通过对国内外有害气体相关标准的调查分析及比较，就目前铁路隧道施工作业环境的卫生标准提出了建议：①职业接触限值种类方面，应与国家标准一致、与国际接轨；②职业接触限值大小方面建议采用国际上比较宽松的标准，建议有害气体一氧化碳职业接触限值区分高原和非高原的情况；③对施工隧道明确分区，不同区段采用不同的卫生标准。

The following suggestions are made on the health standards of working environment in railway tunnels under construction in China, on basis of investigations and analysis on the standards of gases in railway tunnels in China and foreign countries: first, the types of the occupational exposure limits should be identical with those specified in China's national standards and should meet the requirements of the relevant international standards; secondly, loose international values should be adopted for the occupational exposure limits and the occupational exposure limits for carbon monoxide should be different between high altitude areas and nonhigh altitude areas; thirdly, the tunnels should be divided into sections, for which different health standards should be adopted.