Mold is everywhere in indoor and outdoor air, and there are countless species and genus (sub-species) inhabiting every continent on the planet. Mold reproduces using spores which are microscopic and can be carried by the air very far from their original source. Live mold spores or dead spores can inflict the same health concerns to humans and animals. Mold spores produce mycotoxins (allergenic or toxigenic, depending on species) which enter the blood via respiration and cause several well documented health related symptoms. Toxigenic species cause more severe health risks than allergenic types.
Mold can form within 48 hours after water contacts organic material (substrate), such as: concrete, brick, mortar, wood, plaster, gypsum, carpet, glue, and insulation, etc. Mold cannot form without water present in a substrate, therefore moisture concentration knowledge within the air or within substrates is critical in evaluating the causes of mold contamination in occupied indoor spaces.
Usual causes of mold contamination in indoor spaces are: leaking or broken water pipes; rain or groundwater entering from the roof, windows or basement; inadequate ventilation in bathrooms or kitchens; or moist building materials installed. Mold forms more commonly when a substrate is subjected to water and the moisture concentration is above approximately 15-20% depending on the substrate. Mold also can form “out of thin air” and onto substrates if the relative humidity in the air is over 60%.
The four stages of a typical mold testing and remediation project are as follows:
1- Interview the client and or tenants to visually observe the mold contamination. Determine the source of water infiltration using a moisture meter, visual observations and common sense.
2- Depending on the source of water infiltration discovered in step 1. Take engineering, construction, plumbing, landscaping, HVAC modifications, waterproofing and general repair measures to stop the water/moisture from entering the indoor space.
3- Retain the services of a professional mold remediation contractor to remove all mold contaminated substrates under properly vented negative air pressure. It is also critical to remove mold contaminated substrates two feet past the visual mold contamination line to ensure the only non-mold contaminated substrates are left in the occupied space. If removal is not an option on some substrates then a one part bleach to ten parts water solution should be scrubbed onto affected areas. An antimicrobial protectant can be applied also if needed.
4- Test the air within the mold contaminated occupied space for mold species and genus types and concentrations prior to and after the mold removal project. Then compare both sets of results to at least one outdoor background sample. Having indoor air samples comparable to the outdoor air sample ensures the investigation and remediation have been completed to the best extent possible in the given area. Confirmation sampling also provides a clean bill of health for the client that the investigation and remediation were performed properly.
If mold remediation is required and building is built prior to 1982, then the client will likely need to have an asbestos survey prior to beginning the remediation phase.
It is in the client’s best interest to have a separate company perform the mold investigation and remediation activities. This ensures checks and balances amongst consultant and remediation contractor and adherence to the scope of work and industry standards, thereby the client gets non-biased information from more than one source and real workable remedies that lead to permanent solutions.