| Subject | English | Arabic |
| radiol. | radioactive tracer | مقتفي نشاط إشعاعي |
| 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 | مقتفي الإشعاعات |
| environ. | radioactive tracer technique | تقنية مقتفي الأثر الإشعاعي |