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Biogenics Research Institute
Other Respiratory Tract Disorders
Hypersensitivity Pneumonitis
Idiopathic Intersitial Lung Disease

Environmental Survey

An environmental survey is one of the initial steps taken after obtaining an environmental history to aid in the determination of a probable causative environment. The environmental histories should reveal clues concerning a possible contamination that is useful in directing the patient, a family member, or a plumbing or air conditioning contractor in making the visual observations to obtain specimens.

Smell Test

The first step, by a third party that does not live in the home, is to determine if there is a "moldy" odor to the home. If an odor is detected, attempts must be made to localize the smell to specific rooms.


Dog urine on carpet


Visual Inspection

A visual inspection is then done around areas of potential excessive moisture including beneath sinks, around commodes, shower stalls, and tubs, and behind washing machines, clothes dryers, refrigerators, and dishwashers. Additional inspection includes checking for evidence of broken or unsealed concrete foundations, leaks from inside potted plants, animals urinating or marking territory on carpets, outside water from floods, and roof leaks into wall spaces. An existent basement, wine cellar, or a wall that abuts dirt (split-level slabs) become the prime suspect area for moisture migrating through poorly sealed concrete.


Forced-air heating and cooling systems may be investigated by obtaining cotton-tipped swabs of the evaporator coil, plenum, and registers for microscopic evaluation and culture to identify type of mold. (Swabs are useful only for identification but not for quantification). Most forced-air systems have a plenum manufactured on site consisting of fiberboard. This becomes the most likely area of contamination in the system. Plugs can be cut from the plenum and proximal ducts to determine if a contamination is present and the extent into the duct system.

Humidity Measurement

The relative humidity can be easily checked with a simple hygrometer. A continuously elevated inside humidity can lead to diffuse mold growth in micro-environments that may be difficult to detect.

Gravity Air Culture

Finally, a gravity air culture under controlled conditions can confirm excessive levels of viable, aerosolized microbes (mold and/or bacteria) within the air of the home. These levels become very important in helping determine the site of a contamination and whether remediation has been effective.

Air Conditioning Vent


An environmental survey can be highly effective in identifying the source of a contamination obviating the need for an environmental investigation by a professional.

Our area of the world is semi-arid South Texas. Life-styles, climate, building techniques and materials, and home management will differ to a degree between countries and regions of countries.