1. Carbon monoxide
2. Dust
3. Radon gas
4. Cat hair

Answer C - Radon exposure is the second leading cause of lung cancer after smoking. Radon gas is produced naturally by the breakdown of uranium in the ground and can get into your home undetected. You can't see, smell or taste it - the only way to know if you have a radon problem is to test your home.

1. Hot beverages, like tea or instant coffee
2. In a pot, to get water to boil faster on the stove
3. To mix instant cereal
4. None of the above

Answer D - Hot water from house pipes increases the leaching of lead in your water. To reduce exposure to lead, have your water tested and do not use hot water from taps to make hot beverages, to mix instant cereal or to get water to boil faster on the stove.

1. Outside the main sleeping areas
2. In the living room
3. In the basement
4. In the kitchen

Answer A - Carbon monoxide (CO) is a harmful gas that has no colour, smell or taste. When you breathe in CO, it reduces your body's ability to carry oxygen in the blood. Install a Canadian Standards Association (CSA) CO detector in hallways outside of sleeping areas.

1. Remove it with soap and water
2. Find the source of the moisture that allowed it to grow and fix it
3. Both (a) and (b)
4. Soak it with bleach

Answer C - Mould growth in a house may cause respiratory problems and allergic reactions in some people. Find the cause and fix it, then clean up the mould with soap and water. You don't need bleach.

1. When it makes your ears ring
2. When you can't understand someone shouting who is a metre away
3. When people from two postal codes away complain about the racket
4. None of the above

Answer B - The regular use of some consumer products, such as sound-making toys and personal stereo devices at very loud levels, can lead to permanent hearing loss over time. Limit your exposure to loud noise.