1) danger factors
2) causes of hidden peril
3) hidden danger factor
Based on test,administration department and practical investigation,using the theory of safety system engineering,it was conducted to expound the present situation and characteristics of fishing vessels′traffic accidents at sea in Zhejiang Province,and to analyze the hidden danger factors existed in the accidents, and finally,to bring up countermeasure to control the hidden danger of accidents.
4) risk factor
Objective The purposes of the investigation were to determine the prevalence of birth defects and to examine the risk factors that maybe make this population more susceptible to the development of birth defects so and to supply some core risk factors for the intervention project on birth defects in Gansu province, West China.