-= 6° such procedures if extensively employed are likely to have significant immediate, long term and perhaps irreversible effects on life forms present on and near the atoll. By affecting life systems on which man depends this will also affecthabitants of the atoll. For areas in which radioactivity is uniformly distributed population exposure will be reduced in proportion tm the area manipulated. For this reason such procedures are likely to be most effectively pursued on a selective basis in areas where local high concentrations of radioactivity exist or where inhabitants will spend large fractions of their time. It will be exceedingly difficult even when detailed soil profile data from the radiological survey become available to balance the benefits of population exposure reduction against the consequence to life systems of extensive soil manipulation. deposited somewhere. Soil removed will have to be If deposited in the ocean adjacent to the atoll, the physical effects on marine forms could be Esteand will have to be evaluated as will the consequences of adding additional " padioactivity to the marine environment. Reduction of dose by covering contaminated areas with uncontaminated soil from sources outside the atoll could introduce plant disease and parasites. (S)Effects on Food Chains Soil manipulation procedures are Likely to have direct impact on most terrestrial food chains. Direct destruction of vegetation ~~ by these procedures is likely to be less important than the disturbance of surface soil relationships necessary for sustaini