Which hazardous solid is commonly found in a field environment?

The correct choice for the hazardous solid commonly found in a field environment is asbestos. Asbestos is a naturally occurring mineral that was widely used in construction materials and other products until its health risks became widely recognized. It can be found in older structures, insulation, and some types of equipment, particularly in areas that have not been thoroughly renovated or where older products are still in use.

Field environments, especially in construction or military contexts, may encounter materials that were manufactured with asbestos. The potential for exposure to airborne asbestos fibers makes it particularly hazardous to individuals working in or around these environments.

When considering the other substances listed, lead, mercury, and cadmium, while they are certainly hazardous materials often associated with industrial settings, agriculture, or specific locations (like areas of contamination), asbestos is more characteristically prevalent in older field environments that have not been fully updated or decontaminated.