Damp Spaces and Mold

And now, for the rest of the story…

Also laden with: pollen, fungi, algae, and protozoa

Fungus as part of nature…

• Mold, type of fungus, is part of nature

• Needs moisture, food source

• Types and amounts of mold differ with time of year, place, and other factors

• Some in all homes• Visible growth in home

indicates a moisture problem

Key elements for mold growth

• Moisture• Active leak• Water intrusion• High humidity

• Nutrition• Wood• Paper (cellulose)• Wallpaper• Gypsum• Carpet• Insulation• Dirt

• Oxygen• Needs to be present

• Temperature • 59°F-86°F• 95°F-122°F

• Light• Acidity and pH

Testing for Mold

• Why?• Better spend the money for mitigation

• There is no one “bad” type of mold

• Interpretation can be controversial

• Storage/transport of samples

• Tape method (visible mold)• Culture methods

• Anderson samplers• Cassela samplers• Rodac plates

• Impingers• Filters• Microscopy (scanning and epifluorescence)

• Polymerase Chain Reaction (PCR) or ERMI

Contaminants that can cause allergy-like symptoms

• Moisture related• Mold• Cockroach• Bacteria• Dust mites

• Non-moisture related• Chemicals• Pets• Smoking

Studies and reports

• Building dampness and mold was associated with 30-50% increases in a variety of respiratory and asthma-related outcomes (1)

• Wide range of respiratory health effects including asthma development, asthma exacerbation, current asthma, respiratory infections, upper respiratory tract symptoms, cough, wheeze, and dyspnoea. (2)

1) Meta analysis of epidemiological studies in IOM by Fisk, Lei-Gomez, Mendel, 20072) WHO IAQ Guidelines on dampness and mold, 2009

From CDC Website Taken from IOM

Mendell and colleagues…• Most recent meta-analysis published in EHP, data through late

2009 and published in June 2011• Evidence of association between indoor dampness-related

factors • asthma development, exacerbation, current and ever asthma, • dyspnea, wheeze, cough, respiratory infections, bronchitis, allergic rhinitis, eczema, and upper

respiratory tract symptoms;

• Data on indoor dampness and mold suggests causation of asthma exacerbation in children;

• Current data does not support measurement of indoor allergens, bacteria or mold– Instead, mitigate and prevent indoor dampness;

• Hygiene hypothesis-- • moderate exposures to certain microbial agents, especially at early ages, may prevent

allergies and allergic asthma;

WHO 2009• Exposure to microbial contaminants is associated with:

• Respiratory symptoms• Allergies• Asthma• Immunological reactions

• Individual species cannot be identified*• Emissions include spores, cells, fragments of cells and VOCs• People exposed to multiple agents simultaneously• Problems with accurately measuring exposure• Large number of symptoms from exposures

*Exception are common allergies to pollens, dust mites, pets, and pests

WHO Executive Summary

• Health risks addressed by considering “dampness as the risk indicator”

• Remediation of dampness reduces adverse health outcomes, including rare conditions*

• Public enemy #1: Spores, cells, fragments, and volatile organic compounds

• Exposure to microbial contaminants is clinically associated with respiratory symptoms, allergies, asthma and immunological reactions.

*hypersensitivity pneumonitis, allergic alveolitis, chronic rhinosinusitis and allergic fungal sinusitis

Health Problems Associated With Mold Particles

• Allergies and Asthma• 5-10% of people• 40% of asthmatics• Hypersensitivity

reactions in working populations

• Irritant reactions• Infections (rare)• Toxic reactions?

Who is at most risk?• Individuals with chronic respiratory disease;

(asthma; emphysema,COPD; bronchitis)

• Immune suppressed individuals may be at higher risk for infection;(transplant patients taking immuno-suppressive drugs; HIV

positive; other people with serious diseases that may compromise the immune system)

• Candida and Aspergillus species continue to be the most common cause of invasive fungal disease in immune compromised individuals;

Mold Induced Illness—occupational exposures

• Hypersensitivity pneumonitis• Allergic lung syndrome (progressive)• High exposures to mold and organic dust• Relatively rare

(1% of exposed individuals develop disease)• Farmer’s lung (moldy hay/grain)• Bagassosis (moldy sugar cane/ molasses)• Maple bark stripper’s disease• Tobacco worker’s lung• Mushroom workers

Farmer’s Lung

Accounts for more than 30% of adults disabled by respiratory illness and mold is a key factor in development of this disease;

• dusty fields or buildings • handling moldy hay • working in silos • feeding or working with feedstuffs • working in com silage • uncapping silos • cleaning grain bins • exposed to bird droppings or feather, hair, or fur dust • exposed to fish meal

Health: Mold Infections

• Histoplasma or Cryptococus • Rare in healthy people• Source: Usually Bird or

Bat droppings

• Opportunistic infections: weakened immune system• Bone Marrow Transplant• Uncontrolled diabetes• Medication for cancer or

transplant• HIV+

“Toxic” moldMolds are toxigenic, not “toxic” themselves

They produce “mycotoxins.” Mycotoxins can be:• cytotoxic• carcinogenic• estrogenic• neurotoxic*From ingestion of mycotoxins (NAS 2000)

•Inadequate or insufficient evidence that inhalation of environmental mold by healthy adults causes: fatigue, neuropsychiatric symptoms, cancer, reproductive effects, rheumatologic and other immune diseases, respiratory disease, asthma, etc.

•Mold does not need to be actively growing and “alive” to be an allergen to people;

Mycotoxins• Low molecular weight natural products that are secondary

metabolites produced by filamentous fungi;

• Readily airborne and respirable (<1um- 7um);

• Not clear whether or not levels found in damp buildings are high enough to cause adverse health effects;

Examples:

Penicillium produces penicillin;

Aspergillus flavus produces aflatoxin;

Stachybotrys chartarum produces trichothecenes and satratoxin

The Toxic Hype: Stachybotrys chartarum

• Called “black” or “toxic” mold in media;• Acute idiopathic pulmonary hemorrhage– not proven;

• High cellulose/low nitrogen content; (fiberboard, gypsum board, paper, dust, lint)

• Needs lots of constant moisture for growth;• Toxins in air

• Spores only sometimes have toxins• Stachy doesn’t release many spores

Stachybotrys chartarum (atra)continued…

• Remember: Jury is still out regarding health risks for inhalation exposures to this mold in the environment;

• Not uncommon;• Other molds:

• appear black• produce toxins

• Clean the same way as other molds• Treat as any mold… need a healthy respect for mold and health effects they may cause;

Endotoxins• Found in components of the outer membrane in Gram-

negative bacteria

• Composed of proteins, lipids and lipopolysaccharides

• “Toxin” on the cell wall is liberated as a result of cell lysis

• Found in environments with dust particles or aqueous aerosols

• Heavy exposure can cause respiratory symptoms• Moderate to low exposure may be protective

(1 3)- β-D-glucans• From most fungi, some bacteria and most higher plants;

• Non-allergenic, water-insoluble structural cell-wall components;

• Linked to chitin and mannan (proteins, lipids and carbohydrates in the cell wall);

• Have immunomodulating properties that may affect respiratory health;

Dampness and Health WHO 2009

Continued

DryDryWater can enter a building through…

Plumbing leaks &drainage problems

Home Moisture U of MN Extension

Activity

• Shower …………………....................• Clothes dry (vented outside)………………….

• Clothes dry (hanging or inside vent) …………

• Cooking (dinner for 4) …………………………..

• Boil (10 minutes, 6-inch pan)…………………….

• Storage of firewood indoors…………• House plants (5- 7 plants)……………………

• Respiration (family of 4)……………………….

• Pilot light……………………………….• New construction…………………….• Seasonal high outdoor humidity……

Pints of water put into the air

0.52/ 5 min.

0

4.68- 6.18/ load

1.22 (1.58 gas)

0.48 cover /0.57 uncovered

400-800 (6 months)

0.86-0.96/ day

0.44/ hour

0.37 or less/day

10+ /day

64-249 /day

Perspective on Mold• Mold may cause health problems

• Allergy-type symptoms are the most common• People can react very differently to mold• The color of the mold is irrelevant• For the most part, mold is not regulated by the government

• By keeping your home dry, you can prevent mold growth

• Visible mold growth should NOT be tolerated in occupied indoor areas

• Cleaning recommendations vary and one must consider:• Amount of visible growth • Materials affected• Sensitivity of individuals in the household

Identify water problems

• Evidence of past water intrusion• Discolored ceiling tiles from roof leaks or ice dams

• Loose floor tiles• Plumbing fixtures with leaks• Musty odors• Discolored basement carpet or carpet pad• Moldy vents (HVAC system)• Bathroom tiles and walls• Windows

Neil Carlson- U of MN

Neil Carlson- U of MN

Neil Carlson- U of MN

Neil Carlson- U of MN

Use of biocides for mold mitigation

• The underlying moisture or water problem must be fixed to prevent mold from returning;

• Thorough drying required before rebuilding;

• Bleach may be used to kill fungus/mold and should be a part of disinfecting after flooding situations (sewage contamination)• ½ cup bleach per gallon of water• never mix bleach with ammonia

• Remember: people can have allergic type symptoms to both dead and living mold;

Biocides used to inhibit mold growth

• Can add health risk to individuals• In particular, individuals who may be very sensitive

(immune compromised, chronically ill, very young, very old);

• “Effectiveness” of chemicals is questionable against the broad category of fungus/mold

• Primary method to prevent mold growth must include moisture/water control!

Manage water and humidity…• Repair leaks, clean moldy surfaces;• Reduce indoor humidity to <50%• Use exhaust fans (bathroom and kitchen)• Maintain good drainage around foundation;• If a water problem occurs, clean and dry items and

materials within 24-48 hours.

Global trends contribute to dampness and mold • Energy conservation not properly implemented- tightened

envelope, ventilation deficiency, improper insulation

• Urbanization- building type and density, degradation of housing, housing availability and social inequity

• Climate change- extreme weather conditions and shifting of climate zones

• Quality and globalization of building materials and components-construction concepts and techniques

(WHO 2009)

From the New Yorker Magazine