The route of exposure plays a significant role in how quickly and extensively a toxicant reaches different body sites. Common routes include inhalation, ingestion, dermal contact, and injection. For example, inhaled toxicants can rapidly enter the bloodstream through the lungs and reach systemic circulation, affecting multiple body sites. Ingested toxicants undergo first-pass metabolism in the liver before reaching other organs, while dermal exposure leads to absorption through the skin.
