One beneficial use of radioisotopes is
(1) detection of disease
(2) neutralization of an acid spill
(3) decreasing the dissolved o2(g) level in seawater
(4) increasing the concentration of co2(g) in the atmosphere

A radioisotope is beneficial for detection of disease. Some major uses of this are:
=> Smoke detectore
=> checking of stock
=> aid for biomedical research for cellular structure and bone formation in mammals
=> use to treat cancerous tumors
=> used in research of red blood cells
=> use as a tracer to diagnose anemia
=> use to detect presence of sulfur in the air
=> used in dental fixtures
=> used for science and drug metabolism studies.