at i m -12- : ye Having this background notice that human lung tissue has a well known carcinogenic potential under a number of situations, including exposure to jonizing radiations; and that in the Hanrord dog study induction of lung cancer was observed after exposure to plutonium aerosols. These are a sufficient basis to establish plutonium induced lung cancer as a_ legitimate concern for humans. The following is a review of the official guidance for estimating the carcinogenic effects from exposure to radioactive particulates. ‘1. "(210} The NCRP has arbitrarily used 10% of the volume of the organ es the significant volume for irradiation of tne gonads. There are some cases in which choice of a significant volume or area is virtually meaningless. For example, if a single particle of radioactive material fixed In either lung or lymon noce may be carcinocenic, ine averacaing or dese either over tee lura, nr one cubic centimeter may have |titile to do witn the cacc.. Use of siantficant volumes or Zreas must be looxed on as one of the round off devices which in special cases must give way to detailed study.” NCRP Report #39 Basic Radiation Protection Criteria January 15, 1971. (emphasis added) he « |