There are acouple of companies out there doing trauma scene training now, its quite new.
I have done a few of these jobs over the years and as long as you have some traoning in advanced hygiene,pathogens and chemicals and use common sense with the correct ppe, then they are good earners. The only costly expence is the disposal of everything after the job, but if you contact your local eho or hospital then they can point you in the right direction.