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An Introduction to Mold

An Introduction to Mold. Prepared with the assistance of the USEPA Indoor Environment National Laboratory and Leif Albertson – UAF Fairbanks. Topics. Overview Indicators Health Effects Investigation Remediation Prevention . I. Overview. Key information Types of molds

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An Introduction to Mold

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  1. An Introduction to Mold Prepared with the assistance of the USEPA Indoor Environment National Laboratory and Leif Albertson – UAF Fairbanks

  2. Topics • Overview • Indicators • Health Effects • Investigation • Remediation • Prevention

  3. I. Overview • Key information • Types of molds • Factors contributing to mold growth

  4. Types of Molds Under a microscope • What are molds? • Part of class of “biological” contaminants that includes bacteria, mildew, viruses, animal dander, dust mites, cockroaches, pollens • Part of “Fungi” kingdom that includes molds, yeasts, mushrooms, rusts • Microscopic organisms that form and colonize through airborne spores

  5. Types of Molds (continued) • Over 100,000 different types; about 10 different species common indoors

  6. Factors Contributing to Mold Growth What do molds need to grow? • Food supply • Warm temperatures, and… • Moisture

  7. Factors Contributing to Mold Growth (cont.) • #1 - Food Sources • Organic sources • Soils, food, plant matter • Human and animal hair and dander • Clothing and fabric fibers • Fibers from floor coverings, insulation, building materials • Building materials • Certain materials –particleboard, LP siding, OSB, expanded styrene, cellulose insulation – all better food sources, absorb and hold moisture

  8. Factors Contributing to Mold Growth (cont.) • #2 - Heat sources • Higher indoor temperatures common from unregulated sources – woodstoves and fireplaces • Inadequate ventilation and overcrowded spaces also contribute • Warm air holds more moisture than cold air = higher temperatures in homes = higher humidity levels

  9. Factors Contributing to Mold Growth (cont.) • #3 – Moisture and vapor sources • Moisture sources • Building envelope leaks • Plumbing leaks • (dishwashers, toilets, plumbing fittings, washing machines, water heaters)

  10. Optimum Relative Humidity

  11. Factors Contributing to Mold Growth (cont.) • Water vapor sources • Moisture often results not from water intrusion but from high relative humidity (RH) in home • Damp soil & basements (vapor flows from high RH to low RH) • Occupant activities (breathing, showering, cooking, dishwashing, laundry, plants…average of 2.91 gal/day (Tsongas, 1999) • Condensation happens in cold spots

  12. Source Health and Energy Testing Services, NE http//www.healthandenergy.com/

  13. II. Indicators • Key information • Recognizing indicators of potential mold infestation • Finding sources of information

  14. Recognizing Indicators • Known or suspected water damage • Occupants may know of leak, flood, water intrusion (helpful to know extent, length, actions taken) • Visible signs of water damage – may be clearly evident • Less visible signs require further visual investigation behind wallpaper, baseboards, cabinets; in crawlspaces, on building exteriors, rust, drywall staining

  15. Recognizing Indicators • Reports from maintenance or custodial staff • Know building history, repairs, structural issues • May be first to report occupant complaints • Musty/mildew odors • Indicator of bacterial growth; may not be visible

  16. Recognizing Indicators • Visible mold • Appearance of spores not only indicator • Range of colors (all “black” molds are not toxic, though proceed with caution) • Growth patterns vary, depending on point of moisture contact

  17. II. Indicators 5. Reported health problems • Clear links allergy/respiratory • Possible flu-like symptoms, repeated viral infections, fatigue, frequent ER visits/hospitalizations

  18. III. Health Impacts • Key information • Types of impacts • Who is at most at risk

  19. Health Impacts “Exposure to damp and moldy environments may cause a variety of health effects, or none at all.” www.CDC.gov/mold • Health impacts vary widely and are individual in impact. • Health issues can result from a variety of environmental issues and it can be difficult to identify specific causes.

  20. Types of Effects • Irritant • Exposure can irritate eyes, skin, nose, throat, and lungs, in allergic and non-allergic individuals • Effect is dose-related, usually transient • Allergen • Common symptoms runny nose, itchy eyes, sneezing, sore throat, nasal congestion, eczema, dermatitis • In high concentrations, molds can trigger symptoms in individuals with no known allergies • Long-term exposure can sensitize an individual, inducing allergies and airway-reactivity

  21. Types of Effects (cont.) • Infectious • Direct infection occurs when pathogens attack immune-compromised individuals • E.g., Aspergillus fumigatus known to cause aspergillosis (ABPA) • Toxic (rare) • Toxic molds produce chemicals called mycotoxins • Certain species (e.g, stachybotrus, fusarium, trichoderma) are known carcinogens • Mycotoxins readily absorbed by intestinal lining, airways, skin • Presence of toxic molds usually associated with long-standing water problem

  22. Who is most at risk? • Individuals with lower-airway diseases • Asthma, chronic bronchitis • Molds directly tied to presence, persistence and increased severity of asthma episodes • Young children (birth to age 2 – critical window) • Allergic sensitization/genetic predisposition • Incidence of RSV • Elders • Individuals with compromised immune systems • Individuals with allergies (upper respiratory)

  23. IV. Investigation • Key information • Objectives of investigation • Types of sampling

  24. Objectives of Investigation • Identify all moldy areas • If occupant reports mold, search throughly (under sinks, in cabinets, behind toilets, behind furniture; sub-floor, drywall, crawl space) • Identify all possible causes • Plumbing or appliance leaks? High humidity? Condensation? • Reduce exposure to occupants in home/building • Develop plan for clean-up/remediation • Ensure that maintenance staff and occupant are informed

  25. Types of Samples • When is sampling necessary? • If legal action is being considered or there are serious health impacts that require specialized medical treatment. • Is species identification necessary? • Identifying species of mold or airborne sampling is not recommended for investigation or remediation • Microscope can help confirm presence of mold • No standards for exposure levels of mold / spores

  26. V. Remediation

  27. First Things First Mold clean-up is not effective until the source of moisture is addressed. Mold is a moisture problem

  28. Mold Remediation • Less than 10 sq ft • PPE (minimum) • N-95 respirator, gloves, goggles • Containment: None required • Between 10 sq ft and 100 sq ft • PPE limited or full (use “professional judgment”) • Respirator (N-95, half-face, full-face) • Gloves, goggles, foot covering • Disposable overalls/disposable full body clothing

  29. Mold Remediation Continued • Containment: Limited • Polyethylene sheeting ceiling to floor around affected area, slit entry, covering flap • Maintain area under negative pressure with HEPA filtered fan unit. • Block supply and return air vents within containment area • More than 100 sq ft • Call in professionals / get training

  30. Safety Guidelines & Resources • To prevent exposure and assure containment, critical that maintenance staff employ safety guidelines…

  31. Safety Guidelines - Occupants • Home-owner or tenant information • Prevention and clean-up for small areas (cleaning non-porous surfaces and wood with detergent; repair moisture source; dry material, etc) • Many people use bleach, which kills mold, but is not a good cleaning agent • Bleach is a strong respiratory irritant • Surfactant (soap) is better

  32. VI. Prevention • Key information • Principles for existing homes & buildings • Principles for new construction & renovations

  33. Principles for Existing Homes • Work with occupants, maintenance and custodial staff to focus on prevention practices • Keep it clean • Keep it dry • Keep it well ventilated • Keep it well maintained

  34. Principles for Existing Homes (cont.) 1. Clean • Control dust sources • Regular cleaning • Carpet removal where possible • Use of walk-off mats • Hepa-filter vacuuming • Reduced clutter • Shoes-off policy

  35. Principles for Existing Homes (cont.) 2. Dry & Ventilated • Ventilation • Install & use exhaust fans vented to outdoors in kitchens and bathrooms, clothes dryers–eliminate moisture that builds up from everyday activities • Attic and crawl spaces – Keep humidity below 50% to prevent condensation on building materials • Water damage • Thoroughly clean & dry water-damaged carpets and building materials (within 24 hours, if possible) or • Consider removal or replacement

  36. New Construction & Renovation • New homes and buildings • Water damage costs up to 3X more to fix than to properly install, maintain moisture controls • Employ mold-resistant construction products and practices • Ensure contractors trained in installation of key moisture-abatement materials (specifically, vapor barriers) • Install proper ventilation to ensure regulated temperatures and vapor/moisture reduction

  37. Additional Resources on Mold Indoor Air Quality Association www.iaqa.org American Industrial Hygiene Association (AIHA)www.aiha.org U.S. Environmental Protection AgencyNew Residential Mold Guide  http//epa.gov/mold/ U.S. Environmental Protection AgencyMold Resourceshttp//www.epa.gov/iaq/pubs/moldresources.html

  38. Additional Resources on Mold Mold Remediation in Schools and Commercial Buildings, March 2001http//www.epa.gov/mold/mold_remediation.html U.S. Centers for Disease Control and PreventionMolds in the Environment http//www.cdc.gov/mold/faqs.htm Questions and Answers on Stachybotrys chartarum and other moldshttp//www.cdc.gov/nceh/airpollution/mold/stachy.htm Managing Water Infiltration Into Buildingshttp//www.dehs.umn.edu/iaq/flood.html

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