[lmm]

I didn't see anything in your links that addressed second-hand smoke specifically? I think there's a broad consensus that a) tobacco is a significant cause of premature death b) low outdoor air quality (e.g. high PM25) is a significant cause of premature death. But given that tobacco smoke does not show up in your link's list of major contributors to low outdoor air quality, that does not add up to a statement that second-hand smoke is significantly dangerous.

[dahart]

You’re talking about the WHO link specifically? You’re right, that link doesn’t mention secondhand smoke because it doesn’t have a list of major contributors (doesn’t mention cars or factories either). I’d agree it’s probably not a great example of what you’re asking about. I really only posted the WHO link because the WHO uses similar language to the CDC saying things like ‘there are no safe levels of exposure to pollution.’ Might not answer your question, but I think the WHO pollution guidelines published a few months are good reading (https://apps.who.int/iris/handle/10665/345329).

To clarify what I was talking about above, I’m saying the close exposure to smokers is high in urban areas -- in proximity, frequency, and density. There’s also broad consensus that the risks and harms of secondhand smoke are greater in proportion to proximity of the smokers, and that downtown urban areas where people congregate have higher concentrations of cigarette smoke than other places. I’m not personally claiming that average Pm2.5 air quality over time sees a measurable impact from cigarettes. (Even if true, I would expect cigarettes are dwarfed by cars --- but 6 trillion cigarettes a year isn’t nothing, right?) I’m really primarily claiming that being in an urban area like a downtown city center is high exposure to secondhand smoke, being very close to smokers is often a many times per hour occurrence in busy urban areas, walking and entering/exiting buildings.

The CDC link does reference the Surgeon General’s report, which links to a whole pile of primary sources on secondhand smoke. You can also Google around for primary sources for links between smoking and general air pollution. I just tried and found a handful of papers studying outdoor smoke exposure levels, e.g., https://erj.ersjournals.com/content/48/3/918. The main consensus that I see is that for a range of small distances like 10-20 feet, outdoor exposure is plenty high enough to be very concerned about the risks, and that high traffic areas can collect smoke and increase exposure.

[lmm]

> Even if true, I would expect cigarettes are dwarfed by cars --- but 6 trillion cigarettes a year isn’t nothing, right?

I don't really understand this reasoning - the way I see it any effect that's dwarfed by cars might as well be nothing, there's no sense worrying about a splinter in a broken leg.

> The CDC link does reference the Surgeon General’s report, which links to a whole pile of primary sources on secondhand smoke. You can also Google around for primary sources for links between smoking and general air pollution. I just tried and found a handful of papers studying outdoor smoke exposure levels, e.g., https://erj.ersjournals.com/content/48/3/918. The main consensus that I see is that for a range of small distances like 10-20 feet, outdoor exposure is plenty high enough to be very concerned about the risks, and that high traffic areas can collect smoke and increase exposure.

Hmm, sounds like there's a measurable impact which is honestly more than I expected. Still, it seems like a rather cherry-picked measurement; they compare levels in the evening when the traffic street is presumably mostly empty, and note that the traffic street had worse air quality after midnight. They notably don't compare levels in the morning or afternoon when traffic would actually be present and the traffic street presumably had overwhelmingly worse levels of pollution. And they jump straight to recommending a ban on smoking. To my mind to put that on any kind of rational basis you'd have to first set a safe level of PM25 and then propose banning the biggest contributors to PM25 on streets that exceeded it - but reading between the lines of that paper, I assume that once you measure PM25 over a full 24 hours that would mean banning cars long before banning smoking.

[dahart]

> Any effect that’s dwarfed by cars might as well be nothing, there’s no sense worrying about a splinter in a broken leg.

Now we’re conflating several different things. The overall contribution to AQI metrics might be dwarfed by cars, but the overall mortality is not - estimated rates of mortality from smoking related causes is higher than the estimated rates of mortality from pollution.

There might be no sense in looking at cigarette smoking to reduce AQI metrics, but there’s every reason to look at smoking to reduce premature death & hundreds of billions in unnecessary health care expenditure, right?

I don’t want to play armchair researcher and defend that paper, it just happened to be a primary source that I found online. If you want to pick apart the methodology, it’d be better to find a different primary source that empirically demonstrates that proximal secondhand smoke is not harmful.

I take responsibility for sending a slightly wrong impression, I didn’t mean to suggest that smoking is a huge contributor to pollution per-se, I see my comments implied that, but I was only trying to say that outdoor smoke in urban areas is a real risk factor to non-smokers, that exposure to secondhand smoke downtown is a very common occurrence, and it seems to be supported by some research. The point I was making is that secondhand smoke can and does affect people outdoors even if it doesn’t push the AQI, and the reason is proximity - smokers are on average hanging around much closer to non-smokers than cars are. The bulk of cars are far away on the freeway, while the bulk of smokers during the day are working near me, pre-pandemic anyway.

[lmm]

> Now we’re conflating several different things. The overall contribution to AQI metrics might be dwarfed by cars, but the overall mortality is not - estimated rates of mortality from smoking related causes is higher than the estimated rates of mortality from pollution.

But "smoking related causes" is conflating two very different things. If you want to ban smoking because it's harmful to smokers, that's a very different argument from banning smoking because it's harmful to others. It would be very convenient for people who want (out of what is - to them - legitimate concern, but is coming from a very different cultural background to that of most smokers) to ban smoking if secondhand smoking were clearly harmful, but frankly if this kind of paper is the best they have then I strongly suspect that it actually isn't.

> If you want to pick apart the methodology, it’d be better to find a different primary source that empirically demonstrates that proximal secondhand smoke is not harmful.

It's hard to publish a negative result and hard to get funding for work that goes against the narrative. And fundamentally the onus is on the people claiming an effect to demonstrate that it's real.

> The point I was making is that secondhand smoke can and does affect people outdoors even if it doesn’t push the AQI, and the reason is proximity - smokers are on average hanging around much closer to non-smokers than cars are.

Again that's something that I think would need to be scientifically shown rather than just assumed.

[dahart]

To be clear, secondhand smoke has absolutely been scientifically proven to kill people. We’ve been discussing the margins of outdoor secondhand smoke, which is, I admit, harder to demonstrate conclusively with simple stats. Outdoor conditions vary wildly, and proximity certainly matters.

I agree that it’s hard to publish a negative result, but the fact is that I gave you a primary research source that was trivial to find and claims to show only a moderate effect, and you’re still rationalizing your discounting of it and rationalizing why you don’t have any primary sources to support the view that outdoor secondhand smoke isn’t harmful.

It would be silly to claim that secondhand smoke is not harmful outdoors, because we already know for a fact that exposure to secondhand smoke is harmful, and being outdoors just reduces the exposure depending on conditions - wind, dissipation, distance, partial enclosure, etc. There’s no question about whether it’s harmful, the only question is how much.

People aren’t banning smoking because it’s sometimes risky. People are banning smoking because it’s always risky, and non-smokers don’t always have control over their exposure levels. The outdoor exposure levels might be considerably lower than indoor exposure, but why should you tolerate any exposure at all? If you can smell it, you’re breathing additional pollution and toxins. You haven’t given any reasons at all that we should accept and tolerate lower-than-indoor levels of risk and damage just because they’re lower. Some people prefer none, and isn’t that a right they should have in public places? Why should people even tolerate the smell if they don’t like it? Would you tolerate a small amount of tastable but moderately low risk poop from your neighbors in your drinking water, given a choice?

[lmm]

> To be clear, secondhand smoke has absolutely been scientifically proven to kill people.

News to me. If that's true, why do conversations about secondhand smoke involve so much rhetoric and so little science?

> People aren’t banning smoking because it’s sometimes risky. People are banning smoking because it’s always risky, and non-smokers don’t always have control over their exposure levels. The outdoor exposure levels might be considerably lower than indoor exposure, but why should you tolerate any exposure at all? If you can smell it, you’re breathing additional pollution and toxins. You haven’t given any reasons at all that we should accept and tolerate lower-than-indoor levels of risk and damage just because they’re lower. Some people prefer none, and isn’t that a right they should have in public places?

If they should have that kind of right, they should have that right in respect to other sources of air pollution like cars or wood fires too. If it's about risk, we should set a safe level and ban the biggest contributors to it. If it's about cost/benefit, we should do an honest assessment of how much benefit is required to justify how much pollution, and set a corresponding tax level on all sources of air pollution, or a cost/benefit level for which kind of sources we'll allow and which we'll ban. Maybe the missing reason here is that we're quietly putting a higher value on the pleasures of cars (i.e. of upper/middle class people) than the pleasures of smoking (i.e. of lower-class people)?

> Would you tolerate a small amount of tastable but moderately low risk poop from your neighbors in your drinking water, given a choice?

I think the fact that you go for a disgust-based argument is pretty telling: this isn't about the health risks of secondhand smoke, it's about a cultural disgust of smoking and smokers.

I hate smoking and smokers as much as anyone, but this thread has really made me think about public officials' eagerness to ban it.