What are the three primary exposure pathways for humans in toxicology?

The three primary exposure pathways for humans in toxicology are dermal adsorption, inhalation, and ingestion. Each of these pathways represents a different method by which substances can enter the human body and potentially cause harmful effects.

Dermal adsorption refers to the absorption of chemicals through the skin. This pathway is significant as many toxic substances can penetrate the skin barrier, especially when they are in liquid form or combined with solvents that enhance skin permeability.

Inhalation involves the respiratory system, where contaminants present in the air can be breathed in. This pathway can be particularly concerning with volatile organic compounds, particulates, and gases, which can quickly affect health due to direct entry into the bloodstream via the lungs.

Ingestion is the process by which toxins enter the body through the digestive system, typically via food or water that is contaminated. This pathway can be critical for assessing risks associated with pollutants in drinking water or food products.

Understanding these pathways is essential for evaluating exposure risks and implementing safety measures to protect public health. The other choices do not accurately reflect the established pathways in toxicology, such as referring to "digestion" instead of ingestion or introducing terms like "atmospheric exposure," which lacks specificity. This distinction highlights the importance of correct terminology in toxicology.