Case StudyIndoor Environmental Quality

Indoor Air Quality Evaluation of Microbiological Contamination at a Retail Site

By October 30, 2008 No Comments

The Phylmar Group, Inc.

An indoor air quality evaluation was performed for a major real property developer and manager to investigate a series of complaints lodged by several tenant employees at one of the firm’s large southern California retail facilities. The complaints included eye, throat and respiratory irritation; headaches and dizziness; and allergic reactions and bronchitis. The employees stated that their symptoms began shortly after a water pipe broke flooding part of the tenant space. While efforts to dry various porous and non-porous surfaces appeared successful, residual moisture had been trapped by insulation located between the outside and interior wall of the building. This space between the two walls was also contiguous with a return air plenum supplying the office space with conditioned air. During the next several months microbiological growth occurred on the insulation, and was suspected to have become airborne via the return air plenum. The employees and tenant threatened litigation.

Tenant management and employees were interviewed to understand the spatial and temporal nature of the symptoms. The outside wall was opened, and bulk samples of visible fungal growth were collected for speciation. The fungus was identified as toxin-producing Stachybotrys, and abatement proceeded under the consultant’s direction. Once the abatement was completed, air sampling was performed to demonstrate the successful elimination of the microbiological material in the tenant space. The consultant resolved employee symptoms by eliminating the microbiological contaminant, and successfully avoided litigation through effective risk communication with opposing counsel, tenant, and employees.