What symptom is NOT associated with blood agents?

The symptom that is not associated with blood agents is blistering of the skin. Blood agents, such as cyanide, primarily function by interfering with the body's ability to use oxygen at the cellular level. This leads to symptoms primarily related to respiratory distress and central nervous system involvement, including irritation of the nose, eyes, or throat, coughing, and tightness of the chest as the body's oxygen supply is compromised.

Blistering of the skin is characteristic of blister agents or chemical warfare agents like mustard gas, which cause chemical burns and create blisters upon contact with the skin. In contrast, blood agents do not typically cause skin blistering as their primary route of harm is through inhalation or ingestion rather than direct skin exposure. Thus, while the other symptoms are resulting from the physiological effects of blood agents, blistering is distinctly associated with different types of chemical agents.