Use smoke detectors and Carbon monoxide alarms. Make sure the batteries are fresh. Never use the stove to heat the home. This is a fire hazard as well as a pollution source when used this way. If you must use these, never do so in a closed room, and open the window a bit for fresh air.
Most space heaters can cause serious burns, too.
However, lead-contaminated dust is the most common source. The issue, especially for small children, is that, as they crawl and play, they collect dust on their hands and toys. When these are put into the mouth, or when eating, tiny bits of lead are eaten. Even though the child does not look sick, these small amounts of lead can cause serious problems. Lead paint was made until 1978.