| Subject | English | Spanish |
| environ. | radioactive tracer A radioactive isotope which, when injected into a biological or physical system, can be traced by radiation detection devices, permitting determination of the distribution or location of the substance to which it is attached | trazador radiactivo |
| textile | radioactive tracer | trazador radioactivo |
| environ. | radioactive tracer | trazador radiactivo |
| chem. | radioactive tracer | trazador |
| dril. | radioactive tracer survey | estudio con trazador radioactivo |
| environ. | radioactive tracer technique | técnica de traza radiactiva |
| med. | tracer radioactive method | método de marcado radioactivo |