Bromoform (CHBr₃), dibromochloromethane (CHBr₂Cl), and dibromomethane (CH₂Br₂) in the atmosphere were measured at various sites, including tropical islands, the Arctic, and the open Pacific Ocean. Up to 40 ppt of bromoform was observed along the coasts of tropical islands under a sea breeze. Polybromomethane concentrations were highly correlated among the coastal samples, and the ratios CH₂Br₂/CHBr₃ and CHBr₂Cl/CHBr₃ showed a clear tendency to decrease with increasing CHBr₃ concentration. These findings are consistent with the observations that polybromomethanes are emitted mostly from macroalgae whose growth is highly localized to coastal areas and that CHBr₃ has the shortest lifetime among these three compounds. The relationship between the concentration ratios CHBr₃/CH₂Br₂ and CHBr₂Cl/CH₂Br₂ suggested a large mixing/dilution effect on bromomethane ratios in coastal regions and yielded a rough estimate of 9 for the molar emission ratio of CHBr₃/CH₂Br₂ and of 0.7 for that of CHBr₂Cl/CH₂Br₂. Using these ratios and an global emission estimate for CH₂Br₂ (61 Gg/yr (Br)) calculated from its background concentration, the global emission rates of CHBr₃ and CHBr₂Cl were calculated to be approximately 820(±310) Gg/yr (Br) and 43(±16) Gg/yr (Br), respectively, assuming that the bromomethanes ratios measured in this study are global representative. The estimated CHBr₃ emission is consistent with that estimated in a very recent study by integrating the sea-to-air flux database. Thus the contribution of CHBr₃ and CHBr₂Cl to inorganic Br in the atmosphere is likely to be more important than previously thought.