Microbial growth in homes

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Microbial growth in homes

  1. 1. Microbial Growth in Homes Presented by: Bernard L. Fontaine, Jr., CIH, CSP The Windsor Consulting Group, Inc. 14 Sheinfine Avenue, South River, NJ 08882 Email: windsgroup@aol.com TEL: (732) 221-5687
  2. 2. Microbial Growth in Homes ● Over a million species of fungi and bacteria ● Less than 10% microorganisms identified ● Fungi are multi-cellular – bacteria single cell ● Hyphae from fungi grow to form mycelium 2
  3. 3. Microbial Growth in Homes ● Hyphae are vegetative or reproductive ● Vegetative hyphae get nutrients for fungus ● Reproduction may produce aerial hyphae and spores ● Spores released from colony to disperse fungus 3
  4. 4. Microbial Growth in Homes ● Fungal growth depends on ambient temperature, free water, nutrients, and time ● Fungi lack chlorophyll – get energy from organic compounds ● Fungi excrete enzymes into food and digest substrate and absorb water-soluble compounds 4
  5. 5. Microbial Growth in Homes ● Temperature: Range 0oC (cryophile) to 50oC (thermophile) Most growth between 20-30 oC ● Water: Most fungi require free water but Asp. species extract moisture from the air ● Nutrients: Minimal – organics with carbon 5
  6. 6. Microbial Growth in Homes ● Time: Adequate moisture and nutrients at suitable temperature First few days: Produce vegetative hyphae Once hyphae base established over 5-7 days then start spore production for fungus flourish and spread 6
  7. 7. Microbial Growth in Homes ● Fungi and/or bacteria comes from: ◘ ◘ ◘ ◘ ◘ Plants Food Soil Air Contaminated indoor/outdoor materials 7
  8. 8. Microbial Growth in Homes ● Environmental Health Hazards: ◘ Irritation of eyes, nose, throat, and skin ◘ Infections – local or superficial (athlete’s feet); local and deep (lung); or invasive 8
  9. 9. Microbial Growth in Homes ● Environmental Health Hazards: ◘ Infections – brain abscesses, corneal ulcers, endocarditis, necrotizing esophagitis, cysts, liver disease, meningitis, peritonitis, pneumonia, sinusitis, and fatal systemic diseases 9
  10. 10. Microbial Growth in Homes ● Environmental Health Hazards: ◘ ◘ ◘ as Allergies up to 20% of the US population Most serious allergic problem is asthma UK study showed wheezing in children a predictor for fungal growth in the home 10
  11. 11. Microbial Growth in Homes ● Environmental Health Hazards: ◘ Mycotoxins: Metabolites of fungi that can have detrimental effects in humans Often produced when nutrients limited Affect immune system, blood, nervous system, genetics, and some are human carcinogens 11
  12. 12. Microbial Growth in Homes ● Environmental Health Hazards: ◘ Endotoxins: Metabolites of bacteria causing detrimental effects in humans Fever, malaise, elevated white blood cell count, respiratory distress, shock, and possible death 12
  13. 13. Microbial Growth in Homes ● Indoor Indicating Fungal Species Alternaria sps. Aureobasidium sps. Cladosporium sps. Trichoderma sps. Aspergillus sps. Chaetomium sps. Penicillium sps. Fusarium sps. 13
  14. 14. Microbial Growth in Homes ● Common Outdoor Fungal Species Ascospores Botrytis sps. Pithomyces sps. Myxomycetes sps. Basidiospores Epicoccum sps. Ulocladium sps. Periconia sps. 14
  15. 15. Microbial Growth in Homes ● Moisture Control Key to Prevent Microbial Growth ◘ Check moisture content of lumber – Wood is considered dry (<19% moisture) ◘ Cover building materials delivered onsite ◘ Seal framed house with plastic sheeting ◘ Insert driers to reduce moisture content 15
  16. 16. Microbial Growth in Homes ● Moisture Control Key to Prevent Microbial Growth ◘ ◘ ◘ ◘ Store building materials on pallets Cover dirt with plastic sheeting Cover exposed building materials Schedule construction on drier days 16
  17. 17. Microbial Growth in Homes ● Moisture Control Key to Prevent Microbial Growth ◘ ◘ ◘ ◘ ◘ Fix leaks and seepage along foundation Remove water from basement or slab Keep windows and doors closed Avoid condensation in HVAC ducts Install dehumidifiers inside residence 17
  18. 18. Microbial Growth in Homes ● Inspection Key to Prevent Microbial Growth ◘ Suppliers to inspect all building materials ◘ Cover loads delivered to construction site ◘ Framers and site construction managers check lumber for visible fungal growth ◘ Report unsatisfactory building materials 18
  19. 19. Microbial Growth in Homes ● Inspection Key to Prevent Microbial Growth ◘ Check flashing around windows and doors, roof vents, and chimney ◘ Gutters drain water away from house ◘ Adequate ventilation in attic space ◘ Report water leaks immediately 19
  20. 20. Microbial Growth in Homes ● Testing for Microbial Growth ◘ Inspect all building surfaces ◘ Air samples for fungal or bacterial counts ◘ Surface samples for fungal spores mycelial fragments, and mycotoxins 20
  21. 21. Microbial Growth in Homes ● Testing for Microbial Growth ◘ Surface samples for bacteria and endotoxins ◘ Air temperature and relative humidity ◘ Moisture measurements of affected building substrates 21
  22. 22. Microbial Growth in Homes ● Remediation for Microbial Growth ◘ Define work area and Level I-V ◘ Set up containment barriers, air locks, and decontamination chambers ◘ Post warning signs for other trades and emergency response personnel 22
  23. 23. Microbial Growth in Homes ● Remediation for Microbial Growth ◘ Install air filtration devices and air movers ◘ Inspect containment for leaks ◘ Test airflow and static pressure inside the containment barrier 23
  24. 24. Microbial Growth in Homes ● Remediation for Microbial Growth ◘ Remove damaged building materials ◘ HEPA vacuum all affected building substrates ◘ Damp wipe affected surfaces with a biocide 24
  25. 25. Microbial Growth in Homes ● Remediation for Microbial Growth ◘ ◘ ◘ ◘ Dry building substrates with dehumidifier Apply antl-microbial coating Inspect work for quality of workmanship Clean work area, tools, and equipment 25
  26. 26. Microbial Growth in Homes ● Post-Remediation for Microbial Growth ◘ Visually inspect all building surfaces for visible microbial growth, dampness, and containment of work area ◘ If acceptable, conduct air and surface sampling inside/outside work area 26

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