Methods Retrospectivesurvey was conducted in 636 workers.
方法对636名接触工人作了回顾性调查。
2
METHODS The main problems were found out by retrospectivesurvey method, and could be solved through establishing a system of management.
方法采用回顾性总结的方法,找出问题,提出相应对策。
3
Methods Retrospectivesurvey and descriptive research analysis were made with annuals reports of infections diseases during 1984 and 2003 in Baoan District.