Search

Application of crop residues and chemical nitrogen (N) fertilizer is a conventional practice for achieving high yield in a rice system. However, the fallacious combination of N fertilizers with crop straw not only significantly reduces the N use efficiencies (NUEs) but also leads to serious environmental problems. The present study employed five treatments including no N fertilization and no straw incorporation (ck), N fertilization incorporation only (S0), N fertilization with 40% straw (S40), N fertilization with 60% straw (S60), and N fertilization with 100% straw (S100) to improve N use efficiency as well as reduced Cd distribution in rice. The crop yields were largely enhanced by fertilization ranging from 13 to 52% over the straw addition treatments. Compared with ck, N fertilizer input significantly decreased soil pH, while DOC contents were raised in response to straw amendment, reaching the highest in S60 and S100 treatments, respectively. Moreover, straw addition substantially impacted the Cd accumulation and altered the bacterial community structure. The soil NH4+-N concentration under S0 performed the maximum in yellow soil, while the minimum in black soil compared to straw-incorporated pots. In addition, the soil NO3−-N concentration in straw-incorporated plots tended to be higher than that in straw-removed plots in both soils, indicating that crop straw triggering the N mineralization was associated with native soil N condition. Furthermore, the NUE increased with 15 N uptake in the plant, and the residual 15 N in soil was increased by 26.8% with straw addition across four straw application rates. Overall, our study highlights the trade-offs between straw incorporation with N fertilizer in eliminating potential Cd toxicity, increasing fertilizer-N use efficiencies and help to provide a feasible agricultural management. [ABSTRACT FROM AUTHOR]

Straw residues, as one of the conservation farming practices, are being strongly encouraged in China, including some cadmium-polluted areas. Nowadays, a portion of this plant residue is promoted to be removed for reducing excess metal(loid) in the soil and to be used for bioenergy production. Nevertheless, the possible influences of contaminated straw or the burial of its derived biochars on Cd accumulation in soil and data based on health risk assessment associated with different status and extent of soil contamination were relatively unknown. Thus it is important to provide a more systematical understanding of contaminated straw burial at specific contamination zones, which may provide useful guidance for straw utilization. In this study, we harvested two genotypes of rice straw from 6 contaminated levels among three soil types to comprehensively study the total Cd contents in straws and its derived biochars and correlate the sets of straw characteristics and Cd contents in three different contamination zones. The total Cd concentration in straws grew at a steady rate relatively with increasing soil Cd contamination levels, compared to those in biochars which performed more fluctuate due to the strong burning. According to correlational analyses, three-way ANOVA showed that the moisture, ash, volatile and fixed carbon were all significantly affected by straw CdTotal contents (p < 0.001). Such relationships were attributed to guide straw removal portions for gasification. Meanwhile, there was a significant correlation between straw Cd concentration and soil types (p < 0.001), confirming that it might be worth determining soil remediation by straw removal according to site-specific farmland conditions. This work will help to assess efforts toward predicting Cd concentration in the paddy soils related to kinds of contamination status and would also give useful guidance to make sustainable management strategies for crop straws in polluted regions. Novelty statement This work provided data on how much rice straw is needed to remove to ensure the minimal amount to control soil contamination and reduce costs according to site-specific conditions and soil Cd contamination status. It also explains the correlations between straw characteristics related to bioenergy use and soil conditions which would give guidance to balance using crop straw for increased bioenergy production and the need to also protect, preserve, and enhance soil resources. [ABSTRACT FROM AUTHOR]

Objective: To investigate personal exposures to nitrogen oxides (NO X ) and nitrogen di-oxide (NO 2 ) and the influence of baseline personal characteristics, living environment and daily activity patterns of the participants on the exposures among adults over 35 in Tianjin and Shanghai., Methods: In this panel study, 91 healthy nonsmoking adults aged over 35 from Tianjin and Shanghai participated in our study. The study was conducted in summer and winter. The participants were followed for three times with an interval of at least two weeks. Only participants in Shanghai were followed once in winter because of the COVID-19 pandemic. Twenty-seven participants completed follow-up visits in both seasons. We measured their 24 h personal exposures to NO X and NO 2 and collected their baseline and time-activity information through questionnaire/diary. The linear mixed model was used to analyze the associations between potential influencing factors and personal NO X and NO 2 exposure levels., Results: There were 349 follow-up visits with valid 24 h personal NO 2 and NO X exposure measurements in the two cities. The ave-rage 24 h personal exposures to NO 2 and NO X (volume fraction) in Tianjin participants were 18.0×10 -9 and 26.2×10 -9 in summer, and 31.0×10 -9 and 54.9×10 -9 in winter, respectively; and the average 24 h personal exposures to NO 2 and NO X in Shanghai participants were 38.7×10 -9 and 100.0×10 -9 in summer, and 45.5×10 -9 and 139.2×10 -9 in winter, respectively. The results of univariate regression analysis showed that their personal NO X exposure levels were significantly associated with city, season, gender, average daily cooking times, and ambient NO 2 concentrations measured at fixed-site monitoring stations. In addition to the above factors, the personal NO X exposure levels were also significantly associated with educational level and the personal NO 2 exposure levels were also significantly associated with passive smoking, average daily home time, cooking energy type, residential distance from main traffic road, and use of kitchen ventilators. Multivariate regression analysis showed that the personal exposure levels of NO 2 and NO X were significantly lower in Tianjin than that in Shanghai, were significantly lower in summer than that in winter, and were significantly and positively associated with ambient NO 2 concentrations measured at fixed-site monitoring stations. In addition, personal NO X exposure levels were significantly lower in females than in males, and personal NO 2 exposure levels were significantly positively associated with average daily cooking times and significantly inversely associated with average daily home time. For every interquartile range ( IQR ) increase (12.7×10 -9 ) in ambient NO 2 , the personal NO 2 exposure levels increased by 27.5% (95% CI : 17.0%-38.9%), and personal NO X exposure levels increased by 16.1% (95% CI : 7.1%-25.8%)., Conclusion: Season, city and ambient NO 2 concentrations are significant influencing factors of personal exposure levels of NO 2 and NO X. At the same time, the personal exposures levels of NO 2 are also affected by lifestyle factors. Our study provides scientific evidence for making precise air pollution control decisions and reducing the exposure levels of NO X in the population.

Particulate matter with diameters ≤2.5 μm (PM 2.5 ) has been identified as a significant air pollutant contributing to premature mortality. Nevertheless, the specific compositions within PM 2.5 that play the most crucial role remain unclear, especially in areas with high pollution concentrations. This study aims to investigate the individual and joint mortality risks associated with PM 2.5 inorganic chemical compositions and identify primary contributors. In 1998, we conducted a prospective cohort study in four northern Chinese cities (Tianjin, Shenyang, Taiyuan, and Rizhao). Satellite-based machine learning models calculated PM 2.5 inorganic chemical compositions, including sulfate (SO 4 2- ), nitrate (NO 3 - ), ammonium (NH 4 + ), and chloride (Cl - ). A time-varying Cox proportional hazards model was applied to analyze associations between these compositions and cardiorespiratory mortality, encompassing nonaccidental causes, cardiovascular diseases (CVDs), nonmalignant respiratory diseases (RDs), and lung cancer. The quantile-based g-computation model evaluated joint exposure effects and relative contributions of the compositions. Stratified analysis was used to identify vulnerable subpopulations. During 785,807 person-years of follow-up, 5812 (15.5%) deaths occurred from nonaccidental causes, including 2932 (7.8%) from all CVDs, 479 (1.3%) from nonmalignant RDs, and 552 (1.4%) from lung cancer. Every interquartile range (IQR) increase in SO 4 2- was associated with mortality from nonaccidental causes (hazard ratio: 1.860; 95% confidence interval: 1.809, 1.911), CVDs (1.909; 1.836, 1.985), nonmalignant RDs (2.178; 1.975, 2.403), and lung cancer (1.773; 1.624, 1.937). In the joint exposure model, a simultaneous rise of one IQR in all four compositions increased the risk of cardiorespiratory mortality by at least 36.3%, with long-term exposure to SO 4 2- contributing the most to nonaccidental and cardiopulmonary deaths. Individuals with higher incomes and lower education levels were found to be more vulnerable. Long-term exposure to higher levels of PM 2.5 inorganic compositions was associated with significantly increased cardiopulmonary mortality, with SO 4 2- potentially being the primary contributor. These findings offer insights into how PM 2.5 sources impact health, aiding the development of more effective governance measures., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Co-published by Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, and American Chemical Society.)

Previous studies have shown that exposure to black carbon (BC, a tracer of traffic-related air pollution) and psychosocial stress are both associated with adverse cardiac effects, but whether psychosocial stress could modify the cardiac effects of BC is unclear. To investigate the potential modifying effect of psychosocial stress on the associations between acute exposure to BC and typical cardiac health variables, real-time personal 24 h measurements were conducted in a repeated-measure study among adults with elevated blood pressure (high-risk group) and a panel study among normal adults (low-risk group) in China. Measured cardiac health variables included ST-segment depression events, heart rate, and heart rate variability (HRV) variables. Perceived Stress Scale, State Anxiety Inventory and Self-rating Depression Scale were used to assess the recent psychosocial stress status of the participants, and a composite stress index was established based on these scales. Generalized linear mixed-effects model was used to analyze the associations between BC exposure and cardiac health variables and potential effect modification by psychosocial stress. A total of 97 24 h measurements among 97 participants in the repeated-measure study and 202 24 h measurements among 87 participants in the panel study were included in the final analysis. Acute BC exposure was significantly associated with increased ST-segment depression events and heart rate and decreases in HRV in both studies. The marginal effects of acute BC exposure on most cardiac health variables generally tended to be amplified under higher vs low levels of psychosocial stress in both studies, with the composite stress index apparently modifying the associations of BC exposure with most ST-segment depression events and HRV variables. These findings suggest that psychosocial stress may increase the participants' cardiac susceptibility to BC exposure, which could be helpful for the identification of susceptible individuals in the context of traffic-related air pollution., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Co-published by Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, and American Chemical Society.)

Several literatures have examined the risk of chronic respiratory diseases in association with short-term ambient PM 2.5 exposure in China. However, little evidence has examined the chronic impacts of PM 2.5 exposure on morbidity of chronic respiratory diseases in cohorts from high pollution countries. Our study aims to investigate the associations. Based on a retrospective cohort among adults in northern China, a Cox regression model with time-varying PM 2.5 exposure and a concentration-response (C-R) curve model were performed to access the relationships between incidence of chronic respiratory diseases and long-term PM 2.5 exposure during a mean follow-up time of 9.8 years. Individual annual average PM 2.5 estimates were obtained from a satellite-based model with high resolution. The incident date of a chronic respiratory disease was identified according to self-reported physician diagnosis time and/or intake of medication for treatment. Among 38,047 urban subjects analyzed in all-cause chronic respiratory disease cohort, 482 developed new cases. In CB (38,369), asthma (38,783), and COPD (38,921) cohorts, the onsets were 276, 89, and 14, respectively. After multivariable adjustment, hazard ratio and 95% confidence interval for morbidity of all-cause chronic respiratory disease, CB, asthma, and COPD were 1.15 (1.01, 1.31), 1.20 (1.00, 1.42), 0.76 (0.55, 1.04), and 0.66 (0.29, 1.47) with each 10 μg/m 3 increment in PM 2.5 , respectively. Stronger effect estimates were suggested in alcohol drinkers across stratified analyses. Additionally, the shape of C-R curve showed an increasing linear relationship before 75.00 μg/m 3 concentrations of PM 2.5 for new-onset all-cause chronic respiratory disease, and leveled off at higher levels. These findings indicated that long-term exposure to high-level PM 2.5 increased the risks of incident chronic respiratory diseases in China. Further evidence of C-R curves is warranted to clarify the associations of adverse chronic respiratory outcomes involving air pollution., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)