Ritchie Shoemaker is a recently retired mold doctor who has run his own panel of tests on something like 6,000 patients. He frequently looks at family members who are living in the same bad house, where one person is sick and the other is not. His belief is that whether people get sick with exposures is highly determined by HLA DR genotype. http://www.survivingmold.com/diagnosis/lab-tests Hopefully at some point, this work will be published in the literature. It would be really helpful if it were. I'm not sure how the study of mycotoxins in urine from spouses who have shared environments would be especially helpful, even if it is true that exposures are a cause of CFS. For instance, if the exposure that made you sick was in your workplace, then I would imagine that your husband had expelled all of those toxins a long time ago and that his urine would now come up as negative. If your current home is problematic, then I would imagine that your husband's urine would come up as positive, since his body would be working to expel the mycotoxins as soon as they came into his body. Neither of those findings would shed any light on what we presume to be a possible cause of CFS -- a body that is inefficient at expelling mycotoxins and thus that has large quantities of them sequestered, releasing them only gradually over time. I would guess that the main difference between someone with CFS and someone healthy, living/working in a bad building, is that the quantity of toxins that came out in the CFS sufferer's urine would be relatively small in comparison to the amount that came out in the healthy person's urine. But this test does not measure quantity present, only +/-. So I'm still not sure what the point would be. I'm not familiar with any tests that will measure presence of mycotoxins in the body other than this urine one. Shoemaker's tests look at the status of various cytokines and hormones in the system, with the belief that they are altered in specific ways amongst people suffering from mold illness.