Conclusion: The pollution of the centralized air ventilation system and microenvironment in public place were grave, threatening the population health.The hygiene control must be go on enhancing.

• 结论：下城区公共场所集中空调系统和公共场所微小环境各环节污染严重已对人群健康构成一定威胁，应加大监督管理力度。