Investigation of anxiety levels of 1637 healthcare workers during the epidemic of COVID-19.

OBJECTIVE: This study aimed to investigate the anxiety levels of healthcare workers and to provide guidance on potential accurate social and psychological interventions for healthcare workers during the epidemic of COVID-19 in Zhejiang Province, China. METHODS: Healthcare workers from five hospitals in Zhejiang Province were randomly selected into this study. Zung Self-Assessment Scale for Anxiety (SAS) was used to evaluate the anxiety status of the included 1637 healthcare workers. RESULTS: The total anxiety score of healthcare workers in Zhejiang Province was 30.85 ± 6.89. The univariate analysis showed that the anxiety level of healthcare workers was related to gender, education, occupation, physical condition, job risk coefficient, and with family members on the first-line combating COVID-19 (P <0.05). The multivariate analysis showed that physical condition and job risk coefficient were predictors of anxiety levels of healthcare workers. CONCLUSIONS: During the epidemic of COVID-19, 1637 healthcare workers generally had an increased tendency to have anxiety. Individualized assessment of the anxiety level of healthcare workers should be provided, and different interventions should be given based on the evaluation results.

Impact of MSWI bottom ash codisposed with MSW on landfill stabilization with different operational modes.

The aim of the study was to investigate the impact of municipal solid waste incinerator (MSWI) bottom ash (BA) codisposed with municipal solid waste (MSW) on landfill stabilization according to the leachate quality in terms of organic matter and nitrogen contents. Six simulated landfills, that is, three conventional and three recirculated, were employed with different ratios of MSWI BA to MSW. The results depicted that, after 275-day operation, the ratio of MSWI BA to fresh refuse of 1 : 10 (V : V) in the landfill was still not enough to provide sufficient acid-neutralizing capacity for a high organic matter composition of MSW over 45.5% (w/w), while the ratio of MSWI BA to fresh refuse of 1 : 5 (V : V) could act on it. Among the six experimental landfills, leachate quality only was improved in the landfill operated with the BA addition (the ratio of MSWI BA to fresh refuse of 1 : 5 (V : V)) and leachate recirculation.

Effects of two sludge application on fractionation and phytotoxicity of zinc and copper in soil.

The potential harm of heavy metals is a primary concern in application of sludge to the agricultural land. A pot experiment was conducted to evaluate the effect of two sludges on fractionation of Zn and Cu in soil and their phytotoxicity to pakchoi. The loamy soil was mixed with 0%, 20%, 40%, 60% and 80% (by weight) of digested sewage sludge (SS) and composted sludge (SC). The additions of the both sludges caused a significant raise in all fractions, resulting in that exchangeable (EXCH) and organic matter (OM) became predominance for Zn and organic bound Cu occupied the largest portion. There was more available amount for Zn and Cu in SS treatments than SC treatments. During the pot experiment, the concentration of Zn in EXCH, carbonate (CAR) and OM and Cu in EXCH and OM fractions decreased in all treatments, so their bioavailability reduced. Germination rate and plant biomass decreased when the addition rate was high and the best yield appeared in 20% mixtures at the harvest of pakchoi. The two sludges increased tissue contents of Zn and Cu especially in the SS treatments. Zn in pakchoi was not only in relationship to deltaEXCH and deltaCAR forms but also in deltaOM forms in the sludge-soil mixtures. Tissue content of Cu in pakchoi grown on SC-soils could not be predicted by deltaEXCH. These correlation rates between Zn and Cu accumulation in pakchoi and variation of different fractions increased with time, which might indicate that sludges represented stronger impacts on the plant in long-term land application.

[Multianalysis between chlorophyll-a and environmental factors in Qiandao Lake water].

In this paper, the regression equation between chlorophyll-a (Chla) and some environmental factors was calculate by multiple stepwise regression, based on the monthly monitoring data in the Qiandao Lake from Jan. 1999 to Dec. 2000, and modified Carlson trophic state index for all the sampling sites was also analyzed. The results indicated that the spatial and temporal distribution of chlorophyll a in the sampling sites were varied strongly, the concentration of chlorophyll a in the Xin'an river changed from 50 mg.m-3 to 30 mg.m-3, but that in the lake was under 5 mg.m-3. The modified Carlson trophic state index (TSIM) for the sampling sites in southeast of the lake was under 37 (belonging to olligotrophic), and the others were under 53 (belonging to mesotrophic). In different sampling sites, the significant environmental affecting factors for chlorophyll a were different. However, the relationships between chlorophyll a and water temperature and total phosphorus were positive, and that between chlorophyll a and diaphaneity was negative.

[Agricultural application of sludge dredged from landscape water bodies].

The feasibility and ecological effects of agricultural application of sludge dredged from the Grand Canal (Hangzhou Section) were studied. Applied too much dredged sludge to red soil and paddy soil affected the germination of alpine fescue [Fescuta ovina var. brachyphylla (Schult.) Piper] and colver (Trifolium repens. L) seeds, while there wasn't significantly affects in pot experiment. While the application rate was lower than 270 t.hm-2, the growth of pakchoi (Brassica chinensis L.) increased as application rate increasing. While the application rate was higher than 270 t.hm-2, the growth of pakchoi decreased. The flowers and grasses in garden were more suitable for the dredged sludge application, and there was significant increase of growth while the application rate was lower than 1080 t.hm-2. Contents of copper and zinc exceed hygiene standard, while the application rate was above 1350 t.hm-2. While the application rate was lower than 450 t.hm-2, the pollution of the groundwater had not been observed. The results showed that land application was an economical and feasible way for the disposal of sludge dredged from landscape water bodies, and horticultural application was more safe and economical than agricultural application.