The impact of polar fraction of the fine particulate matter on redox responses in different rat tissues

Aqueous PM2.5 promotes lipid accumulation, classical macrophage polarisation and heat shock response

Fine particulate matter (PM2.5) is an air pollutant that enhances susceptibility to cardiovascular diseases. Macrophages are the first immune cells to encounter the inhaled particles and orchestrate an inflammatory response. Given their role in atherosclerosis development, we investigated whether aqueous PM2.5 could elicit atherogenic effects by polarising macrophages to a pro-oxidative and pro-inflammatory phenotype and enhancing foam cell formation. The RAW264.7 macrophage cell line was exposed to PM2.5 for 48 h, with PBS as the control. Aqueous PM2.5 induced apoptosis and reduced cell proliferation. In surviving cells, we observed morphological, phagocytic, oxidative, and inflammatory features (i.e. enhanced iNOS, Integrin-1β, IL-6 expression), indicative of classical macrophage activation. We also detected an increase in total and surface HSP70 levels, suggesting macrophage activation. Further, exposure of high-cholesterol diet-fed mice to PM2.5 resulted in aortic wall enlargement, indicating vascular lesions. Macrophages exposed to PM2.5 and non-modified low-density lipoprotein (LDL) showed exacerbated lipid accumulation. Given the non-oxidised LDL used and the evidence linking inflammation to disrupted cholesterol negative feedback, we hypothesise that PM2.5-induced inflammation in macrophages enhances their susceptibility to transforming into foam cells. Finally, our results indicate that exposure to aqueous PM2.5 promotes classical macrophage activation, marked by increased HSP70 expression and that it potentially contributes to atherosclerosis.

Particulate matter 2.5 accelerates aging: Exploring cellular senescence and age-related diseases

Exposure to Particulate matter 2.5 (PM2.5) accelerates aging, causing declines in tissue and organ function, and leading to diseases such as cardiovascular, neurodegenerative, and musculoskeletal disorders. PM2.5 is a major environmental pollutant and an exogenous pathogen in air pollution that is now recognized as an accelerator of human aging and a predisposing factor for several age-related diseases. In this paper, we seek to elucidate the mechanisms by which PM2.5 induces cellular senescence, such as genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, and mitochondrial dysfunction, and age-related diseases. Our goal is to increase awareness among researchers within the field of the toxicity of environmental pollutants and to advocate for personal and public health initiatives to curb their production and enhance population protection. Through these endeavors, we aim to promote longevity and health in older adults.

Toxicological Effects of Fine Particulate Matter (PM2.5): Health Risks and Associated Systemic Injuries-Systematic Review

Previous studies focused on investigating particulate matter with aerodynamic diameter ≤ 2.5 µm (PM2.5) have shown the risk of disease development, and association with increased morbidity and mortality rates. The current review investigate epidemiological and experimental findings from 2016 to 2021, which enabled the systemic overview of PM2.5's toxic impacts on human health. The Web of Science database search used descriptive terms to investigate the interaction among PM2.5 exposure, systemic effects, and COVID-19 disease. Analyzed studies have indicated that cardiovascular and respiratory systems have been extensively investigated and indicated as the main air pollution targets. Nevertheless, PM2.5 reaches other organic systems and harms the renal, neurological, gastrointestinal, and reproductive systems. Pathologies onset and/or get worse due to toxicological effects associated with the exposure to this particle type, since it can trigger several reactions, such as inflammatory responses, oxidative stress generation and genotoxicity. These cellular dysfunctions lead to organ malfunctions, as shown in the current review. In addition, the correlation between COVID-19/Sars-CoV-2 and PM2.5 exposure was also assessed to help better understand the role of atmospheric pollution in the pathophysiology of this disease. Despite the significant number of studies about PM2.5's effects on organic functions, available in the literature, there are still gaps in knowledge about how this particulate matter can hinder human health. The current review aimed to approach the main findings about the effect of PM2.5 exposure on different systems, and demonstrate the likely interaction of COVID-19/Sars-CoV-2 and PM2.5.

Forecasting PM10 concentrations using time series models: a case of the most polluted cities in Turkey

Particulate matter (PM), which is one of the most important parameters in the area of air pollution, has widespread impacts on human health. Hence, the prediction of the probable concentration of PM is a highly significant subject with regard to primary warning for the protection of a population. Turkey is among the European countries with polluted air in terms of the concentration of PM with a diameter smaller than 10 μ m (PM₁₀). The PM₁₀ data supplies significant knowledge about how much pollution is in the air and which city is the most polluted. In this study, the values of PM₁₀ for the most polluted cities in Turkey are forecasted using time series models, including autoregressive integrated moving average (ARIMA), error, trend and seasonal (ETS), and singular spectrum analysis (SSA). Forecast values of PM₁₀ averaging period of 24 h for the year 2019 are obtained using SSA as the optimum time series method. The results show that the annual means of PM₁₀ concentrations in 2019 in Hatay and Yalova, the most polluted cities, will not exceed the 50 μgm^- 3 value according to air quality standards determined by the European Commission. The air quality levels of eight other cities, which are Adana, Ankara, Icel, Istanbul, Kirklareli, Sakarya, Samsun, and Sivas, will reach acceptable standards between 50 and 70 μgm^- 3 for annual mean in 2019. The remaining eight cities, Amasya, Bursa, Denizli, Kahramanmaras, Kutahya, Manisa, Nigde, and Tekirdag, continue to be the most polluted cities in 2019 according to the average annual PM₁₀ values. This study also reveals that the average PM₁₀ value of the most polluted cities in Turkey will be 68.97 μgm^- 3 for the 24-h average in 2019.