There is fairly large gap between NEPA regulations and guidance which requires health analysis when significant health effects are expected from an environmental change AND practice where this is rarely done.

I'm attaching an article that I colleague and I wrote on the topic in 2008.  It discusses the law as well as practical obstacles.  The National Academies publication on HIA says much the same thing as well.

Guidance on NEPA re-enforces this.  Both Federal interagency guidance for SIA identifies health in the scope of social effects.  EPA guidance on EJ analysis in NEPA is fairly explicit in the need to analyze potentially disproportionate environmental and health impact when the impacts would occur on minority populations. 

Recent practice examples are few.  Health was included in the NEPA/CEQA analysis for the I-710 expansion in LA, but the quality of the analysis was not great.

In Washington, the state agency has recently agreed to include a comprehensive health impact assessment as part of their analysis of the growth of coal rail transport infrastructure.   

The Bay Area MTC included health performance measures in their recent RTP analysis -  this is also a useful prototype demonstrates the feasibility of health forecasting analysis.   Our 2009 health analysis of a proposed congestion pricing scheme in San Francisco also demonstrated the feasibility of health analysis.  

Happy to share addition references

Hope this helps

Rajiv