there exists a wide variety of strains of fungi and bacteria that can cause allergic and sometimes fatal reactions to humans who are exposed to these strains . many of these contaminant strains exist and grow in buildings , structures and transportation sources used by people in everyday routine situations . a device simulating one or more of the noxious contaminants is used to train dogs to detect these contaminants in varying situations . a non - intrusive method for training one or more dogs to detect contaminants in a building or other structure , using the device , is also provided . by using dogs trained by the method , trainers can then instruct these contaminant - detecting dogs to precisely and efficiently locate areas of active contamination for future remediation without damage to the site under investigation .