associated with individual short-term exposure to PM1, PM2.5 and PM10 in patients with allergic rhinoconjunctivitis

BACKGROUND

The susceptibility of allergic rhinoconjunctivitis (ARC) patients to air pollution has yet to be clarified.

OBJECTIVES

Based on a repeated measurement panel study, we explored the association of short-term PM exposure with lung function in ARC patients and to further identify the susceptible populations.

METHODS

Personal PM exposure, including PM₁, PM_2.5 and PM₁₀, was monitored consecutively for three days before outcomes measurements. Lung function indices including forced vital capacity (FVC), forced expiratory volume in 1 s (FEV₁), peak expiratory flow (PEF), and forced expiratory flow at 25-75 % of the vital capacity (FEF_25-75) were measured. Serum total immunoglobulin E (IgE), specific-allergen IgE, blood eosinophil and basophils, and the symptoms severe scores were tested in each visit. Linear mixed effect models were applied to estimate the association between PM exposure and lung function. Furthermore, stratified and overlapping grouped populations based on IgE levels were implemented to characterize the modification role and the modulating threshold of IgE at which the association turned significantly negative.

RESULTS

Short-term PM personal exposure was associated with a significant decrease in lung function in ARC patients, especially for small airway respiratory indexes. The highest estimates occurred in PM₁, specifically a 10 μg/m³ increase reduced FEV₁/FVC, PEF and FEF_25-75 by 1.36 % (95 %CI: -2.29 to -0.43), 0.23 L/s (95 %CI: -0.42 to -0.03) and 0.18 L/s (95 %CI: -0.30 to -0.06), respectively. Notably, PM-induced decreases in lung function were stronger in patients with higher IgE levels (IgE ≥ 100 IU/mL), which were related to higher inflammatory cytokines and symptoms scores. Further, PM-associated lung function declines enhanced robustly and monotonically with increasing IgE concentration. Potential modulating thresholds of IgE occurred at 46.8-59.6 IU/mL for significant PM-lung function associations.

CONCLUSION

These novel findings estimated the short-term effects of PM on lung function in ARC patients, and the threshold values of IgE for the significant and robust associations.

Acute cardiorespiratory response to air quality index in healthy young adults

BACKGROUND

Little is known about the acute health impacts of air quality index (AQI) on cardiorespiratory risk factors.

OBJECTIVES

To assess the short-term links of AQI with cardiorespiratory risk factors in young healthy adults.

METHODS

We performed a longitudinal panel study with 4 repeated visits in 40 healthy young adults in Hefei, Anhui Province, China from August to October 2021. Cardiorespiratory factors included systolic blood pressure (BP), diastolic BP (DBP), mean arterial pressure (MAP) and fractional exhaled nitric oxide (FeNO). We collected hourly AQI data from a nearby air quality monitoring site. Linear mixed-effects model was applied to assess the effects of AQI on BP and FeNO.

RESULTS

The study participants (75.0% females) provided 160 pairs of valid health measurements with average age of 24 years. The mean AQI level was 44.43 during the study period. There were significant positive associations of AQI with three BP parameters and FeNO at different lag periods. For example, an interquartile range increase in AQI (26.54 unit) over lag 0-24 h was associated with increments of 6.69 mmHg (95%CI: 2.95-10.44), 5.71 mmHg (95%CI: 3.30-8.13), 6.04 mmHg (95%CI: 3.46-8.62) and 5.67% (95%CI: 1.05%-16.05%) in SBP, DBP, MAP and FeNO, respectively. The results were robust after controlling for PM₁. We did not find effect modifications by gender, BMI, physical activity, or AQI category level on the associations.

CONCLUSIONS

The current findings on associations of AQI with cardiorespiratory factors might add evidence of the acute adverse cardiorespiratory consequences following air pollution.

Association between short-term exposure to ambient PM1 and PM2.5 and forced vital capacity in Chinese children and adolescents

This study aims to examine the association between short-term exposure to ambient PM₁, PM_1-2.5, and PM_2.5 and forced vital capacity (FVC). Population data were obtained from a school-based cross-sectional survey in Shandong in 2014. Distributed lag non-linear models were used to examine the association between exposure to PM₁, PM_1-2.5, and PM_2.5 and FVC at the day of FVC measurement and the previous 6 days (lag 0 to 6 days). A total of 35,334 students aged 9 to 18 years were included in the study, and the mean exposure concentrations of ambient PM₁, PM_1-2.5, and PM_2.5 for them were 47.4 (standard deviation [SD] = 21.3) μg/m³, 32.8 (SD = 32.2) μg/m³, and 80.1 (SD = 47.7) μg/m³, respectively. An inter-quartile range (IQR, 24 μg/m³) increment in exposure to PM₁ was significantly associated with a lower FVC at lag 0 and lag 1 day (β =  - 80 mL, 95% CI =  - 119, - 42, and β =  - 37 mL, 95% CI =  - 59, - 16, respectively), and an IQR (54 μg/m³) increment in exposure to PM_2.5 was significantly associated with a lower FVC at lag 0 and lag 1 day (β =  - 57 mL, 95% CI =  - 89, - 18, and β =  - 34 mL, 95% CI =  - 56, - 12, respectively) after adjustment for gender, age, body mass index category, residence, month of the survey, intake of eggs, intake of milk, physical activity, and screen time. No significant associations were observed for PM_1-2.5. The inverse associations of PM₁ and PM_2.5 with FVC were larger in males, younger children, those overweight or obese, and those with insufficient physical activity levels. Short-term exposure to ambient PM₁ and PM_2.5 was associated with decreased FVC, and PM₁ may be the primary fraction of PM_2.5 causing the adverse pulmonary effects. Our findings emphasize the need to address ambient PM, especially PM₁, pollution for affecting pulmonary health in children and adolescents.

Short-Term Associations between Size-Fractioned Particles and Cardiopulmonary Function in COPD Patients: A Panel Study in Shanghai, China, during 2014-2021

It remains unknown which size fractions dominate the adverse cardiopulmonary effects of particulate matter (PM). Therefore, this study aimed to explore the differential associations between size-fractioned particle number concentrations (PNCs) and cardiopulmonary function measures, including the forced expiratory volume in one second (FEV₁), the forced vital capacity (FVC), and the left ventricular ejection fraction (LVEF). We conducted a panel study among 211 patients with chronic obstructive pulmonary disease (COPD) in Shanghai, China, between January 2014 and December 2021. We applied linear mixed-effect models to determine the associations between cardiopulmonary function measures and PNCs ranging from 0.01 to 10 μm in diameter. Generally, only particles <1 μm showed significant associations, i.e., ultrafine particles (UFPs, <0.1 μm) for FVC and particles ranging from 0.1 to 1 µm for FEV₁ and LVEF. An interquartile range (IQR) increment in UFP was associated with decreases of 78.4 mL in FVC. PNC_0.1-0.3 and PNC_0.3-1 corresponded to the strongest effects on FEV₁ (119.5 mL) and LVEF (1.5%) per IQR increment. Particles <1 µm might dominate the cardiopulmonary toxicity of PM, but UFPs might not always have the strongest effect. Tailored regulations towards particles <1 µm should be intensified to reduce PM pollution and protect vulnerable populations.

Short-term effects of gaseous air pollutants on outpatient visits for respiratory diseases: a case-crossover study in Baotou, China

Air pollution is a major public health problem throughout the world. Although there have been several studies in this field, most of them have focused on particulate matter and only covered a few key cities. This study aimed to assess a potential association between exposure to gaseous air pollutants and outpatient visits for respiratory diseases in Baotou, China. Daily outpatient visits for respiratory diseases and daily averages of air pollutants and meteorological parameters from 2015 to 2020 were obtained. Time-stratified case-crossover design and restricted cubic splines were used to perform the analyses. Stratified analyses were performed in different hospital departments and districts. Significant association between the concentrations of air pollutants and outpatient visits for respiratory diseases was observed. The odds ratios of outpatient visits for respiratory diseases associated with per 10 μg/m³ increases in concentrations of NO₂ and SO₂, and per 10 mg/m³ increases in concentrations of CO were 1.033 (95% CI: 1.018 to 1.049), 0.965 (95% CI: 0.954 to 0.976), and 1.038 (95% CI: 1.006 to 1.071), respectively. Short-term exposure to NO₂, SO₂, and CO was positively associated with outpatient visits for respiratory diseases, with stronger effects among children. The relationship between O₃ and respiratory diseases varied at different concentrations.

Recent Insights into Particulate Matter (PM2.5)-Mediated Toxicity in Humans: An Overview

Several epidemiologic and toxicological studies have commonly viewed ambient fine particulate matter (PM_2.5), defined as particles having an aerodynamic diameter of less than 2.5 µm, as a significant potential danger to human health. PM_2.5 is mostly absorbed through the respiratory system, where it can infiltrate the lung alveoli and reach the bloodstream. In the respiratory system, reactive oxygen or nitrogen species (ROS, RNS) and oxidative stress stimulate the generation of mediators of pulmonary inflammation and begin or promote numerous illnesses. According to the most recent data, fine particulate matter, or PM_2.5, is responsible for nearly 4 million deaths globally from cardiopulmonary illnesses such as heart disease, respiratory infections, chronic lung disease, cancers, preterm births, and other illnesses. There has been increased worry in recent years about the negative impacts of this worldwide danger. The causal associations between PM_2.5 and human health, the toxic effects and potential mechanisms of PM_2.5, and molecular pathways have been described in this review.

Traffic-related air pollution associated pulmonary pathophysiologic changes and cardiac injury in elderly patients with COPD

Traffic-related air pollution (TRAP) has shown enormous environmental toxicity, but its cardiorespiratory health impact on chronic obstructive pulmonary disease (COPD) has been less studied. We followed a panel of 45 COPD patients with 4 repeated clinical visits across 14 months in a traffic-predominated urban area of Beijing, China, with concurrent measurements of TRAP metrics (fine particulate matter, black carbon, oxides of nitrogen and carbon monoxide). Linear mixed-effect models were performed to evaluate the associations and potential pathways linking traffic pollution to indicators of spirometry, cardiac injury, inflammation and oxidative stress. We observed that interquartile range increases in moving averages of TRAP exposures at prior up to 7 days were associated with significant reductions in large and small airway functions, namely decreases in forced vital capacity of 3.1-9.3% and forced expiratory flow 25-75% of 5.9-16.4%. Higher TRAP levels were also associated with worsening of biomarkers relevant to lung injury (hepatocyte growth factor and surfactant protein D) and cardiac injury (high-sensitivity cardiac troponin I, B-type natriuretic peptide and soluble ST2), as well as enhanced airway/systemic inflammation and oxidative stress. Mediation analyses showed that TRAP exposures may prompt cardiac injury, possibly via worsening pulmonary pathophysiology. These findings highlight the importance of traffic pollution control priority in urban areas.

Health impact assessment of air pollution in an area of the largest coal mine in Brazil

Coal exploration and burning activities are among the activities with the greatest potential to cause atmospheric pollution due to the combustion process of this mineral and the consequent release of particles that, in significant quantities, can pose a potential health risk, mainly respiratory and cardiovascular diseases. The Candiota region, in the extreme south of Brazil, concentrates 40% of the national reserves of mineral coal, and its burning is capable of releasing air pollutants, including particulate matter (PM). Some environmental and epidemiological studies have been carried out in the region, but so far, there is no investigation to estimate the impact of PM on health outcomes. The current study aimed to estimate the mortality attributed to the PM, as well as the benefits in health indicators associated with the reduction of air pollution to the limits set forth in local legislation and the WHO. Daily data on PM levels collected from an air quality monitoring station over a year were used, as well as population data and health indicators from 7 cities influenced by mining activities, such as total mortality and cardiovascular diseases and hospitalizations for cardiac and respiratory problems. In a scenario where PM levels are within legal limits, a percentage greater than 11% of cardiovascular deaths was attributed to pollution by PM2.5, and the reduction in PM10 and PM2.5 levels may be responsible for the increase in the expectation of life in up to 17 months and monetary gains of more than $ 24 million, due to the reduction in hospitalizations and mortality. Studies of this nature should be important tools made available to decision-makers, with a view to improving environmental laws and a consequent improvement in the quality of life and health indicators of the population.

COVID-19, a double-edged sword for the environment: a review on the impacts of COVID-19 on the environment

This review paper discusses the most relevant impacts of the COVID-19 pandemic on the environment. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) originated in Wuhan, China, in December 2019. The disease has infected 70 million people and caused the death of 1.58 million people since the US Food and Drug Administration issued an Emergency Use Authorization to develop a vaccine to prevent COVID-19 on December 11, 2020. COVID-19 is a global crisis that has impacted everything directly connected with human beings, including the environment. This review discusses the impacts of COVID-19 on the environment during the pandemic and post-COVID-19 era. During the first months of the COVID pandemic, global coal, oil, gas, and electricity demands declined by 8%, 5%, 2%, and 20%, respectively, relative to 2019. Stay-at-home orders in countries increased the concentrations of particles in indoor environments while decreasing the concentrations of PM2.5 and NOX in outdoor environments. Remotely working in response to the COVID-19 pandemic increased the carbon, water, and land footprints of Internet usage. Microplastics are released into our environment from the mishandling and mismanagement of personal protective equipment that endanger our water, soils, and sediments. Since the COVID-19 vaccine cannot be stored for a long time and spoils rapidly, more awareness of the massive waste of unused doses is needed. So COVID-19 is a double-edged sword for the environment.

Pollution, Inflammation, and Vaccines: A Complex Crosstalk

The importance of pollution in determining human health is becoming increasingly clear, also given the dramatic consequences it has had on recent geopolitical events. Yet, the consequences of contamination are not always straightforward. In this paper, we will discuss the effects of different pollutants on different aspects of human health, in particular on the immune system and inflammation. Different environmental pollutants can have different effects on the immune system, which can then promote complex pathologies, such as autoimmune disorders and cancer. The interaction with the microbiota also further helps to determine the consequences of contamination on wellbeing. The pollution can affect vaccination efficacy, given the widespread effects of vaccination on immunity. At the same time, some vaccinations also can exert protective effects against some forms of pollution.

Polydeoxyribonucleotide Attenuates Airway Inflammation Through A2AR Signaling Pathway in PM10-Exposed Mice

Purpose

Inhalation of air containing high amounts of particular matter (PM) causes various respiratory disorders including asthma, chronic obstructive pulmonary disease, and lung cancer. The changes of expression of inflammatory factors by polydeoxyribonucleotide (PDRN) administration in the PM₁₀-exposed trachea inflammation model were evaluated.

Methods

PM₁₀ was administered to mouse trachea to induce acute inflammatory damage, and changes in inflammatory factors were observed after administration of PDRN and 3,7-dimethyl-1-propargylxanthine (DMPX) for 3 days daily. Expression of inflammatory cytokines, adenosine A_2A receptor (A_2AR), protein kinase A (PKA), 3΄,5΄-cyclic adenosine monophosphate responsive element binding protein (CREB) were detected by enzyme‐linked immunosorbent assay, immunofluorescence, and western blot assay.

Results

PM-exposed trachea showed increased tumor necrosis factor (TNF)-α and interleukin (IL)-1β expression, and expression of TNF-α and IL-1β was inhibited by PDRN treatment in PM-exposed mice. PM-exposed trachea showed increased nuclear factor (NF)-κB phosphorylation, and phosphorylation of nuclear factor-kappa B was inhibited by PDRN treatment in PM-exposed mice. PM-exposed trachea showed increased expression of A_2AR, but PDRN treatment more enhanced A_2AR expression in PM-exposed mice. PKA phosphorylation was not changed and CREP phosphorylation was decreased, however PDRN treatment increased phosphorylation of PKA and CREB in PM-exposed mice. DMPX treatment blocked all the effects of PDRN on PM-exposed mice, demonstrating that the action of PDRN occurs via A_2AR.

Conclusions

PDRN treatment attenuated inflammation in the trachea of the PM₁₀-exposed mice. This improving effect of PDRN can be ascribed to the activation of A_2AR through the cAMP-PKA pathway.