27 * present levels of radiation are sufficiently low that variation by such a factor is not critical. If the radiation levels were to approach applicable guidance of the FRC it would be necessary to define the exposure of individual population groups much more closely « On exception to the geographical uniformity described is the localized distribution of ilodine-131 from atmospheric weapons testing or substantial venting of underground explosions. in 1968. This has not produced significant exposure Similar local contamination is also possible from nuclear facilities. These are monitored, and there are no data indicating significant exposure in 1968. - Question 4 According to the H. E. W.'s Radiological Health Data and Reports, American Air, rain, and river-water is regularly monitored for gross radioactivity. Is anyone monitoring the sea? Especially on the Continental Shelf? What has made the average level of gross beta contamination in American fp air chronically teh times higher than the average gross beta contamination in Canadian air for the past 12 months? | Is it true that, during the atmospheric tests, Canada received more fallout than we did? If so, then why is our air more contaminated now? © According to the Radiation Alert Network, gross beta radioanalysis of the air is "insufficient to assess total human radiation exposure from fallout." Apparently, gross beta analysis fails to detect tritium, carbon-l4, iron-55, beryllium-7, manganese-54, chromium-51, argon-57, and krypton-85, as well as all the alphaemitting nuclides like uranium, thorium, plutonium, radiu, radom,and polonium-210, . be In your opinion, do the present systems of environmental monitoring provide sufficient data for anyone to comprehend the extent to which we are contaminating our environment? -.