]]]]]]]]]]   Says Low Radon Levels May Be Harmless     [[[[[[[[[[[[[[[ 
                       By Malcolm W. Browne,              (11/16/1988)
            [Kindly uploaded by Freeman 07656GAED]

                 Special to the New York Times
           Government warnings may be exaggerated, the physicist says.

          LOS  ANGELES, Sept. 27--Although  exposure to high  levels of 
        the radioactive gas radon causes lung cancer, exposures to  low 
        concentrations  of  the gas may present no hazard  at  all,  an 
        environmental physicist asserted today at the annual meeting of 
        the American Chemical Society.
          The  physicist,  Dr. Bernard L. Cohen of  the  University  of 
        Pittsburgh, said the level of radon that is  hazardous  has not 
        been determined, and he declined to make a direct challenge  to 
        the Federal Government's recent strong warnings about the broad 
        extent of the radon threat nationwide.
          But he cited data that suggested that the Government is being 
        overly  cautious in urging renovation of millions of houses  to 
        reduce radon dangers.
          The  Environmental  Protection Agency says action  to  reduce 
        radon  contamination is warranted in homes with  levels  higher 
        than four picocuries per liter of air. A picocurie is one tril-
        lionth of a curie, which is a standard measure of radiation.
                   
                        Millions of Homes Affected

          The  Federal  Government has warned that millions  of  houses 
        have  levels  of  the naturally occurring  gas  exceeding  that 
        level.   If Dr. Cohen's theory is correct, however, the  number 
        of houses requiring corrective measure may be much lower.
          But Dr. C. Richard Cothern of  the  Environmental  Protection 
        Agency  said: "Unless and until we know that there is a  thres-
        hold  hazard  level,  it is prudent to  assume  that  even  the 
        smallest  amounts  of radon are dangerous." [A  totally  stupid 
        statement, BG. PS: Which of course you can see for yourself.  I 
        just  couldn't let this pass.  We live in a sea of carcinogens, 
        but our lives are getting longer and longer.  Only two types of 
        deadly serious cancers are way up: lung cancer caused by  smok-
        ing and melanoma which is possibly caused by sunlight.  Smoking 
        plus radon may increase susceptibility to lung cancer, so  stop 
        smoking!   Take  beta  carotene,  but  don't  worry  about  the 
        smallest conceivable amount of radon gas that can be measured--
        the  dose  makes  the  poison--worry  about  falling  in   your
        bathtub.]      
          Dr.  Cohen's  tentative  findings are the latest  in  a  long 
        debate  over  the  health effects of extremely  low  levels  of 
        radiation.  Some scientists believe that any exposure to ioniz-
        ing  radiation increases the risk of cancer; others,  including 
        Dr. Cohen, have argued that there is a threshold below which no 
        danger  exists. [Is there any one molecule or atom of any  sub-
        stance that is in the least bit dangerous to a human being?,BG]
          Dr.  Cohen's  findings are based on a review  of  studies  of 
        average radon levels and average lung cancer rates in  counties 
        in  the  United  States, and in  Scandinavia  and  China.   The
        studies,  he  said,  have found that areas  with  high  average 
        levels of radon tend to have low average rates of lung cancer.
          Dr. Cothern of the E.P.A. said agency officials believed that 
        Dr. Cohen's work "warrants more investigation."
          He said: "It's certainly true that no one knows whether there 
        is  a  threshold  of radon exposure, below which  there  is  no 
        hazard."
          
                        Up to 20,000 Cancers a Year

          Senior  Federal  health officials have  estimated  that  from
        5,000 to 20,000 Americans die each year from lung cancer caused 
        by  long-term  exposure to radon.  Most, but not all  of  these 
        deaths,   the  officials  have  said,  occur   among   smokers.  
        Cigarette smoking dramatically raises the danger from radon.
          Dr.  Cohen's  theory would cast doubts  on  these  estimates, 
        although he did not attack them directly.  He and other  envir-
        onmental  experts who spoke here today said that if the  thres-
        hold theory becomes generally accepted, scientists will have to 
        reconsider many current assumptions regarding radiation risks.
          "There doesn't seem  to  be any doubt that radon  is  by  far 
        the most dangerous radiation most of us face," Dr. Cohen  said.
        "But  if  it turns out that radon is harmless below  a  certain 
        level,  then  we should probably stop worrying about  the  very 
        much lower risks created by the fallout from the Chernobyl  re-
        actor accident, medical X-rays, reactor gas leaks and so on."
          Radon,  an  element,  is  an  odorless  gas  created  by  the 
        radioactive  decay of uranium, thorium and radium.  Most  radon 
        is produced by uranium-bearing minerals in soil and seeps  into 
        houses from the ground.  Radon in soil also dissolves in water, 
        which  can  carry it into homes where it is released  into  the 
        air.  The radon decays radioactively in a few days, but in some 
        conditions  it  can  accumulate to high  levels.   When  humans
        breathe the gas into their lungs, the products of its decay can 
        cause lung cancer.

                        Predicting Lung Cancer Rates

          Dr. Cohen noted that the risk of contracting lung cancer as a 
        result of exposure to varying radon levels is calculated large-
        ly  on  the basis of studies of workers in  uranium  and  other 
        mines in the United States, Czechoslovakia, Canada and Scandin-
        avia.
          Predictions  of lung cancer rates in ordinary homes are  made
        by  extrapolating the radon dose rates miners were  exposed  to 
        compared  with their lung cancer rates.  By this  standard,  he 
        said, one could expect roughly 10,000 Americans to die of radon 
        exposure each year.
          "These estimates predict that the lung cancer rate in an area 
        should  be substantially affected by the average radon  level," 
        he  said,  "and  that  there   should  be  a  strong   positive 
        correlation  between  them.  However,  essentially  every  area 
        found  to have a high average radon level seems to have  a  low 
        average lung cancer rate."
          In one area in southeastern Finland, he found, homes have  an
        average radon level of eight picocuries per liter of air, which 
        is eight times as high as the world average and three times the 
        average  for Finland as a whole.  Yet the lung cancer  rate  in 
        that area is significantly lower than elsewhere in Finland, Dr. 
        Cohen said.
          
                        U.S. and Swedish Studies

          Another study cited by Dr. Cohen dealt with Skaraborg  County 
        in Sweden, where the average indoor radon level, 12  picocuries 
        per liter of air, is the highest yet reported for a large area,
        but  where the lung cancer rate is only 75 percent as  high  as 
        Sweden's national average.
          A  similar negative correlation between average radon  levels 
        and the lung cancer rate emerged from studies in Guangdong Pro-
        vince, China, and in 310 counties in the United States.  In the 
        statistics  on American counties, Dr. Cohen said, the  negative 
        correlation is weak, but statistically significant.
          These results do not contradict the belief that high exposure 
        to radon results in a high risk of lung cancer, Dr. Cohen said.  
        In any case, the studies involved averages, rather than case by 
        case comparisons of the radon exposure rates of individual lung
        -cancer victims and healthy control groups.
          Dr.  Cothern suggested that the startling coincidence of high 
        radon  levels and low cancer rates in Dr. Cohen's  study  might 
        have  been  skewed  by  'confounding"  factors--influences  not 
        related to radon risks, like differences in smoking rates or in 
        the amount of time people spend in their homes.
          Participants  in today's meetings agreed, in any  case,  that 
        exposure to high levels of radon exposure is dangerous, and  is 
        also far more pervasive than had been realized a few years ago.
          Dr.  Tom C. Hess of the physics department at the  University 
        of  Maine  in Orono reported that investigators had  found  one
        house  whose  water supply contained 2  million  picocuries  of 
        radon per liter, enough to contaminate the air in the house  to 
        a level far higher than any ever reported in a uranium mine.    

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