What are the four routes of exposure?

‘Routes of exposure’ refers to the entry points through which toxic chemicals enter the body. The four routes of exposure include:

• Inhalation – Inhaling airborne contaminants is the most common way that chemicals enter the body. Every time you inhale, you take in air together with any chemicals that may be present in the air. Airborne chemicals are typically released by contaminated gas, vapors, mists, fumes, and dust.
• Absorption – Direct contact with the skin, eyes or mouth is another way that chemicals can enter the body. Common chemicals that enter the body through absorption include liquids, particulates of dust and smoke, vapors, and gases.
• Ingestion – This includes a variety of liquid and solid chemicals that enter the body through the mouth when you eat or drink. Cigarettes are a common route of exposure through ingestion in smokers. 
• Injection – Injection is one of the least common routes of entry. This may occur through accidents involving contaminated sharp objects or broken glass or through the misuse of syringe needles.

Understanding the routes of exposure is key to being able to take effective preventive measures.