By Dick Clapp 

Rachel Carson has been in the news quite a lot recently, first as the object of a diatribe by a U.S. Senator, and also in a series of news stories commemorating what would have been her 100th birthday last week.  Tim Lambert at Deltoid has addressed the false allegations about Carson and DDT, so I will focus on Dan Gardner’s rant (Ottawa Citizen, May 25, 2007) denouncing Rachel Carson and the Prevent Cancer Now coalition spokespeople, Liz Armstrong and Angela Rickman, which was startlingly wrong-headed and riddled with errors. 

Gardner’s piece was apparently intended both to respond to Armstrong and Rickman’s eloquent column on the need for cancer prevention (published in the Toronto Star earlier that week), and to undermine celebration of the 100th anniversary of Rachel Carson’s birth a couple of days later.  He begins by taking issue with the statistics about rising rates of childhood cancers in Canada, and invokes a quote from a 2004 Progress Report on Cancer Control.  In fact, the childhood cancer statistics in the past two decades are steadily increasing, in Canada, the U.S. and Europe.  In Ontario, the rates have been projected to rise through the year 2015, most notably for lymphomas.

Gardner then goes on to minimize the risk of childhood cancer by saying that the rates only rose from a “very tiny level to a slightly higher but still very tiny level” which he describes as 0.0168 per cent annually.  Here, he mistakes the annual incidence rate of 16.8 per 100,000 for a per cent risk of childhood cancer.  The correct per cent, for children aged 0-14 is actually 0.23 per cent, 14 times higher than Gardner’s calculation, using standard methods of which he is apparently unaware.

Then, in a particularly Orwellian section, he talks about the fact that cancer is becoming the number one cause of death is actually good news, not bad news.  This is because other leading killers have been declining faster than cancer.  He veers off to ridicule Rachel Carson for a quote in Silent Spring, noting that cancer accounted for a much higher per cent of deaths in 1958 than in 1900.  In fact, Rachel Carson was referring to the growing awareness of cancer in 1962.  In the sentence preceding the one Gardner quotes, she says “The increase itself is no mere matter of subjective impressions.”  She was exactly right in this chapter, and Gardner is exactly wrong in his interpretation of cancer risk.

Gardner winds up with a straw man argument: Even if there were a cancer epidemic, it would be wrong to blame it on “contamination of the environment by synthetic chemicals.”  He alleges that no reputable scientific body considers this to be the case.  Setting aside which scientific body we should pay attention to, the point Rachel Carson and her many current supporters in Canada and elsewhere have tried to make is that we should seek to avoid carcinogenic exposures wherever possible and thereby prevent cancers.  If that means producing less carcinogenic chemicals in the first place, or phase out synthetic chemicals that deplete stratospheric ozone so that we are more exposed to ultraviolet radiation, or find alternatives to using asbestos in manufactured goods, or help teenagers avoid taking up cigarette smoking, or support tobacco farmers who want to grow food crops or produce cellulosic ethanol, we should do all these things.  Not a single case of cancer will be prevented by dismissing the prescience of Rachel Carson or the commitment of her present-day followers.

Dick Clapp
Professor in the Department of Environmental Health at Boston University School of Public Health, and co-Chair of Greater Boston Physicians for Social Responsibility. Dr. Clapp served as Director of the Massachusetts Cancer Registry from 1980-1989 and worked in two environmental health consulting groups in addition to his teaching and research activities. He was a consultant to the U.S. EPA Science Advisory Board in its 1995 and 2000 reviews of the dioxin reassessment.