Objective To study environmental safety reference standard values of commonly encountered pathogenic microorganisms, and provide the basis for environmental risk assessment of a high-level biosafety laboratory (BSL).Methods Using human exposure dose calculation methods as the basic principle in combination with microbial hazard evaluation methods , an infectious dose calculation model of human exposure to pathogenic microorganisms by breathing was proposed . Based on research on characteristics of commonly encountered pathogenic microorganisms at home and abroad , the environ-mental safety threshold reference standard and environmental risk protection zone for such microorganisms were obtained . Results An the environmental risk assessment standard calculation method for commonly encountered highly pathogenic microorganisms was proposed , and the minimum infectious dose and environmental safety threshold of seven commonly encountered pathogenic microorganisms were obtained , including SARS coronavirus , highly pathogenic avian influenza virus, Mycobacterium tuberculosis, Bacillus anthracis, Yersinia pestis,Francisella tularensis, and epidemic hemorrhagic fever virus.Conclusion The results can be used as a reference standard of infectious aerosols in a high-level BSL for environ-mental risk assessment , laboratory risk control and emergency management .

Based on the theory of toxin in The Inner Canon of Yellow Emperor （《黄帝内经》）， this paper explores the concept and connotation of toxin from several aspects， including medicinal toxicity， pathogenic toxicity， pathoge-nesis and treatment of toxin pathogen. It explores the mechanism and significance of using toxin substances in curing and inducing diseases， sorts out the etiological and pathological evolution of toxic pathogens， clarifies the derivation and differentiation process from external toxins to internal toxins， and elucidates the interactions between toxin and other pathogenic factors such as phlegm， stasis， dampness， and fire. It further distinguishes the logical hierarchy of toxin caused by metabolic disorders such as sugar， fat， and drowning， clarifies that the essence of the etiology of "hidden toxin"， and determines the corresponding treatment principles and methods for toxic pathogens. It establishes a theoretical framework of traditional Chinese medicine toxic pathogen theory， providing theoretical basis for the clinical treatment of many diseases.