Acute upper and lower respiratory infections are main causes of mortality and morbidity in children. Air pollution has been recognized as an important contributor to development and exacerbation of respiratory infections. However, few studies are available in China. In this study, we investigated the short-term effect of air pollution on hospital visits for acute upper and lower respiratory infections among children under 15 years in Ningbo, China. Poisson generalized models were used to estimate the associations between air pollution and hospital visits for acute upper and lower respiratory infections adjusted for temporal, seasonal, and meteorological effects. We found that four pollutants (PM2.5, PM10, NO2, and SO2) were significantly associated with hospital visits for acute upper and lower respiratory infections. The effect estimates for acute upper respiratory infections tended to be higher (PM2.5 ER = 3.46, 95% CI 2.18, 4.76; PM10 ER = 2.81, 95% CI 1.93, 3.69; NO2 ER = 11.27, 95% CI 8.70, 13.89; SO2 ER = 15.17, 95% CI 11.29, 19.19). Significant associations for gaseous pollutants (NO2 and SO2) were observed after adjustment for particular matter. Stronger associations were observed among older children and in the cold period. Our study suggested that short-term exposure to outdoor air pollution was associated with hospital visits for acute upper and lower respiratory infections in Ningbo. 相似文献
In this paper, a crosslinked carboxymethyl starch (CCMS) was prepared with corn starch as the raw material, epichlorohydrin as the crosslinking agent, and chloroacetic acid as the etherifying agent through a series of crosslinking, alkalization, and etherification reactions, respectively. Nano-TiO2 was loaded onto the surface of the CCMS by the sol-gel method to obtain a TiO2/CCMS composite. The TiO2/CCMS composite was characterized by XPS, XRD, SEM, and BET. XPS showed that the surface chemical composition of the TiO2/CCMS composite material contained titanium; XRD diffraction patterns indicated that the crystal form of the TiO2/CCMS composite was a combination of the CCMS and anatase TiO2. The surface morphology obtained by SEM showed that there were nano-TiO2 particles on the surface of the CCMS. The specific surface area of the TiO2/CCMS composite was larger than that of CCMS. The adsorption-photodegradation performance of the TiO2/CCMS composite was also studied under UV irradiation, and the results showed that significant adsorption-photodegradation synergies occurred.
Environmental Science and Pollution Research - Most prevailing processes are incapable of removing Cr(III)-organic complexes efficiently and facing the problem of in-process formation of highly... 相似文献
Heating at 100 °C for 5–10 min is a common method for treating wastewater containing recombinant DNA in many bio-laboratories in China. In this experiment, plasmid pET-28b was used to investigate decay efficiency of waste recombinant DNA during thermo-treatment. The results showed that the decay half-life of the plasmid was 2.7–4.0 min during the thermo-treatment, and even heating for 30 min the plasmids still retained some transforming activity. Low pH promoted the decay of recombinant DNA, but NaCl, bovine serum albumin and EDTA, which existed in the most wastewater from bio-laboratories, protected DNA from degradation. Thus, the decay half-life of plasmid DNA may be longer than 2.7–4.0 min practically. These results suggest that the effectiveness of heating at 100 °C for treating waste recombinant DNA is low and a gene pollution risk remains when those thermo-treated recombinant DNAs are discharged into the environment. Therefore other simple and effective methods should be developed. 相似文献
In the previous work (Zheng et al., 2007, Zheng et al., 2009), a data assimilation method, based on ensemble Kalman filter, has been applied to a Monte Carlo Dispersion Model (MCDM). The results were encouraging when the method was tested by the twin experiment and a short-range field experiment. In this technical note, the measured data collected in a wind tunnel experiment have been assimilated into the Monte Carlo dispersion model. The uncertain parameters in the dispersion model, including source term, release height, turbulence intensity and wind direction have been considered. The 3D parameters, i.e. the turbulence intensity and wind direction, have been perturbed by 3D random fields. In order to find the factors which may influence the assimilation results, eight tests with different specifications were carried out. Two strategies of constructing the 3D perturbation field of wind direction were proposed, and the result shows that the two level strategy performs better than the one level strategy. It is also found that proper standard deviation and the correlation radius of the perturbation field play an important role for the data assimilation results. 相似文献