Understand Mold

An Icky but Necessary Guide

Science of Mold

Learn about mold basics and characteristics.

Where it Grows

Where should you look for mold? And how does it grow?

Health Effects

Mold exposure can affect our health and make us sick.

Mold Testing Methods

What is the best way to test for mold? A comparison of 5 methods.

Science of Mold

Learn about the types of mold of its common organisms.

Where it Grows

Where should you look for mold? And how does it grow.

Health Effects

Mold exposure can affect our health and make us sick.

Mold Testing Methods

What is the best way to test for mold? A comparison of 5 methods.

Science of Mold

Mold (fungus) is found in all environments where it plays a vital role in our ecosystem, biodegrading waste organic matter (old leaves, un-picked fruit, etc.). Mold is unique in that it is an allergen (can make you sneeze or cough), it produces toxins (chemicals), and it can be a pathogen (that may infect). Mold can be visible or nearly invisible when it first begins growing on a surface and when the spores are airborne. Although musty smells can indicate mold growth, mold can also grow without creating an odor.

Types of Mold

Allergenic molds

Allergenic molds affect people who have allergies, respiratory illness, or asthma. These molds can cause a hypersensitive reaction resulting in an extreme inflammatory response in the respiratory system. About 20%-30% of the population is susceptible to mold and/or other allergens, that lead to reactions like allergic rhinitis. People without allergies are often unaffected by these molds in small amounts.

Pathogenic molds

Pathogenic molds can cause infections or diseases. Most healthy individuals with a healthy immune system regularly fight off pathogens. However, pathogenic molds are dangerous to compromised or weakened immune systems, most commonly affecting infants, the elderly, and people with suppressed immune systems.

Toxic molds

Toxic molds produce mycotoxins, poisonous chemicals dangerous to humans. Unlike allergenic and pathogenic molds, toxic molds intentionally harm other living things rather than merely being a side effect. Some of the most deadly chemicals on the planet are mycotoxins. People are exposed to mycotoxins via inhalation, ingestion, or dermal exposure (skin contact) which can lead to debilitating cognitive symptoms or even organ failure. 

Antigenistic molds

Antigenistic molds act as super antigens in the body of a mold sensitive patient. These super antigens are not easily processed by the body and often result in auto-immune symptoms and diseases.

Common Mold Organisms & Characteristics

Cladosporium

A common indoor and outdoor mold found in many environments. It is commonly isolated from soil, plant debris, and leaf surfaces. It can be found inside, growing on a variety of materials, i.e. textiles, wood, moist windowsills, tile grout, sheetrock, and sub-flooring, wherever relative humidity is elevated.

Nocardia sp

Nocardia is a genus of Gram-positive bacteria with 85 known species. It forms branching filaments, acting as fungi, but is truly a bacteria. Nocardia are found worldwide in soil, rich in organic matter. In addition, Nocardia are oral microflora found in healthy gingiva and periodontal pockets. Some species are non-pathogenic while others can cause nocardiosis. Most Nocardia infections are acquired by inhalation or through traumatic introduction.

Alternaria

A common saprobe or plant pathogen isolated from plant debris, soils, foods, and textiles. Grows well on cellulose surfaces (e.g. wallboard and paint) with low moisture. Can lead to opportunistic infections in immunocompromised and wound patients and can act as a super antigen in susceptible individuals.

Penicillium

Penicillium is a filamentous fungi with over 350 species found in soil, decaying vegetation, and the air. Penicillium is commonly considered a contaminant but may cause infections, particularly in immunocompromised hosts. This fungi produces penicillin, a molecule used as an antibiotic that kills or stops the growth of certain bacteria in the body. Penicillium also produces mycotoxins such as ochratoxin A.

Aspergillus

A common type of indoor and outdoor mold with over 300 species. Certain species are opportunistic pathogens in both humans and animals. They have been implicated in invasive infections, colonizations, cases of toxicoses, and non-specific allergic responses. A number of species are active mycotoxin producers.

Candida

Candida is a yeast with approximately 154 species. Candida is the most common cause of opportunistic mycoses worldwide. It is also a frequent colonizer of human skin and mucous membranes and is part of the normal flora of skin, mouth, vagina, and stool. As well as being a pathogen and a colonizer, it is found in the environment, particularly on leaves, flowers, water, and soil. Infections with Candida albicans, glabrata, tropicalis, and krusei have caused disease and death in patients.

Where it Grows

Roof and Attic
  • Flashing, gutter, or canale leaks
  • Bad seals around penetrations, like chimneys
Rooms
  • Closets with high humidity
  • Window and roof leaks
  • Flooding
Laundry Room
  • Washing machine mold
  • High humidity
  • Plumbing leaks
Kitchen
  • Plumbing leaks around sink and drain pipes
  • High humidity in cabinets
  • Refrigerator ice maker leaks
  • Decaying food and trash
Air Conditioning Systems
  • HVAC systems causing condensation
  • Mold inside HVAC systems (on coils and in ducting)
  • Inadequate ventilation
Bathroom
  • Plumbing leaks around sink, bathtub, shower, and toilet
  • Elevated humidity
  • Caulking that is lifted or broken
Windows
  • Moisture from bad seals
Basement and Crawlspace
  • Moisture transfer through cement floors and walls
  • Water settling against foundation
  • Dirt crawlspaces without proper ventilation
  • Standing water in sump pumps

How it Grows

Mold can be found anywhere water is allowed to remain for 48 hours or more. Humidity above 60% can also lead to mold growth. Mold needs a food source, water source, and warm temperatures to grow.

Food Source

Such as wood supports, drywall backing, wallpaper, carpet, cabinetry, books, cardboard boxes.

Water Source

Such as a busted pipe, roof leak, poorly graded building site, flooding, high humidity, or other moisture causing event or conditions.

Warm Temperatures

40º – 120º F

Know the Mold Symptoms

Where it grows

Roof and Attic
  • Flashings, gutter, or canale leaks
  • Bad seals around penetrations, like chimneys
Air Conditioning Systems
  • HVAC systems causing condensation
  • Mold inside HVAC systems (on coils and in ducting)
  • Inadequate ventilation
Rooms
  • Closets with high humidity
  • Window and roof leaks
  • Flooding
Bathroom
  • Plumbing leaks around sink, bathtub, shower, and toilet
  • Elevated humidity
  • Caulking that is lifted or broken
Laundry Room
  • Washing machine mold
  • High humidity
  • Plumbing leaks
Windows
  • Moisture from bad seals
Kitchen
  • Plumbing leaks around sink and drain pipes
  • High humidity in cabinets
  • Refrigerator ice maker leaks
  • Decaying food and trash
Basement and Crawlspace
  • Moisture transfer through cement floors and walls
  • Water settling against foundation
  • Dirt crawlspaces without proper ventilation
  • Standing water in sump pumps

How it grows

Mold can be found anywhere water is allowed to remain for 48 hours or more. Humidity above 60% can also lead to mold growth. Mold needs a food source, water source, and warm temperatures to grow.

Food Source

Such as wood supports, drywall backing, wallpaper, carpet, cabinetry, books, cardboard boxes.

Water Source

Such as a busted pipe, roof leak, poorly graded building site, flooding, high humidity, or other moisture causing event or conditions.

Warm Temperatures

40º – 120º F

How Mold Exposure Affects Our Health

Mold Exposure Health Symptoms

  • Multiple Chemical Sensitivity (MCS) 
  • Mast Cell Activation Syndrome (MCAS)
  • Sleep Disorders

  • Chronic Fatigue Syndrome

  • Psoriasis

  • Muscle Weakness

  • Restless Legs Syndrome

  • Hearing Loss

  • Meniere’s Disease

  • Vertigo & Dizziness

  • Asthma

  • Aspergillosis

  • Chronic Rhinosinusitis

  • Allergic Fungal Sinusitis

  • Fibromyalgia
  • ALS (Lou Gehrig’s Disease)

  • Chronic Inflammatory Response Syndrome (CIRS)

  • Gastric Reflux Disease (GERD)

  • Irritable Bowel Syndrome

  • Cancer

  • Arthritis
  • Systemic Fungal Symptoms
  • Yeast Infection

  • Candidiasis

  • Brain Fog

  • Headaches

  • Migraines

  • Polycystic Ovary Syndrome

Environmentally Acquired Illnesses

The term environmentally acquired illness (EAI) typically refers to environmental causes of inflammatory illness in exposed individuals. Some of the more common sources of EAI include mold exposure, biotoxin exposure, tick bites, exposure to volatile organic compounds (VOCs), exposure to pesticides and herbicides, and high levels of particulate matter in air (dust). 

These environmental exposures can produce illnesses such as mold toxicity, Lyme disease, multiple chemical sensitivity (MCS), chronic inflammatory response syndrome (CIRS), chronic fatigue syndrome (CFS), fibromyalgia, mast cell activation syndrome (MCAS), etc. Additionally, non-environmentally acquired illnesses can worsen when exposed to environmental toxins. Although many different environmental triggers can lead to EAI, in our experience as a mycology laboratory, indoor mold exposure is the most common.

Mold Exposure & Chemical Sensitivity

Mold in our environment can pose a significant health risk, especially to those who are genetically susceptible. Chemically sensitive people have adverse reactions to a spectrum of synthetic and natural toxins and toxicants found in their environment, including those produced by mold. Elevated concentrations of mold spores have been known to produce autoimmune reactions and many other health symptoms including chemical sensitivities. It is for these reasons that exposure to common disinfectants, biocides, and fungicides, which can set off chemical sensitivities in mold exposed individuals, should be avoided. It is highly recommended that solutions that are as natural as possible be used to help mitigate indoor mold exposure.