Hi All,

I am currently doing some preliminary research on a environmental
justice type project involving the EPA's TRI data.

(http://www.epa.gov/triexplorer/chemical.htm)

Roughly, we are looking to track (on a national scale from 1990-2000)
certain chemicals and discern their relationship between the
chemicals' locale and the racial composition of the neighboring
locales.

The problem is that with a simple query, we are returned too many
chemicals.

(the real problem is that, I'm an economist, not a chemist!)

My question is:  Which toxics are best suited to track?  Which are
most dangerous?  Should we track classes rather than individual chemicals? 
Only carcinogens?  Only PBTs?  

Maybe, a better question is, which chemicals SHOULDN'T we track?

BTW  I also have another, separate question that hasn't been answered
yet here:

(http://answers.google.com/answers/main?cmd=threadview&id=41012)

Thanks,
vlad

EPA has identified 33 chemicals that are priorities as air toxics --
most are listed on TRI.  You might want to consider these as a
workable subset of toxics for your project.  The chemical list can be
found at:

http://www.epa.gov/ttn/atw/nata/34poll.html

National-Scale Air Toxics Assessment Overview: The 33 Pollutants
AIR POLLUTANTS INCLUDED IN THE ASSESSMENT 
1. acetaldehyde          18. formaldehyde 
2. acrolein              19. hexachlorobenzene 
3. acrylonitrile         20. hydrazine  
4. arsenic compounds     21. lead compounds 
5. benzene               22. manganese compounds 
6. beryllium compounds   23. mercury compounds 
7. 1, 3-butadiene        24. methylene chloride  
8. cadmium compounds     25. nickel compounds 
9. carbon tetrachloride  26. perchloroethylene  
10. chloroform           27. polychlorinated biphenyls (PCBs) 
11. chromium compounds   28. polycyclic organic matter (POM)* 
12. coke oven emissions  29. propylene dichloride 
13. 1, 3-dichloropropene 30. quinoline 
14. diesel particulate matter  31. 1, 1, 2, 2-tetrachloroethane 
15. ethylene dibromide    32. trichloroethylene  
16. ethylene dichloride   33. vinyl chloride 
17. ethylene oxide 
18. formaldehyde

Vlad,

Since I don't know the nature of your research, and having had some
experience in the environmental field, I can only advise you on the
following.

There are so many chemicals in the world that could cause harm to
humans, that the EPA has a method of classifying them.  There are
toxics that cause immediate health consequences and death; and there
are toxins that cause long term health consequences such as cancer and
birth defects.  The carcinogenics are classified with likely or
probable carcinogenicity.  For legal cases and environmental justice
matters, I hear that the focus is always on likely carcinogenics (or
carcinogenics), which have the highest probability of causing cancer
in rats.

My recommendation is to focus on these if you have no other guidance. 
However, for environmental justice, what you should be looking at is
the density of industrial facilities that have the potential to emit
all sorts of compounds, including those that are highly toxic (causing
immediate death), as well, correlated to the socioeconomic composition
of the surrounding communities.

The EPA has numerous guidances on Environmental Justice.

Claudietta