PRIME Engineering & Environmental Building ServicesMolds and Problems

While some molds are more infamous than others, all molds are potentially harmful to human health. We need to think of mold in terms of the “dose response”; a little may not be a problem, a lot can cause illness but some people are more sensitive to certain types of mold than other people, just like allergic reactions.

BLACK MOLD is a myth. Molds come in a literal rainbow of colors. Yes, some mold, such as Stachybotrys tend to be black when its growth accumulates. However, other molds, many innocuous, may also be black. The color of mold depends on the species of mold being examined and the organic matter on which the mold is feeding. A single species of mold can develop several colors, the same way Flamingos are pink because they only each pink colored shrimp.  Only with microscopic examination, can mold be properly analyzed and identified.

For good reference, see photos of the mold Ceratocystis/Ophistoma.

The following molds tend to be found outdoors in Florida.  Also shown are relative densities (spores/cubic meter of air). Variability with outdoor samples over short time spans and changing weather conditions can occur, which may result in a lack of confidence in the data when comparing outdoor to indoor samples.

Typical Florida Outdoor Fungal Comparisons (spores/m3) *

Fungal Type

Low

Medium

High

Alternaria sp.

7

13

193

Basidiospores

27

373

10579

Bipolaris/Dreschlera group

7

13

187

Botrytis sp.

7

13

293

Chaetomium sp.

7

13

201

Cladosporium sp.

27

427

7817

Curvularia sp.

7

40

1034

Epicoccum sp.

7

20

314

Nigrospora sp.

7

17

213

Oidium sp.

7

13

158

Penicillium/Aspergillus types

27

213

3675

Rusts

7

13

361

Smuts

7

40

680

Stachybotrys sp.

7

13

400

Torula sp.

7

13

141

* 2012 Courtesy TEST America, EMLAB P&K microbiology laboratory, statistically derived data

When necessary, PRIME Engineering & Environmental Building Services utilizes the above national accredited laboratory database of typical outdoor fungal concentrations to compare indoor to outdoor samples as an aid in interpreting conditions along with the other important aspects of an assessment (including but not limited to visual observations and moisture mapping).

Mycotoxins

Molds can produce toxic substances called mycotoxins. Some mycotoxins cling to the surface of mold spores; others may be found within spores. More than 200 mycotoxins have been identified from common molds, and many more remain to be identified. Some of the molds that are known to produce mycotoxins are commonly found in moisture-damaged buildings. Exposure pathways for mycotoxins can include inhalation, ingestion, or skin contact. Although some mycotoxins are well known to affect humans and have been shown to be responsible for human health effects, for many mycotoxins, little information is available.

Aflatoxin B1 is perhaps the most well known and studied mycotoxin. It can be produced by the molds Aspergillus flavus and Aspergillus parasiticus and is one of the most potent carcinogens known. Ingestion of aflatoxin B1 can cause liver cancer. There is also some evidence that inhalation of aflatoxin B1 can cause lung cancer. Aflatoxin B1 has been found on contaminated grains, peanuts, and other human and animal foodstuffs. However, Aspergillus flavus and Aspergillus parasiticus are not commonly found on building materials or in indoor environments.  Much of the information on the human health effects of inhalation exposure to mycotoxins comes from studies done in the workplace and some case studies or case reports.

Many symptoms and human health effects attributed to inhalation of mycotoxins have been reported including: mucous membrane irritation, skin rash, nausea, immune system suppression, acute or chronic liver damage, acute or chronic central nervous system damage, endocrine effects, and cancer. More studies are needed to get a clear picture of the health effects related to most mycotoxins. However, it is clearly prudent to avoid exposure to molds and mycotoxins.  Some molds can produce several toxins, and some molds produce mycotoxins only under certain environmental conditions. The presence of mold in a building does not necessarily mean that mycotoxins are present or that they are present in large quantities.

Note: Information on ingestion exposure, for both humans and animals, is more abundant — wide range of health effects has been reported following ingestion of moldy foods including liver damage, nervous system damage, and immunological effects.

Microbial Volatile Organic Compounds (mVOCs)

Some compounds produced by molds are volatile and are released directly into the air. These are known as microbial volatile organic compounds (mVOCs). Because these compounds often have strong and/or unpleasant odors, they can be the source of odors associated with molds. Exposure to mVOCs from molds has been linked to symptoms such as headaches, nasal irritation, dizziness, fatigue, and nausea. Research on MVOCs is still in the early phase.

Glucans or Fungal Cell Wall Components (also known as β-(1->)-D-Glucans)

Glucans are small pieces of the cell walls of molds which may cause inflammatory lung and airway reactions. These glucans can affect the immune system when inhaled. Exposure to very high levels of glucans or dust mixtures including glucans may cause a flu-like illness known as Organic Dust Toxic Syndrome (ODTS). This illness has been primarily noted in agricultural and manufacturing settings.

Spores

Mold spores are microscopic and are naturally present in both indoor and outdoor air. Molds reproduce by means of spores. Some molds have spores that are easily disturbed and waft into the air and settle repeatedly with each disturbance. Other molds have sticky spores that will cling to surfaces and are dislodged by brushing against them or by other direct contact. Spores may remain able to grow for years after they are produced. In addition, whether or not the spores are alive, the allergens in and on them may remain allergenic for years.  Therefore, remediation firms and/or techniques that only focus on “killing” mold are sub-standard and typically ineffectual for the complaintants/occupants.

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475 19th Place
Vero Beach, FL 32960
Phone: (772) 410–3752

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