Stachybotrys, Fusarium and Trichothecene Mycotoxins

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Mates,

This is an article I wrote for my BLOG

<http://californiasmalltownlawyer.blogspot.com/2006/01/stachybotrys-fusa\

rium-and.html> -- thought you might be interested.

Regards,

Cyn

Coulter Mulvihill

Mold Litigation Consulting Attorney

PO Box 1007

Monrovia CA 91017-1007

(626) 358-7471

Stachybotrys, Fusarium and Trichothecene Mycotoxins Stachybotrys,

Fusarium and Trichothecene Mycotoxins

Trichothecenes are mycotoxins produced by certain molds, including some

molds frequently detected indoors. This article discusses (very

generally) what trichothecenes are; some available studies on dosage

rates; and briefly, why " toxic mold " indoors may – or may not –

be producing toxins.

What Trichothecenes Are

Trichothecenes are toxic fungal metabolites of certain molds in the

genus Fusarium, Myrotecium (also called Myrothecium in some

publications) Trichoderma, Acremonium (formerly Cephalosporium),

Verticimonosporium, Cylindrocarpon, Microdochium, and Stachybotrys.

Other genus produce mycotoxins, but those are not grouped as

trichothecenes1.

In general, the indoor mold tests that I see test for Fusarium and

Stachybotrys. Sometimes, those tests include Trichoderma, but

Trichoderma spp. are usually isolated in plants and soil2. So, this

article only discusses Fusarium spp. and Stachybotrys spp.

The species of Fusarium known to produce trichothecenes are Fusarium

solani, Fusarium chlamydosporum, Fusarium lateritium, Fusarium oxysporum

and Fusarium poae. Stachybotrys chartarum (obsolete atra, alternans) can

produce trichothecenes, including satratoxins F, G, and H, roridin E,

and verrucarin J3. I do not know if the recently identified species

Stachybotrys yunnanesis, Stachybotrys chlorohalonata, Stachybotrys

elegans, Stachybotrys microspora, Stachybotrys nephrospora produce

either trichothecenes or other mycotoxins4.

Trichothecenes are the only (declassified) mycotoxin adapted for use in

biological warfare5. Known as T-2, trichothecenes are suspected –

but not proven – as the " yellow rain " in Laos to a cause of Gulf War

Syndrome6.

The Merck Veterinary Manual states, " The trichothecene mycotoxins are

highly toxic at the subcellular, cellular, and organic system level . .

.. Given in sublethal toxic doses via any route, the trichothecenes are

highly immunosuppressive in mammals . . .7 "

Trichothecene Dosages

The common wisdom that the dosage of trichothecene mycotoxins needed to

cause injury is unknown is outdated by research gathered and correlated

after the first Gulf War. There have been several studies on the

`efficiency' of various methods of using trichothecenes as a

biowarfare agent. One 1997 study shows ingestion as the most lethal

route; a 2005 study shows inhalation as the more effective route8. In

the 2005 study, In laboratory rats, the dose to cause 50% lethality in

laboratory rats is 4 mg/kg when ingested. For dermal exposure to rats,

the 50% lethality range is 2-12 mg/kg. In mice, the inhalation lethality

is 1.2 mg/kg9.

2 mg dermal contact can cause skin damage to humans; 1 microgram contact

to the eye can cause corneal damage to humans; and in inhalation

studies, 1/20th of a milligram per kilogram causes death in half of all

rats; heartier guinea pigs can last up to 2 mg per kilogram10. If I have

done my math and conversions correctly, that is the equivalent of 180 lb

person absorbing by inhalation 16o mg (about 1/100th of an ounce).

The Army estimates that an inhalation dosage with a 50/50 chance to kill

a human is 200 mg to 1800 mg and must take place in a minute11. There

are no controlled respiratory studies done on humans, of course,

although there are several unfortunate post-mortem studies of people and

other mammals who died of stachybotrytoxicosis, particularly in times of

food shortages12.

Indoor Mold and the Production of TrichothecenesIt is important to

realize that even if a mold capable of producing mycotoxins is found in

an indoor environment, that does not mean that it is necessarily doing

so13. " Isolation of a toxigenic fungus from a building does not imply

the presence of mycotoxin, since the physical conditions necessary for

mycotoxin production are very specific, and are often different from

those required for growth of the parent mold14. " However, a 2005 study

found aerosolized trichothecenes produced by Stachybotrys spp. in indoor

environments, confirming it can happen15.

Even in controlled laboratory conditions, the amount of trichothecenes

and the strength of the trichothecenes vary by species and strain of

mold16.

A Special ThanksA special thanks to TMV, Sharon, ff, Deano and Bill for

their ideas, encouragement and tips on trichothecenes. Endnotes 1.

Wannemacher, W. et. al., Medical and Chemical Aspects of Biological

Warfare, Ch. 34, Trichothecene Mycotoxins, 1997. 2. s, G.J.,

Chaverri, P., Farr, D.F., & McCray, E.B. (n.d.) Trichoderma Online,

Systematic Botany & Mycology Laboratory, ARS, USDA. 3. Jarvis, B.B. et.

al. Trichothecenes produced by Stachybotrys atra from Eastern Europe.

Appl Environ Microbiol. 1986 May; 51(5): 915–918. 4. Li, D.W. et.

al. Taxonomic history and current history of Stachybotrys chartarum and

related species. Indoor Air 2005; 15 (Suppl 9): 5-10. 5. Locasto, D.A.,

et. al., Chemical, Biological, Nuclear, Radiological, and Explosive

(CBNRE) - T-2 Mycotoxins, 2005. 6. Augerson, W. A Review of the

Scientific Literature as it Pertains to Gulf War Illness, Vol 5:

Chemical and Biological Warfare Agents, 2000.

Hu, H. et. al. The Use of Chemical Weapons: Conducting an Investigation

Using Survey Epidemiology, Journal of the American Medical Association,

August 4, 1989 - Vol. 262, No. 5. Locasto, D.A., et. al., Chemical,

Biological, Nuclear, Radiological, and Explosive (CBNRE) - T-2

Mycotoxins, 2005. Vesser, D.A. et. Al. Gulf War Close Out Report,

Biological Warfare Investigation, 2001.

Wannemacher, W. et. al., Medical and Chemical Aspects of Biological

Warfare, Ch. 34, Trichothecene Mycotoxins, 1997. 7. Merck Veterinary

Manual (2006) Trichothecene Toxicosis. 8. Locasto, D.A., et. al.,

Chemical, Biological, Nuclear, Radiological, and Explosive (CBNRE) - T-2

Mycotoxins, 2005. Wannemacher, W. et. al., Medical and Chemical Aspects

of Biological Warfare, Ch. 34, Trichothecene Mycotoxins, 1997. 9.

National Institutes of Health, Centers for Disease Control. Toxic

Effects of Fungi, Damp Indoor Spaces and Health (2004), p. 131. 10.

Augerson, W. A Review of the Scientific Literature as it Pertains to

Gulf War Illness, Vol 5: Chemical and Biological Warfare Agents, 2000.

11. Augerson, W. A Review of the Scientific Literature as it Pertains to

Gulf War Illness, Vol 5: Chemical and Biological Warfare Agents, 2000.

12. Hintikka EL. Human stachybotrytoxicosis. In: Wylie TD, Morehouse LG,

eds. Mycotoxigenic Fungi, Mycotoxins, Mycotoxicoses. New York: Marcel

Dekker; 1987:87-89. Environmental Health Investigation Branch.

California Morbidity, Health Effects of Toxin-Producing Indoor Molds in

California, California Department of Health Services, April 1998. 13.

Chapman, J.A. Stachybotrys chartarum (chartarum = atra = alternans) and

other problems caused by allergenic fungi. Allergy Asthma Proc. 2003

Jan-Feb;24(1):1-7. 14. McNeel, S. et. al. Fungi & Indoor Air Quality,

Health & Environment Digest Vol 10, No. 2, pages 9-12, May/June

1996.Wilkins, K. et. al. Patterns of volatile metabolites and

nonvolatile trichothecenes produced by isolates of Stachybotrys,

Fusarium, Trichoderma, Trichothecium and Memnoniella. Environ Sci Pollut

Res Int. 2003;10(3):162-6. 15. Brasel, T.L. et. al. Detection of

Airborne Stachybotrys chartarum Macrocyclic Trichothecene Mycotoxins in

the Indoor Environment, Applied and Environmental Microbiology, November

2005, p. 7376-7388, Vol. 71, No. 110099-2240.