Fighting Mold — The Homeowners' Guide

Understanding mold

• Mold can be harmful or helpful — depending on where it grows.
• Mold needs moisture to grow.
• Mold does not grow on dry materials.
• Mold growing inside a home can affect the occupants.
• Occupants can learn to recognize mold.

Molds are microscopic fungi, a group of organisms which also includes mushrooms and yeasts. Fungi are highly adapted to grow and reproduce rapidly, producing spores and mycelia in the process.
You encounter mold every day. Foods spoil because of mold. Leaves decay and pieces of wood lying on the ground rot due to mold. That fuzzy black growth on wet window sills is mold. Paper or fabrics stored in a damp place get a musty smell that is due to the action of molds.
Molds can be useful to people. The drug penicillin is obtained from a specific type of mold. Some foods and beverages are made by the actions of molds. The good kinds of molds are selected and grown in a controlled fashion.
Molds are undesirable when they grow where we don’t want them, such as in homes. Over 270 species of mold have been identified as living in Canadian homes. Molds that grow inside may be different from the ones found outdoors.

What makes molds grow?

Molds will grow if we provide them with moisture and nutrients. If we keep things dry, molds do not grow.
High moisture levels can be the result of water coming in from the outside, through the floor, walls or roof; or from plumbing leaks; or moisture produced by the people living in the home, through daily activities like bathing, washing clothes or cooking. Water enters the building when there is a weakness or failure in the structure. Moisture accumulates within the home when there is not enough ventilation to expel that moisture.
Different kinds of molds grow on different materials. Certain kinds of molds like an extremely wet environment. Other kinds of molds may be growing even if no water can be seen. Dampness inside the material can be enough to allow them to grow.

Why are molds a concern?

Damage to materials is one concern. Materials get stained or discoloured, and over time they are ruined. Moldy paper and cardboard disintegrate over time. Fabrics are damaged. Continued mold growth can be indicative of moisture conditions favourable for growth of fungi that cause wood rot and structural damage.
When molds are growing inside the home, there may be health concerns. Molds release chemicals and spores.
Health experts indicate that, depending on the type of mold present in a home, the amount and degree of exposure, and the health condition of the occupant, the health effects of mold can range from being insignificant to causing allergic reactions and illness.
Pregnant women, infants, the elderly and those with health problems, such as respiratory disease or a weakened immune system, are more at risk when exposed to mold. Consult your family physician if you believe there is someone who may be at risk.

Is there a mold problem?

Molds are always found in the air outside and in all buildings. They come into the home in many ways — through open windows or doors, on clothing, pets, food or furniture. The problem starts when mold grows inside the home.
Some mold growing, for example on the window sill but not elsewhere, is not a cause of concern. You can clean the mold yourself. The presence of mold is a sign that there is too much moisture in your home — a situation which must be corrected.
Inspect the home to find the extent of the mold.

How can you tell if it is mold?

Discoloration
Discoloration is a sign of mold. However, all discoloration is not due to mold. Carpeting near baseboards, for example, can be stained by outdoor pollution entering the home. Stains or soot may also be caused by the smoke from burning candles or cigarettes.
Mold may be any colour: black, white, red, orange, yellow, blue or violet. Dab a drop of household bleach onto a suspected spot. If the stain loses its colour or disappears, it may be mold. If there is no change, it probably isn't mold.
Smell/Odour
Sometimes molds are hidden and cannot be seen. A musty or earthy smell often indicates the presence of molds. But a smell may not be present for all molds. Even when you don't notice a smell, wet spots, dampness or evidence of a water leak are indications of moisture problems and mold may follow.

How much mold is growing?

One way to know is to estimate the area of the mold.
Mold is considered to cover a “small area” if the patch is no larger than a square meter. There should be no more than three patches, each patch smaller than a square meter. Clean up small areas yourself using a detergent solution, household rubber gloves and a dust mask for protection. Refer to How to clean-up small problems for the procedure.
Small moldy areas in homes may become larger over time, if ignored, so it’s important to clean up and remove even small patches of mold.
The mold area is considered “moderate” if there are more than three patches, each patch smaller than a square meter, or there is one or more isolated patches larger than a square meter but smaller than 3 square metres (size of a 4 x 8 foot sheet of plywood). Assessment by a professional is recommended. You can clean up moderate amounts of mold but you must follow the proper procedures and use the proper protective equipment. Refer to Moderate area clean-up for the procedure.
A mold area is considered “extensive” if a single patch of mold is larger in area than a sheet of plywood. Being exposed to this much mold is not a good idea. Do not attempt to clean up large areas of mold yourself. You need professional help to determine why the mold is there in the first place and how to clean it up.

When should you seek professional help?

You may need professional help when:

• There is a lot of mold
• The home is very damp and moist
• Mold comes back after repeated cleaning
• A family member suffers from asthma or respiratory problems or other health problems that appear to be aggravated inside the home

How to clean up mold problems

• “Small areas” of mold can be cleaned with a detergent solution.
• Wear a mask, safety goggles and rubber gloves.
• Seek professional help if there is a lot of mold or if mold comes back after cleaning.

Bleach is NOT recommended

The presence of organic (humic) materials, the pH (acidity/alkalinity) of the water, the surface material and contact time affect the effectiveness of bleach for disinfection. Since these factors are not generally controlled, bleach cannot be relied upon for disinfection. The most compelling reason for advising against bleach is that fumes are harmful but in addition, overuse of bleach will result in increased releases of chlorinated effluents which can be harmful to the environment.

“Small area” clean-up

You can clean up “small areas” of mold (fewer than three patches, each smaller than a square meter) yourself. The minimum protective wear needed are:

• safety glasses or goggles;
• a disposable dust mask (3M 8210 or equivalent); and
• household rubber gloves.

Infants and other family members with asthma, allergies or other health problems should not be in the work area or adjacent room during the cleaning.

Washable surfaces:

Scrub with an unscented detergent solution; then sponge with a clean, wet rag and dry quickly.
Using an unscented detergent will make it easier for you to detect residual moldy odours.

Moldy drywall:

Clean the surface with a damp rag using baking soda or a bit of detergent. Do not allow the drywall to get too wet.
Mold that comes back after cleaning is usually an indication that a source of moisture has not been removed. Seek professional help from a trained IAQ investigator.

"Moderate area" clean-up

• Clean “moderate areas” of mold, but wear proper protective equipment and follow precautions.
• Seek professional help if there is a lot of mold or if mold comes back after cleaning.

If you follow the proper procedures and use the proper protective equipment, you can clean up “moderate areas” of mold. “Moderate” means more than 3 patches of mold, each smaller than one square meter, or one or more isolated patches larger than one square meter but smaller than 3 square meters (size of a 4 x 8 foot sheet of plywood).

Safety precautions

• Wear a disposable dust mask (for example, 3M 8210 or equivalent), glasses or safety goggles and household rubber gloves.
• Isolate the area to be cleaned with plastic sheeting, taped to walls and ceiling.
• Infants and other family members suffering from asthma, allergies or other health problems should not be in the work area or adjacent room during the cleaning.

A small clean up should take minutes (not hours) to finish. When the clean up takes hours to a day to finish, it is suggested that you upgrade to a better filter, such as a half-face respirator with charcoal cartridges. An exhaust fan installed in a window in the room being cleaned would prevent contamination of other areas of the house as well as provide ventilation.

General cleaning

Vacuum surfaces with a vacuum cleaner which has a High Efficiency Particulate Air (HEPA) filter or is externally exhausted. Scrub or brush the moldy area with a mild unscented detergent solution. Rinse by sponging with a clean, wet rag. Repeat. Dry quickly. HEPA vacuum the surfaces that were cleaned as well as surrounding areas.

Cleaning wood surfaces

Vacuum loose mold from wood surfaces using a HEPA or externally exhausted vacuum. Try cleaning the surface of the wood with detergent and water. Rinse with a clean, damp rag and dry quickly. If the staining does not come off, sand and vacuum the surface of the wood with a vacuum/sander combination. It is important to vacuum at the same time to prevent mold spores from being dispersed into the air. Note that wood affected by rot may need to be replaced.

Cleaning concrete surfaces

Vacuum the concrete surfaces to be cleaned with a HEPA or externally exhausted vacuum cleaner. Clean up surfaces with detergent and water. If the surfaces are still visibly moldy, use TSP (trisodium phosphate). Dissolve one cup of TSP in two gallons of warm water. Stir for two minutes. Note: TSP must not be allowed to come in contact with skin or eyes. Saturate the moldy concrete surface with the TSP solution using a sponge or rag. Keep the surface wetted for at least 15 minutes. Rinse the concrete surface twice with clean water. Dry thoroughly, as quickly as possible.

Moldy drywall

The paper facings of gypsum wallboard (drywall) grow mold when they get wet or repeatedly wet and don’t dry quickly. Cleaning with water containing detergent not only add moisture to the paper but also can eventually damage the facing. If the mold is located only on top of the painted surface, remove it by general cleaning (see above). If the mold is underneath the paint, the moldy patch and other moldy material behind it are best cut out and the surrounding areas also cleaned. This should be done by a mold clean-up contractor. New materials may become moldy if the moisture entry has not been stopped. If this is the case, replacement of the materials should be deferred until the source of the moisture is corrected. The affected areas should be temporarily covered with plastic sheeting and sealed at the edges.
Any areas that show new patches of mold should be cleaned promptly.

Dealing with an ongoing problem

Repair to the building envelope is required if moisture is entering the home from the outside. At the same time, steps should be taken inside the home to reduce the occupants’ exposure to mold.

Step 1 — Discard moldy or damaged materials

Wear a dust mask and gloves. Furnishings, such as mattresses, carpets, or sofas that got wet or have been stored in damp conditions should be discarded. Discard items that are no longer needed. Use this opportunity to reduce the amount of furnishings — this means fewer materials to absorb moisture and grow mold. Clothes and other items that have been cleaned should be stored in sealed plastic bags to prevent re-contamination.

Step 2 — Vacuum

Proper vacuuming reduces the amount of mold spores. All surfaces in the home (floors, walls, ceilings, shelves) and non-washable furnishings (such as sofas, chairs, etc.) must be vacuumed thoroughly.

Step 3 — Prevent

Keep moisture generated within the home to a minimum by conscientiously following the prevention steps presented in the next section.

Step 4 — Clear wet areas

Pull carpets and furnishings away from walls that get wet. Carpets and underpads that are moldy should be cut out and discarded.

Step 5 — Dry

Take steps to dry up areas that get wet. Monitor the relative humidity of the air. Use a portable dehumidifier, if necessary. Ensure that the condensate drain pan of the dehumidifier is emptied regularly.

Step 6 — Isolate

If the mold is limited to one area, isolate the area if possible. Cover the affected surfaces with plastic sheeting secured at the edges with duct tape. Note that this is only a temporary measure to minimize your exposure.

Step 7 — Clean

Healthy individuals can regularly clean “small” and “moderate” areas of mold, thus preventing these from getting out of hand, by following the safety precautions and cleaning guidelines.

Step 8 — Seek professional help

Consider seeking professional help from trained IAQ investigators to identify appropriate remediation steps inside the home. Removing large amounts of mold will require the services of mold clean-up contractors.

Preventing mold

• Keep the home dry.
• Find and fix water leaks.
• Discard clutter and excess stored materials.
• Clean and maintain the home regularly.
• Encourage lifestyle practices that reduce moisture.

Basic steps to prevent and reduce mold growth

Mold needs moisture to grow. Controlling the moisture and keeping the home dry prevents the growth of mold.

• Check your home for signs of moisture and molds.
• Find out if water is coming in from the outside and if substantial moisture is produced inside the home.
• Fix any water leaks promptly.
• Think of the different ways moisture is produced inside the home (for example, cooking, bathing, plant jungle). Remove the moisture as it is produced by using exhaust fans. In the absence of fans, open windows for a short time, but note that the wind can push the moisture to other parts of the home.
• Measure how much moisture is in the air. To find the relative humidity in your home, you’ll need a hygrometer. You can buy one at a hardware store or electronics store. A hygrometer costs from $10 to $60. Relative humidity in the home should be under 45 per cent in the winter (or lower to avoid condensation on windows). If necessary, use a dehumidifier to lower the relative humidity.
• Reduce the amount of stored materials, especially items that are no longer used. Molds grow on fabrics, paper, wood and practically anything that collects dust and holds moisture.

Mold-proofing your home, room by room

Basement or crawl space

• Reduce the amount of clothes, paper and furnishings stored in the basement. Discard badly damaged materials. Eliminate clutter to improve air circulation. Only washable items should be stored.
• Dehumidify the basement during the warm months.
• Avoid carpets on slab-on-grade or below grade floors.
• Periodically clean the drain in your basement floor. Use half a cup of bleach, let it stand for a few minutes, then flush with plenty of water. Keep the drain trap filled with water.
• Avoid standing water. Keep sump pits covered (you can use plywood wrapped with plastic).
• Regularly clean and replace furnace filters. Use a pleated one-inch filter, not a coarse filter.
• If you have a heat recovery ventilator (HRV), clean the filter inside the HRV often.
• If you notice molds or signs of dampness, such as water on your windows or wet spots elsewhere, do not humidify. Disconnect furnace humidifiers that are no longer used.
• If you have electric baseboards, vacuum the units, or have a professional clean them for you.

Laundry areas

• Check that your clothes dryer exhausts to the outside.
• Remove lint every time you use the dryer.
• Don’t hang-dry laundry indoors.
• Dry your laundry tub and washing machine after you use them.

Bathrooms

• Check the bathroom fan to make sure it exhausts to the outside.
• Turn the bathroom fan on when you shower. Keep it running for a few minutes after you finish your shower.
• Take short showers.
• Keep surfaces that get wet, such as the walls around the bathtub and shower, clean and dry.
• If there is a carpet in your bathroom, remove it.
• Check for water leaks.
• Keep drains in good shape by removing debris from them.

To clean a drain:

• Pour a handful of baking soda into it.
• Add a cup of vinegar.
• Put the plug in the drain.
• Let the vinegar and baking soda work for about 20 minutes.
• Run fresh water into the drain.

If the drain is still clogged, use a small plumbing snake.

Kitchen

• If the fan over your stove exhausts outside, use it when you cook.
• Minimize open boiling.
• Keep your drains in good shape. Follow the steps in the Bathrooms section above.
• There’s a drip pan at the back of the refrigerator. Pull the refrigerator out to clean the drip pan. At the same time, vacuum dust from the coils at the back of the refrigerator.
• Check under the kitchen sink to make sure there are no leaks.
• Take out the garbage daily to prevent odours and spoiling.

Closets and bedrooms

• Get rid of clothes and other stored items that you don’t use. Keeping your closets and bedrooms tidy makes it easier for air to circulate — and harder for mold to grow.

Other parts of the home

• A dehumidifier helps to reduce moisture in the home during the warmer months. Close the windows when the dehumidifier is running.
• When family and friends come into the home, have them take off their shoes.
• Vacuum often. If you are buying a vacuum cleaner, try to get one with a HEPA filter. (See below).
• Clean hard floors with a damp mop.
• Do not bring in furniture, clothing, books etc. that have been stored in a moldy place into your home.
• Cut down the number of potted plants in the house—soil is a good place for mold.

Exterior

• Regularly check the condition of the roof and exterior finish for any places where water might enter.
• Make sure that eavestroughs and downspouts are connected and working properly and that they are free of debris.
• Install downspout extensions to lead water away from the building.
• Deal promptly with any problems that you find.

Frequently asked questions about mold

Should I have my house air tested for mold?

This is the question most frequently asked by homeowners who think their home may have a mold problem. Testing is generally not recommended for homeowners. Testing of moldy materials or an air sample identifies the types of molds that may be present but does not identify the cause/source of moisture. The type of mold does not change the procedures for cleaning up areas of mold less than 3 square meters. You have to clean up the mold and correct the problem irrespective of the type of mold. The cost of testing may be better spent hiring a professional investigator or fixing the problem.
Testing of a moldy material involves sending a swab, an imprint on a Scotch tape or a piece of the material to a competent laboratory. Air sampling requires specialized equipment. An air sample typically captures mold spores in a period of minutes. Since replicate samples must be taken due to variations in the airborne molds over time (even hours) and compared with outdoor samples, air testing is both expensive and time-consuming. Interpretation of test results may not be very useful, since there are no advocated "safe levels" of indoor molds and the results will not tell the health risks from the molds.

The air feels dry — can I humidify?

Before you add moisture to the air, measure the relative humidity. Air that feels dry may not be really dry. It may be moldy. High relative humidity (over 45 per cent) promotes the growth of molds and dust mites. The moisture in the air may condense on colder exterior walls where molds start to grow.
If your physician has advised you to use a humidifier in your child’s bedroom at night, monitor the relative humidity. Turn the humidifier on and off as necessary. In the morning, take steps to make sure the room gets dry. Clean and empty the humidifier after each use.

What advantages do HEPA vacuums provide?

Ordinary vacuums capture large particles only — small mold spores pass through the vacuum into the air. HEPA vacuums have special filters that capture small particles. A central vacuum cleaner which is exhausted to the outside also removes mold spores. A regular portable vacuum is useful only if its exhaust goes outside the home. Vacuuming removes settled dust that contains an accumulation of mold spores over time. Reducing the settled dust reduces molds.
Vacuuming with any vacuum cleaner (ordinary, central or HEPA) stirs dust and mold during the process. Wear a dust mask so you will not be breathing more mold.

Is vacuuming with a HEPA or externally exhausted vacuum cleaner recommended for serious mold problems only?

Vacuum regularly with a HEPA or externally exhausted vacuum cleaner to prevent the ongoing accumulation of dust and molds. The need for HEPA or external exhaust vacuuming increases with the severity of the mold problem.
If a furnishing has been wet at some time in the past or has been exposed to dampness over a prolonged period of time, vacuuming with HEPA or externally exhausted vacuum is unlikely to remove the mold growing beneath the surface. It is better to discard the item.

Where do you find a HEPA vacuum cleaner?

Vacuum cleaner dealers carry HEPA vacuums. Consider purchasing one as an upgrade to what you may be using. A HEPA vacuum is a good investment in the long term whether you have mold or not. A generic canister HEPA vacuum cleaner costs approximately $300. Brand name products of the same type may cost more. You may inquire if the dealer has a HEPA vacuum cleaner to rent. Contractors who clean up or renovate houses for mold should also have this equipment.

Does painting over a moldy surface take care of the mold?

Painting over mold only masks the problem. Paint does not kill the mold nor stop it from growing. Surfaces that are washable should be cleaned with a detergent solution, following the procedure suggested above, then allowed to dry. If you are going to paint, remove mold first.

Does cleaning stop the mold growth?

Mold will reappear until its source of moisture is removed. High moisture levels that are not corrected can make the molds grow back quickly. Cleaning is only a temporary but essential measure.
You can help by making a conscious effort to keep the home dry. Obviously, water must be prevented from entering the home. But you can help by controlling moisture that you produce.

How does one clean clothes that are moldy?

Non-washable clothing can be dry cleaned.
Wash clothes with a detergent solution to which a cup of bleach is added. Make sure the detergent you use does not contain ammonia. Repeat as necessary until the moldy odour is gone.
Clothes and other items that have been cleaned should be stored in sealed plastic bags to prevent re-contamination.

Measuring Humidity in Your Home

Straight Facts About Humidity

Humidity is the amount of moisture or water vapour in the air. You, your family, and your pets produce moisture when you breathe or perspire. Even your indoor plants produce moisture. We add water vapour to indoor air through routine household activities: cooking, showering, bathing, doing laundry, and dishwashing. More moisture can enter your home from the surrounding soil through a basement or crawl space.

When is Humidity a Problem?

We need humidity for our comfort and health. But too much or too little humidity can produce a host of difficulties for householders (see Table 1). Some of the problems are no more than nuisances; others could be far more serious. Many are familiar to Canadians. They often occur during the heating season when our windows are closed, and indoor air circulation and ventilation are reduced.

Figure 1 Do you have a humidity problem?

Table 1 Humidity problems

	Too much humidity	Too little humidity
Typical symptoms	Condensation on windows  Wet stains on walls and ceilings  Moldy bathroom  Musty smells  Allergic reactions	Chapped skin and lips  Scratchy nose and throat  Breathing problems  Static and sparks  Problems with electronic equipment
Long-term effects	Damage to the house and its contents  Ongoing allergies Other health problems	Continuing discomfort  Damage to furniture and other items

Diagnosing the Humidity Problem

Instead of guessing whether or not you have a humidity problem inside your house, why not find out for sure?
A small, inexpensive and easy-to-use instrument called a hygrometer (sometimes referred to as a humidity sensor or relative humidity indicator) can measure the humidity level in your house and confirm whether the house has too much or too little humidity. Once you know for sure, you can decide whether any action is required and, if so, what action.

Relative Humidity

Humidity is normally measured as relative humidity (RH). RH is a percentage that indicates the amount of moisture in the air relative to the maximum amount the air can hold at that temperature. For instance, when air at a given temperature contains all the water vapour it can hold at that temperature, it has a RH of 100 per cent. If the humidity exceeds 100 per cent, moisture will begin to condense from the air. If the air contains only half the water it can hold at that temperature, the RH is 50 per cent.
Warm air can hold more moisture than cool air, so that the RH of a sample of air will change as the temperature changes, even though the actual amount of moisture in the sample air does not. For example, as a sample of air cools the RH rises.

Buying a Hygrometer

The two types of hygrometers that are most suitable for household use are mechanical hygrometers and electronic hygrometers. Table 2 highlights important characteristics of each type. For most households, either type will perform satisfactorily if properly used and calibrated. (See Getting Accurate Readings for information about calibration.)
Hardware stores, department stores, building supply stores and electronics stores often carry hygrometers. In fact, hygrometers are usually sold wherever you would buy a room thermometer. Hygrometers and room thermometers are often combined into a single piece of equipment.

Using Your Hygrometer

Your hygrometer will show the relative humidity (RH) in your house. Although the RH will not be exactly the same throughout your home, one hygrometer per house is usually sufficient. You should place it where the humidity symptoms are most obvious, in the room that you are most concerned about, or where your family spends the most time. Because hygrometers are small, they can be moved around in your house from time to time.
Don’t place your hygrometer near a radiator, a heat register or a chimney, or in any other location where it could be affected by direct heat.
Remember that a hygrometer does not produce instant results. It may take up to two hours to provide a stable reading in a new location or to adjust to sudden changes in relative humidity.

Figure 2 Suitable types of hygrometers

Table 2  Hygrometer choices

	Mechanical hygrometers	Electronic hygrometers
Cost	$7 to $30	About $15 to $60
Appearance	Usually plastic; often round with a pointer and dial display	Plastic construction, LCD display
Batteries required	No	Yes
Sensitivity to humidity	May “stick” if humidity does not change for a long time	Sometimes slow to respond to changes in humidity
Accuracy	Reasonably accurate once calibrated	Usually accurate in the mid- to high-humidity ranges; can be inaccurate in the lower ranges (below 30 per cent relative humidity)
Ease of calibration	Some can be physically corrected by adjusting the pointer	Cannot be physically corrected

Getting Accurate Readings

You should make sure that your hygrometer provides accurate readings. The technical term for this is calibration. When you calibrate your hygrometer, you are testing its accuracy by comparing it with an independent standard.
Calibration Made Simple All hygrometers should be calibrated. Some are not properly set when they leave the factory. Others, even the best models on the market, may experience what is known as drift, which means that they do not hold their accuracy over long periods and need to be re-calibrated.
Calibration is easy. A step-by-step procedure using everyday household items is described in Table 3. The basic principle is to create a small-scale environment where the relative humidity is known. You place your hygrometer in this environment and compare its reading to the known humidity level.
How Often Should You Calibrate? Once you have calibrated your hygrometer, you can be confident that you are getting accurate readings. Even so, you should re-calibrate your hygrometer once a year, especially if it is a mechanical instrument, to make sure that it continues to work properly.
Table 3 Calibrating Your Hygrometer

Ingredients	125 ml (about 1/2 cup) table salt 50 ml (about 1/4 cup) tap water
Equipment	hygrometer a coffee cup a 5 L (1.1 gal.) Ziploc™ bag or a well-sealed pressure cooker
Step 1 — Get to know your hygrometer	If your hygrometer has a pointer, look for screws or knobs on it that will allow you to move the pointer. If there are none, or if you have an electronic hygrometer, physical adjustment will not be possible, but you can still calibrate.
Step 2 — Prepare the mixture	Place the tap water and the table salt in the coffee cup and stir for a several seconds.
Step 3 — Set up	Put the coffee cup and your hygrometer inside the plastic bag or pressure cooker, and seal tightly. Note that salty water can damage your hygrometer if it comes in direct contact with it. Put the bag or pressure cooker in a draft-free place and out of direct sunlight, where the room temperature is likely to remain even.
Step 4 — Check your RH reading	After 8 to 12 hours, note your hygrometer’s RH reading. Your hygrometer should read about 75 per cent. If it does, you do not need to adjust it. If it does not read close to 75 per cent, note the difference between your hygrometer reading and 75 per cent.
Step 5 — Correct to the standard	If your hygrometer is adjustable, immediately adjust the reading to 75 per cent. If your hygrometer cannot be adjusted, record the difference you noted in Step 4. In the future, each time you take a reading from your hygrometer, you will need to add or subtract that difference.

Figure 3 Hygrometer calibration using everyday household items

Humidity: How Much Is Too Much, How Much is Too Little?

Experts have developed rules of thumb to help homeowners make decisions regarding humidity levels in their house. The limits should be used as guides only. Acceptable or comfortable humidity levels will actually vary from season to season, from house to house, and even between rooms in the same house.

Rules of Thumb

To prevent window condensation during the heating season, the recommended indoor RH is 30 per cent to 50 per cent. When it is below -10°C (14°F) outdoors, recommended indoor RH is 30 per cent.

Taking Action

Humidity can be controlled. If the relative humidity in your home is too high, you can reduce it; if it is too low, you can increase it.
In summer, you can reduce house humidity levels by the use of a dehumidifier (see the About Your House fact sheet Choosing a Dehumidifier) or by running an air conditioner.
In winter, a house that is too wet usually has some high moisture sources (for example, a damp basement, roof leaks, many plants). Deal with these problems first. If high humidity persists, you may need to make simple changes in your family’s habits, such as remembering to open or close doors or windows. Or, you can install equipment, such as exhaust fans in bathrooms or a heat recovery ventilator (HRV), to remove excess humidity.
Very low indoor RH levels in the winter may result from cold, dry air leaking in from outside. In this case, sealing up the house by weatherstripping and caulking will improve humidity conditions indoors and may reduce your heating bills at the same time.
If low humidity problems persist, despite airtightening the house, consider the use of a humidifier. Humidifiers — both stand-alone humidifiers and humidifiers attached to your furnace — will increase indoor RH levels. But if they are not installed, used and maintained properly, they can also be sources of excess moisture and mold in your home.

Curing Yeast Infections in Hospital Patients

Curing Yeast Infections in Hospital Patients Using a Pathogen

May 8, 2010 Frank Parker

Researchers may have found a cure for yeast infections in hospital patients. And they used another cause of hospital acquired bacterial infection to do so.

One of the agents that cause hospital-acquired infections associated with medical implants is also the common cause of thrush yeast infection, Candida albicans. This fungus is present in and on all of us. Normally it doesn’t cause a problem unless a patient’s resistance is lowered. It can also thrive on plastic surfaces, which is why it sometimes causes problems for patients with catheters, pace-makers or prosthetic limbs.

Pathogen Resistant to Most Antibiotics

The bacterium Pseudomonas aeruginosa is also very common, existing in soil and pond water. Again, humans are normally resistant to infection by this pathogen but it is extremely resistant to most antibiotics. When patients whose immune systems are compromised – for example as a result of undergoing treatment for cancer or because they have AIDS – come in contact with P. aeruginosa then almost any part of the body can succumb to serious infection. (Kenneth Todar, Todar’s Online Textbook of Bacteriology, accessed 8 May 2010)
P. aeruginosa also causes serious problems in patients with cystic fibrosis or burns. So it is quite surprising to find that this deadly pathogen could lead to a cure for hospital acquired yeast infections. But that is what researchers at University College Cork have found, as reported in the May 2010 edition of Microbiology. ("Fighting fungal infections with bacteria," University College Cork Latest News, Accessed 8 May 2010)
The team discovered that molecules produced by P. aeruginosa bacteria were able to hinder the development of C. albicans ‘biofilms’ on silicone, when the yeast cells clump together on the surface of the plastic. This biofilm formation is a key aspect of C. albicans infection and is problematic as biofilms are often resistant to the antibiotics used to treat them.

Designing Drugs to Destroy Yeast

The team was led by Dr John Morrissey who said, “Candida albicans can cause very serious deep infections in susceptible patients and it is often found in biofilm form. It is therefore important to understand the biofilm process and how it might be controlled.”
It is not the intention to introduce the bacterium directly to medical equipment carrying the yeast biofilm. Rather, researchers believe that understanding the mechanism by which the bacterium interacts with the yeast to destroy it will help them to design drugs that can be used to disperse the biofilm after it forms or that might be incorporated in the plastic to prevent biofilm formation on medical implants.
“The next steps are to identify the chemical that the bacterium produces and to find out what its target in the yeast is. We can then see whether this will be a feasible lead for the development of new drugs for clinical application,” according to Dr Morrissey.
Dr Morrissey is a lecturer in UCC’s College of Science, Engineering and Food Science where his team conducts research into sensing and signalling in yeasts. His work includes seeking ways to exploit yeasts and fungi in industrial applications for biotechnology.

Read more at Suite101: Curing Yeast Infections in Hospital Patients Using a Pathogen http://medical-biotechnology.suite101.com/article.cfm/curing-yeast-infections-in-hospital-patients-using-pathogen#ixzz0nbW9CY3O

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A Speech by Chetan Bhagat at Symbiosis - Worth Reading It!

 Dear All, 


Please Read this and Try to Implement in your life at least the core of the speech.  I'm sure it will help you improve your life.

Here below is the content of his speech:

Don't just have career or academic goals. Set goals to give you a balanced, successful life. I use the word balanced before successful. Balanced means ensuring your health, relationships, mental peace are all in good order.
There is no point of getting a promotion on the day of your breakup. There is no fun in driving a car if your back hurts. Shopping is not enjoyable if your mind is full of tensions.

"Life is one of those races in nursery school where you have to run with a marble in a spoon kept in your mouth. If the marble falls, there is no point coming first. Same is with life where health and relationships are the marble. Your striving is only worth it if there is harmony in your life. Else, you may achieve the success, but this spark, this feeling of being excited and alive, will start to die.

One thing about nurturing the spark - don't take life seriously. Life is not meant to be taken seriously, as we are really temporary here. We are like a pre-paid card with limited validity. If we are lucky, we may last another 50 years. And 50 years is just 2,500 weekends. Do we really need to get so worked up?

It's ok, bunk a few classes, scoring low in couple of papers, goof up a few interviews, take leave from work, Enjoy with your friends, fall in love, little fights with your loved Ones . We are people, not programmed devices.

"Don't be serious, be sincere."!

Train Your Dog

When understanding how to train a dog, you need to understand the reasons behind your dog’s specific behaviors. Dogs are not like humans, and may demonstrate behavior that is “bad” when not properly trained. To avoid this, it’s important to know how to train your dog properly and professionally. Here is a general guide to help familiarize you with the process of dog training, and the methods you can use to understand how to train a dog.
Socialize Your Dog
Many people fail to realize that an important part of understanding how to train a dog involves socialization. Socialization is just as much a part of dog training as obedience-related commands. The concept of socialization is fairly simple: expose your dog to as many situations, events and environments as possible. Dogs that are not properly socialized at a young age will tend to be fearful of new situations, which may cause aggressive or defensive behavior. This is also one of the most important concepts to understand about how to train a puppy, since puppies will be the most open to a socialization dog training program.
To socialize your dog, begin by first making it a point to bring them outside of the house each day. Take them for walks in areas with a lot of people, such as a park or crowded street. Make sure your dog is well-behaved enough so that they can interact in these environments without getting excited. It’s best to do this when your dog is still a puppy, since they are more prone to being open to new experiences. The concept of “how to train a dog” involves the willingness to expose your dog to new activities.
How to Train a Puppy
Apart from socializing a puppy with the outside world, it’s also very important to start a home puppy training program as soon as your puppy becomes a member of your household. Puppies are open to learning new things, and will respond best if you begin establishing their role at an early age. When understanding how to train a puppy, it’s important that you are extremely patient. Not all puppies are able to understand commands right away, and may require some time to become acquainted with their new home.
Spend at least 4 hours with your puppy each day, though this time should not be dedicated entirely to training. Take your puppy out into the yard, engaging in healthy outdoor playtime. You can also help expend some of their seemingly limitless energy by taking a quick jog around the yard, while having them harnessed on a leash. When understanding how to train a dog, it’s important that you are first familiar with how to train a puppy.
Generally speaking, there are two ways to get your dog to do what you want. The first is through the use of punishment. The second is through the use of positive dog training. Positive Training is the most effective and intelligent method to train a dog. Still you should know about punishment to improve your dog’s performance.
Punishment
Punishments implant fear in your dog. This can lead to aggression and other behavior problems. Also, punishment as a training method is not usually effective as the dog needs to learn correct behavior as much as he needs to learn what you consider inappropriate behavior.
Positive Dog Training
Positive dog training puts the spotlight on the things your dog does right, and it is the most effective way to train your dog. Positive dog training is quite simple and can be broken down to include just two techniques: ignoring bad behavior and rewarding good behavior.
There are many situations in which you should ignore bad behavior. Of course, this doesn’t apply to every situation, but for training in many areas, such as, barking, begging, ignoring the bad behavior is very effective.
Ignore Bad Behavior
Many pet owners make the mistake of unintentionally rewarding bad behavior. For example, your dog jumps all over when you walk in the door, so you pet him and talk to him. After all, you’re as happy to see him at the end of a long day as he is to see you. The problem is that now your dog associates jumping with getting attention.
Even if you yell at a dog (which you should never do) some dogs may still think that is positive. To many dogs any attention is good attention.
What you need to do instead is ignore the bad behavior. Of course, you can still say “NO” when your dog is misbehaving. But you should say “NO” and then move on.
Are you trying to train your dog not to bark or whine? Then don’t keep talking to him when he is barking or whining. Just completely ignore him when he is making noise. As soon as he quiets down, pay attention to him. He will begin to associate being quiet with getting what he wants.
If the dog jumps on you when you walk through the door, simply cross your arms and turn away from the dog. Say “sit”, and if he complies THEN pet him. If he does not, simply walk away.
Reward Good Behavior
When your dog does something right, such as obeying a command, going to the bathroom outside or waiting patiently for you to let him out of his crate, go overboard with the praise. Do whatever you can to make it well worth your dog’s while to behave.
By rewarding good behavior, you are doing more than just teaching him what he should NOT do. You are also using positive dog training to show him what he SHOULD do.
Another problem with punishing your dog is that they often have no idea what the punishment is all about. This isn’t to say that you should never let your dog know when his behavior is inappropriate, but there are many times when ignoring the bad behavior is the way to go.
Positive dog training teaches your dog self-confidence and helps to build a bond of trust between the owner and their pet. Practice positive training, and see just how quickly you get the results you desire.
How to Train a Dog – Playtime
Another important part of understanding how to train a dog involves being willing to engage in playtime. Just like humans, dogs need some time to play and relax. In order to make obedience training more effective, you need to understand that knowing how to train a dog will also require you to designate a period of time each day to playing with your dog. Having this time to relax with your dog will not only teach you how to train your dog more effectively, it can help you to de-stress as well.

Dog Training Guidance