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 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*

This study explored the feasibility of mineral element content and ratios of nitrogen isotopes to discriminate the cultivation mode of Dendrobium nobile in order to provide theoretical support for the discrimination of the cultivation mode of D. nobile. The content of 11 mineral elements(N, K, Ca, P, Mg, Na, Fe, Cu, Zn, Mn, and B) and nitrogen isotope ratios in D. nobile and its substrate samples in three cultivation methods(greenhouse cultivation, tree-attached cultivation, and stone-attached cultivation) were determined. According to the analysis of variance, principal component analysis, and stepwise discriminant analysis, the samples of different cultivation types were classified. The results showed that the nitrogen isotope ratios and the content of elements except for Zn were significantly different among different cultivation types of D. nobile(P<0.05). The results of correlation analysis showed that the nitrogen isotope ratios, mineral element content, and effective component content in D. nobile were correlated with the nitrogen isotope ratio and mineral element content in the corresponding substrate samples to varying degrees. Principal component analysis can preliminarily classify the samples of D. nobile, but some samples overlapped. Through stepwise discriminant analysis, six indicators, including δ~(15)N, K, Cu, P, Na, and Ca, were screened out, which could be used to establish the discriminant model of D. nobile cultivation methods, and the overall correct discrimination rates after back-substitution test, cross-check, and external validation were all 100%. Therefore, nitrogen isotope ratios and mineral element fingerprints combined with multivariate statistical analysis could effectively discriminate the cultivation types of D. nobile. The results of this study provide a new method for the identification of the cultivation type and production area of D. nobile and an experimental basis for the quality evaluation and quality control of D. nobile.
Dendrobium ; Minerals ; Discriminant Analysis ; Multivariate Analysis ; Nitrogen Isotopes

To explore the suitable fertilizing pattern for Saposhnikovia divaricata in the genuine producing area, a field trial was carried out to investigate the changes in the yield and quality of medicinal materials and soil in different fertilization patterns, such as organic fertilizer substitution(organic fertilizer+NPK fertilizer) and chemical fertilizer reduction(organic fertilizer+NPK fertilizer decrement and organic fertilizer+NPK fertilizer decrement+soil conditioner). The comprehensive analysis of all treatments was based on the medicine quality evaluation data set and soil quality evaluation data set, respectively, by CRITIC weight method. The results showed that(1) the yield of S. divaricate increased by 4.93%-12.67% under the organic fertilizer substitution mode, and the yield increased by 44.43% under the treatment of chemical fertilizer reduction YHT15, which was higher than that of the organic fertilizer substitution mode.(2) The quality of S. divaricate under the two fertilization modes was superior to the standard in the Chinese Pharmacopoeia, and the application of biochar was helpful to improve the quality of S. divaricate quality, with an increase of 82.83%-181.54%. CRITIC method analysis showed that fertilization treatments with high comprehensive scores were YHT15, YH30, and YH15.(3) Soil quality under the two fertilization modes was higher than that under the control. The fertilization treatments with higher comprehensive scores of soil quality were YHT15, YHT30, and YHT. The fertilization mode of adding biochar as soil conditioner, applying an appropriate amount of organic fertilizer, and reducing part of chemical fertilizer is the appropriate way to develop ecological plantation of S. divaricata in the Baicheng area in the western Jilin province. The specific fertilization mode is as follows. The basic fertilizer was 361 kg·hm~(-2) superphosphate+110 kg·hm~(-2) potassium sulfate+82 kg·hm~(-2) organic fertilizer+10 000 kg·hm~(-2) rice husk biochar, and urea was applied as top fertilizer three times, 29, 29, and 20 kg·hm~(-2), respectively.
Agriculture ; Fertilizers/analysis* ; Soil ; Apiaceae ; Nitrogen/analysis*

Nitrogen dioxide (NO₂) is an important indoor air pollutant, with both outdoor and indoor sources contributing to indoor NO₂ exposure levels. Considering the association of high NO₂ exposure with adverse health effects, the Standards for indoor air quality (GB/T 18883-2022) have been revised to further restrict indoor NO₂ limit values. The 1-h average concentration limit value for NO₂ has been reduced from 0.24 mg/m³ to 200 μg/m³.This study analyzed the technical contents related to the determination of the limits of indoor NO₂ in Standards for Indoor Air Quality (GB/T 18883-2022), including source, exposure level, health effects, and the process and evidence basis for determining the limit value. It also proposed prospects for the direction for the implementation of the indoor NO₂ standard.
Humans ; Air Pollution, Indoor/adverse effects* ; Nitrogen Dioxide ; Air Pollutants/analysis* ; China ; Air Pollution/adverse effects*

Nitrogen dioxide (NO₂) is an important indoor air pollutant, with both outdoor and indoor sources contributing to indoor NO₂ exposure levels. Considering the association of high NO₂ exposure with adverse health effects, the Standards for indoor air quality (GB/T 18883-2022) have been revised to further restrict indoor NO₂ limit values. The 1-h average concentration limit value for NO₂ has been reduced from 0.24 mg/m³ to 200 μg/m³.This study analyzed the technical contents related to the determination of the limits of indoor NO₂ in Standards for Indoor Air Quality (GB/T 18883-2022), including source, exposure level, health effects, and the process and evidence basis for determining the limit value. It also proposed prospects for the direction for the implementation of the indoor NO₂ standard.
Humans ; Air Pollution, Indoor/adverse effects* ; Nitrogen Dioxide ; Air Pollutants/analysis* ; China ; Air Pollution/adverse effects*

Objective: To assess the association between short-term exposure level of nitrogen dioxide and the hospitalization risk of heart failure. Methods: Based on China-PEACE Retrospective Heart Failure Study, 117 364 hospitalized patients with heart failure were recruited from 92 hospitals in 62 cities throughout China between January 1, 2015 and December 31, 2015. The daily exposure level of nitrogen dioxide, temperature, and humidity in the same cities during the same period were also collected. We applied the generalized additive model and Bayesian hierarchical model to quantify the lagged effect and cumulative effect of short-term (0-3 days) exposure to ambient nitrogen dioxide on the hospitalization risk of heart failure. We further conducted stratified analyses by age, region, and season to identify any difference in the associations between short-term nitrogen dioxide exposure and heart failure among subgroups. Results: The mean age for participants in the analysis was (70.32±12.22) years. The median, minimum and maximum of daily nitrogen dioxide concentration in 62 cities from January 1, 2015 to December 31, 2015 was 26.4 μg/m³, 2.33 μg/m³ and 150.25 μg/m³, respectively. The exposure level of nitrogen dioxide at the same day was associated with the hospitalization risk of heart failure (OR=1.022, 95%CI: 1.012, 1.031). Significant effects were also observed in the moving average concentrations from lag 0-1 to lag 0-3 day (OR=1.020, 95%CI: 1.009, 1.030; OR=1.016, 95%CI: 1.004, 1.028; OR=1.013, 95%CI: 1.001, 1.026). Moreover, all of the associations between short-term exposure to nitrogen dioxide and the risk of heart failure hospitalization were statistically significant, with no significant difference in all subgroups stratified by age, region, and season. Conclusion: A higher level of short-term exposure to nitrogen dioxide could trigger more hospitalizations with heart failure.
Aged ; Aged, 80 and over ; Air Pollutants/analysis* ; Air Pollution/analysis* ; Bayes Theorem ; China/epidemiology* ; Environmental Exposure/analysis* ; Heart Failure/epidemiology* ; Hospitalization ; Humans ; Middle Aged ; Nitrogen Dioxide/analysis* ; Particulate Matter/analysis* ; Retrospective Studies ; Sulfur Dioxide/analysis*

Objective: To investigate and monitor the occupational hazards in the Teaching and Research Laboratory (hereinafter referred to as the place) of a university, so as to provide basis for the occupational health work in the university. Methods: November 2014, 46 places in a university were selected by stratified random sampling, and the occupational health risk factors were investigated. Results: Indoor temperature, humidity, sulfur dioxide, nitrogen dioxide, carbon monoxide and carbon dioxide were detected in 21 sites, xylene and hydrofluoric acid were detected in 6 sites, and colony count was detected in 18 sites, the power frequency electric field intensity was measured in 23 places, and the x-ray radiation dose was measured in 4 places. Noise was measured at 21 sites, with 7 sites exceeding the standards accounting for 33.3% (7/21) ; 21 sites were detected for illumination and 10 sites for nonconformity accounting for 47.6% (10/21) ; 10 sites for Microwave Radiation and 3 sites exceeding the standards accounting for 30% (3/10) ; and 25 sites were detected for outdoor air volume and air velocity, the percentage of unqualified was 72% (18/25) in 18 sites, among which the wind velocity was statistically significant in teaching, research and experimental sites (P=0.010) . Conclusion: The occupational hazards in the teaching and research places of a university should be paid attention to, and the engineering protection and personal protection should be strengthened in the experiment.
Air Pollution, Indoor/analysis* ; Humans ; Humidity ; Nitrogen Dioxide/analysis* ; Occupational Exposure ; Occupational Health ; Universities

OBJECTIVE: To investigate the potential effect of modification of antihypertensive medications on the association of nitrogen dioxide (NO₂) long-term exposure and chronic kidney disease (CKD). METHODS: Data of the national representative sample of adult population from the China National Survey of Chronic Kidney Disease (2007-2010) were included in the analyses, and exposure data of NO₂ were collected and matched. Generalized mixed-effects models were used to analyze the associations between NO₂ and CKD, stratified by the presence of hypertension and taking antihypertensive medications. The stratified exposure-response curves of NO₂ and CKD were fitted using the natural spine smoothing function. The modifying effects of antihypertensive medications on the association and the exposure-response curve of NO₂ and CKD were analyzed. RESULTS: Data of 45 136 participants were included, with an average age of (49.5±15.3) years. The annual average exposure concentration of NO₂ was (7.2±6.4) μg/m³. Altogether 6 517 (14.4%) participants were taking antihypertensive medications, and 4 833 (10.7%) participants were identified as having CKD. After adjustment for potential confounders, in the hypertension population not using antihypertensive medications, long-term exposure to NO₂ was associated with a significant increase risk of CKD (OR: 1.38, 95%CI: 1.24-1.54, P < 0.001); while in the hypertension population using antihypertensive medications, no significant association between long-term exposure to NO₂ and CKD (OR: 0.96, 95%CI: 0.86-1.07, P=0.431) was observed. The exposure-response curve of NO₂ and CKD suggested that there was a non-linear trend in the association between NO₂ and CKD. The antihypertension medications showed significant modifying effects both on the association and the exposure-response curve of NO₂ and CKD (interaction P < 0.001). CONCLUSION The association between long-term exposure to NO₂ and CKD was modified by antihypertensive medications. Taking antihypertensive medications may mitigate the effect of long-term exposure to NO₂ on CKD.
Adult ; Air Pollutants/analysis* ; Air Pollution/analysis* ; Antihypertensive Agents/adverse effects* ; Environmental Exposure/analysis* ; Humans ; Hypertension/epidemiology* ; Middle Aged ; Nitrogen Dioxide/analysis* ; Particulate Matter ; Renal Insufficiency, Chronic/epidemiology*

At present, the death cases of simple asphyxiant gas acute poisoning are increasing sharply. Common asphyxiant gases in death cases include nitrogen, helium, carbon dioxide, methane, propane, laughing gas, etc. Simple asphyxiant gas has no affinity for biological matrices and escapes quickly, which puts forward new requirements for autopsy procedures, selection and collection of samples, laboratory analysis and identification. This paper reviews the research and development process of death cases caused by simple asphyxiant gas acute poisoning and put forwards the collection and analysis strategy of the samples in such cases. The most valuable biological samples in such cases should be lung tissues associated with the airways, followed by brain tissue and cardiac blood. Gaseous samples from the esophageal cavity, tracheal cavity, pulmonary bronchi, gastric and cardiac areas are also recommended as valuable samples. In the case of postmortem examination, the gas should be injected into gas sample bag directly. Biological materials such as tissue and blood should be directly sealed in head-space vials and analyzed by using the headspace gas chromatography-mass spectrometry.
Carbon Dioxide/analysis* ; Autopsy ; Gas Chromatography-Mass Spectrometry ; Methane/analysis* ; Nitrogen