Effects Of Air Mixed Pollutants On The Microecology In Respiratory Tract Of Rats

Air pollution emerges with the development of modern industry ,dense population of city and rapid increase of the use of coal and petroleum fuels. At present pollutants are released about 6 hundred million tons per year all over the world, which result in severe threaten to mankind environment. In developing country, air pollution mainly is caused by coal combustion. In western developed country, air pollution mainly is caused by exhaust gas of car. In our country, fume discharged by coal combustion about make up 70% of total air pollutants, which mainly cuse air pollution, industrial production is 20%, traffic is 10%. The long-term effects of lower concentration environmental pollutants on the body could damage and corrupt cells of respiratory react, influence immunity function and destroy defensive system.Respiratory tract is the main portal of entry through which the suspended particulate matter of air and other noxious substances enter the human body, and respiratory system is the target organ of air pollution. The research of microecology shows that there are microbial both inside and outside of animal body including human being. These microbial consist of a biological membrane to defense invasion of bacteria in normal conditions. Normal co-exist bacteria flora can defend the invasion of pathogenic bacteria.Pharynx is the physiological part connecting oral, nasal cavity, lower respiratory tract and esophagus and connecting outside. It is also the physiological part through which many bacteria invade the lower respiratory tract and lungs and cause infections. Normal bacteria flora living on pharynx fluctuates in a physiological range, when the body is in health, which constitutes the first important microbial barrier to microbiological barrier to defend outside effects. When pathogens invade, the membrane of pharynx and nose is the first choice location of colonization, across which pathogens can reach the lower respiratory tract and lungs and progress to cause corresponding pathogenic reactions.Under environmental factors, host and microbiology keep dynamic microeubiosis. In this equilibrium, normal flora constitute one of the major factors that disease and health exchange in host. Microeubiosis in microbiological criteria includes quality, quantity and location. The criteria of location refer to ecological space, I.e. the examination to normal flora determine the location of examination firstly; for the same species of microbiology, autochthony is in situ and allochthony is in ectopia. Autochthony and allochthony is the same biologically but they are different ecologically; autochthony is beneficial, if it transfer to allochthony, which is harmful. Quality standard refers to differentiate and identify various species. Quantity standard refers to detect in quantity total number of bacteria and number of live bacteria of various species in ecological environment, which is the major content of microecology and one of important methods to identify whether it is autochthony or allochthony as well. The converted conditions of normal flora are very complex, which is affected by many factors, and basicallly, they are affected by outer environment and determined by physiological function and pathological function of host. For any kind of bacteria, as long as it reachs the certain number or colonization on the corresponding location, it can break microeubiosis and microdysbiosis happens and cause disease of host.At present, many studies of air pollution on health are limited to health investigation, risk analysis and pollutive source control. But there have been no reports of the effect of air pollution on microecology of respiratory tract and mechanism. An intensive research on the mechanism of air pollution to microecology of respiratory tract was carried out via using animal model. Wistar rats were poisoned by imitating real air pollution. The effects and mechanism of air pollution on health were analyzed from microecology angles. When human body was affected by abnormal factors, microeubiosis may be interfered or destroyed and microbiology changes in quantity quality and locations and function of biological barrier of microbiology may be impaired, at this time, some microbiology may change from physiological to pathological. The research showed that the amount of pathogens such as Staphylococcus intermedius,β- Streptococcus, etc. increased obviously after poison by imitating real air pollution. The amount of normal flora and opportunistic pathogen such as Staphylococcus epidermidis, Staphylococcus hyicus, Nesseria, Proteus,α-Streptococcus decreased obviously after poison by imitating real air pollution. The amount of anaerobic bacteria such as Fusobacterium and opportunistic pathogen of Clostridium increased obviously after poison by imitating real air pollution. Thus, changes of microecology of pharynx can be considered, certain pathogens colonization and decrease of the amount of normal flora can cause infection.From the change of microecology of respiratory tract of animal model of Wistar rats poisoned by imitating real air pollution, the dense of aerobic bacteria of pharynx of rats poisoned by imitating real air pollution fluctuated dramatically (p<0.01). The dense of anaerobic bacteria was obviously higher than prior to poison and presented dramatic difference (p<0.05) and the dense of anaerobic bacteria presented the tendency of time-dependent fluctutant, I.e. it increase d obviously on the first day and decreased obviously on the fifteenth day and it increased obviously on thirtieth day. That indicated microdysbiosis of pharynx was caused after poison of the first day, and bacteria multiplified largely ,but temporary compensation state occur with prolongation of time, after that, equilibrium was breaked down again and resulted in decompensation. That demonstrates that the dense of bacteria of respiratory tract was changed by air pollution and present microdysbiosis. The research studied the changes of microbial population of respiratory from microecology angles and demonstrate the effect on human body and gave a fully evidence for microecology imbalance and respiratory diseases caused by air pollution. These findings provide a sound theozitical basis for ecological prevention and treatment of respiratory tract and exploitation of ecological preparation.