Indoor Air Quality has become the pollution-related health issue of the 90's. In recent years, the EPA has ranked poor Indoor Air Quality among the top five health risks caused by pollution.
Pollutants enter our bodies by ingestion (eating or drinking), by absorption through our skin, or by inhalation (breathing). Of course, of the three, only breathing is something we do continually. Studies indicate that we spend 90% of our time in an indoor environment, so, the quality of the indoor air we breathe is very critical to our health and well-being. Employers are finding that providing good indoor air quality promotes increased productivity and reduced lost time due to illness.
As the public becomes more aware of the health effects of poor indoor air quality, the demand for government regulation will increase. OSHA has proposed regulations aimed at promoting good indoor air quality for the workplace already. Municipalities around the U.S. have begun enacting ordinances requiring building owners and operators to control tobacco smoke in their restaurants, bars, and places where many people are in close proximity to one another.
Until more definitive legislation regarding IAQ is enacted, the primary incentive to provide good quality indoor air is the possibility of litigation. The number of personal injury liability lawsuits due to poor quality indoor air is increasing. Settlements and awards have reached the $500,000 mark per plaintiff. Just the potential of this kind of litigation should be incentive for potential defendants to assure good IAQ in all buildings for which they are responsible.
Another benefit of providing clean indoor air is that the building interior and furnishings will be cleaner requiring less housekeeping and maintenance. In addition, a clean HVAC system operates more efficiently and requires less maintenance, reducing operational costs. All in all, providing good IAQ will improve the bottom line.
ASHRAE standard 52.1-1992 is used to measure the performance of most filters used in HVAC systems and air cleaning systems. Besides measuring air flow resistance, two filtration performance measurements can be made depending on the type of filter. The dust weight arrestance test indicates how well a filter captures larger, heavier particles (greater than 10 microns). It is used to evaluate panel filters used in HVAC systems and as pre-filters in air cleaners. These filters usually are not very effective on fine dusts and smokes (less than 8-10 microns). The dust spot efficiency test indicates how well a filter captures small particulates (.3-6 microns) such as fine dusts and smokes. It is usually used to evaluate pleated filters, bag filters and electronic filters. Military standard 282 (not an ASHRAE standard) measures the percentage removal of 0.3 micron particles of D.O.P. smoke. These are very high efficiency filters. A high efficiency particulate air filter (HEPA) is 99.97% efficient using this test. By comparison, a 95% dust spot filter is about 65% D.O.P.
Pre-filters are used in air cleaners to filter lint, dust, and other large particles. Usually a flat panel or a 1-2 inch pleat is used. Minimal performance should be at 80-90% arrestance. Better Pre-filters are at least 30% dust spot efficient. Frequent changing of disposables or cleaning of reusable filters prolongs the life of the main filter.
The Main Filter removes fine particulates. The minimum efficiency should be 60% dust spot. If tobacco smoke is a concern, the minimum efficiency should be 95% dust spot. Special air cleaning requirements may call for a 95% D.O.P. or 99.97% D.O.P. HEPA filter.
Final Filters are used when a high level of air cleanliness is required. Often a 950/%-99.97% D.O.P. filter is used after a 60%95% dust spot filter. This configuration protects the more costly final filter
Adsorbent Filters are used to remove odors, chemical vapors, and gases. No mechanical or electronic filter can remove these contaminants. The adsorbent material most often used is activated carbon or charcoal. It is capable of removing over 200 different odors, vapors, or gases. Carbon is primarily used to filter organic odors, solvents, volatile organic compounds (VOC's), and tobacco smoke. Carbon filters are available in three types:
Type 5 is a proprietary material which adsorbs and chemically reacts with acid vapors, chlorine, flourine, bromine, and iodine. Color changes from yellow to white.
The rate at which air in a room is cleaned (called air changes per hour, or ACH), is critical to an air cleaning system installation. If the air cleaner is too small or if there are not enough air cleaners, the air may not be cleaned to an acceptable level. The following procedure will help determine the air flow needed in cubic feet per minute, or CFM. Once the CFM required is determined, the size or quantity of air cleaners can be determined.
First, select a contaminant level and required air exchange rate, for example:
CONTAMINANT'S vs. REQUIRED AIR EXCHANGE RATE
Next, determine room volume:
Determine CFM required to clean the room:
This material is provided by your allergist to help you understand the role substances in your environment play in the occurrence of symptoms. This information will make it possible for you to reduce your exposure to these items so your body can become stronger. Many patients have enjoyed feeling better after making a few changes in their indoor environments. An allergy is an over reaction to substances which are ordinarily- harmless to other individuals. It can be described as a hypersensitivity reaction to a sensitizing substance called an allergen which is recognized as foreign by the body. Allergy reactions are often due to excessive amounts of a natural antibody, antibody E. Allergic individuals produce too much antibody E and as a result may experience symptoms of allergy.
House dust, pollen, mold, animal dander, dust mites, cockroaches, and foods are common allergens. Medicines and chemicals can also cause allergic symptoms.
You Total Allergy Load is the sum total of the factors which contribute to the production of allergic symptoms.
Example: The Bucket Theory
All day long you are exposed to various contaminants in the environment. This exposure can be a stress to your immune system. Too much stress and exposure can result in symptoms and fatigue.
When you go to sleep at night, you need an allergen-free environment in order for your immune system to repair itself However, if your bedroom is full of allergens and pollutants, instead of recovering, you may feel worse upon arising than when you went to bed.
Most of us spend about 33% of our time (8 hours) in our bedrooms which often have the highest allergen content of any indoor area. It makes sense to remove as many allergens and pollutants as possible from your bedroom, so you can wake up feeling better than when you went to bed.
Where do pollen grains occur?
Trees, weeds, flowers, and grasses produce pollen grains which become airborne as the wind blows. Approximately a quarter of a million plants use the wind for transporting pollen grains. Insects such as bees play a role in the distribution of pollen from plant to plant.
Pollen from different plants occur at different times of the year in the various parts of the country. Your local TV or radio station may report the pollen count on a daily basis. It is important to know the times of pollination in your area so you can implement avoidance measures to reduce your symptoms.
No, you can experience exposure to pollen inside your home. These allergens are carried indoors on our clothing, pets, and they infiltrate through doors and windows.
Animal dander is not the hair or fur of the animal, but is old skin scales which are constantly shed. Older animals produce more dander than young ones because their skin is drier. Animal dander is extremely light weight and tiny in size, (approx. 2.5 microns) and can stay airborne for hours. (1 micron = 1/25,000 in.)
No, the primary cat allergen, Felis domesticus allergen I, is a glycoprotein found in the sebaceous glands of the cat's hair roots and in their sublingual salivary glands. It is also present in the urine of male cats.
During grooming the allergen from the sebaceous glands is deposited with the saliva on the cat's fur. When it dries, it flakes off and is released into the air.
Why do I have symptoms even when I am not near the cat?
Cat dander sticks to our clothing and personal belongings and is easily transported wherever we go. This is why cat dander has been found in schools and offices where an animal has never lived. Its ability to remain airborne and to permeate every area of the house makes it extremely hard to control.
Mold, mildew, and fungi are all terms generally used to describe a group of diverse plants which appear as woolly or powdery growth. They have been recognized as an allergen for over 100 years. Mold infestation is mentioned in the Bible in Leviticus chapters 11-14.
Molds are everywhere, indoors and out, in every type of climate, and in every social and economic condition. They grow in places we would not expect. They are elusive and will be more prevalent at different times of the day or night depending on the type of mold. A single mold can germinate and produce hundreds of thousands of airborne spores in 4-9 days.
Surveys have shown that high mold and pollen counts frequently occur at the same time of year. Hay fever symptoms may be caused by mold rather than pollen.
Mold needs moisture, food, which can be any organic matter, and preferably warm temperatures. Relative humidity below 40% discourages mold growth.
Molds are found in soil and in decaying leaves, straw, grains, and wood. Any contact with these things can expose you to mold. Mowing the grass; raking leaves, working in the soil, working in a garage, barn, hay field, or grain storage areas, cleaning out pet litter and sleeping areas, or cleaning your closet can bring on symptoms associated with mold allergy.
Lifestyles That Increase Mold Counts
Poor housekeeping practices - dirty dishes and food left around the house, trash kept in the house in cans or compactors, dirty clothes lying around, and infrequent housecleaning-can all increase mold growth.
The use of ceiling fans in lieu of air conditioning can increase mold levels in homes. Higher thermostat settings mean the air conditioner operates less so humidity is not removed from the air.
Inefficient filters allow dirt to accumulate on coils, the drain pan, and duct work. This dirt becomes "food" for mold. Washable, electrostatic filters which contain media treated with an anti-microbial inhibitor are preferred and have proven effective in reducing mold levels in homes.
What part of the cockroach produces the allergen?
It is the cast skins of the cockroach which causes most of the allergic reactions.
Is there a relationship between cockroach allergy and asthma?
Yes. A study conducted in inner city Atlanta found a high proportion of children admitted to emergency rooms for asthma had high sensitivities to cockroach and dust mites.
How to reduce exposure to cockroach allergen?