Previous studies demonstrated that short-term exposure to gaseous pollutants (nitrogen dioxide (NO2), sulfur dioxide (SO2), and ozone (O3)) had a greater adverse effect on cardiovascular disease. However, little evidence exists regarding the synergy between gaseous pollutants and cardiovascular disease (CVD). Therefore, we aimed to estimate the effect of individual gaseous pollutants on hospital admissions for CVD and to explore the possible synergistic effects between gaseous pollutants. Daily hospitalization counts for CVD were collected from January 1, 2014, to December 31, 2015. We also collected daily time series on gaseous pollutants from the Environment of the People’s Republic of China, including NO2, SO2, and O3. We used distributed lag nonlinear models (DLNMs) to assess the association of individual gaseous pollutants on CVD hospitalization, after controlling for seasonality, day of the week, public holidays, and weather variables. Then, we explored the variability across age and sex groups. In addition, we analyzed the synergistic effects between gaseous pollutants on CVD. Extremely low NO2 and SO2 increase the risk of CVD in all subgroup at lag 7 days. The greatest effect of high concentration of SO2 was observed in male and the elderly (≥ 65 years) at lag 3 days. Greater effects of high concentration of O3 were more pronounced in the young (< 65 years) and female at lag 3 days, while the effect of low concentration of O3 was greater in male and the young (< 65 years) at lag 0 day. We found a synergistic effect between NO2 and SO2 for CVD, as well as between SO2 and O3. The synergistic effects of NO2 and SO2 on CVD were stronger in the elderly (≥ 65) and female. The female was sensitive to synergistic effects of SO2-O3 and NO2-O3. Interestingly, we found that there was a risk of CVD in the susceptible population even for gaseous pollutant concentrations below the National Environmental Quality Standard. The synergy between NO2 and SO2 was significantly associated with cardiovascular disease hospitalization in the elderly (≥ 65). This study provides evidence for the synergistic effect of gaseous pollutants on hospital admissions for cardiovascular disease.
Adsorption and degradation of levonorgestrel (LNG) by two hydrophytes, Cyperus alternfolius (CA) and Eichhornia crassipes (EC), were investigated under light-shielding conditions in the water column. Variations of LNG concentrations in water, plant root epidermis, root, stem and leaf of the plants were analyzed. The results indicated that the removal efficiency of LNG by hydrophytes over the period of 50 days was significantly greater than the blank control (p 〈 0.05), with the removal rates of 79.80%± 3.10% and 78.86% ± 2.55% for CA and EC, respectively. Compared with bio-adsorption, bio-conversion of LNG was found to be the dominant elimination pathway, evidenced by relatively high conversion rates (77.31% ±2.68% for CA and 77.82% ± 2.95% for EC), while the adsorption rates were lower (1.77% ± 0.90% for CA and 1.05% ± 0.40% for EC). The bio-adsorption and conversion of LNG showed no significant differences between the two hydrophytes. Additionally, the mineralization on root epidermis played an important role in the reduction of LNG in water. 相似文献