Mold/Indoor Air Quality

The DOTSON Group provides a comprehensive range of Indoor Environmental Quality Surveys for residential, commercial and institutional buildings. Residential and commercial surveys may be conducted for the prevention or in response to sick building syndrome or for allergy and asthma symptom prevention and management.

Mold Assessment
Kyle Dotson has conducted indoor environmental quality assessments of many commercial buildings, and thousands of water intrusion related mold causation assessments of residential buildings. A subset of the sample results from these mold assessments was published in the paper entitled Prevalence of Stachybotrys in Outdoor Air of Houston Area Residences in the proceedings of the ISIAQ conference Indoor Air 2002. Kyle Dotson is an author of the American Industrial Hygiene Association's Guidelines on the Assessment, Remediation and Post-Remediation Verification of Mold in Buildings. (available at www.aiha.org). The purpose of these surveys may be specific such as for mold growth, to investigate unknown causes of sick building syndrome, and/or for allergy and asthma symptom prevention and management.

Nosocomial Infection Control
Institutional building surveys, such as for hospitals, may be provided by DOTSON Group in support of Hospital Environmental and Risk Control professionals as well as Construction Contractors in compliance with Infection Control Risk Assessment requirements that must be implemented to prevent nosocomial infections.

Allergy and Asthma Indoor Air Quality - Residential and Commercial Buildings
The DOTSON Group provides comprehensive allergy and asthma indoor air quality related services for residential and commercial buildings. A guidance document for building owners regarding Indoor Air Quality in Commercial and Institutional Buildings has been published by the Occupational Safety and Health Administration (OSHA) and can be downloaded at http://www.osha.gov/Publications/3430indoor-air-quality-sm.pdf. DOTSON assessment services conform to all relevant professional guidelines and recommendations, including the recently published professional guidelines contained in the National Institutes of Health (NIH) Expert Panel Report 3 (EPR3): Guidelines for the Diagnosis and Management of Asthma. This document is the current State of the Art for the allergy and asthma prevention and management. The full report (440 pages) is available at www.nhlbi.nih.gov/guidelines/asthma/asthgdln.htm.

Regarding Indoor Environmental Quality, the National Institutes of Health expert report recommends:

• Use of humidifiers and evaporative (swamp) coolers is not generally recommended in homes of patients who have asthma and are sensitive to house-dust mites or mold.
• Employed persons who have asthma should be queried about possible occupational exposures, particularly those who have new-onset disease.
• Indoor fungi are particularly prominent in humid environments and homes that have problems with dampness. Children who live in homes with dampness problems have increased respiratory symptoms, but the relative contribution of fungi, house-dust mites, or irritants is not clear. Because an association between indoor fungi and respiratory and allergic disease is suggested by some studies, measures to control dampness or fungal growth in the home may be beneficial.
• Vacuuming removes mite allergen from carpets but is inefficient at removing live mites.
• Remove carpets from the bedroom.
• A major study demonstrated efficacy of cockroach avoidance as part of an overall plan for allergen
• Remove from the home carpets that are laid on concrete.
• Room air-filtering devices are not recommended for control of mite allergens, because the allergens are associated with large particles which remain airborne for only a few minutes after disturbance. They are, therefore, not susceptible to removal by air filtration.
• Mattress covers are recommended in addition to other measures.
• Chemical agents are available for killing mites and denaturing the antigen; however, the effects are not dramatic and do not appear to be maintained for long periods. Therefore, use of these agents in the homes of persons who have asthma and are sensitive to house-dust mites should not be recommended routinely.
• Reduce indoor humidity to or below 60 percent, ideally between 30 and 50 percent. Reducing relative humidity is a practical way to control house-dust mites and their allergens in homes in temperate climates. House-dust mite levels can be reduced by use of dehumidifiers to maintain levels to or below 60 percent, ideally 30–50 percent, relative humidity.
• Patients sensitive to components of house dust should avoid using conventional vacuum cleaners, and these patients should stay out of rooms where a vacuum cleaner is being or has just been used.
• If patients vacuum, they can use a dust mask, a central cleaner with the collecting bag outside the home, or a cleaner fitted with a HEPA filter or with a double bag.
• The strongest associations between mold-spore exposure and asthma have been with the outdoor fungi, such as Alternaria. Patients can reduce exposure during peak pollen season by staying indoors with windows closed in an air-conditioned environment particularly during the midday and afternoon when pollen and some spore counts are highest.
• Indoor air-cleaning devices cannot substitute for the more effective dust-mite and cockroach control measures described previously, because these heavy particles do not remain airborne. However, air-cleaning devices (i.e., HEPA and electrostatic precipitating filters) have been shown to reduce airborne dog allergen, cat dander, mold spores, and particulate tobacco smoke. Use of an air cleaning device containing a HEPA filter may reduce exposure, especially if added to other avoidance measures. However, most studies of air cleaners have failed to demonstrate an effect on asthma symptoms or pulmonary function. Air cleaners that are designed to work by the generation of ozone and that emit ozone into the air should be avoided by persons who have asthma.
• There is insufficient evidence to recommend cleaning air ducts of heating/ventilation/air conditioning systems.

 

Other consumer information is available at the Asthma and Allergy Foundation of America toll-free hotline at 800–727–8462 or the Allergy and Asthma Network/Mothers of Asthmatics at 800–878–4403.

Organizations in Northern California that are interested in retaining the DOTSON Group for a professional assessment of the Indoor Environmental Quality of an office, institution, or commercial facility (sorry, residential services no longer provided) may contact Kyle Dotson, CIH at 408-234-1409. For a competent professional assessment in other areas of the US, a local Certified Industrial Hygienist experienced in Indoor Environmental Quality may be found at www.aiha.org.

The DOTSON Group no longer provides services to individual homeowners as excellent information resources are now available to individual homeowners in the Healthy Housing Inspection Manual, published by the CDC National Center for Environmental Health here.