Science Reporting Caution: Be careful what you claim from a study

The Sunday Edition featured an essay by host Michael Enright about a new study that questions the link between second-hand smoke and lung cancer. The host talked about the Stanford study in the context of the fiftieth anniversary of the landmark Surgeon General’s report on lung cancer and smoking. He overstated the conclusion of the study when he said second-hand smoke does not cause lung cancer. The public health community complained in large numbers. The program clarified the statement on its website and on air. One group of complainants, represented by Garfield Mahood, President of Campaign for Justice on Tobacco Fraud, asked for a review. They felt the essay and its retraction were inaccurate and that there was a bias and an attack on anti-smoking activists, who he said prefer to be called tobacco control advocates. I found the items did not live up to CBC policy on science reporting but there was no evidence of bias.


As the president of the Campaign for Justice on Tobacco Fraud, and on behalf of a group of other individuals largely involved in public health and tobacco control policy, you complained about an essay delivered by host Michael Enright on the January 19 broadcast of The Sunday Edition. There was also a separate complaint from the Council of Ontario Medical Officers of Health of the Association of Local Health Agencies in Ontario. The group represents all medical health officers in the province.

You were alarmed that Mr. Enright referred to a Stanford University study that questioned the link between second-hand smoke and lung cancer. You thought he was wrong to do so, and that he got many of his facts wrong as well. “His editorial, presented with the authority of a magisterial bull, is both ignorant and irresponsible,” you said.

Enright had used the occasion of the fiftieth anniversary of the U.S. Surgeon General’s landmark report on smoking and cancer to talk about a new study on second-hand smoke conducted by researchers at Stanford University. You pointed out that the study had not yet been peer reviewed and therefore should not have been cited. His essay, which you characterized as “a rant,” was based on a news report of a discussion of the study at a conference. The Surgeon General and many other peer reviewed studies affirm a link between lung cancer and second-hand smoke, and there was no mention of this fact. You wrote:

There have been dozens of peer-reviewed articles on the subject in question published in the last two decades. Using a “weight of evidence” approach standard in epidemiology, the Surgeon General concluded in 1986 and reaffirmed in both 2006 and 2014 that SHS does cause cancer in non-smokers.

You also pointed out that Enright was wrong when he stated that the 1964 Surgeon General’s report “established for the first time the clear linkage between smoking and lung cancer.” You said that the first time a causal relationship was established was in a report of the U.K. College of Physicians and Surgeons two years earlier.

You also thought he “demeaned ‘anti-smoking activists’ by attributing to them the fact that ‘second hand smoke kills,’” and going on to say no it doesn’t. You pointed out that it wasn’t anti-smoking activists who made the link, but scientists and epidemiologists:

Mr. Enright attributes the finding that SHS can cause morbidity and mortality in non-smokers to these same “anti-smoking activists”. Overlook on this occasion that “anti-smoking” is tobacco industry language designed to associate tobacco control work with the “antis” of the alcohol prohibition movement. On its face, Mr. Enright’s accusation about who originated the finding is both ridiculous and mischievous. Tobacco control activists did not create the evidence that SHS kills. That conclusion is the finding of respected researchers, the Surgeon General and other prestigious authorities, and reflects the work of the field of epidemiology in several countries. The so-called “anti-smoking activists” have simply been acting in the public interest by educating the public about this significant risk. If not captured by substantial bias, why would Mr. Enright object to smokers being informed that their spouses, children, or co-workers are subject to a significant risk from SHS?

As further evidence of Mr. Enright’s bias you accused him of using descriptors that are “tobacco industry language designed to associate tobacco control work with the ‘antis’ of the alcohol prohibition movement.” You feel that the term “tobacco control community” is more neutral and that is your preferred term of reference.

Mr. Enright clarified some of the points he initially made in a second broadcast on February 2, but you felt it was inadequate and did not address your main concerns.

You also went on to cite other programming from ten years ago to prove a history of bias. Please note I will not refer to anything other than the matter at hand. The Ombudsman’s website clearly states complaints must be made within a year of broadcast. It is my responsibility to consider the policy issues raised in your complaint about this broadcast.


The Executive Producer of The Sunday Edition, Susan Mahoney, responded to your complaints. She did not agree with your assessment of the essay but said she “did agree with you in one respect.” She said the essay “could have been clearer.” She explained the program had taken steps on air and on its web site to “ensure that it is.”

She clarified that Mr. Enright did not defend smoking or say that second-hand smoke was harmless:

In fact, what he said is that the widespread passage of laws restricting where people can smoke is sensible. And he emphasized that second-hand smoke likely exacerbates lung conditions such as emphysema and asthma.

She explained that Enright and the program referenced the Stanford study because an account of it had been published in the Journal of the National Cancer Institute, and that the editors of that “prestigious” journal thought the “results as sufficiently significant that they approved an article summarizing them.” She pointed out that the scientists involved in the Stanford study are “respected medical researchers” and the report is in the process of peer review. The essay was written to mark the 50th anniversary of the Surgeon General’s report, she said, and it was in that context that this new study was noted. She acknowledged that the 2014 Surgeon General report, and many others, confirm a link between second-hand smoke and cancer, but that was not what was newsworthy in this case:

But it is against this background that Mr. Enright set the surprising conclusions of a newsworthy new study that appears to contradict that widely-accepted knowledge.

She acknowledged that this study is not conclusive, but the findings are “intriguing and newsworthy” because they “run counter to the accepted wisdom on the subject and if confirmed may mean a re-evaluation of the risks we associate with second-hand smoke. That was the point of the essay.”

She also acknowledged that other earlier studies linked smoking to lung cancer, but the U.S. version was the first report to get significant media attention in Canada and the United States. The point was to emphasize the impact it had and the lives that have since been saved because of the impact of the report.

She told you that Enright meant no disrespect by referring to you and your colleagues involved in the control of tobacco. She said that using the term “anti-smoking activists, while a term you find fraught, is used widely to “describe those ads, campaigns, individuals and organizations opposed to smoking.” It was used for clarity. She thanked you for drawing her attention to the sensitivity on this matter.

She agreed that part of the essay was not clear. Mr. Enright said:

“Anti-smoking activists were quick to pronounce that "Second Hand Smoke Kills." Well, no, it doesn't, actually. A recent article in the Journal of the National Cancer Institute described the details of a study involving 76,000 women over a period of more than 10 years. The bottom-line conclusion: the study found no statistically significant causal relationship between lung cancer and exposure to passive smoke. The study did not explore if passive smoke exacerbates other lung conditions such as asthma and emphysema, which it probably does. It focussed solely on the question of whether or not passive smoke causes lung cancer.”

She said that Mr. Enright agrees he was too definitive and categorical in his statement. The programmers acknowledge that the study does not support that conclusion. She referred you to an update published January 22 on the website. In that article, Mr. Enright acknowledges that he overstated the conclusion of the report and provides some more context and facts:

While this latest study suggests that the risk that secondhand smoke will result in lung cancer is small – even insignificant – it cannot be interpreted as the final word on the subject. One of the study's senior investigators, Heather Wakelee, MD, associate professor of medicine and oncology at Stanford, says that because only 901 women in the study developed lung cancer, and only 152 of those cases occurred in never-smokers, “It’s hard to say anything conclusive with such small numbers.”

Dr. Wakelee continues: “We don't want people to conclude that passive smoking has no effect on lung cancer. We think the message is, this analysis doesn’t tell us what the risk is, or even if there is a risk.”

He characterized the debate on second hand smoke as “deeply polarized.” He said there are “credible scientists” who do not think second hand smoke poses significant risk and others, along with major government and health agencies, who say it does.

A shorter version of this essay was read on air on February 2. Since it is difficult to access on the web site, I am reproducing it here in its entirety:

My opening remarks on the program frequently provoke response from listeners, but recently, there has been quite a flood of mail. Two weeks ago, I wrote about a new study that found no statistically significant link between lung cancer and second-hand smoke… this from the Medical Officers of Health of the province of Ontario.

“Tobacco use remains a leading scourge on the health of the public. To suggest otherwise without acknowledging the abundant evidence to the contrary is wholeheartedly irresponsible. Not only is it incorrect, it causes harm by reinforcing the cultural messages implanted by the tobacco industry that smoking should be tolerated everywhere.”

That was from Gordon Fleming, on behalf of the Council of Ontario Medical Officers of Health.

Evidence of the risks of smoking to the smoker is indeed overwhelming. But my remarks focused on a new study which suggests the risks of second-hand smoke may not be what we have been led to believe they are. It's not the only study to that effect and if confirmed, may mean we have to re-evaluate how we look at the risks of second-hand smoke.

It is an astonishing conclusion. But as I wrote in an up-date which we posted on our website this past week, I may have over-stated it when I said that second-hand smoke does not cause lung cancer and won't kill you.

You can find that update, along with more about that new study and related information, on our website at


While Mr. Enright’s essay was linked to the fiftieth anniversary of the landmark U.S. Surgeon General’s report on smoking and lung cancer, it focused on a study that had been in the news. Reading the headline in the Journal of the National Cancer Institute makes it seem like a notable finding: “No Clear Link Between Passive Smoking and Lung Cancer.” It is perfectly valid to have talked about it, and to even question conventional wisdom. While you heard derision and a “rant,” I did not. There was also an underlying message that societal efforts to ban smoking were good and necessary. The essay begins:

It is hard to overestimate the value of the report by Dr. Luther Terry. He established for the first time, the clear linkage between smoking and lung cancer. And he did much more. Dr. Terry showed that smoking was a serious contributing factor in cardiovascular disease and emphysema.

The tobacco companies, of course, went ballistic and spent and are still spending billions to fight the essential wisdom of the Terry report.

It has been estimated that something more than eight million lives have been saved since the surgeon general's report. Yet still, more than 400,000 Americans die each year from smoking-related causes.

It is legitimate to raise questions and to cite other opinions about the level of risk second-hand smoke represents. It is legitimate to ask, if it is a lower risk than other factors, then is it the best way to justify complete smoking bans. It is legitimate to cite researchers who say the reason for banning smoking in public places is social more than scientific. The essay was not rigorous enough, but I detected no malice.

The problem was in what was claimed for the study and the categorical statement that second-hand smoke does not cause lung cancer. It failed, even in the correction, to acknowledge the weight of the evidence, and the consensus in the epidemiological community, that there is a link. It is acceptable to provide other views; it is important to put those other views in a proper perspective. CBC policy says we “seek truth in matters of public interest.” The policy calls on CBC journalists to “invest time and skills to learn, understand and clearly explain the facts to our audience.” The program could have done a better job in doing so.

There is an obligation to provide context and frame an important public policy debate. This was an opening essay, and not a full treatment of the issue, but the framing and context are still important here. Your observation that Mr. Enright cited the 1964 Surgeon General’s report but ignored the 2014 one is a reasonable criticism. Because again, as you point out, the way epidemiologists make decisions is based on a review of many studies before they draw conclusions, and the major reviews of those studies have come to a decidedly different decision than the Stanford study. The 50th anniversary report of the Surgeon General has this to say about second-hand smoke:

Exposure to second hand smoke and its effects was the sole topic of the 1986 report. With regard to the effects of parental smoking on child respiratory health, that report addressed the range of outcomes considered in the 1984 report, comprehensively reviewed the evidence, and offered summary conclusions, but it did not provide statements on the strength of evidence for causation. The 1986 report did, however, comprehensively cover the relationship of lung cancer to exposure to second hand smoke and concluded that involuntary smoking caused lung cancer in never smokers. This causal conclusion was repeated in the 2006 report, which also addressed exposure to second hand smoke. That report also found sufficient evidence to infer causation for the principal adverse effects considered in the earlier reports.

In fairness to the program, it did publish a correction of its categorical statement that second-hand smoke does not cause cancer, and provided more background and context about the Stanford study. Mr. Enright states “he may have overstated it” when he said second-hand smoke does not cause lung cancer and may not kill you. But there is still a kind of equivalence to both sides that does not seem to be supported by the overwhelming body of research. So when Mr. Enright states that “the science of whether or not second hand smoke causes lung cancer is deeply polarized,” he is overstating the case. As he correctly notes, most government and national health organizations say that it does. The debate is around the magnitude of the risk involved and what the response to it should be. This is a legitimate issue to raise.

The treatments lack nuance: “Exploding the myth that second-hand smoke causes cancer,” on the basis of this one study indicates that. Again, the program went some way to clarify in its web update, which provides more details from the study. It was important to put the Stanford study, so heavily relied on for the initial essay, into better context. The essay claimed more for it than is accurate. It is a reminder that scientific studies need thorough evaluation before CBC journalists report on them.

There is another CBC policy that requires programmers to do just that. CBC policy on reporting on scientific issues has several cautions that apply to this episode:

We take care to understand properly and reflect the true implications of medical or scientific study results that we obtain, especially those involving statistical data.

We will exercise caution with regard to results disclosed at a conference but not yet published in a peer-reviewed scientific journal.

In matters of human health we will take particular care to avoid arousing unfounded hopes or fears in persons living with or close to those living with serious illnesses. We will also avoid suggesting unproven benefits or risks to health related to changes in habits of consumption of food or pharmaceutical products.

This is not a question of bias, but there did not seem to be the time taken to “understand properly and reflect the true implications” of the study.

As for your contention that Mr. Enright “demeaned” you and others involved in tobacco control, I think Ms. Mahoney was correct when she told you no such disrespect was present. The term “anti-smoking activists” is widely used and well understood by the audience. CBC language policy balances clarity against respecting the wishes of a described group. It states journalists should use terms and descriptors that are as neutral as possible: “Journalistic style is accurate, concise and accessible.” As the policy also notes, language evolves over time and staff might want to evaluate which terms are used, but the terms used in this piece were appropriate and no indication of bias.

Reporting on scientific studies requires a rigor, even in the context of an opening essay, that was lacking here. That was the policy violation. The essay and the subsequent explanations endorse the value of a smoke-free environment and the work that has gone into creating it. To question the reasoning for the “sensible laws restricting where people could not smoke” is hardly an attack on anti-smoking activists. There is no evidence of bias.

Esther Enkin
CBC Ombudsman