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Indoor environments

Wood burning

In the fall and winter, many Ottawa residents burn wood as a primary or additional heat source for their homes. Wood burning creates pollution and steps should be taken to burn wood safely in order to reduce the quantity of smoke both inside and outside the home.

Wood smoke is one of the largest pollutants affecting air quality in Ottawa. Smoke moves easily in the outside air and is drawn indoors where it can build up inside the home. We spend 85 per cent of our time indoors during the winter months so it is important that our indoor air is clean. Young children, the elderly and the chronically ill are most vulnerable to the affects of wood smoke. They are also most likely to spend more time indoors during the winter.

Although many people enjoy the smell of wood burning, the smoke contains chemicals and contaminants that are not healthy for us or for our environment. Well-documented health effects associated with wood smoke include respiratory infections and irritations, the onset of asthma, and, in rare cases, deadly carbon monoxide poisoning.

To help protect your health and the health of your family and neighbours:

  • Replace older wood burning equipment with new, high-efficiency and low-emission appliances.
  • Look for a wood stove that has been approved by the US Environmental Protection Agency and certified by the Canadian Standards Association.
  • Start your fire with newspaper and dry kindling.
  • Burn only clean, dry and well-seasoned wood and newsprint.
  • Never burn garbage and products such as cardboard, which contains chemicals that end up in our lungs.
  • Keep fires small and hot. Smouldering fires create more smoke.
  • Install smoke alarms and a carbon monoxide detector in your home.

For more information, please contact Ottawa Public Health at 613-580-6744 or visit the Environment Canada web site.


Animal bites can be dangerous. Find out more about dog bites, and rabies.

Safe Visits to Live Animal Exhibits

Children love to visit farms and other exhibits which feature live animals. They are fascinated and entertained by the exhibits and develop an enhanced appreciation for other living things.

Unfortunately, there have been a number of outbreaks of E coli illness over the past few years in North America resulting from contamination at petting farms and agricultural exhibits. This can result in serious illness and death in vulnerable populations such as children.

It is important for parents to be aware of specific steps to prevent the transmission of diseases such as E coli infection to children and to ensure a safe and enjoyable experience.

Ensure that the following precautions are followed when visiting a Petting Zoo, farm or other animal exhibit with children in your care:

Recommendations Pertaining to the General Public:

  1. Wash hands with soap and water after touching the animals.
  2. Wash hands with soap and water before eating.
  3. Avoid touching your face and mouth before washing your hands with soap and water.
  4. Do NOT use baby wipes in place of handwashing as they do not kill germs like
    E. coli
  5. Pay attention to any signs that indicate which animals can and cannot be touched.
  6. Do NOT drink unpasteurized milk (directly from the cow).
  7. Do NOT eat or drink while touching animals.
  8. Visit the doctor if you develop bloody diarrhea.

For more information regarding the prevention of illness at animal exhibits, please call Ottawa Public Health at 613-580-6744.

Radon in Your Home

What is radon?

Radon is a naturally occurring radioactive gas released when uranium in soil and/or rock breaks down. Radon is invisible, odourless and tasteless. Radon does not tend to be a health issue outdoors, as atmospheric mixing dilutes the gas to low concentrations.  However, in a confined space – like a basement – radon can accumulate to high levels, which can present a health risk.   


How can I be exposed?

 Radon can seep into a building through dirt floors, cracks in foundations or concrete, sump pumps, joints and basement drains.  Well water can also contain trapped radon, which may be released into the air when water is drawn.

© Department of Natural Resources Canada. All rights reserved.

Radon can seep into a building through dirt floors, cracks in foundations or concrete, sump pumps, joints and basement drains.  Well water can also contain trapped radon, which may be released into the air when water is drawn.

What are the health implications?

When a radioactive gas, like radon, is inhaled, it naturally breaks down into radioactive particles that can be trapped in your lungs when you breathe in. This may cause damage to lung tissue, which can develop into lung cancer over the course of a lifetime.

The health risks from radon exposure are long-term and often depend on three things:

  1. The level of radon in your home or building
  2. The length of time you are exposed to radon
  3. Your smoking habits or exposure to second-hand smoke

What can I do?

Studies by Health Canada have shown that radon concentrations vary a great deal across Canada, making it impossible to predict radon levels in any one home or building. The only way to know if you are being exposed to radon gas is to test for it. Testing for radon is easy and affordable. Health Canada suggests that you use a long-term radon detector for a minimum of three months.
There are two options to test buildings for radon:

  1. Do-it-yourself radon test kit
    Can be purchased over the internet, at local hardware, home improvement, or building supply stores, or from Ottawa Public Health*
    The cost of testing ranges from $25 - $170
    *to purchase a kit from Ottawa Public Health, please call: 613-580-6744
  2. Hire a radon testing company
    For a list of certified Canadian radon testing companies consult the Canadian National Radon Proficiency Program (C-NRPP) or call 1-855-722-6777.

What are the acceptable concentrations?

The current Health Canada guideline for radon in indoor air for dwellings is 200 Becquerels per cubic metre, or less.

How can I fix my radon problem?

If a long term radon detection test shows a living or active space to be above the Canadian guideline of 200 Becquerels/m3, Health Canada and Ottawa Public Health recommend that home or building owners consult a certified radon professional to determine the best radon reduction plan to lower radon levels. The concentration of radon gas will determine how quickly you should lower your radon exposure - the higher the level of radon gas in a building, the faster you should take action to reduce your exposure.

How soon to take action to reduce the radon level?

>600 Bq/m³ - Remediate within 1 year 200 - 600 Bq/m³ - Remediate within 2 years <200 Bq/m³ - No action required
Sick house Sad house Happy house

Contact the Canadian National Radon Proficiency Program at 1-800-269-4174 or visit the following website for a list of certified radon professionals who can help reduce the level of radon in your home.


Health Canada, Cross-Canada Survey of Radon Concentrations in Homes – Final Report
Public Health Ontario, Radon Burden of Illness


Health Canada – Radon
How to Fix the Problem?
Canadian Lung Association
Canadian – National Radon Proficiency Program

Contact information
For more information contact
Ottawa Public Health: 613 580 6744


A fully-grown cockroach has a flattened brown oval body with long spiny legs and measures 15mm (3/4”) in length. Roaches can be brought into the home in the form of egg cases that have been laid in groceries, rugs, used appliances, etc. They are not always a sign of poor housekeeping.

Cockroaches thrive in areas where food, water, and shelter are readily available. They tend to live in darkened or damp areas such as around sinks, behind stoves and refrigerators, in drains and cracks. They are often only seen at night. Control of cockroaches can be difficult due to their long life cycle. Every 20 to 28 days, a female drops one to four egg cases (ootheca); each contains 35 to 50 nymphs. Over a period of 100 days, the nymphs reach the adult stage. Consequently any place infested with cockroaches will also be infested with their eggs. You cannot expect instant results.

Remove their sources of food and water

  • Store food in sealed, washable containers
  • Clean any food spills up as soon as they occur 
  • Don’t leave dirty dishes in the sink overnight; empty garbage containers daily and rinse out all recyclable items before putting them in the recycling bin
  • Thoroughly wet-mop floors and baseboards, especially under rugs, furniture, and behind appliances 
  • Wash inside food storage cabinets and keep them clean 
  • Vacuum regularly wherever crumbs or dry pet foods might fall
  • Repair any leaking taps or plumbing and empty pet water dishes nightly (refill in morning)

Block their points of entry and remove areas of shelter

  • Use a foam or silicone caulk to seal all holes in ceilings, floors and walls, particularly around water and drain pipes; a 2mm crack is all they need
  • Remove as much clutter as possible from your home. Don’t keep cardboard boxes and paper bags as these are ideal breeding areas

Physical control

  • Use as many traps as possible to monitor the location of roaches in your home so you know where to concentrate your efforts. Place them under sinks and in the corners of rooms where roaches have been seen at night. 
  • To prepare your own traps, darken the inside of a quart-sized mason jar by wrapping it in paper or painting the inside black; coat the inside of the jar with petroleum jelly to prevent the roaches from escaping. In the morning kill the roaches by drowning them in hot, soapy water and then place the dead insects in the garbage.
  • You can vacuum roaches. To ensure all roaches are destroyed, the vacuum bag should be immediately immersed in hot, soapy water or placed in a sealed plastic bag or container (with no holes in it) for disposal.

Kill those that remain

  • Place small piles (1/4 teaspoon each) of household borax powder in places where they will stay dry, but are out of the reach of children and pets, e.g. under the refrigerator.
  • Borax, diatomaceous earth or silica aerogel with an attractant added are commercially available – they are effective and non-toxic. (Note: Ultrasonic or “electronic” devices neither kill nor repel cockroaches). 
  • Freeze bags of pet food or birdseed to eliminate any cockroaches in them
  • When the external temperature is minus 18oC (0oF), infested appliances or furniture should be left in the garage for several days, as the cold temperature will kill the roaches and their eggs.
  • Alternatively, you can use the services of a pest control contractor to control a cockroach infestation.

In an apartment building or other multi-unit dwelling, community effort is essential to ensure an effective cockroach management program.

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What are moulds?

Moulds are members of the fungus family, along with mushrooms and yeast. There are thousands of different types of moulds, and they are usually present in air, indoors and outdoors. Moulds play an important role in helping to compost decaying materials like plants. But they can pose health risks as well.

How do moulds grow?

Moulds can get inside buildings through doors, windows, heating, ventilation, and air conditioning systems, and through small openings and cracks in walls and foundations. They can also be brought in on clothing, shoes and the skin and hair of people and pets.

Indoor, moulds need two things in order to grow: nutrients (food) and moisture. Nutrients available indoors include

  • dust,
  • lint,
  • dander,
  • building materials,
  • furnishings.

Moulds usually grow in areas, which are damp or humid in places like

  • bathrooms,
  • air ducts,
  • humidifiers,
  • porous insulation,
  • fan coil units,
  • condensation or drip pans.

They can also grow on building materials such as

  • drywall,
  • ceiling tiles,
  • carpet,
  • wallpaper,
  • window casings,
  • foundation walls, especially if these are damp or wet.

How can moulds affect your health?

When most kinds of moulds are present in indoor air at the same level as outdoors, they usually do not pose a health risk. Moulds that grow indoors are usually different from typical outdoor moulds, and can pose more risks to health.

Moulds can release spores (their offspring) and various chemicals into the air. When mould levels build up, they can trigger allergies and asthma attacks in some people. Certain types of moulds can be even more hazardous, especially when they actually grow on indoor surfaces. Some moulds can produce toxins, which can poison indoor air and cause illness. Exposure to elevated levels of indoor moulds can affect health in four major ways:

  • Irritation, causing symptoms like eye, throat, and skin irritation.
  • Allergies, including symptoms similar to hay fever, asthma attacks (between 10% and 30% of asthmatics are allergic to moulds), and dermatitis. Allergies to indoor moulds may not be detected by standard allergy tests, which measure reactions to outdoor moulds.
  • Toxicity, which can cause headaches and flu-like symptoms like fever and cough, diarrhoea and fatigue. Breathing in mould toxins has been linked to serious illnesses and with sick building syndrome (SBS).
  • Infection, normally a risk only for people with severely weakened immune systems, such as those on chemotherapy and people living with HIV/AIDS, and for victims of severe burns whose skin has been damaged. Only certain moulds can cause infection.

Who is at risk?

Anyone can be affected by moulds, but some people are more susceptible than others, including:

  • People with asthma or allergies to moulds;
  • Infants and young children, whose lungs are still developing; and
  • People with weakened immune systems.
  • Factors that increase the risk to health include:
    • Exposure to high levels of moulds;
    • Exposure to moulds for a long period of time, or repeated exposures to elevated levels for short periods; and
    • Exposure to those species of mould, which can produce toxins (poisons).

What is Stachybotrys atra?

Stachybotrys atra (or chartarum) is one species of mould, which can produce toxins (poisons). It is dark green to black in colour, and grows on cellulose-based materials like wood, paper, and drywall when these have been damp or wet for prolonged periods of time. It does not grow on food or on materials like bathroom tiles, and does not grow in the body.

Stachybotrys has been linked to severe illness and deaths of several infants in Cleveland. The infants developed bleeding of the lungs. It is suspected, though not proven, that the infants were exposed to high levels of mould toxins by breathing Stachybotrys spores. The toxins produced by Stachybotrys can cause haemorrhage. Infants are more susceptible to airborne toxins than older children and adults because their lungs are growing very quickly.

There is little documentation available about how commonly Stachybotrys occurs in indoor environments. Until more studies have been done, experts recommend that infants under one year of age should not be exposed to buildings with mould problems or un-repaired water-damage. This is good advice for people of all ages.

What can you do about Moulds?

The best way to reduce indoor mould contamination is to prevent or control conditions that encourage its growth. All surfaces and furnishings should be kept as clean and as dry as possible. Water leaks or condensation problems should be remedied without delay. Caution must be used during mould cleanup, which can release mould particles and spores into the air. A professional can provide guidance on proper clean-up measures. When experiencing extensive mould growth, which may occur when it takes a long time for things to dry after a flood, professional help may be necessary. If you notice mould or moisture accumulation in public buildings like schools, you should notify the principal or superintendent.

Moulds are found everywhere in the environment, both indoors and outdoors. Most moulds are not harmful, but some people with allergies, asthma or other lung conditions, or immune problems may be more at risk from exposure to some moulds. However, no one should be expected to live or work in buildings with ongoing mould problems. If you or a family member experience symptoms that are severe or long-lasting, consult your health care provider and discuss if moulds are a possible cause.

Where can you get more information?

The following agencies can provide information on indoor moulds, their health effects, proper mould clean-up procedures, and advice on health problems related to indoor air quality.

Ottawa Public Health, Environment & Health Protection Division Tel: 613-580-6744, ext. 23806.

Canada Mortgage and Housing Corporation:Tel.: 613-748-2367 TDD: 613-748-2447

The Lung Association CAN-DO Program: Tel.: 1-800-97-CANDO

Bed bugs

Bed bugs are small, brownish insects about the size of an apple seed. They typically come out at night to bite. Anyone anywhere can get bed bugs.

Bed bugs can be brought into a home on used furniture and used clothing. They can also be brought home in your suitcase after travelling.

Bed bugs can be identified and controlled using a licensed pest control company. There are things you can do to control bed bugs such as thorough vacuuming, steam cleaning, drying clothes at high temperatures, reducing clutter and sealing cracks and crevices.

There are no known diseases spread by bed bugs.

If you have bed bugs you can stop bites by “making your bed an island”.

Make your bed an island

Reduce bites right away by isolating the bed.

  1. Get rid of clutter in your room.
  2. To kill the bed bugs and eggs, place bedding and pillows in the dryer on a hot setting for at least 30 minutes 
  3. Pull your bed away from the wall and curtains, and leave it in the centre of the room.
  4. Vacuum your mattress and box spring very well with the vacuum's crevice tool. Make sure to go over seams, handles and buttons. This will remove bugs found on the surface. 
  5. Vacuum your bed frame and headboard including areas where there are screws and fasteners. 
  6. Throw away the vacuum bag contents in a sealed plastic bag and place it in an outdoor garbage can.
  7. If there are cracks or holes in your bed frame, apply some caulking to prevent the bugs from getting in. 
  8. Place your mattress and box spring in a zippered mattress cover.
  9. Do not use bed skirts as the bed bugs will use them to climb back into your bed.
  10. Keep bed sheets and blankets tucked in so they do not touch the ground.
  11. Cover the feet and legs of the bed frame with petroleum jelly (Vaseline). This will make these surfaces slippery and will prevent the bugs from climbing into your bed. Clean the legs and apply a new coat of petroleum jelly as needed.

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What can Ottawa Public Health do to help?

Public Health Inspectors and Public Health Nurses are available to provide information and to answer questions. Please Note: Public Health Inspectors/Nurses will not visit for the purpose of identifying bed bugs. For more information on bed bugs, call the Ottawa Public Health Information Line at 613-580-6744.


If a tenant has a problem with bed bugs, they should notify their landlord, superintendant or property manager so they can take action to try and control the bed bugs. It is the landlord’s responsibility to maintain the rental unit so that it is fit for habitation. It is the tenant’s responsibility to cooperate with the landlord to help manage the bed bug problem.

For additional assistance, the tenant/landlord should call 311 and ask for Bylaw Property Standards

Help may also be available for vulnerable clients dealing with bed bugs. If you are a low income tenant, or if you are receiving Ontario Works or the Ontario Disability Support Program (ODSP), please call 3-1-1, select your language, then ‘4’ for Social Services.  

Rat Control

As rats can be carriers of disease, ingesting food or water that has been contaminated by rat urine or droppings may pose risks to human health.

OPH provides education to those experiencing rodent issues in their home. If you are experiencing a rat infestation and require professional services, you may wish to contact a licensed pest control company.

Since rats can damage your property, look for the following signs of rodent activity:

  • Live sightings
  • Rodent droppings
  • Chewed or damaged items
  • Small holes or burrows in the ground outside of the residence

There are steps you can take to prevent rats on your property.

Step 1: Eliminate food and water sources

  • Maintain composters to prevent rodents from entering
  • Secure garbage (both indoor and outdoor) in rodent proof containers with tight fitting lids
  • Remove pet food right after feeding and clean waste from pet enclosures
  • Eliminate water sources such as, but not limited to, leaky faucets, bird baths and standing water
  • Keep areas around bird feeders and birdbaths clean. Remove bird feeders during a rodent infestation

Step 2: Eliminate hiding and living places

  • Cut tall grass and weeds back from the home’s foundation
  • Remove clutter from around the home, garage and inside the shed
  • Lift wood piles on stands 30 cm (12 inches) off the ground and away from the home

Step 3: Protect buildings

  • Repair cracks in the home’s foundation
  • Use metal weathering stripping under exterior doors
  • Cover dryer, fresh air and attic vents with fine metal screening

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