Aldicarb stable isotopes are a set of isotopes that are used to study the behavior and fate of aldicarb, a highly toxic pesticide, in the environment. These isotopes are non-radioactive and can be used to trace the movement of aldicarb in soil, water, and biological systems. The use of stable isotopes allows researchers to gain insight into the environmental impacts of aldicarb and develop strategies for its safe and effective use.