What is the immediate route of exposure concern for individuals located downwind of a spill?

Inhalation is the immediate route of exposure concern for individuals located downwind of a spill because airborne contaminants can be dispersed through the atmosphere by wind. When a hazardous material is released, it may evaporate or become aerosolized, allowing the particles or vapors to travel significant distances. Individuals downwind are at risk of inhaling these substances, which can lead to acute respiratory effects or systemic toxicity, depending on the nature of the material.

While absorption through the skin and ingestion are potential routes of exposure, they are typically not as immediate as inhalation in the context of a vapor or aerosol release. Injection is generally not applicable in the scenario of a spill, as it would require direct contact with a device or a means not usually associated with environmental spills. Therefore, inhalation is the most critical concern for rapid exposure among those in the vicinity of a hazardous materials spill.