Air Pollution/analysis* ; Environmental Exposure/analysis* ; China/epidemiology* ; Air Pollutants/analysis* ; Particulate Matter/analysis* ; Environmental Monitoring

BACKGROUND: Metabolic Dysfunction-associated Steatotic Liver Disease (MASLD) has become a global epidemic, and air pollution has been identified as a potential risk factor. This study aims to investigate the non-linear relationship between ambient air pollution and MASLD prevalence. METHOD: In this cross-sectional study, participants undergoing health checkups were assessed for three-year average air pollution exposure. MASLD diagnosis required hepatic steatosis with at least 1 out of 5 cardiometabolic criteria. A stepwise approach combining data visualization and regression modeling was used to determine the most appropriate link function between each of the six air pollutants and MASLD. A covariate-adjusted six-pollutant model was constructed accordingly. RESULTS: A total of 131,592 participants were included, with 40.6% met the criteria of MASLD. "Threshold link function," "interaction link function," and "restricted cubic spline (RCS) link functions" best-fitted associations between MASLD and PM_2.5, PM₁₀/CO, and O₃ /SO₂/NO₂, respectively. In the six-pollutant model, significant positive associations were observed when pollutant concentrations were over: 34.64 µg/m³ for PM_2.5, 57.93 µg/m³ for PM₁₀, 56 µg/m³ for O₃, below 643.6 µg/m³ for CO, and within 33 and 48 µg/m³ for NO₂. The six-pollutant model using these best-fitted link functions demonstrated superior model fitting compared to exposure-categorized model or linear link function model assuming proportionality of odds. CONCLUSION Non-linear associations were found between air pollutants and MASLD prevalence. PM_2.5, PM₁₀, O₃, CO, and NO₂ exhibited positive associations with MASLD in specific concentration ranges, highlighting the need to consider non-linear relationships in assessing the impact of air pollution on MASLD.
Humans ; Nitrogen Dioxide ; Cross-Sectional Studies ; Air Pollution/analysis* ; Air Pollutants/analysis* ; Particulate Matter/analysis* ; Liver Diseases ; Environmental Exposure/analysis*

OBJECTIVE: To observe the effects of moxa smoke through olfactory pathway on learning and memory ability in rapid aging (SAMP8) mice, and to explore the action pathway of moxa smoke. METHODS: Forty-eight six-month-old male SAMP8 mice were randomly divided into a model group, an olfactory dysfunction group, a moxa smoke group and an olfactory dysfunction + moxa smoke group, with 12 mice in each group. Twelve age-matched male SAMR1 mice were used as the blank group. The olfactory dysfunction model was induced in the olfactory dysfunction group and the olfactory dysfunction + moxa smoke group by intraperitoneal injection of 3-methylindole (3-MI) with 300 mg/kg, and the moxa smoke group and the olfactory dysfunction + moxa smoke group were intervened with moxa smoke at a concentration of 10-15 mg/m³ for 30 min per day, with a total of 6 interventions per week. After 6 weeks, the emotion and cognitive function of mice was tested by open field test and Morris water maze test, and the neuronal morphology in the CAI area of the hippocampus was observed by HE staining. The contents of neurotransmitters (glutamic acid [Glu], gamma-aminobutyric acid [GABA], dopamine [DA], and 5-hydroxytryptamine [5-HT]) in hippocampal tissue of mice were detected by ELISA. RESULTS: The mice in the blank group, the model group and the moxa smoke group could find the buried food pellets within 300 s, while the mice in the olfactory dysfunction group and the olfactory dysfunction + moxa smoke group took more than 300 s to find them. Compared with the blank group, the model group had increased vertical and horizontal movements (P<0.05) and reduced central area residence time (P<0.05) in the open field test, prolonged mean escape latency on days 1-4 (P<0.05), and decreased search time, swimming distance and swimming distance ratio in the target quadrant of the Morris water maze test, and decreased GABA, DA and 5-HT contents (P<0.05, P<0.01) and increased Glu content (P<0.05) in hippocampal tissue. Compared with the model group, the olfactory dysfunction group had increased vertical movements (P<0.05), reduced central area residence time (P<0.05), and increased DA content in hippocampal tissue (P<0.05); the olfactory dysfunction + moxa smoke group had shortened mean escape latency on days 3 and 4 of the Morris water maze test (P<0.05) and increased DA content in hippocampal tissue (P<0.05); the moxa smoke group had prolonged search time in the target quadrant (P<0.05) and increased swimming distance ratio, and increased DA and 5-HT contents in hippocampal tissue (P<0.05, P<0.01) and decreased Glu content in hippocampal tissue (P<0.05). Compared with the olfactory dysfunction group, the olfactory dysfunction + moxa smoke group showed a shortened mean escape latency on day 4 of the Morris water maze test (P<0.05). Compared with the moxa smoke group, the olfactory dysfunction + moxa smoke group had a decreased 5-HT content in the hippocampus (P<0.05). Compared with the blank group, the model group showed a reduced number of neurons in the CA1 area of the hippocampus with a disordered arrangement; the olfactory dysfunction group had similar neuronal morphology in the CA1 area of the hippocampus to the model group. Compared with the model group, the moxa smoke group had an increased number of neurons in the CA1 area of the hippocampus that were more densely packed. Compared with the moxa smoke group, the olfactory dysfunction + moxa smoke group had a reduced number of neurons in the CA1 area of the hippocampus, with the extent between that of the moxa smoke group and the olfactory dysfunction group. CONCLUSION The moxa smoke could regulate the contents of neurotransmitters Glu, DA and 5-HT in hippocampal tissue through olfactory pathway to improve the learning and memory ability of SAMP8 mice, and the olfactory is not the only effective pathway.
Male ; Animals ; Mice ; Olfactory Pathways ; Smoke/adverse effects* ; Serotonin ; Aging ; Dopamine ; Olfaction Disorders/etiology*

Cell Differentiation ; Myeloid Differentiation Factor 88/metabolism* ; NF-kappa B/metabolism* ; Particulate Matter/toxicity* ; Signal Transduction ; Toll-Like Receptor 4/metabolism* ; RAW 264.7 Cells

Humans ; Coal ; Dust/analysis* ; Anthracosis ; China/epidemiology* ; Coal Mining ; Occupational Exposure

OBJECTIVE: This study assesses the impact of smoke-free legislation on the incidence rate for acute myocardial infarction (AMI) and stroke in Shenzhen. METHODS: Data on ischemic ( n = 72,945) and hemorrhagic ( n = 18,659) stroke and AMI ( n = 17,431) incidence covering about 12 million people in Shenzhen from 2012 to 2016 were used. Immediate and gradual changes in incidence rates were analyzed using segmented Poisson regression. RESULTS: Following the smoke-free legislation, a 9% (95% CI: 3%-15%) immediate reduction was observed in AMI incidence, especially in men (8%, 95% CI: 1%-14%) and in those aged 65 years and older (17%, 95% CI: 9%-25%). The gradual annual benefits were observed only in hemorrhagic and ischemic stroke incidence, with a 7% (95% CI: 2%-11%) and 6% (95% CI: 4%-8%) decrease per year, respectively. This health effect extended gradually to the 50-64 age group. In addition, neither the immediate nor gradual decrease in stroke and AMI incidence rates did not show statistical significance among the 35-49 age group ( P > 0.05). CONCLUSION Smoke-free legislation was enforced well in Shenzhen, which would generate good experiences for other cities to enact and enforce smoke-free laws. This study also provided more evidence of the health benefits of smoke-free laws on stroke and AMI.
Male ; Humans ; Middle Aged ; Adult ; Incidence ; Interrupted Time Series Analysis ; Stroke/etiology* ; Myocardial Infarction/etiology* ; China/epidemiology* ; Tobacco Smoke Pollution

Humans ; Diabetes Mellitus, Type 2/epidemiology* ; Air Pollution/adverse effects* ; Air Pollutants/toxicity* ; Risk Assessment ; Particulate Matter ; Environmental Exposure

Objective To explore the overall level,distribution characteristics,and differences in household fine particulate matter (PM_2.5) pollution caused by fuel burning in urban and rural areas in China. Methods The relevant articles published from 1991 to 2021 were retrieved and included in this study.The data including the average concentration of household PM_2.5 and urban and rural areas were extracted,and the stoves and fuel types were reclassified.The average concentration of PM_2.5 in different areas was calculated and analyzed by nonparametric test. Results The average household PM_2.5 concentration in China was (178.81±249.91) μg/m³.The mean household PM_2.5 concentration was higher in rural areas than in urban areas[(206.08±279.40) μg/m³ vs. (110.63±131.16) μg/m³;Z=-5.45,P<0.001] and higher in northern areas than in southern areas[(224.27±301.66) μg/m³ vs.(130.11±140.61) μg/m³;Z=-2.38,P=0.017].The north-south difference in household PM_2.5 concentration was more significant in rural areas than in urban areas[(324.19±367.94) μg/m³ vs.(141.20±151.05) μg/m³,χ²=-5.06,P<0.001].The PM_2.5 pollution level showed differences between urban and rural households using different fuel types (χ²=92.85,P<0.001),stove types (χ²=74.42,P<0.001),and whether they were heating (Z=-4.43,P<0.001).Specifically,rural households mainly used solid fuels (manure,charcoal,coal) and traditional or improved stoves,while urban households mainly used clean fuels (gas) and clean stoves.The PM_2.5 concentrations in heated households were higher than those in non-heated households in both rural and urban areas (Z=-4.43,P<0.001). Conclusions The household PM_2.5 pollution caused by fuel combustion in China remains a high level.The PM_2.5 concentration shows a significant difference between urban and rural households,and the PM_2.5 pollution is more serious in rural households.The difference in the household PM_2.5 concentration between urban and rural areas is more significant in northern China.PM_2.5 pollution in the households using solid fuel,traditional stoves,and heating is serious,and thus targeted measures should be taken to control PM_2.5 pollution in these households.
Humans ; Particulate Matter/analysis* ; Air Pollution, Indoor/analysis* ; Cooking ; Environmental Exposure/analysis* ; China ; Rural Population

Objective: To investigate the association of mixed exposure to greenness and nitrogen dioxide(NO₂) and hypertension among the older adults aged 65 years and over in China. Methods: The study subjects were from the Chinese Longitudinal Healthy Longevity Survey from 2017 to 2018. A total of 15 423 older adults aged 65 years and over meeting the criteria were finally included in the study. A questionnaire survey was used to collect information on demographic characteristics, lifestyle habits and self-reported prevalence of hypertension. Blood pressure values were obtained through physical examination. The level of normalized difference vegetation index(NDVI) was measured by the Medium-resolution Imaging Spectral Radiator(MODIS) of the National Aeronautics and Space Administration(NASA). The concentration of NO₂ was from China's surface air pollutant data set. Meteorological data was from NASA MERRA-2. The exposure to NDVI and NO₂ for each study subject was calculated based on the area within a 1 km radius around their residence. The association between mixed exposure of NDVI and NO₂ as well as their interaction and hypertension in older adults was analyzed by using the multivariate logistic regression model. The restrictive cubic spline(RCS) function was used to explore the exposure-response relationship between greenness and NO₂ and the risk of hypertension in study subjects. Results: The mean age of 15 423 older adults were (85.6±11.6). Women accounted for 56.3%(8 685/15 423) and 55.6%(8 578/15 423) lived in urban areas. The mean time of residence was (60.9±28.5) years. 59.8% of participants were with hypertension. The mean NDVI level was 0.41±0.13, and the mean NO₂ concentration was (32.18±10.36) μg/cm³. The results of multivariate logistic regression analysis showed that NDVI was inversely and linearly associated with the hypertension in older adults, with the OR(95%CI) value of 0.959(0.928-0.992). Compared with the T₁ group of NDVI, the risk of hypertension was lower in the T₃ group, with the OR(95%CI) value of 0.852(0.769-0.944), and the trend test was statistically significant(P<0.05). Compared with the T₁ group of NO₂, the risk of hypertension was higher in the T₂ and T₃ groups, with OR(95%CI) values of 1.160(1.055-1.275) and 1.244(1.111-1.393), and the trend test was statistically significant (P<0.05). The result of the RCS showed that NDVI was inversely and linearly associated with hypertension in older adults. NO₂ was nonlinearly associated with hypertension in older adults. The interaction analysis showed that NDVI and NO₂ had a negative multiplicative interaction on the risk of hypertension, with OR(95%CI) value of 0.995(0.992-0.997). Conclusion: Exposure to greenness and NO₂ are associated with hypertension in older adults.
Aged ; Humans ; Female ; Nitrogen Dioxide ; Air Pollution ; Prevalence ; Hypertension/epidemiology* ; China/epidemiology* ; Particulate Matter/analysis*

Objective: To analyze the short-term effect of individual atmospheric PM_2.5 exposure on the diversity, enterotype, and community structure of gut microbiome in healthy elderly people in Jinan, Shandong province. Methods: The present panel study recruited 76 healthy elderly people aged 60-69 years old in Dianliu Street, Lixia District, Jinan, Shandong Province, and followed them up five times from September 2018 to January 2019. The relevant information was collected by questionnaire, physical examination, precise monitoring of individual PM_2.5 exposure, fecal sample collection and gut microbiome 16S rDNA sequencing. The Dirichlet multinomial mixtures (DMM) model was used to analyze the enterotype. Linear mixed effect model and generalized linear mixed effect model were used to analyze the effect of PM_2.5 exposure on gut microbiome α diversity indices (Shannon, Simpson, Chao1, and ACE indices), enterotype and abundance of core species. Results: Each of the 76 subjects participated in at least two follow-up visits, resulting in a total of 352 person-visits. The age of 76 subjects was (65.0±2.8) years old with BMI (25.0±2.4) kg/m². There were 38 males accounting for 50% of the subjects. People with an educational level of primary school or below accounted for 10.5% of the 76 subjects, and those with secondary school and junior college or above accounting for 71.1% and 18.4%. The individual PM_2.5 exposure concentration of 76 subjects during the study period was (58.7±53.7) μg/m³. DMM model showed that the subjects could be divided into four enterotypes, which were mainly driven by Bacteroides, Faecalibacterium, Lachnospiraceae, Prevotellaceae, and Ruminococcaceae. Linear mixed effects model showed that different lag periods of PM_2.5 exposure were significantly associated with a lower gut α diversity index (FDR<0.05 after correction). Further analysis showed that PM_2.5 exposure was significantly associated with changes in the abundances of Firmicutes (Megamonas, Blautia, Streptococcus, etc.) and Bacteroidetes (Alistipes) (FDR<0.05 after correction). Conclusion: Short-term PM_2.5 exposure is significantly associated with a decrease in gut microbiome diversity and changes in the abundance of several species of Firmicutes and Bacteroidetes in the elderly. It is necessary to further explore the underlying mechanisms between PM_2.5 exposure and the gut microbiome, so as to provide a scientific basis for promoting the intestinal health of the elderly.
Aged ; Humans ; Male ; Middle Aged ; Feces/microbiology* ; Gastrointestinal Microbiome ; Particulate Matter ; RNA, Ribosomal, 16S/genetics* ; Female