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

Associations of short-term ambient temperature exposure with lung function in middle-aged and elderly people: A longitudinal study in China

The short-term associations of ambient temperature exposure with lung function in middle-aged and elderly Chinese remain obscure. The study included 19,128 participants from the Dongfeng-Tongji cohort's first (2013) and second (2018) follow-ups. The lung function for each subject was determined between April and December 2013 and re-assessed in 2018, with three parameters (forced vital capacity [FVC], forced expiratory volume in 1 s [FEV1], and peak expiratory flow [PEF]) selected. The China Meteorological Data Sharing Service Center provided temperature data during the study period. In the two follow-ups, a total of 25,511 records (average age: first, 64.57; second, 65.80) were evaluated, including 10,604 males (41.57%). The inversely J-shaped associations between moving average temperatures (lag01-lag07) and FVC, FEV1, and PEF were observed, and the optimum temperatures at lag04 were 16.5 °C, 18.7 °C, and 16.2 °C, respectively. At lag04, every 1 °C increase in temperature was associated with 14.07 mL, 9.78 mL, and 62.72 mL/s increase in FVC, FEV1, and PEF in the low-temperature zone ( Collapse

Key Words

• Ambient temperature
• Generalized additive mixed model
• Linear mixed-effects model
• Lung function
• Middle-aged and elderly people
• Vulnerable groups

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Affiliation(s)

Weihong Qiu Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China Department of Epidemiology and Health Statistics, School of Public Health, Fujian Medical University, Fuzhou 350122, China
Bin Wang Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
Xiaobing Feng Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
Heng He Department of Epidemiology and Health Statistics, School of Public Health, Fujian Medical University, Fuzhou 350122, China
Lieyang Fan Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
Zi Ye Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
Xiuquan Nie Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
Ge Mu Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
Wei Liu Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
Dongming Wang Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
Min Zhou Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
Weihong Chen Department of Occupational and Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China

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Phosphocholine-induced energy source shift alleviates mitochondrial dysfunction in lung cells caused by geospecific PM2.5 components

Fine particulate matter (PM2.5) is globally recognized for its adverse implications on human health. Yet, remain limited the individual contribution of particular PM2.5 components to its toxicity, especially considering regional disparities. Moreover, prevention solutions for PM2.5-associated health effects are scarce. In the present study, we comprehensively characterized and compared the primary PM2.5 constituents and their altered metabolites from two locations: Taiyuan and Guangzhou. Analysis of year-long PM2.5 samples revealed 84 major components, encompassing organic carbon, elemental carbon, ions, metals, and organic chemicals. PM2.5 from Taiyuan exhibited higher contamination, associated health risks, dithiothreitol activity, and cytotoxicities than Guangzhou's counterpart. Applying metabolomics, BEAS-2B lung cells exposed to PM2.5 from both cities were screened for significant alterations. A correlation analysis revealed the metabolites altered by PM2.5 and the critical toxic PM2.5 components in both regions. Among the PM2.5-down-regulated metabolites, phosphocholine emerged as a promising intervention for PM2.5 cytotoxicities. Its supplementation effectively attenuated PM2.5-induced energy metabolism disorder and cell death via activating fatty acid oxidation and inhibiting Phospho1 expression. The highlighted toxic chemicals displayed combined toxicities, potentially counteracted by phosphocholine. Our study offered a promising functional metabolite to alleviate PM2.5-induced cellular disorder and provided insights into the geo-based variability in toxic PM2.5 components.

Impact of antioxidants on PM2.5 oxidative potential, radical level, and cytotoxicity

Antioxidants are typically seen as agents that mitigate environmental health risks due to their ability to scavenge free radicals. However, our research presents a paradox where these molecules, particularly those within lung fluid, act as prooxidants in the presence of airborne particulate matter (PM2.5), thus enhancing PM2.5 oxidative potential (OP). In our study, we examined a range of antioxidants found in the respiratory system (e.g., vitamin C, glutathione (GSH), and N-acetylcysteine (NAC)), in plasma (vitamin A, vitamin E, and β-carotene), and in food (tert-butylhydroquinone (TBHQ)). We aimed to explore antioxidants' prooxidant and antioxidant interactions with PM2.5 and the resulting OP and cytotoxicity. We employed OH generation assays and electron paramagnetic resonance assays to assess the pro-oxidative and anti-oxidative effects of antioxidants. Additionally, we assessed cytotoxicity interaction using a Chinese hamster ovary cell cytotoxicity assay. Our findings revealed that, in the presence of PM2.5, all antioxidants except vitamin E significantly increased the PM2.5 OP by generating more OH radicals (OH generation rate: 0.16-24.67 pmol·min-1·m-3). However, it's noteworthy that these generated OH radicals were at least partially neutralized by the antioxidants themselves. Among the pro-oxidative antioxidants, vitamin A, β-carotene, and TBHQ showed the least ability to quench these radicals, consistent with their observed impact in enhancing PM2.5 cytotoxicity (PM2.5 LC50 reduced to 91.2 %, 88.8 %, and 75.1 % of PM2.5's original level, respectively). Notably, vitamin A and TBHQ-enhanced PM2.5 OP were strongly associated with the presence of metals and organic compounds, particularly with copper (Cu) contributing significantly (35 %) to TBHQ's pro-oxidative effect. Our study underscores the potential health risks associated with the interaction between antioxidants and ambient pollutants.

Association of blood cadmium concentration with chronic obstructive pulmonary disease progression: a prospective cohort study

BACKGROUND

Prior studies in patients with chronic obstructive pulmonary disease (COPD) had indicated a potential correlation between cadmium (Cd) exposure and reduction in lung function. Nevertheless, the influence of Cd exposure on the progression of COPD remained unknown. Exploring the relationship between Cd exposure and the progression of COPD was the aim of this investigation.

METHODS

Stable COPD patients were enrolled. Blood samples were collected and lung function was evaluated. Regular professional follow-ups were conducted through telephone communications, outpatient services, and patients' hospitalization records.

RESULTS

Each additional unit of blood Cd was associated with upward trend in acute exacerbation, hospitalization, longer hospital stay, and death within 2 years. Even after adjusting for potential confounding factors, each 1 unit rise in blood Cd still correlated with a rise in the frequencies of acute exacerbation, longer hospital stay, and death. Moreover, COPD patients with less smoking amount, lower lung function and without comorbidities were more vulnerable to Cd-induced disease deterioration.

CONCLUSION

Patients with COPD who have higher blood Cd concentration are susceptible to worse disease progression.

Personal Exposure to Source-Specific Particulate Polycyclic Aromatic Hydrocarbons and Systemic Inflammation: A Cross-Sectional Study of Urban-Dwelling Older Adults in China

Environmental exposure to ambient polycyclic aromatic hydrocarbons (PAHs) can disturb the immune response. However, the evidence on adverse health effects caused by exposure to PAHs emitted from specific sources among different vulnerable subpopulations is limited. In this cross-sectional study, we aimed to evaluate whether exposure to source-specific PAHs could increase systemic inflammation in older adults. The present study included community-dwelling older adults and collected filter samples of personal exposure to PM2.5 during the winter of 2011. Blood samples were collected after the PM2.5 sample collection. We analyzed PM2.5 bound PAHs and serum inflammatory cytokines (interleukin (IL)1β, IL6, and tumor necrosis factor alpha levels. The Positive Matrix Factorization model was used to identify PAH sources. We used a linear regression model to assess the relative effects of source-specific PM2.5 bound PAHs on the levels of measured inflammatory cytokines. After controlling for confounders, exposure to PAHs emitted from biomass burning or diesel vehicle emission was significantly associated with increased serum inflammatory cytokines and systemic inflammation. These findings highlight the importance of considering exposure sources in epidemiological studies and controlling exposures to organic materials from specific sources.

The mediating role of exhaled breath condensate metabolites in the effect of particulate matter on pulmonary function in schoolchildren: A crossover intervention study

The role played by metabolites in exhaled breath condensate (EBC) in the effect of PM on schoolchildren's pulmonary function has received little attention. Accordingly, we examined whether metabolites in EBC mediated the effect of PM10, PM2.5, and PM1 on the pulmonary function of schoolchildren at a residential primary school who had received an air-cleaner cross-over intervention. Samples of EBC were collected from a total of 60 schoolchildren and subjected to metabolomics analysis. We found that the effect of PM on six pulmonary function indicators was mediated by the following nine lipid peroxidation-related and energy metabolism-related metabolites present in EBC: 4-hydroxynonenal, arachidoyl ethanolamide, dl-pyroglutamic acid, 5-deoxy-d-glucose, myristic acid, lauric acid, linoleic acid, l-proline, and palmitic acid. However, while all nine of these metabolites mediated the effects of PM on boys' pulmonary function, only 4-hydroxynonenal, arachidoyl ethanolamide, and dl-pyroglutamic acid mediated the effects of PM on girls' pulmonary function. Overall, our results show that (1) short-term exposure to PM affected the schoolchildren's pulmonary function by causing an imbalance between lipid peroxidation and glutathione-based antioxidant activity and by perturbing energy metabolism in respiratory system and (2) there was a sex-dependent antioxidant response to PM exposure, with boys being less resistant than girls.

Long non-coding RNAs mediate the association between short-term PM2.5 exposure and circulating biomarkers of systemic inflammation

Although short-term fine particulate matter (PM2.5) exposure is associated with systemic inflammation, the effect of lncRNA on these association remains unknown. This study aims to investigate whether the plasma lncRNA mediate the effect of short-term PM2.5 exposure on systemic inflammation. In this cross-sectional study, plasma Clara cell protein 16 (CC16), interleukin 6 (IL-6), IL-8, tumor necrosis factor-α (TNF-α) and lncRNA expression levels were measured in 161 adults between March and April in 2018 in Shijiazhuang, China. PM2.5 concentrations were estimated 0-3 days prior to the examination date and the moving averages were calculated. Multiple linear regressions were used to evaluate the associations between PM2.5, the four biomarkers and lncRNA expression levels. Mediation analyses were performed to explore the potential roles of lncRNA expression in these associations. The median concentration of PM2.5 ranged from 39.65 to 60.91 mg/m3 across different lag days. The most significant effects on IL-6 and TNF-α per interquartile range increase in PM2.5 were observed at lag 0-3 days, with increases of 0.70 pg/mL (95% CI: 0.33, 1.07) and 0.21 pg/mL (95% CI: 0.06, 0.36), respectively. While the associations between PM2.5 and IL-8 (0.68 pg/mL, 95% CI: 0.34, 1.02) and CC16 (3.86 ng/mL, 95% CI: 1.60, 6.13) were stronger at lag 0 day. Interestingly, a negative association between PM2.5 and the expression of four novel lncRNAs (lnc-ACAD11-1:1, lnc-PRICKLE1-4:1, lnc-GPR39-7:2, and lnc-MTRNR2L12-3:6) were observed at each lag days. Furthermore, these lncRNAs mediated the effects of PM2.5 on the four biomarkers, with proportions of mediation ranged from 2.27% (95% CI: 1.19%, 9.82%) for CC16 to 35.60% (95% CI: 17.16%, 175.45%) for IL-6. Our findings suggested that plasma lncRNA expression mediat the acute effects of PM2.5 exposure on systematic inflammation. These highlight a need to consider circulating lncRNA expression as biomarkers to reduce health risks associated with PM2.5.

Linkage between Airborne Particulate Matter and Viral Pandemic COVID-19 in Bucharest

The long-distance spreading and transport of airborne particulate matter (PM) of biogenic or chemical compounds, which are thought to be possible carriers of SARS-CoV-2 virions, can have a negative impact on the incidence and severity of COVID-19 viral disease. Considering the total Aerosol Optical Depth at 550 nm (AOD) as an atmospheric aerosol loading variable, inhalable fine PM with a diameter ≤2.5 µm (PM2.5) or coarse PM with a diameter ≤10 µm (PM10) during 26 February 2020-31 March 2022, and COVID-19's five waves in Romania, the current study investigates the impact of outdoor PM on the COVID-19 pandemic in Bucharest city. Through descriptive statistics analysis applied to average daily time series in situ and satellite data of PM2.5, PM10, and climate parameters, this study found decreased trends of PM2.5 and PM10 concentrations of 24.58% and 18.9%, respectively compared to the pre-pandemic period (2015-2019). Exposure to high levels of PM2.5 and PM10 particles was positively correlated with COVID-19 incidence and mortality. The derived average PM2.5/PM10 ratios during the entire pandemic period are relatively low (<0.44), indicating a dominance of coarse traffic-related particles' fraction. Significant reductions of the averaged AOD levels over Bucharest were recorded during the first and third waves of COVID-19 pandemic and their associated lockdowns (~28.2% and ~16.4%, respectively) compared to pre-pandemic period (2015-2019) average AOD levels. The findings of this research are important for decision-makers implementing COVID-19 safety controls and health measures during viral infections.

Association of long-term exposure to air pollution with chronic sleep deprivation in South Korea: A community-level longitudinal study, 2008-2018

BACKGROUND AND OBJECTIVE

Although there are many findings about the effects of fine particulate matter (PM_2.5) and sleep deprivation on health respectively, the association between PM_2.5 and chronic sleep deprivation has rarely been investigated. Thus, we aimed to investigate this association using a nationwide survey in South Korea.

METHOD

We examined the association between long-term exposure to PM_2.5 and chronic sleep deprivation using a national cross-sectional health survey covering the entire 226 districts in inland South Korea from 2008 to 2018, with a machine learning-based national air pollution prediction model with 1 km² spatial resolution.

RESULTS

Chronic sleep deprivation was positively associated with PM_2.5 in the total population (odds ratio (OR): 1.09, 95% confidence interval (CI): 1.05-1.13) and sub-population (low, middle, high population density areas with OR: 1.127, 1.09, and 1.059, respectively). The association was consistently observed in both sexes (males with OR: 1.09, females with OR: 1.09)) and was more pronounced in the elderly population (OR: 1.12) than in the middle-aged (OR: 1.07) and young (OR: 1.09) populations.

CONCLUSIONS

Our results are consistent with the hypothesis regarding the relationship between long-term PM_2.5 exposure and chronic sleep deprivation, and the study provides quantitative evidence for public health interventions to improve air quality that can affect chronic sleep conditions.

The potential role of plasma miR-4301 in PM2.5 exposure-associated lung function reduction

The effect of PM_2.5 exposure on lung function reduction has been well-documented, but the underlying mechanism remains unclear. MiR-4301 may be involved in regulating pathways related to lung injury/repairment, and this study aimed to explore the potential role of miR-4301 in PM_2.5 exposure-associated lung function reduction. A total of 167 Wuhan community nonsmokers were included in this study. Lung function was measured and personal PM_2.5 exposure moving averages were evaluated for each participant. Plasma miRNA was determined by real-time polymerase chain reaction. A generalized linear model was conducted to assess the relationships among personal PM_2.5 moving average concentrations, lung function, and plasma miRNA. The mediation effect of miRNA on the association of personal PM_2.5 exposure with lung function reduction was estimated. Finally, we performed pathway enrichment analysis to predict the underlying pathways of miRNA in lung function reduction from PM_2.5 exposure. We found that each 10 μg/m³ increase in the 7-day personal PM_2.5 moving average concentration (Lag0-7) was related to a 46.71 mL, 1.15%, 157.06 mL/s, and 188.13 mL/s reductions in FEV₁, FEV₁/FVC, PEF, and MMF, respectively. PM_2.5 exposure was negatively associated with plasma miR-4301 expression levels in a dose‒response manner. Additionally, each 1% increase in miR-4301 expression level was significantly associated with a 0.36 mL, 0.01%, 1.14 mL/s, and 1.28 mL/s increases in FEV₁, FEV₁/FVC, MMF, and PEF, respectively. Mediation analysis further revealed that decreased miR-4301 mediated 15.6% and 16.8% of PM_2.5 exposure-associated reductions in FEV₁/FVC and MMF, respectively. Pathway enrichment analyses suggested that the wingless related-integration site (Wnt) signaling pathway might be one of the pathways regulated by miR-4301 in the reduction of lung function from PM_2.5 exposure. In brief, personal PM_2.5 exposure was negatively associated with plasma miR-4301 or lung function in a dose‒response manner. Moreover, miR-4301 partially mediated the lung function reduction associated with PM_2.5 exposure.

The effects of metals and mixture exposure on lung function and the potential mediating effects of oxidative stress

Exposure to metals is associated with lung function decline. However, limited data are available about effects of co-exposure of metals on lung function. Additionally, the mechanism of the association between metals and lung function remains unclear. We conducted a longitudinal panel study in 2017-2018 among 45 healthy college students. Urinary 15 metals, lung function, biomarkers of oxidative stress and inflammation of participants were measured. Linear mixed effect (LME) and Bayesian kernel machine regression (BKMR) models were applied to explore the associations of urinary metals and mixture with lung function. Furthermore, we analyzed the mediating effect of biomarkers in the association between urinary metals and lung function. LME models showed the negative associations of aluminum (Al), vanadium (V), manganese (Mn), cobalt (Co), nickel (Ni), cadmium (Cd) or antimony (Sb) with Forced vital capacity (FVC), and V, Co, Ni, and Sb with Forced expiratory volume in one second (FEV1). BKMR models indicated the overall effect of metals mixture was negatively associated with FEV1 and FVC; urinary Sb was identified as the major contributor to decreased FVC and FEV1. Urinary 8-hydroxydeoxyguanosine mediated the association of Al, Mn, or Sb with FVC and the relationship of V with FEV1. The results revealed the longitudinal dose-response relationships of urinary metals with pulmonary function among healthy adults. Oxidative stress may be the underlying mechanisms of metals exposure associated with decreased lung function. Due to the small sample size, the interpretation of the results of this study should be cautious, and more studies are needed to verify the findings of this study.

The role of systemic inflammation and oxidative stress in the association of particulate air pollution metal content and early cardiovascular damage: A panel study in healthy college students

Exposure to fine particulate matter (PM_2.5) has been associated with adverse cardiovascular outcomes. However, the effects of toxic metals in PM_2.5 on cardiovascular health remain unknown. To investigate the early cardiovascular effects of specific PM_2.5 metal constituents at the personal level, we conducted a panel study on 45 healthy college students in Caofeidian, China. Personal exposure concentrations and cardiovascular effect markers were monitored simultaneously within one year in four study periods. Four linear mixed-effects models were used to analyze the relationship between personal exposure to PM_2.5 and 15 metal fractions (Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Sb, and Pb) with soluble CD36 (sCD36), C-reactive protein (CRP), and oxidized low-density lipoprotein (OX-LDL) levels, heart rate, and blood pressure. The concentrations of most individual metals (Mn, Cu, Zn, As, Se, Mo, Cd, Sb and Pb) were the highest in winter. Meanwhile, there were significant differences in inflammatory (sCD36 and CRP) and oxidative stress (OX-LDL) markers in the serum of participants over the four seasons. In particular, the estimated effects of personal metal exposure (such as V, As, Se, Cd, and Pb) on sCD36 and pulse pressure (PP) levels were consistently significant across the four LME models. A significant mediating role of sCD36 was also found in the relationship between personal exposure to Zn and Cr and changes in PP levels. Our findings provide clues and potential mechanisms regarding the cardiovascular effects of specific toxic constituents of PM_2.5 in healthy young adults.

Air pollution associated acute respiratory inflammation and modification by GSTM1 and GSTT1 gene polymorphisms: a panel study of healthy undergraduates

Epidemiological evidence has linked air pollution with adverse respiratory outcomes, but the mechanisms underlying susceptibility to air pollution remain unclear. This study aimed to investigate the role of glutathione S-transferase (GST) polymorphism in the association between air pollution and lung function levels. A total of 75 healthy young volunteers aged 18-20 years old were recruited for six follow-up visits and examinations. Spirometry was conducted to obtain lung function parameters such as forced vital capacity (FVC), and forced expiratory volume in 1 s (FEV₁). Nasal fluid concentrations of interleukin-6 (IL-6), interleukin-8 (IL-8), tumor necrosis factor-α (TNF-α), and 8-epi-prostaglandin F2α (8-epi-PGF2a) were measured using ELISA kits. Linear mixed-effect models were used to evaluate the association of air pollutants with respiratory outcomes. Additionally, polymorphisms of glutathione S-transferase mu 1 (GSTM1) and glutathione S-transferase theta 1 (GSTT1) were estimated to explore its role in the association between air pollutants and lung function. We found that short-term exposure to atmospheric particulates such as PM_2.5 and PM₁₀ can cause an increase in nasal biomarkers of inflammation, oxidative stress, and lung function, while air gaseous pollutant exposure is linked with decreased lung function, except for CO. Stratification analyses showed that an increase in nasal inflammatory cytokines caused by exposure to atmospheric particulates is more obvious in subjects with GSTM1-sufficient (GSTM1⁺) than GSTM1-null (GSTM1^-), while elevated lung function levels due to air particles are more significant in subjects with the genotype of GSTM1^- when compared to GSTM1⁺. As for air gaseous pollutants, decreased lung function levels caused by O₃, SO₂, and NO₂ exposure is more manifest in subjects with the genotype of GSTM1^- compared to GSTM1⁺. Taken together, short-term exposure to air pollutants is associated with alterations in nasal biomarkers and lung function levels in young healthy adults, and susceptible genotypes play an important mediation role in the association between exposure to air pollutants and inflammation, oxidative stress, and lung function levels.

PM2.5-related DNA methylation and the association with lung function in non-smokers

PM_2.5 exposure leads to lung function alteration. The potential pathway underlying above association, especially the role of DNA methylation is unclear. The objectives of this study are to evaluate the associations of personal PM_2.5 concentrations with DNA methylation at the epigenome-wide level, and investigate how PM_2.5-related DNA methylation affects lung function. A total of 402 observations of non-smokers were selected from the Wuhan-Zhuhai cohort. PM_2.5 exposure was estimated through a model established in the same population. Blood DNA methylation levels were determined through Illumina Infinium MethylationEPIC BeadChips. Lung function was tested through spirometry on the day of blood sampling. The associations of PM_2.5 exposure with DNA methylation and DNA methylation with lung function were determined through linear mixed models. Ten PM_2.5-related CpG sites (mapped to 7 different genes) were observed with false discovery rate <0.05. Methylation levels of cg24821877, cg24862131, cg23530876, cg11149743 and cg10781276 were positively associated with PM_2.5 concentrations. While methylation levels of cg10314909, cg08968107, cg18362281, cg24663971 and cg17834632 were negatively associated with PM_2.5 concentrations. The top CpG was cg24663971 (P = 1.51✕10^-9). Among the above 10 sites, significantly positive associations of methylation levels of cg24663971 with FVC%pred and FEV₁%pred, and cg10314909 with FVC, FVC%pred, and FEV₁%pred were observed. Age had modification effect on the associations between cg24663971 methylation and FVC%pred, and the associations were more obvious among participants with age ≥58 years. In conclusion, PM_2.5 exposure was associated with DNA methylation, and PM_2.5-related DNA methylation was associated with lung function among Wuhan urban non-smokers.

Oxidative stress response in pulmonary cells exposed to different fractions of PM2.5-0.3 from urban, traffic and industrial sites

The aim of this work was to study the relationship between oxidative stress damages and particulate matter (PM) chemical composition, sources, and PM fractions. PM_2.5-0.3 (PM with equivalent aerodynamic diameter between 2.5 and 0.3 μm) were collected at urban, road traffic and industrial sites in the North of France, and were characterized for major and minor chemical species. Four different fractions (whole PM_2.5-0.3, organic, water-soluble and non-extractable matter) were considered for each of the PM_2.5-0.3 samples from the three sites. After exposure of BEAS-2B cells to the four different fractions, oxidative stress was studied in cells by quantifying reactive oxygen species (ROS) accumulation, oxidative damage to proteins (carbonylated proteins), membrane alteration (8-isoprostane) and DNA damages (8-OHdG). Whole PM_2.5-0.3 was capable of inducing ROS overproduction and caused damage to proteins at higher levels than other fractions. Stronger cell membrane and DNA damages were found associated with PM and organic fractions from the urban site. ROS overproduction was correlated with level of expression of carbonylated proteins, DNA damages and membrane alteration markers. The PM_2.5-0.3 collected under industrial influence appears to be the less linked to cell damages and ROS production in comparison with the other influences.

Effect of Acute PM2.5 Exposure on Lung Function in Children: A Systematic Review and Meta-Analysis

Objective

The objective of this study was to conduct a systematic review and meta-analysis to identify the adverse effects of acute PM2.5 exposure on lung function in children.

Design

Systematic review and meta-analysis. Setting, participants and measures: Eligible studies analyzing PM2.5 level and lung function in children were screened out. Effect estimates of PM2.5 measurements were quantified using random effect models. Heterogeneity was investigated with Q-test and I² statistics. We also conducted meta-regression and sensitivity analysis to explore the sources of heterogeneity, such as different countries and asthmatic status. Subgroup analyses were conducted to determine the effects of acute PM2.5 exposure on children of different asthmatic status and in different countries.

Results

A total of 11 studies with 4314 participants from Brazil, China and Japan were included finally. A 10 μg/m³ increase of PM2.5 was associated with a 1.74L/min (95% CI: -2.68, -0.90) decrease in peak expiratory flow (PEF). Since the asthmatic status and country could partly explain the heterogeneity, we conducted the subgroup analysis. Children with severe asthma were more susceptible to PM2.5 exposure (-3.11 L/min per 10 μg/m³ increase, 95% CI -4.54, -1.67) than healthy children (-1.61 L/min per 10 μg/m³ increase, 95% CI -2.34, -0.91). In the children of China, PEF decreased by 1.54 L/min (95% CI -2.33, -0.75) with a 10 μg/m³ increase in PM2.5 exposure. In the children of Japan, PEF decreased by 2.65 L/min (95% CI -3.82, -1.48) with a 10 μg/m³ increase of PM2.5 exposure. In contrast, no statistic association was found between every 10 μg/m³ increase of PM2.5 and lung function in children of Brazil (-0.38 L/min, 95% CI -0.91, 0.15).

Conclusion

Our results demonstrated that the acute PM2.5 exposure exerted adverse impacts on children's lung function, and children with severe asthma were more susceptible to the increase of PM2.5 exposure. The impacts of acute PM2.5 exposure varied across different countries.

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.

Personal PM2.5 Elemental Components, Decline of Lung Function, and the Role of DNA Methylation on Inflammation-Related Genes in Older Adults: Results and Implications of the BAPE Study

Epidemiological evidence of the effects of PM_2.5 elements on lung function and DNA methylation is limited. We conducted a longitudinal panel study of 76 healthy older adults aged 60-69 years in Jinan, China, from September 2018 to January 2019. We periodically measured individual 72 h PM_2.5 and element concentrations, lung function, and DNA methylation levels of eight inflammation-related genes. We used linear mixed-effect models to investigate the effects of exposure to personal PM_2.5 elements on the lung function and DNA methylation. Mediation analysis was used to investigate the underlying effect mechanism. Negative changes in the ratio of forced expiratory volume in 1 s to forced vital capacity, ranging from -1.23% [95% confidence interval (CI): -2.11%, -0.35%] to -0.77% (95% CI: -1.49%, -0.04%), were significantly associated with interquartile range (IQR) increases in personal PM_2.5 at different lag periods (7-12, 13-24, 25-48, 0-24, 0-48, and 0-72 h). Arsenic (As), nickel, rubidium (Rb), selenium, and vanadium were significantly associated with at least three lung function parameters, and IQR increases in these elements led to 0.12-5.66% reductions in these parameters. PM_2.5 elements were significantly associated with DNA methylation levels. DNA methylation mediated 7.28-13.02% of the As- and Rb-related reduced lung function. The findings indicate that exposure to elements in personal PM_2.5 contributes to reduced lung function through DNA methylation.

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

Association of inflammation and lung function decline caused by personal PM2.5 exposure: a machine learning approach in time-series data

Numerous studies focused on the association between lung function impairment and inflammation caused by fine particulate matter (PM_2.5), but the causal relationships are difficult to clarify. In the current study, twenty healthy Chinese young adults who participated in 7 days of observation every four seasons were enrolled, and autoregression models (AM) and classification and regression trees (CART) in a machine learning framework were applied to analyze the association among PM_2.5 exposure, inflammation, and lung function from a data structure perspective. There were strong cross-correlations between personal dose of PM_2.5 (Dw) and lung functions (vital capacity (VC), forced vital capacity (FVC), etc.). These cross-correlation coefficients were associated with inflammatory indicators (uteroglobin (UG), serum amyloid (SAA), and fractional exhaled nitric oxide (FeNO)). CART reported that inflammatory indicators UG and SAA had the predictive ability of the directional association between Dw and FVC at 1-day lag and that high levels of UG and SAA predicted that PM_2.5 exposure induced lung function decline. Consistently, lower lung function indicators at a 2-day lag after personal PM_2.5 exposure predicted the high value of inflammatory indicator FeNO. Taken together, we applied machine learning algorithms to analyze repeated measurement data, finding that inflammation and lung function decline caused by PM_2.5 could affect each other.

Cumulative effects of air pollution and climate drivers on COVID-19 multiwaves in Bucharest, Romania

Over more than two years of global health crisis due to ongoing COVID-19 pandemic, Romania experienced a five-wave pattern. This study aims to assess the potential impact of environmental drivers on COVID-19 transmission in Bucharest, capital of Romania during the analyzed epidemic period. Through descriptive statistics and cross-correlation tests applied to time series of daily observational and geospatial data of major outdoor inhalable particulate matter with aerodynamic diameter ≤ 2.5 µm (PM2.5) or ≤ 10 µm (PM10), nitrogen dioxide (NO₂), ozone (O₃), sulfur dioxide (SO₂), carbon monoxide (CO), Aerosol Optical Depth at 550 nm (AOD) and radon (²²²Rn), we investigated the COVID-19 waves patterns under different meteorological conditions. This study examined the contribution of individual climate variables on the ground level air pollutants concentrations and COVID-19 disease severity. As compared to the long-term average AOD over Bucharest from 2015 to 2019, for the same year periods, this study revealed major AOD level reduction by ~28 % during the spring lockdown of the first COVID-19 wave (15 March 2020-15 May 2020), and ~16 % during the third COVID-19 wave (1 February 2021-1 June 2021). This study found positive correlations between exposure to air pollutants PM2.5, PM10, NO₂, SO₂, CO and ²²²Rn, and significant negative correlations, especially for spring-summer periods between ground O₃ levels, air temperature, Planetary Boundary Layer height, and surface solar irradiance with COVID-19 incidence and deaths. For the analyzed time period 1 January 2020-1 April 2022, before and during each COVID-19 wave were recorded stagnant synoptic anticyclonic conditions favorable for SARS-CoV-2 virus spreading, with positive Omega surface charts composite average (Pa/s) at 850 mb during fall- winter seasons, clearly evidenced for the second, the fourth and the fifth waves. These findings are relevant for viral infections controls and health safety strategies design in highly polluted urban environments.

Impacts of exposure to air pollution, radon and climate drivers on the COVID-19 pandemic in Bucharest, Romania: A time series study

During the ongoing global COVID-19 pandemic disease, like several countries, Romania experienced a multiwaves pattern over more than two years. The spreading pattern of SARS-CoV-2 pathogens in the Bucharest, capital of Romania is a multi-factorial process involving among other factors outdoor environmental variables and viral inactivation. Through descriptive statistics and cross-correlation analysis applied to daily time series of observational and geospatial data, this study aims to evaluate the synergy of COVID-19 incidence and lethality with air pollution and radon under different climate conditions, which may exacerbate the coronavirus' effect on human health. During the entire analyzed period 1 January 2020-21 December 2021, for each of the four COVID-19 waves were recorded different anomalous anticyclonic synoptic meteorological patterns in the mid-troposphere, and favorable stability conditions during fall-early winter seasons for COVID-19 disease fast-spreading, mostly during the second, and the fourth waves. As the temporal pattern of airborne SARS-CoV-2 and its mutagen variants is affected by seasonal variability of the main air pollutants and climate parameters, this paper found: 1) the daily outdoor exposures to air pollutants (particulate matter PM2.5 and PM10, nitrogen dioxide-NO₂, sulfur dioxide-SO₂, carbon monoxide-CO) and radon - ²²²Rn, are directly correlated with the daily COVID-19 incidence and mortality, and may contribute to the spread and the severity of the pandemic; 2) the daily ground ozone-O₃ levels, air temperature, Planetary Boundary Layer height, and surface solar irradiance are anticorrelated with the daily new COVID-19 incidence and deaths, averageingful for spring-summer periods. Outdoor exposure to ambient air pollution associated with radon is a non-negligible driver of COVID-19 transmission in large metropolitan areas, and climate variables are risk factors in spreading the viral infection. The findings of this study provide useful information for public health authorities and decision-makers to develop future pandemic diseases strategies in high polluted metropolitan environments.

Mechanism of biochanin A alleviating PM2.5-induced oxidative damage based on an XRCC1 knockout BEAS-2B cell model

PM_2.5 induces oxidative/antioxidant system imbalance and excessive release of reactive oxygen species (ROS) and produces toxic effects and irreversible damage to the genetic material including chromosomes and DNA. Biochanin A (BCA), an isoflavone with strong antioxidant activity, effectively intervenes against PM_2.5-induced oxidative damage. The X-ray repair cross-complementary protein 1 (XRCC1)/BER pathway involves DNA damage repair caused by oxidative stress. This paper aims to explore the mechanism of BCA alleviating oxidative DNA damage caused by PM_2.5 by establishing the in vitro cell model based on CRISPR/Cas9 technology and combining it with mechanism pathway research. The results showed that PM_2.5 exposure inhibited the expression of BER and NER pathway proteins and induced the overexpression of ERCC1. BCA showed an effective intervention in the toxicity of PM_2.5 in normal cells, rather than XRCC1 knock-out cells. This laid a foundation for further exploring the key role of XRCC1 in PM_2.5-caused oxidative damage and the BER/DNA damage repair pathway.

Personal PM2.5-bound PAH exposure, oxidative stress and lung function: The associations and mediation effects in healthy young adults

Decreased lung function is an early hazard of respiratory damage from fine particulate matter (PM_2.5) exposure. Limited studies have explored the association between PM_2.5-bound polycyclic aromatic hydrocarbons (PAHs) and lung function, but studies at the personal level in healthy young adults are scarce. Here, we assessed personal PM_2.5 and PM_2.5-bound PAH levels in a panel of 45 healthy young adults by a time-weighted model. The aims were to investigate the relationship between personal exposure and lung function by a linear mixed effect model, and to explore the mediating effects of oxidative stress in this association. The results showed that personal exposure to PM_2.5 and PAHs had the greatest negative effect on forced expiratory volume in 1 s (FEV₁), peak expiratory flow rate (PEF) and forced expiratory flow between 25% and 75% vital capacity (FEF_25-75) at lag 3 days. An IQR increase in personal PM_2.5 exposure was associated with a change of 0.35% (95% CI: 0.27%, 0.42%) in FEV₁, 0.39% (95% CI: 0.29%, 0.47%) in PEF and 0.36% (95% CI: 0.27%, 0.45%) in FEF_25-75. An IQR increase in personal PAH exposure was associated with a decrease of 0.63% (95% CI: 0.55%, 0.69%) in FEV₁, 0.69% (95% CI: 0.61%, 0.75%) in PEF and 0.66% (95% CI: 0.57%, 0.72%) in FEF_25-75. Additionally, exposure to PM_2.5 and PAHs resulted in the strongest positive effects on urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) and 8-iso-prostaglandin-F_2α (8-iso-PGF_2α). Of these, 8-OHdG mediated 10.33%, 8.87% and 9.45% of the associations of personal PM_2.5 exposure with FEV₁, PEF and FEF_25-75, respectively. Our results revealed that personal exposure to PM_2.5 and PAHs was associated with lung function decline in healthy young adults, and urinary 8-OHdG mediated the association between personal PM_2.5 and lung function.

Tissue-Protective Effect of Erdosteine on Multiple-Organ Injuries Induced by Fine Particulate Matter

Background

Fine particulate matter (PM2.5) is the air pollutant that most threatens global public health. The purpose of this study was to observe the inflammatory and oxidative stress injury of multiple organs induced by PM2.5 in rats and to explore the tissue-protective effect of erdosteine.

Material/Methods

We randomly divided 40 male Wistar rats into a blank control group, a saline group, a PM2.5 exposure group, and an erdosteine intervention group. We assessed changes in organs tissue homogenate and biomarkers of inflammation and oxidative stress in serum and bronchoalveolar lavage fluid (BALF).

Results

(1) The expressions of IL-6, IL-1β, TNF-α, 8-OHdG, 4-HNE, and PCC in serum and BALF of the PM2.5 exposure group increased, but decreased after treatment with erdosteine, suggesting that erdosteine treatment attenuates inflammatory and oxidative stress injury. (2) The expression of γ-GCS in serum and lungs in the PM2.5 exposure group increased, but did not change significantly after treatment with erdosteine. This suggests that PM2.5 upregulates the level of γ-GCS, while erdosteine does not affect this protective response. (3) The expression of T-AOC in serum, lungs, spleens, and kidneys of the PM2.5 exposure group decreased, but increased after treatment with erdosteine. Our results suggest that PM2.5 can cause imbalance of oxidation/anti-oxidation in multiple organs, and erdosteine can alleviate this imbalance.

Conclusions

PM2.5 exposure can lead to inflammatory and oxidative stress damage in serum and organ tissues of rats. Erdosteine may be an effective anti-inflammatory and antioxidant that can reduce this injury.

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.

Cardiovascular Effects of Particulate Air Pollution

Inhalation of fine particulate matter (PM_2.5), produced by the combustion of fossil fuels, is an important risk factor for cardiovascular disease. Exposure to PM_2.5 has been linked to increases in blood pressure, thrombosis, and insulin resistance. It also induces vascular injury and accelerates atherogenesis. Results from animal models corroborate epidemiological evidence and suggest that the cardiovascular effects of PM_2.5 may be attributable, in part, to oxidative stress, inflammation, and the activation of the autonomic nervous system. Although the underlying mechanisms remain unclear, there is robust evidence that long-term exposure to PM_2.5 is associated with premature mortality due to heart failure, stoke, and ischemic heart disease. Expected final online publication date for the Annual Review of Medicine, Volume 73 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Associations of short-term PM2.5 exposures with nasal oxidative stress, inflammation and lung function impairment and modification by GSTT1-null genotype: A panel study of the retired adults

PM_2.5 (particulate matter ≤2.5 μm in aerodynamic diameter) is a major urban air pollutant worldwide. Its effects on the respiratory system of the susceptible population have been less characterized. This study aimed to estimate the association of short-term PM_2.5 exposure with respiratory outcomes of the retired adults, and to examine whether these associations were stronger among the subjects with GSTT-null genotype. 32 healthy subjects (55-77 years) were recruited for five follow-up examinations. Ambient concentrations of PM_2.5 were monitored consecutively for 7 days prior to physical examination. Pulmonary outcomes including forced vital capacity (FVC), forced expiratory volume in 1 s (FEV₁), peak expiratory flow (PEF), and fractional exhaled nitric oxide (FeNO), and nasal fluid concentrations of 8-epi-prostaglandin F2 alpha (8-epi-PGF2α), tumor necrosis factor-α (TNF-α), interleukin-8 (IL-8) and IL-1β were measured. A linear mixed-effect model was introduced to evaluate the associations of PM_2.5 concentrations with respiratory outcomes. Additionally, GSTT1 genotype-based stratification was performed to characterize modification on PM_2.5-related respiratory outcomes. We found that a 10 μg/m³ increase in PM_2.5 was associated with decreases of 0.52 L (95% confidence interval [CI]: -1.04, -0.002), 0.64 L (95% CI: -1.13, -0.16), 0.1 (95% CI: -0.23, 0.04) and 2.87 L/s (95% CI: -5.09, -0.64) in FVC, FEV₁, FEV₁/FVC ratio and PEF at lag 2, respectively. Meanwhile, marked increases of 80.82% (95% CI: 5.13%, 156.50%) in IL-8, 77.14% (95% CI: 1.88%, 152.40%) in IL-1β and 67.87% (95% CI: 14.85%, 120.88%) in 8-epi-PGF2α were observed as PM_2.5 concentration increased by 10 μg/m³ at lag 2. Notably, PM_2.5-associated decreases in FVC and PEF and increase in FeNO were stronger among the subjects with GSTT1-null genotype. In summary, short-term exposure to PM_2.5 is associated with nasal inflammation, oxidative stress and lung function reduction in the retired subjects. Lung function reduction and inflammation are stronger among the subjects with GSTT1-null genotype.

Challenges in Diagnosing Occupational Chronic Obstructive Pulmonary Disease

Occupational chronic obstructive pulmonary disease (oCOPD) represents 15–20% of the global burden of this disease. Even if industrial bronchitis has long been known, new occupational hazards continue to emerge and enlarge the number of people exposed to risk. This review discusses the challenges related to the early detection of oCOPD, in the context of new exposures and of limited usage of methods for an efficient disease occupational screening. It underlines that a better translation into clinical practice of the new methods for lung function impairment measurements, imaging techniques, or the use of serum or exhaled breath inflammation biomarkers could add significant value in the early detection of oCOPD. Such an approach would increase the chance to stop exposure at an earlier moment and to prevent or at least slow down the further deterioration of the lung function as a result of exposure to occupational (inhaled) hazards.

Urban Aerosol Particulate Matter Promotes Necrosis and Autophagy via Reactive Oxygen Species-Mediated Cellular Disorders that are Accompanied by Cell Cycle Arrest in Retinal Pigment Epithelial Cells

Urban particulate matter (UPM) is recognized as a grave public health problem worldwide. Although a few studies have linked UPM to ocular surface diseases, few studies have reported on retinal dysfunction. Thus, the aim of the present study was to evaluate the influence of UPM on the retina and identify the main mechanism of UPM toxicity. In this study, we found that UPM significantly induced cytotoxicity with morphological changes in ARPE-19 human retinal pigment epithelial (RPE) cells and increased necrosis and autophagy but not apoptosis. Furthermore, UPM significantly increased G2/M arrest and simultaneously induced alterations in cell cycle regulators. In addition, DNA damage and mitochondrial dysfunction were remarkably enhanced by UPM. However, the pretreatment with the potent reactive oxygen species (ROS) scavenger N-acetyl-L-cysteine (NAC) effectively suppressed UPM-mediated cytotoxicity, necrosis, autophagy, and cell cycle arrest. Moreover, NAC markedly restored UPM-induced DNA damage and mitochondrial dysfunction. Meanwhile, UPM increased the expression of mitophagy-regulated proteins, but NAC had no effect on mitophagy. Taken together, although further studies are needed to identify the role of mitophagy in UPM-induced RPE injury, the present study provides the first evidence that ROS-mediated cellular damage through necrosis and autophagy is one of the mechanisms of UPM-induced retinal disorders.