The Puerto Rican government recently passed a law that sets limits on the levels of noise to be permitted around the country's shorelines. The law is aimed at stopping the us navy's military exercises on the Puerto Rican island of Vieques. The islanders allege that the navy's activities are leading to health and environmental hazards (see, Down To Earth, Vol 9, No 21, March 31, p13). The Puerto Rican government has also filed a lawsuit against the us defence department in the district court of Washington dc, charging that the navy's activities are violating the 1972 Noise Control Act, a us federal regulation and also failing to comply with the new law. The lawsuit seeks a permanent ban on future navy activities.