The new interest in determining small changes in environmental radiation levels as evidenced by the establishment of as low as practicable numerical criteria indicates a need for reliable low-level radiation measurements. Though the expected contributions from routine operation of nuclear facilities are small compared to existing contributions to dose from natural radioactivity, cosmic radiation and fallout, monitoring programs should be modified to document actual levels and improve public relations as originally suggested by the ICRP. The relative value of instantaneous environmental exposure rate measurements and continuous monitoring is described. Model experiments, some by the Health and Safety Laboratory, are being performed to establish the ranges of validity of dose assessment calculations and improve monitoring techniques. The importance of studies of background variations, trends in long-term additions to the environment, and pathway-to-man analyses is described.