We are selling our condo and just got back a mold report. First, I can’t find the outside reading anywhere.  However, the numbers seem sizeable.  (For instance, Aspergillus/Penicillium-like - 6,967;  Stachybotrys 5,767 under the kitchen sink; Aspergillus/Penicillium-like – 33; Stachybotrys – 36,933 in the ceiling where there was a former leak – using 600x).  I live in Los Angeles and the samples were taken during a week of very heavy rain.  Would that impact the results?  There are signs of water damage but no visible mold.  Where can I find out more information about what are considered harmful levels (I know, I know there are no standards but we need to decide what level of compensation/repair is justified).  Thank you very much. Christine , California

 

            In most cases one needs outdoor mold values to compare with in interpreting sampling results.  In your case, the results can be interpreted without an outdoor reference value.

            It must be noted that those samples do not indicate what you are actually being exposed to; that is, there are no samples taken from actual living spaces.

            Those Stachybotrys numbers in the ceiling and under the sink are high to very high, indicating that construction materials in those areas were repeatedly wetted or remained very wet for a week or more.  In most cases Stachybotrys growth would have occurred on the paper face of gypsumboard.

            Aspergillus and Penicillium growth tends to occur in such cases as the wetted materials start drying out.  The relatively low Penicillium/Aspergillus counts suggest that not much drying had occurred yet (this is consistent with the elevated Stachybotrys count).  The relatively low Aspergillus/Penicillium count may also be due to the fact that because of the size of such spores, they are often not seen clearly enough to be counted by the laboratory analyst.  At 600X magnification they are not counted (resulting in an undercount).  Stachybotrys spores on the other hand are quite large, and they are rarely undercounted even at 400 and 600X magnifications.

            If there are signs of water damage, there is also a good probability that a mold infestation exists as well.  Your test results confirm that.  In ceilings the growth is likely to be on the top or back side.  In walls it is often on the inner side.

            Would the rains affect the results?  Of course they can.  The question is in what direction.  In general when fungal organisms have abundant food and moisture, they tend to grow mostly fungal mass.  As growing conditions become more stressed, they start to produce reproductive spores.  As such, you might expect higher airborne mold spore levels a week or more after the water damage and subsequent mold infestation has occurred.

            Reported mold values indicate you have mold infestation problems that need to be remediated.  Since no tests were conducted in living spaces, one cannot determine whether potentially harmful levels are present. 

January 13, 2005