Carbon uptake by cement in China:Estimation and contribution to carbon neutrality goals

Cement is a widely used construction material globally.Its manufacturing contributes to anthropogenic CO_(2)emissions significantly.However,its alkaline compounds can absorb CO_(2)from the surrounding environment and engage in a carbonation reaction,thereby functioning as a carbon sink.As a major cement producer and consumer,China has an important responsibility to rigorously investigate and accurately account for cement carbon uptake.This study presents a comprehensive analytical model of cement carbon uptake from China,revealing a substantial increase in carbon uptake from 1930 to 2021,peaking at 426.77 Mt CO_(2)(95% Confidence Interval:317.67-874.33 Mt CO_(2))in 2021.The uptake accounts for 8.10% to 45.40% of China’s annual land sink and 2.51% to 4.54% of the global land sink.The cumulative carbon uptake by cement is approximately 7.06 Gt CO_(2)(95%CI:5.22–9.44 Gt CO_(2))during this period,offsetting 50.7% of the total emissions(13.91 Gt CO_(2),95%CI:12.44–17.00 Gt CO_(2))from the cement industry.Notably,cement mortar contributed to most absorption(65.64%).From a life cycle perspective,the service stage of cement materials is the period where the largest CO_(2)sink is formed,accounting for 90.03% of the total.Therefore,the potential for carbon sequestration in cement materials and their waste is enormous.Additionally,the model improves the accuracy of cement carbon accounting,supporting both China and global carbon neutrality assessments.Thus,it is crucial for China to achieve its carbon neutrality goals sooner by prioritizing the environmental benefits of cement materials and wastes,and accelerating the development and commercialization of CO_(2)sequestration technologies for cement and its by-products.

Accuracy and capability of tri-ponderal mass index in assessing cardio-metabolic risk factors in Chinese children and adolescents aged 3 to 17 years,compared with body mass index

Background:Tri-ponderal mass index(TMI)has been reported to be a more accurate estimate of body fat than body mass index(BMI).This study aims to compare the effectiveness of TMI and BMI in identifying hypertension,dyslipidemia,impaired fasting glucose(IFG),abdominal obesity,and clustered cardio-metabolic risk factors(CMRFs)in 3-to 17-year-old children.Methods:A total of 1587 children aged 3 to 17 years were included.Logistic regression was used to evaluate correlations between BMI and TMI.Area under the curves(AUCs)were used to compare discriminative capability among indicators.BMI was converted to BMI-z scores,and accuracy was compared by false-positive rate,false-negative rate,and total misclassification rate.Results:Among children aged 3 to 17 years,the mean TMI was 13.57±2.50 kg/m 3 for boys and 13.3±2.33 kg/m 3 for girls.Odds ratios(ORs)of TMI for hypertension,dyslipidemia,abdominal obesity,and clustered CMRFs ranged from 1.13 to 3.15,higher than BMI,whose ORs ranged from 1.08 to 2.98.AUCs showed similar ability of TMI(AUC:0.83)and BMI(AUC:0.85)in identifying clustered CMRFs.For abdominal obesity and hypertension,the AUC of TMI was 0.92 and 0.64,respectively,which was significantly better than that of BMI,0.85 and 0.61.AUCs of TMI for dyslipidemia and IFG were 0.58 and 0.49.When 85th and 95th of TMI were set as thresholds,total misclassification rates of TMI for clustered CMRFs ranged from 6.5%to 16.4%,which was not significantly different from that of BMI-z scores standardized according to World Health Organization criteria.Conclusions:TMI was found to have equal or even better effectiveness in comparison with BMI in identifying hypertension,abdominal obesity,and clustered CMRFs TMI was more stable than BMI in 3-to 17-year-old children,while it failed to identify dyslipidemia and IFG.It is worth considering the use of TMI for screening CMRFs in children and adolescents.