Thursday, June 29, 2006

Surgeon General's Report Publicity Focus on Risks of Minute Levels of Secondhand Smoke Exposure Belies Importance of Dose in Determining Health Risk

It is quite clear that in communicating the findings of the new Surgeon General's report on secondhand smoke, the over-riding message to the public was that even small amounts of secondhand smoke exposure are harmful.

The first line of the press release announcing the release of the report stated: "U.S. Surgeon General Richard H. Carmona today issued a comprehensive scientific report which concludes that there is no risk-free level of exposure to secondhand smoke." It goes on to emphasize that "even brief secondhand smoke exposure can cause immediate harm."

One of the four major conclusions of the report highlighted in the Surgeon General's press conference remarks was that: "There is NO risk-free level of secondhand smoke exposure... ." Later in his remarks, the Surgeon General emphasized that "Breathing secondhand smoke for even a short time can damage cells and set the cancer process in motion. Brief exposure can have immediate harmful effects on blood and blood vessels, potentially increasing the risk of a heart attack."

The fact sheet that accompanies the report is entitled: "There is No Risk-Free Level of Exposure to Secondhand Smoke" and goes on to emphasize that "The U.S. Surgeon General has concluded that breathing even a little secondhand smoke poses a risk to your health."

The first fact noted in the brochure that accompanied the report is that: "There is no safe amount of secondhand smoke. Breathing even a little secondhand smoke can be dangerous."

And the Jim Lehrer interview transcript clearly picked up on this theme, as it was entitled "Surgeon General Concludes There is No Safe Level of Second-Hand Smoke."

The Rest of the Story

There are a number of reasons why I'm not so sure that the publicity focus on the absence of any safe level of exposure to secondhand smoke is entirely appropriate and effective as a public health message.

First, the message is not particularly meaningful. One can say that there is no safe level of exposure to any carcinogen. There is no safe level of exposure to car exhaust. There is no safe level of exposure to the sun's rays. There is no safe level of exposure to X-rays. There is no safe level of exposure to the benzene that is found in some sodas. There is no safe level of exposure to radon in homes. There is no safe level of exposure to arsenic that is found in many people's drinking water.

For that matter, there is no safe speed at which you can drive a car without risk of injury or death. There is no risk-free way to have sex with someone who has HIV infection. There is no safe method to travel from one place to another.

So stating that no amount of secondhand smoke is safe is not particularly meaningful. It also didn't take a 727-page detailed report to draw such a conclusion. We knew that already. It follows logically from the fact that secondhand smoke contains carcinogens. In fact, we have known that no amount of secondhand smoke is safe since at least 1961, when a Philip Morris internal report detailed the many carcinogens and toxins in tobacco smoke.

Second, this emphasis on the hazards of minute levels of, and brief exposures to, secondhand smoke seems to belie the importance that the public must place on assessing the dose of secondhand smoke in making decisions about their potential health risk. Dose consists both of the concentration of the smoke and the duration of exposure, and both of these are important considerations that we want the public to be aware of. Don't we?

Maybe I'm wrong, but isn't it more useful and informative to provide the public with a sense of the relative levels of exposure to secondhand smoke in different environments and situations then to scare the public into simply thinking that any exposure is terrible and that (perhaps) all exposures are equally bad? I think that it is important for the public to have some appreciation of the strong and important relationship between dose and risk. And I'm afraid that the overwhelming emphasis on there being no risk-free level of smoke exposure may obscure the importance of the dose-risk relationship.

Failing to emphasize the dose-risk relationship could have negative public health consequences, both from an individual and a policy perspective. From an individual perspective, is it not possible that some people will conclude that since any secondhand smoke exposure is putting them at risk, it doesn't make sense to reduce their exposure if they cannot eliminate it. In other words, for people who cannot avoid some exposure to secondhand smoke, is there any incentive for them to reduce their exposure if they are repeatedly hammered over the head with the idea that their limited smoke exposure is going to kill them anyway?

And for smokers, what incentive is there for them to cut down on their smoking if it is true that even brief exposure to secondhand smoke may cause them to have a heart attack anyway? If you're going to have a heart attack one way or another, why not continue to smoke and at least enjoy yourself before you keel over?

And the Surgeon General implied to the public that children who are exposed to secondhand smoke are going to eventually develop heart disease and cancer. What he said was: "We have evidence now that every day a child is exposed to secondhand smoke, they have higher incidence of asthma. Eventually, they'll develop cardiovascular disease and cancers over time."

The point is that by making secondhand smoke exposure sound so bad, such that even a tiny and brief exposure is hazardous and such that if you are exposed you are doomed to disease, aren't we taking away an incentive for people who cannot eliminate their exposure entirely to reduce it? Are we not taking away an incentive for smokers to quit smoking if they know that they will still hang out in the same smoky bars and be exposed to secondhand smoke. What's the point of their quitting smoking if the secondhand smoke in these bars is going to kill them anyway and there is no perceived benefit of reducing the level of their exposure?

Frankly, I think the people who are going to be hurt by this report are smokers. While for the most part, nonsmokers will be scared by this news and will largely become more vigilant and more aggressive in their attempts to avoid the smoke, many smokers may be alienated by the suggestion that even a few whiffs of secondhand smoke could kill them. There doesn't seem to be any point in quitting smoking by that logic.

This kind of reminds me of the mistake that public health advocates made in telling gay men in San Francisco that the only way to prevent AIDS was to use a condom every time. For some men, that is not a reasonable or possible dictate. It's not going to happen. But if that man believes that even one time without a condom is going to cause him to get AIDS, what incentive is there for him to make efforts to increase the frequency of condom use, especially when that one time has already occurred?

From a public policy perspective, I'm afraid that the Surgeon General's report is basically going to be a green light to expand efforts to ban smoking outdoors in places where people can easily avoid exposure and that it may actually take the focus off of indoor workplaces with extremely high levels of secondhand smoke exposure, such as casinos and bars. And I think it may result in more of a focus on protecting people with transient, periodic exposure to secondhand smoke and further neglect of people who are exposed regularly.

In his interview with Jim Lehrer, Dr. Carmona kept emphasizing the need to eliminate smoke exposure everywhere - in "any place." He included privately owned cars, homes, recreation places, and workplaces, but did not specifically point out any particular venues where exposure tends to be extremely high. In fact, reading the publicity surrounding the report, the main emphasis seemed to be given to regulation of tobacco smoke exposure in homes, cars, recreation places, and outdoors. By focusing so much on "any" exposure to secondhand smoke, I think the publicity may actually take policy makers' attention away from where the real problem lies.

Third, by emphasizing that any brief exposure to secondhand smoke can cause lung cancer, I believe this publicity may well harm efforts to search for the other causes of lung cancer among nonsmokers. Since I've devoted my career to the role of secondhand smoke in causing lung cancer among nonsmokers, I obviously think this is a critical issue, but by giving people the impression that any nonsmoker who gets lung cancer may well have gotten it from secondhand smoke, even if their exposure was minimal, are we not doing a potential disservice to the search for other causes of non-smoking-related lung cancer?

Fourth, when you give a message like this one - everyone is at risk - do you not undermine efforts to try to reach people who really are at the most risk? By scaring everyone in the population into thinking that they are at risk of disease from secondhand smoke, are we not taking attention away, perhaps, from the groups that are at the highest risk because of the highest levels of exposure? And might not these groups be less likely to take action to protect themselves than if the message was that certain groups are at particularly high risk and need to be protected urgently?

In some ways, this approach is really a cop out. Instead of having the acumen to examine risk levels and set priorities in policy making and intervention, you are basically just throwing up your hands and saying: "Everyone is at risk. Everyone needs to avoid secondhand smoke. Everyone - just don't do it!"

Rather than being a call for specific and prioritized actions to prevent disease in the most effective and efficient manner possible, it seems that the publicity put out by the Surgeon General's office is more of just a general public scare, devoid of any priorities, focus, or policy or intervention directives. It appears more like a vague warning of "Fire," rather then a clear directive like "Fire at 12 Main Street. Evacuate 12 Main Street, and then 8 and 10 Main Street." You don't want to go on television to tell people that there is a fire at 12 Main Street and everyone is potentially at risk. You want to first evacuate those buildings. We need to have some sense of direction and priorities in public health, and they should be based on a rational assessment of levels of risk. And that means that you have to evaluate and consider dose.

In some ways, I believe that the basic message here - everyone is at risk and the dose doesn't matter; no matter how small the dose, you are still at risk - may be a counter-productive one. Or at least it may undermine some of the very important findings of the Surgeon General's report. The report reviewed, for example, the levels of secondhand smoke exposure among different population groups and came to some conclusions that should guide policy makers. But those conclusions are completely obscured by the all-out emphasis on the absence of any safe level of exposure.

Before I close, it is worth noting that I am not offering as a reason why the message - there is no safe level - may be inappropriate is that it is incorrect. I am not suggesting that this message is inaccurate (unlike the claim that a brief exposure can cause heart disease or lung cancer). Of course there is no safe level. There is almost nothing that is completely safe. And especially not exposure to a bunch of carcinogens.

It seems odd to me that the tobacco control field is the only one where we seem adamant on emphasizing the concept of no safe level of exposure (with the possible exception of the "you have to use a condom every time" advocates). I'm not sure what the point is. Perhaps it's to scare people into avoiding smoke. And maybe that's a good thing. But perhaps, instead, the effect will be to obscure intervention and policy priorities. And to pit nonsmokers against smokers more vehemently. And to allow the anti-smoking movement to shift its attention from workplaces to the great outdoors, and then to cars and homes. And to discourage smokers from quitting.

I don't know the answers. But somebody has to ask the questions.

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