Carbon monoxide poisoning happens because of excess exposure to carbon monoxide (CO), a poisonous, colorless, tasteless, odorless gas that is produced from the incomplete burning of fuels that contain carbon.
Head injury is a broad term that describes many different types of conditions — ranging from bumps and bruises to concussions, skull fractures, and serious brain injuries.
Lead poisoning occurs when lead — once a common ingredient in paint and still used in batteries, pipes, pottery, and some cosmetics — builds up in the body.