Thursday, 17 November 2011

BMA retracts claim about smoking in cars

The British Medical Association has now retracted its claim that secondhand smoke is 23 times more concentrated in a car with all the windows open than in a smoky bar.

The original claim—press released around the world this week—stated that:

There is evidence to suggest that the levels of SHS present in vehicles can contribute to a serious health hazard for adults and children. Further studies demonstrate that the concentration of toxins in a smoke-filled vehicle is 23 times greater than that of a smoky bar, even under realistic ventilation conditions.

In the studies a number of ventilation conditions were assessed, where airflow parameters included average driving speed, presence of air conditioning and open windows. Realistic ventilation is described as driving at average roads speeds with all four windows completely open.

The BMA has now rewritten their briefing paper (the previous version has now disappeared) so that it now reads:

There is evidence to suggest that the levels of SHS present in vehicles can contribute to a serious health hazard for adults and children. Further studies demonstrate that the concentration of toxins in a smoke-filled vehicle could be up to 11 times greater than that of a smoky bar.

In the studies a number of ventilation conditions were assessed, where airflow parameters included average driving speed, presence of air conditioning and open windows.

Aside from removing the now-notoriously fictitious "23 times" claim, it is significant that the BMA has removed all reference to "realistic conditions". As I have said before, when experiments have been conducted in realistic conditions (ie. with one or more windows at least partially open), the amount of secondhand smoke in a moving vehicle is much lower than in a smoky bar. When all windows are closed and the ventilation is turned off, however, concentrations are higher than in a smoky bar. Of course they are. Cars are smaller than bars. That's why people who smoke in a car open the window.

The BMA's half-correction is welcome. I wonder if they will use their formidable PR machine to make sure the media get the message? (Rhetorical question). The fact remains that millions of people have now been informed that secondhand smoke in a car under realistic conditions "is 23 times" more concentrated than secondhand smoke in a bar.

Now, with the world's media having moved on, the BMA has little to lose by quietly announcing that what they meant to say was that secondhand smoke in a car under unrealistic conditions "could be up to 11 times" more concentrated than secondhand smoke in a smoky bar.

Perhaps the BMA should launch a campaign to make people smoke under realistic conditions?


UPDATE:

I'm grateful to Ivan who has left a comment leading me to this interview from the Today programme with Dr Vivienne Nathanson, the head of science and ethics at the BMA. The fact that she wants it to be illegal for people to smoke in their own car demonstrates her weak grasp of ethics. This interview demonstrates her weak grasp of science.

Bear in mind that this immediately followed an interview with Simon Clark who mentioned the debunking of the "23 times" claim in the Canadian Medical Association Journal.

Interviewer: What is the evidence?

Nathanson: Well, the evidence is, in fact, that the levels of toxins that can build up in a car do reach 23 times the levels in a smoky bar...

Interviewer: And that is—sorry to interrupt you—but that is peer-reviewed?

Nathanson: Yes, absolutely.

Interviewer: Everyone in the scientific community accepts that it's true?

Nathanson: Absolutely.

Pretty emphatic stuff, there. Of course, what the peer-reviewed study actually says is...

We recommend that researchers and organizations stop using the 23 times more toxic factoid because there appears to be no evidence for it in the scientific literature.

It's also worth reading this blog post which casts a critical eye on some of the other claims in the BMA's latest report.

26 comments:

F***W*T TW****R said...

Or perhaps they should just stick to shoving their fingers up peoples bottoms. (Jeremy Clarkson, todays Sun).

Smoking Hot said...

Wonder if the '23' times will make a re-appearance at the HOC on the 25th?

Ivan D said...

Didn't Nathanson swear that the 23 times number was based on peer reviewed science on the Today programme?

Anonymous said...

The intro to the BMA paper is quite interesting.

Their goal is a tobacco free society by 2035 and they state that this can only be realized by a "comprehensive, WELL FUNDED, tobacco control policy.

As for PM2.5 levels.

11 times the stated 340 ug/m3 in a smoky pub is all of 3,740 ug/m3.

They do NOT state what is the safe level of exposure to this stuff.

The reasonable standard for INSIDE air quality is the standard established by OSHA for workplaces.

This standard is for respirable particulate (not otherwise specified) and includes unspecified dusts and smoke.

The standard for respirable particulate is a time-weighted average over a period of 8 hours.

The standard for respirable particulate for inside air is 5000 ug/m3.

http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=standards&p_id=9992

That 11 times nonsense is 25% lower than the OSHA permissible exposure level!!!!

Gary K.

Bill Gibson said...

Gary

We now have an EU Approved Indoor Air Quality Standard which is operational throughout all EU Member States (EN 13779). As the originally posted copy mysteriously disappeared off the Internet when knowledge of its existance was made public, we have saved a copy here

http://www.freedom2choose.info/docs/EC_Standard_For_Ventilation.pdf

Detailed explanations are here

http://www.camfilfarr.com/Global/Documents/Brochure/IAQ%20and%20Comfort%20air/IAQ_Indoor_Air_Quality_EN-GB.pdf

Anonymous said...

Ivan D - I'm certain she did.

Jay

Ivan D said...

You are correct Jay

Vivienne Nathanson: The evidence is that in fact the levels of toxins that can build up in a car do reach up to 23 times the levels in a smoky bar.

Interviewer: Is that peer reviewed? Everybody in the scientific community accepts it as true?

Vivienne Nathanson: Absolutely, absolutely

She was not mistaken but lying. I work with scientists and most don't believe a word that the BMA utters. This is their head of science and ETHICS.

Pogo said...

23...? 11...?? Any advance on 11?

Snowdon said...

Ivan,

Nice quote. Have you got a link? iPlayer?

Ivan D said...

Sure Chris

http://www.bbc.co.uk/iplayer/episode/b0174gpq/Today_16_11_2011/

Starts at 1:33:30ish with Simon

Anonymous said...

Second-hand smoke in cars: How did the “23 times more toxic” myth turn into fact?
Author AffiliationsFrom the School of Public Health, University of Sydney, Sydney, Australia Correspondence to:Dr. Ross MacKenzie, School of Public Health, Edward Ford Building (A27), University of Sydney NSW 2006, Australia

Recommendations
We recommend that researchers and organizations stop using the 23 times more toxic factoid because there appears to be no evidence for it in the scientific literature. Instead, advocates of smoking bans in cars should simply state that exposure to second-hand smoke in cars poses a significant health risk and that vulnerable children who cannot remove themselves from this smoky environment must be protected. Further, we recommend citing the 2006 study by Rees and Connelly 34 as reliable evidence that the level of particulate matter found in cars where smoking is allowed exceeds that in the safety guidelines of the US Environmental Protection Agency, particularly for children.

http://www.cmaj.ca/content/182/8/796

harley

Anonymous said...

Exposure to SHS levels in private cars under real driving
conditions is not well documented. We identified only one
study, Rees and Connolly (2006), that reported PM2.5
concentrations in smoking cars under real driving
conditions. The authors measured PM2.5 concentrations in
43 car journeys in the US, and found a mean PM2.5
concentration of 272μgm-3 when windows were closed
and 51μg.m-3 when windows were open.

http://www.cieh.org/assets/0/72/948/70644/63875433-a00d-4f97-95be-d5e9875bf754.pdf

harley

SteveW said...

Job done for the BMA, same 23 times figures just regurgitated on Question Time.
Another complaint gone in, don't expect much by way of response.

Anonymous said...

Dr Enstroms pm 2.5 study and his troubles because of it,he had stated in one place I cant remember where that you just cough this stuff up if it gets into your lungs. 1 micron particles quickly swell due to moisture to 2.5 times there size or there about!
....................

He believes that as a result of publicizing his work, his department has responded by refusing his reappointment as a researcher.

http://www.dailybruin.com/index.php/a...




In particular, his research on fine particulate air pollution in California implies that miniscule diesel particles do not have a significant effect on mortality.

His findings contradict conventional wisdom and other studies, which contend that this type of air pollution causes thousands of deaths each year.

“There’s plenty of data from other studies that show this is pretty dangerous,” said Dr. John Telles, a member of the California Air Resources Board, a government agency working to protect air quality.

The controversy over his research refers to his work on fine particulate air pollution, which refers to dirt, soot, chemicals and other particles smaller than 2.5 micrometers.

Harley

Anonymous said...

Fresh link to enstrom

http://www.dailybruin.com/index.php/article/2010/08/ucla_researcher_james_enstrom_not_reappointed_to_position

Anonymous said...

It appears Enstrom busted the nazis pm 2.5 hopes and even exposed one of the appointees that had lied about having a phd. That his bosses hired and knew about,obviously the guy was a player for the nazis to get their precious junk science thru for tighter CALEPA regs on pollution!


Furthermore, over the years, Enstrom and a few of his colleagues in the School of Public Health have sometimes disagreed strongly about research on environmental health issues, such as the actual danger of diesel emissions. Enstrom's peer-reviewed research is one of the things at the center of the debate in California over regulation of diesel emissions—we're not talking about a petty department squabble.

http://thefire.org/article/12323.html

Anonymous said...

Tobacco Control supporters will go to any length to further their cause, LIES are an integral part of their policy and tactics.

Anonymous said...

This reminds me of the Pell Study and the supposed 17 percent reduction in heart attacks in Scotland which was media headlines.

It was proved to be RUBBISH but is still quoted by the media.

Anonymous said...

http://www.huffingtonpost.co.uk/simon-clark/smoking-ban-in-cars-bma-dictate-how-we-live_b_1099243.html

Smoking Ban in Cars: How Dare the BMA Dictate How We Live Our Lives?

SIMONS CHASING THE ENEMY while their on the run!

He is attacking all their JUNK SCIENCE!

Junican said...

I found this quote in the British Medical Journal:

""The government should take a “bold” step to legislate for a ban on smoking in private cars in the United Kingdom, claim doctors’ leaders.

The BMA has called on the four UK administrations to introduce an extension to current smoke free legislation to include a ban on smoking in private cars, claiming there is compelling scientific evidence to support the move.

The Department of Health, however, has rejected the call, saying there are better ways to encourage behaviour change and promising to launch a publicity campaign next year on the dangers of second hand smoke.

MPs are due to debate the issue on 25 November when the House of Commons will have a second reading of Labour …""


If it is true that the DoH has issued the statement mentioned, then it does not look as if Cunningham MP's proposal has any chance of becoming law.

We must welcome the opportunity (next year) of a new debate about SHS, if in fact this 'publicity campaign' is anything other than a new propaganda blitz.

We must gird up our loins to be ready. Does anyone know a multi-millionaire by any chance?

Anonymous said...

Talk to wiel, Junican!

Ann W. said...

Chris, have you seen this?

Risks Associated With Second-Hand Smoke in Cars Carrying Children

ScienceDaily (Jan. 10, 2011)
http://www.sciencedaily.com/releases/2011/01/110110121617.htm

The paper "Myths, facts and conditional truths: What is the evidence on the risks associated with smoking in cars carrying children?" CMAJ July 12, 2011 183:E680-E684; published ahead of print January 10, 2011, is behind a paid wall but can be found at
http://www.cmaj.ca/content/183/10/E680.full.pdf+html

Michael J. McFadden said...

Note that even the new statement plays a very cute trick with weasel-wording:

"In the studies a number of ventilation conditions were assessed, where airflow parameters included average driving speed, presence of air conditioning and open windows."

A "number of" conditions which "included" the ones listed.

They may ALSO have "included" 23 red-nosed clowns crammed into a Volkswagon chain-smoking big cigars.

A tip off that such may not be far from reality is the fact that they gave themselves away by noting that some of the parameters included "air-conditioning." Now obviously it would have been too outright silly for even antismoking nuts to drive around with all the windows open and think that turning the air conditioning on or off would make any difference.

These yahoos are like a murderer whose initial claims that he was away for the whole week of the murders is found to be lying because he was spotted on Tuesday night (when there was no murder.) He now appears before the court and says, "I swear on me muzzah's greave yer hunner! I fegot I'd stopped back inta town jes' to check if I'd left the gas burners on on Tuesday night! But I wuz gone all th'other nights!"

Yeah, right.

- MJM

Michael J. McFadden said...

"Their goal is a tobacco free society by 2035"

Really? I seem to be remembering the big flashy goal of "SmokeFree 2000."

Odd.

- MJM

Anonymous said...

Michael turning the air conditioner on created a lot of benzene real quick! I got the study some where on that one.

harley

Anonymous said...

Excuse me its the car interior components when left closed up in the heat. But it would play on a carcinogen meter as to when they took a sample.



Please do NOT turn on A/C as soon as you enter the car.





Open the windows after you enter your car and then turn ON the AC after a couple of minutes.





Here's why: According to
research, the car dashboard, seats and air freshener emit Benzene, a Cancer causing toxin


(carcinogen - take time to observe the smell of heated plastic in your car).





In addition to causing cancer, Benzene poisons your bones, causes anemia
and reduces white blood cells. Prolonged exposure will cause Leukemia,
increasing the risk of cancer. Can also cause miscarriage.





Acceptable Benzene level indoors is 50 mg per sq. ft. A car parked
indoors with windows closed will contain 400-800 mg of Benzene. If
parked outdoors under the sun at a temperature above 60 degrees F, the
Benzene level goes up to 2000-4000 mg, 40 times the acceptable level.

http://www.snopes.com/medical/toxins/benzene.asp