1.On-site epidemiological investigation of a carbon monoxide poisoning incident
Bin CHAO ; Shiqi QIU ; Xihe NI ; Yaling ZHOU ; Litong LU ; Xiaoou TANG ; Guorong CHEN
Chinese Journal of Industrial Hygiene and Occupational Diseases 2021;39(9):700-702
Nighteen people at a restaurant experienced dizziness headaches and other discomforts in six days. According to the description method, the time and location distribution were found to be concentrated. A second Investigation was conducted at the same time as the onset of the case, the test found that the carbon monoxide concentration of second floor up to 539 mg/m 3. The on-site testing found that when 2 steam generator in snack room on the first floor turned on, the carbon monoxide concentration on the top of elevator on the second floor was 1225.0 mg/m 3. After the accident, the restaurant replaced a steam generator, the carbon monoxide concentration on the top of the new and old steam generator were 350 mg/m 3 and >1 000 mg/m 3, respectively. After the steam generators were fitted with exhaust smoke pipe and exhasust hood, the carbon monoxide concentrations of on the top of the vegetable transfer elevator and the room on the second floor were both 0.4 mg/m 3, and there were no cases of recurrence. It was determined that this was a carbon monoxide poisoning incident caused by a high concentration of carbon monoxide emitted by the steam generators, which spread to the second floor of the private room through the vegetable transfer elevator.
2.On-site epidemiological investigation of a carbon monoxide poisoning incident
Bin CHAO ; Shiqi QIU ; Xihe NI ; Yaling ZHOU ; Litong LU ; Xiaoou TANG ; Guorong CHEN
Chinese Journal of Industrial Hygiene and Occupational Diseases 2021;39(9):700-702
Nighteen people at a restaurant experienced dizziness headaches and other discomforts in six days. According to the description method, the time and location distribution were found to be concentrated. A second Investigation was conducted at the same time as the onset of the case, the test found that the carbon monoxide concentration of second floor up to 539 mg/m 3. The on-site testing found that when 2 steam generator in snack room on the first floor turned on, the carbon monoxide concentration on the top of elevator on the second floor was 1225.0 mg/m 3. After the accident, the restaurant replaced a steam generator, the carbon monoxide concentration on the top of the new and old steam generator were 350 mg/m 3 and >1 000 mg/m 3, respectively. After the steam generators were fitted with exhaust smoke pipe and exhasust hood, the carbon monoxide concentrations of on the top of the vegetable transfer elevator and the room on the second floor were both 0.4 mg/m 3, and there were no cases of recurrence. It was determined that this was a carbon monoxide poisoning incident caused by a high concentration of carbon monoxide emitted by the steam generators, which spread to the second floor of the private room through the vegetable transfer elevator.
4.Effects of rumen microorganisms on the decomposition of recycled straw residue.
Kailun SONG ; Zicheng ZHOU ; Jinhai LENG ; Songwen FANG ; Chunhuo ZHOU ; Guorong NI ; Lichun KANG ; Xin YIN
Journal of Zhejiang University. Science. B 2023;24(4):336-344
Recently, returning straw to the fields has been proved as a direct and effective method to tackle soil nutrient loss and agricultural pollution. Meanwhile, the slow decomposition of straw may harm the growth of the next crop. This study aimed to determine the effects of rumen microorganisms (RMs) on straw decomposition, bacterial microbial community structure, soil properties, and soil enzyme activity. The results showed that RMs significantly enhanced the degradation rate of straw in the soil, reaching 39.52%, which was 41.37% higher than that of the control on the 30th day after straw return. After 30 d, straw degradation showed a significant slower trend in both the control and the experimental groups. According to the soil physicochemical parameters, the application of rumen fluid expedited soil matter transformation and nutrient buildup, and increased the urease, sucrase, and cellulase activity by 10%‒20%. The qualitative analysis of straw showed that the hydroxyl functional group structure of cellulose in straw was greatly damaged after the application of rumen fluid. The analysis of soil microbial community structure revealed that the addition of rumen fluid led to the proliferation of Actinobacteria with strong cellulose degradation ability, which was the main reason for the accelerated straw decomposition. Our study highlights that returning rice straw to the fields with rumen fluid inoculation can be used as an effective measure to enhance the biological value of recycled rice straw, proposing a viable solution to the problem of sluggish straw decomposition.
Animals
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Rumen/metabolism*
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Agriculture/methods*
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Soil/chemistry*
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Microbiota
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Bacteria/metabolism*
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Oryza/metabolism*
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Soil Microbiology
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Cellulose