Projections for temperature-related years of life lost from cardiovascular diseases in the elderly in a Chinese city with typical subtropical climate.

OBJECTIVE: Extreme temperature is an important risk factor for cardiovascular diseases, and the elderly are particularly vulnerable to temperature variation. Global warming and the increasingly aging population are two major global challenges for human health; thus, an urgent need exists to project the temperature-related cardiovascular disease burden regarding both of the aforementioned factors. We aimed to the project temperature-related burden of cardiovascular diseases using years of life lost (YLL) in the elderly in a Chinese city with typical subtropical climate. METHODS: A retrospective time-series study was first conducted to estimate cardiovascular disease burden associated with temperature in the elderly from 2008 to 2015 in Ningbo, China. Then, future projections considering demographic change and adaptation under 19 global-scale climate models (GCMs) and 3 different Representative Concentration Pathways (RCPs) scenarios for the 2050s and 2070s were estimated. RESULTS: The exposure-response curve for temperature on YLL from cardiovascular diseases was U-shaped, with increased YLL for both higher- and lower- than optimal temperature. The projected annual increase in heat-related YLL was outweighed by the decrease in cold-related YLL. However, monthly analysis demonstrated that temperature-related YLL will increase significantly in August. Additionally, heat-related YLL is projected to increase 3.1-11.5 times for the 2050s and 2070s relative to baseline, when considering demographic changes, even with 30% adaptation taken into consideration. CONCLUSIONS: Although annual YLL from cardiovascular diseases in the elderly associated with temperature will decrease in the future, heat-related YLL will increase tremendously, which indicates that more adaptation strategies and greenhouse emission control measures should be undertaken to reduce the future heat-related burden of cardiovascular diseases in the elderly.

An efficient numerical method for a time-fractional telegraph equation.

In this paper a time-fractional telegraph equation is considered. First the time-fractional telegraph equation is transformed into an integral-differential equation with a weakly singular kernel. Then an integral-difference discretization scheme on a graded mesh is developed to approximate the integral-differential equation. The possible singularity of the exact solution is taken into account in the convergence analysis. It is proved that the scheme is second-order convergent for both the spatial discretization and the time discretization. Numerical experiments confirm the validity of the theoretical results.

The burden of ozone pollution on years of life lost from chronic obstructive pulmonary disease in a city of Yangtze River Delta, China.

OBJECTIVE: Ambient ozone is one of the most important air pollutants with respect to its impacts on human health and its increasing concentrations globally. However, studies which explored the burden of ozone pollution on chronic obstructive pulmonary disease (COPD) and estimated the relevant economic loss were rare. OBJECTIVE: We explored the relationships between ambient ozone exposure and years of life lost (YLL) from COPD mortality and estimated the relevant economic loss in Ningbo, in the Yangtze River Delta of China, 2011-2015. METHODS: A time-series study was conducted to explore the effects of ozone on YLL from COPD. Seasonal stratified analyses were performed, and the effect modification of demographic factors was estimated. In addition, the related economic loss was calculated using the method of the value per statistical life year (VSLY). RESULTS: Averaged daily mean maximum 8-h average ozone concentration was 40.90 ppb in Ningbo, China, 2011-2015. The effect of short term ambient ozone exposure on COPD YLL was more pronounced in the cool season than in the warm season, with 10 ppb increment of ozone corresponding to 7.09(95%CI: 3.41, 10.78) years increase in the cool season and 0.31 (95%CI: -2.15, 2.77) years change in the warm season. The effect was higher in the elderly than the young. Economic loss due to excess COPD YLL related to ozone exposure accounted for 7.30% of the total economic loss due to COPD YLL in Ningbo during the study period. CONCLUSIONS: Our findings highlight that ozone exposure was related to tremendous disease burden of COPD in Ningbo, China. The effects were more pronounced in the cool season, and the elderly were more susceptible populations.