Recently, many researchers paid more attentions to the association between air pollution and chronic obstructive pulmonary disease (COPD). Haze, a severe form of outdoor air pollution, affected most parts of northern and eastern China in the past winter. In China, studies have been performed to evaluate the impact of outdoor air pollution and biomass smoke exposure on COPD; and most studies have focused on the role of air pollution in acutely triggering symptoms and exacerbations. Few studies have examined the role of air pollution in inducing pathophysiological changes that characterise COPD. Evidence showed that outdoor air pollution affects lung function in both children and adults and triggers exacerbations of COPD symptoms. Hence outdoor air pollution may be considered a risk factor for COPD mortality. However, evidence to date has been suggestive (not conclusive) that chronic exposure to outdoor air pollution increases the prevalence and incidence of COPD. Cross-sectional studies showed biomass smoke exposure is a risk factor for COPD. A long-term retrospective study and a long-term prospective cohort study showed that biomass smoke exposure reductions were associated with a reduced decline in forced expiratory volume in 1 second (FEV1) and with a decreased risk of COPD. To fully understand the effect of air pollution on COPD, we recommend future studies with longer follow-up periods, more standardized definitions of COPD and more refined and source-specific exposure assessments.
ObjectiveTo investigate the changes of lung function after exposure to fine particulate matter (PM2.5) for 60 days and the expression of miR-146 in mice.MethodsThirty SPF BALB/c mice were treated with noninvasive tracheal instillation of fine particulate matter suspension at different doses (2.5 mg/kg, 5.0 mg/kg, 10.0 mg/kg) for 2 months (two times one week), the blank group and normal saline group were set as control groups. The mice were examined and killed on the next day after the last instillation. Histopathological changes of the lungs, pro-infammatory factors levels in the lung tissues, pulmonary functions and the relative expression of miR-146a and miR-146b in the lung tissues were detected.ResultsPeak inspiratory flow (PIF) and peak expiratory flow (PEF) were decreased significantly after PM2.5 exposure, however, lung resistance increased and maximal voluntary ventilation reduced from the general tendency without significant difference. Hematoxylin-eosin stain showed lymphocyte infiltration and macrophage infiltration by phagocytic particles, alveolar spacer widening, inflammatory response increased with the increase of PM2.5 exposure dosage. Pro-infammatory factors as interleukin-6 in the bronchoalveolar lavage fluid, interferon-γ and tumor necrosis factor-α in the lung homogenate were increased significantly by enzyme linked immunosorbent assay. The relative expressions of miR-146a and miR-146b were up-regulated remarkablely in treatment groups compared to the control group by real-time fluorescence quantitative polymerase chain reaction, which had negative relationships with PIF and PEF.ConclusionsThe lung function of mice decreases significantly after exposure to fine particulate matter, and the expression of miR-146 is up-regulated.
ObjectiveTo systematically analyze the spatiotemporal distribution characteristics and epidemiological trends of tracheal, bronchus, and lung cancer (TBL) disease burden attributed to air pollution globally and in China and the United States from 1990 to 2021. Furthermore, based on predictive models, assess the patterns of disease burden changes from 2022 to 2031, providing a scientific basis for formulating targeted TBL prevention and control strategies. MethodsBased on the Global Burden of Disease (GBD) 2021 database, we analyzed the disease burden data of TBL attributed to air pollution globally and in China and the United States from 1990 to 2021. R Studio 4.3.2 software was used to analyze the corresponding trends and the Bayesian age-period-cohort (BAPC) prediction model was used to predict the status of the disease burden of TBL attributed to air pollution in the world and in China and the United States from 2022 to 2031. ResultsIn 2021, the highest number of deaths and disability-adjusted life years attributed to air pollution were in China (211 400 patients and 4.8947 million person-years), followed by the United States (6 000 patients and 124 300 person-years). The age standardized mortality rate (ASMR) and age standardized disability-adjusted life years rate (ASDR) of TBL due to air pollution in the world and in China and the United States showed a decreasing trend (with an average annual percentage change of<0). From 1990 to 2021, the ASMR and ASDR of TBL in China due to air pollution were much higher than those in the United States and the global average. In terms of gender, from 1990 to 2021, the disease burden of male patients with TBL attributed to air pollution in the world and in China and the United States was much higher than that of female patients. The BAPC prediction model showed that from 2022 to 2031, the ASMR and ASDR of TBL attributed to air pollution will showed an upward trend globally, while they showed a downward trend in China and the United States. ConclusionOver the past 30 years, the air pollution-related TBL disease burden in the world and in China and the United States has continued to decline, but China's level is still significantly higher than the global average. The disease burden in men far exceeds that in women, with men and the elderly population aged ≥50 years being high-risk groups. In the future, the global disease trend may reverse and rise, while China and the United States are expected to continuously decline. However, precise prevention and control for high-risk groups remains a key challenge.