排气通风笼具微环境的动态检测

Dynamic Assessment on Microenvironment of a New Type Exhaust Ventilation Closed-System Cage

目的动态检测屏障环境中用于小鼠的新型排气通风笼具(EVC)的微环境指标。方法测定两种饲养小鼠的EVC笼盒内通风风速和笼盒体积,计算笼盒换气次数。使用刨花垫料时换笼周期设置为7 d,使用玉米芯垫料时换笼周期设置为14 d,分别在每种换笼周期内每日连续检测笼盒内的噪声、压差、温度、相对湿度和氨浓度指标。结果两种EVC笼盒内噪声分别为54.2±3.4 db和55.6±4.1 db,笼盒与屏障环境压差分别为-23.1±9.2 Pa和-27.5±11.6 Pa。从换笼周期第1日起,饲养小鼠的EVC笼盒内的温度差、相对湿度和氨浓度都呈现逐步升高的趋势;使用刨花垫料的两种EVC笼盒其第6日的氨浓度分别达到1.28±0.08 mg/m^3和1.33±0.15 mg/m^3,笼盒内温度分别为23.5±0.27℃和22.8±0.15℃,湿度分别为67.8%±2.2%和70.2%±1.1%;而使用玉米芯垫料的两种EVC笼盒内第12日达到氨浓度分别为1.95±0.46 mg/m^3和2.17±0.33 mg/m^3,笼盒内温度分别为23.8±0.4℃和24.1±0.2℃,湿度分别为70.3%±1.8%和69.6%±1.8%。结论使用EVC笼盒饲养小鼠时,刨花垫料采取每6日换笼及玉米芯垫料采取每12日换笼的方案,可以使笼盒内的微环境指标:噪声、压差、温度、湿度和氨浓度,均符合国标GB14925-2010要求。提示EVC与玉米芯垫料相结合,有助于维持笼盒内微环境稳定,可用于实验动物的生产和相关研究中。

Objective To dynamically assess the micro-environmental changes of the new type exhaust ventilated closed-system cage （EVC）for mice. Methods Based on the measurement of ventilation velocity and volume in EVC cages with mice, the air exchange rate were calculated. The parameters of noise, temperature, differential air pressure, relative humidity, micro-environmental ammonia concentration and macro-environmental ammonia concentration were detected continuously for a 7-day- cycle with wooden shaving bedding and for a 14-day-cycle with corncob bedding. Results The noise in two type EVC were 54.2 ± 3.4 db and 55.6 ± 4.1 db. The differential pressure between EVC and room were -23.1 ± 9.2 Pa and -27.5 ± 11.6 Pa respectively. Since the first day of caging change- cycle, the micro-environmental temperature, humidity and ammonia concentrations has raised gradually in cages. On the sixth day, ammonia concentration in two type of cages reached 1.28 ± 0.08 mg/m3 and 1.33 ±0.15 mg/m3 respectively with wood shaving beddings, the temperature were 23.5± 0.27 ℃ and 22.8 ±0.15 ℃ respectively, the humidity were 67.8% ± 2.2% and 70.2% ± 1.1% respectively. On the twelfth day, ammonia concentration in cages reached 1.95± 0.46 mg/m3 and 2.17 ± 0.33 mg/m3 with corncob beddings, the temperature were 23.8 ±0.4℃ and 24.1±0.2 ℃, and the humidity were 70.3% ± 1.8% and 69.6% ± 1.8% respectively. Conclusions Based on the conditions of current experiment, during 6-day and 12-day caging change-cycle respectively, the micro-environmental parameters, such as： noise, differential air pressure, temperature, humidity and ammonia concentrations met the GB 14925-2010 requirements. EVC system with corncob bedding are highly recommended to maintain a stable micro-environment, that could be used in animal research and animal production.