The occurrence of ochratoxin A in dust collected from a problem household.

Accumulated dust samples were collected from the heating ducts in a household where signs resembling ochratoxin poisoning in animals occurred. Several Penicillium spp. and Aspergillus ochraceous had been identified previously from air samples taken from this house. A composite sample from six collected samples was examined by HPLC, and it was determined that 58 ppb of ochratoxin A was present in this sample. A second set of six samples was collected and determinations were made by HPLC of the ochratoxin content in each sample. All samples, including one sample of dirt from a crawl space, yielded at least a trace of ochratoxin A; however, one sample of dust collected from the heating ducts yielded over 1500 ppb of ochratoxin A, and another sample of dust from a different heating duct yielded 306 ppb of ochratoxin A. Ochratoxin A was confirmed in all samples by LC-MS, and ochratoxin was evident in the samples by TLC analysis. This is believed to be the first report of finding ochratoxin in house dust.