Posted by Mike Ciavattieri on Tue, Jul 13, 2010 @ 01:38 PM
Media reports have linked indoor mold exposure to everything from asthma to headaches. So what’s the real scientific evidence that exposure to mold in your home actually can cause physical symptoms? A recent review of scientific literature about mold-related diseases found that many common claims just don’t hold up under scrutiny.
#1: The term "Toxic mold" - popular reports about the health effects of mold are likely to include the near-famous term “toxic mold.” But that term can be misleading, the experts say. Only certain mold spores produce toxins, and only under certain circumstances - just because a particular mold can produce toxins doesn’t mean it will. Lastly, even if a mold is producing toxins, a person must breathe in a sufficient, and in most cases, large, dose to be affected. It is highly unlikely that anyone could inhale enough mold in their home or office to receive a toxic dose.
#2: The term "Black mold" - the equally infamous cousin to 'toxic mold', this term, technically, does not exist. In actuality, there are a lots of molds that are black (or look black). In fact, many molds classified by frightened homeowners are actually a very dark green. The type of black mold that made the news years ago, associated with a lot of ill health effects, is called Stachybotrys. However, most molds that appear 'black' are fairly common and generally not of concern. The take-home message here is that 'black' molds do not always equal 'bad'.
#3: Mold causes asthma - While allergic responses to inhaling mold are a recognized factor in lower airway disease such as asthma, studies show that outdoor mold is much more likely to cause problems for asthmatics than indoor molds.
#4: Mold causes allergies - The link between mold and allergies is even weaker, the experts say. Current research doesn’t provide a persuasive case that exposure to mold in the outdoor air plays a role in allergies, and studies linking indoor molds to upper airway allergy are even less compelling.
#5: Mold causes skin rashes - Exposure to molds doesn’t contribute to atopic dermatitis, or rashes.
#6: Mold causes sinusitis - There’s no clear-cut evidence that sensitivity to mold causes chronic sinusitis, nor are there conclusive data to show that mold-killing antifungal drugs such as amphotericin, applied to the nasal passages, are an effective treatment for sinusitis.
#7: Mold causes infection. Superficial fungal infections, such as toenail fungus or jock itch, generally result from fungi that develop inside the warm, moist environments found in shoes or tight garments. Thrush can develop inside the mouths of people with weakened immune systems, such as those who have AIDS or cancer. These infections generally are not the result of exposure to mold in the home or workplace.
#8: Mold causes irritation. Mold found indoors, even inside damp buildings, is not likely to cause irritation of the eyes or throat -- and if it does, the effects are short-lived. Symptoms or signs persisting weeks after exposure and those accompanied by complaints related to the nervous system, brain, or whole body (such as those attributed to chronic fatigue) can’t be pinned on the irritant effects of mold exposure.
#9: Mold causes immune system damage. There is no credible evidence to suggest that environmental exposure to mold damages the immune system. The experts warn against immune-based tests given to look for intolerance to mold and other substances in the environment—so-called multiple chemical sensitivity. The authors specifically advise against using blood tests that look for a wide range of non-specific changes in the immune system. They also discourage using tests of autoantibodies, which are abnormal antibodies that the body sometimes produces in reaction against its own tissues. These tests are expensive and do not provide useful information that will help to diagnose or manage diseases related to mold, they say.
#10: Mold causes hypersensitivity pneumonitis. This uncommon inflammation of the lungs, an example of which is Farmer’s Lung, is caused by exposure to an allergen, usually organic dust that may come from animal dander, molds, or plants. A person generally develops this condition only after high-dose or prolonged exposure, or both, to mold or other allergens.
Much of the hoopla over mold exposure came in the wake of Hurricane Katrina, the experts note in their report, which appeared in the Journal of Allergy and Clinical Immunology. The flood-ravaged areas of the Gulf Coast, sadly, have provided a natural laboratory, which enables medical researchers to address lingering questions about the health effects of mold testing ma.
The research cited in this article was provided by: Bush RK, Portnoy JM, Saxon A, Terr AI, Wood RA The medical effects of mold exposure.
J Allergy Clin Immunol. 2006 Feb;117(2):326-33. Review. Erratum in: J Allergy Clin Immunol. 2006 Jun;117(6):1373.
PMID: 16514772 [PubMed - indexed for MEDLINE]
Posted by Mike Ciavattieri on Tue, Feb 10, 2009 @ 11:32 AM
It's been a long, cold, and snowy winter here in Massachusetts and over the past months of performing home inspections I have run into numerous instances of ice dam formation and the subsequent questions from prospective buyers and sellers.
So what causes ice dams? Simply put, ice dam formation is caused when melting snow runs down the roof and then refreezes at the roof edge. The water runs down the roof slope underneath the blanket of snow and then refreezes into a band of ice at the roof edge creating a "dam". Additional snow melt can then pool against the dam and leak into the building through the roof or roof trim. Ice dams can actually form with as little as 1 or 2 inches of snow accumulation given the right weather circumstances.
The question I receive most often is, "what can I do to prevent ice dams?" The answer, while it may sound contradictory at first, is increased amounts of insulation and increased attic ventilation. In order to understand why, one needs to fully understand the mechanisms of ice dam formation: The upper roof (or attic) surface is typically at a temperature that is above freezing - this is what causes the melting at the upper roof surfaces. The lower part of the roof (or attic) surface (along the eaves) is typically below freezing - this is what causes the refreeze. It is heat lost from inside the house is the source of the melting at the upper roof surfaces! Because the lower roof surfaces (particularly the overhangs) are not warmed by indoor heat-loss, these regions can remain at below freezing temperatures, especially during periods of very cold outdoor temperatures.
Check your home carefully when ice dams form, even when there doesn't appear to be a leak. Get in your attic and look at the underside of the roof sheathing and roof trim to make sure they haven't gotten wet. Check the insulation for dampness. And when leaks inside your home develop, be prepared. Water penetration often follows pathways difficult follow. You may wish to hire an inspector that is equipped with an infrared or thermal imaging camera, as this equipment may be able to spot water penetration that is not readily visible with the naked eye. Ultimately, however, you will want to correct the problem to prevent future occurrences:
Insulation: Houses in this region of the country should have attic insulation of at least R-38, or about 12 inches depth of fiberglass or blown in material. The most notable problem area is at the far eaves, or right above where the exterior wall is.
Ventilation: A ‘ridge/soffit' ventilation system is currently the most effective ventilation system, and is the system found in most new construction. If you have an older home, you may still be using a power fan, static roof vent(s) and/or gable end louvers - these simply aren't as good and will have a more difficult time retarding ice dam formation. Ridge/soffit systems should also include foam or plastic baffles at the far eaves to prevent insulation from blocking the soffit intake vents. If you have soffit baffles currently installed, make sure they are not crushed or displaced - they are relatively flimsy items yet they perform a very important function.
Air Leakage: Although insulation is what primarily keeps warm air in our house, small (or large) holes can allow significant volumes of warm indoor air to pass into attic spaces. Some of these sources can include: pull-down staircases, doorways leading to attic staircases, recessed lighting, bathroom exhaust fans, and various holes for cable TV, internet, etc. Take the appropriate measures to seal up or insulate these areas, it may be the difference maker!
Remember: Always wear personal protective equipment when making repairs of any nature. And when in doubt, always hire a professional. Winter is almost over!
Mike Ciavattieri is a Massachusetts Home Inspector and owner of BONSAI Inspection Company, of Abington, MA