Dust & Sooting

House dust is the most common indoor pollutant and is a major contributor to indoor environment problems. However, the public rarely implicates it as the cause. It is a mixture of many things. A speck of dust may contain fabric fibers, insulation, skin, animal dander, dust mites, bacteria, cockroach parts, mold spores, food particles and other debris. Another dust problem that is occasionally encountered is a phenomenon known as “sooting”. Sooting is an unexplained dark mark or film on an interior wall, carpet or furniture surface. Unlike house dust, sooting is caused by a carbon-generating source and is usually created during a combustion process. Sooting can look like and it is frequently mistaken to be mold. Common causes of sooting include the indoor use of tobacco, candles and gas appliances.

House Dust and Sooting Health Effects

House dust is a common cause of year-round runny or stuffy nose, itchy, watery eyes and sneezing symptoms. Dust can also make people with asthma experience wheezing, coughing and shortness of breath. Animal dander, house dust mites and cockroaches are the most common substances in dust that cause these symptoms. Health effects can occur even though there are no visible signs of dust. While sooting can cause significant aesthetic problems, it is not normally considered to be a health threat.

Solving House Dust and Sooting Problems

Many materials in house dust cannot be removed by typical housekeeping methods. For example, no matter how vigorously one dusts or vacuums, the number of dust mites present deep within carpeting, pillows, and mattresses will not be reduced. Vigorous dusting, sweeping and vacuuming can put more dust into the air making symptoms worse. Use of a vacuum with HEPA filtration and dusting with a damp or oiled cloth is recommended for reducing ambient house dust. Ideally, someone other than the dust-sensitive person should do the cleaning. If the dust-sensitive person must clean, they should wear a mask. Use of a vacuum with HEPA-type filtration may also be advisable. The best approach to resolving house dust-related health problems is to consult with an allergist to identify what the affected person is allergic to and then eliminate those allergen contributors from the indoor environment. More detailed information about common allergens in house dust, their health effects and abatement recommendations can be found in the internet links listed below.

It is extremely difficult for a homeowner to resolve a sooting problem without professional help. Resolution of these problems typically involves diagnostic tests of the house (including blow-door and leak tests), HVAC system measurements, infrared measurements of wall insulation and air current studies. These types of studies are beyond the abilities of do-it-yourself homeowners and most health department staff. It is therefore recommended that a professional with extensive experience in such investigations be contacted.

Dust and Sooting Resources on the Internet

• Ohio State University
  http://www.ag.ohio-state.edu/~ohioline/hyg-fact/2000/2157.html
• Building Science Corporation http://www.buildingscience.com/resources/misc/black_stains_on_carpet.htm

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