Tuesday, 16 October 2012

More rubbish science from the BBC

The BBC's Michelle Roberts, who it seems has reprinted a press release from the zealots at Aberdeen University without asking a single significant question about its balance, verity or probity, is probably happy in her ignorance should she live in one of the UK's congested cities. She's lapped-up the 'smoking in cars must be banned' message without even bothering to look at the basic flaws in the scientific reasoning.

First, she mentions the WHO guideline air quality level for PM2.5 of  25 μg/m3 as a 24-hour mean. Then she identifies Aberdeen's background level for PM2.5 at 7.4 μg/m3. Ok, fine so far. Then she notes that particulate levels in a car with a smoker on journeys lasting from 10 minutes to an hour reached up to 85 μg/m3. R i i g h t. So if a child spends an hour a day in a car with a chain-smoker in Aberdeen, Michelle, what will its 24 hour mean exposure level be? And will this exceed the WHO recommendation?  (The answers are 10.6  μg/m3 and 'No', Michelle) 

And astonishingly for the 'Health Editor' of BBC news online she appears wholly ignorant of background levels of  PM2.5 in places other than clean and airy Aberdeen. In London, if you walk or cycle near Marylebone Road, the Blackwall Tunnel or Woolwich Flyover, you'll be exposed to 24 hour mean PM2.5 levels of up to 86.5 μg/m3, 69.6 μg/m3 and 38.3 μg/m3 . Not hourly peaks, 24 hour means. 

So Michelle, the science really 'proves' that a child in North London in a non-smoking house is exposed to over 8x the particulates level of a child in Aberdeen who spends an hour a day in a car with a chain-smoker. 

(London particulate levels from London Air Quality Network site maintained by KCL at  http://www.londonair.org.uk/london/asp/advstatsvariousresults.asp?site1=MY7&site2=TH4&site3=GR8&site4=&stattype=rmax&xvalue=98&zunits=none&startdate=01-jan-2012&enddate=30-aug-2012&submit=View&period=dailymean&species=PM25)  

Update
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To be read in context with my response in the comments (clicky to make big)
 
          

12 comments:

Edward Spalton said...

People do not understand the difference between averages and peaks very well. Thirty years ago I did business with an Irish creamery which was establishing a brand new plant.

There was a limit on the amount of average BOD (Biological Oxygen Demand) which the plant was allowed to drain into the river.

The effluent from the site ran down to a sump. When this reached a top level, a pump would discharge it for a short time into the river.

As luck would have it, the inspector from the Board of Conservators dres his sample just as the pump was discharging. The sample, of course, was way over the permitted limit.

I asked whether the inspector knew the difference between average and temporary levels.
"Yes, but he's a keen fisherman" was the reply.
"Are you going to contest it in court?" I asked.

"Yes and I just hope to Hell the judge isn't one of his fishing pals"
was the answer.

Barnacle Bill said...

I must admit I felt a certain level of unease reading her article this morning Raedwald.
Thank you for clearing up this point.
However, I'm still puzzled by the open window statement, which according to the study made none or very little difference.
As a pipe smoker driving along with the windows adjusted for my smoking I see it go straight out the driver's window when I exhale?

PaulB said...

Raedwald: Michelle Roberts may not have produced a balanced article, but you've got your facts wrong.

First, the data you quote are what the site you use calls "maximum daily (24 hour) mean". i.e. it's the highest average in any rolling 24-hour period this year. The site will plot running 24-hour means for you: the line for Marylebone Road is typically at about 20 ug/m3 and goes above 40 only in occasional peaks.

Second, a child "in a non-smoking house" near a major road is certainly not exposed to anything like the particulate levels on the pavement outside.

John M said...

And it wasn't just her. The BBC ran the same piece on Radio 5, Radio 4 and BBC Breakfast this morning without so much as a suggestion that the "established facts" could possibly be challenged.

In fact they added the BMA's call for a blanket ban in cars without so much as a contrary opinion or view. So much for balanced reporting eh?

Raedwald said...

PaulB - Not so. I haven't got my facts wrong - you simply don't understand the science.

Marylebone Road has extended periods of high peaks and low lows, and one doesn't measure the WHO exposure limit simply by averaging these. For example, in the period Feb to April 2012 this site exceeded the daily exposure level for some 70% of the time. I also wrote 'You'll be exposed to levels ...up to..' so the statement is perfectly true.

As for the dispersion gradients of airborne PM2.5s I suggest you look at the scientific papers on the subject (e.g. www.mdpi.com/2073-4433/2/2/96/pdf) - for low-level housing close to roads, PM2.5 levels are not significantly lower.

PaulB said...

Raedwald: I noticed your creative use of "up to", but you left it out of your last sentence about "8x the particulates level", which is simply wrong.

I note that even in your graph where you cherry-pick the two months with the highest ever PM2.5 levels, the average level looks by eye to be about 30.

As for dispersion gradients, the paper you cite is largely irrelevant, since as the authors note "the contribution of regional sources and indoor activities may outweigh emissions from ground-level sources" in the data they looked at, which is nothing like the Marylebone Road peaks. This paper looks at much more comparable data; on the three peak days with outdoor PM2.5 levels close to 80, the indoor level was between 40 and 50.

G. Tingey said...

In theory, Raedwald is correct, and if it is their car, assuming it is actually SAFE to smoke whilst driving (extra object in drivers' hand / distraction, etc ....)
BUT
There is one slight problem - suppose child reacts to smoke & motion & pukes up in the car, as a result?
Quite a common phenomenon I understand ...
[ I think I'll just 'ave a good Larf ]

Anonymous said...

G Tingey: "suppose child reacts to smoke & motion & pukes up in the car, as a result?"

In my experience brats don't need tobacco smoke to promote nausea in a moving vehicle.

Clearly, actual motion causes illness and vomiting. Conclusion, ban free movement of anyone transporting children. Permits and licences available at the Local council offices.

Yea, that should fit right in with the totalitarian banstabators* agenda.


*For once this is not directed at Mr Tingley, just expanding on the comment.

G. Tingey said...

Anon
Nausea in children (& adults) in moving cars has a lot to do with the firmness of the suspension.

I can remember feeling unwell ( @ age ~ 8 ) in an Austin Devon - very soft suspension, whereas my fathers pre-war Ford Popular ( & the Austin 7 before that) had firm suspension & I felt perfectly OK.

I'm told that, until very recently, US cars still had this problem.

Anonymous said...

"Ford Popular ( & the Austin 7 before that)"

My Da, had two Alvi (?), one of them a convertible, a Standard Coventry, a Morris 18 and ford Popular which I learned to drive in.

Cars these days, no character.

Yvonne said...

@G Tingey. My opinion is that if someone is only able to drive without distraction and perhaps one hand or the other not involved in the process of driving, then I'd rather that that someone is not driving at all. What next? Do not listen to the radio or music as it may be a distraction, or perhaps ban passengers altogether. I'd rather everyone who enjoys a cigarette is be able to smoke when and where it suited them but particularly when they are in the car. Ideally good manners would dictate whether or not to smoke with children present. This would not need 'studies' and such like at taxpayers expense to quantify and lobby for bans.

Michael J. McFadden said...

Very accurate analysis. This is a game the Antismokers have been playing for years. Despite the EPA and the WHO *VERY* explicitly warning against the misuse of their guidelines as standards for shorter periods of comparison, they have been routinely trotted out as the "gold standard" to measure environmental tobacco smoke for ANY length of exposure.

There's a second level of deception here as well: the 25mg level is the ideal set as safe for EVERYONE -- even very elderly patients with emphysema and newborn infants. For older children or reasonably healthy adults the standards are much more lenient -- but that's something that's also never noted.

The trick with almost all antismoking research lies in the fact that they tell partial truths, with the parts and the emphases very carefully selected in order to have the desired effects on the media an populace who believe that they're getting the WHOLE truth from "reputable" sources. Why is the truth twisted like that? Two main reasons: Money and Idealism.

To get their grants from the antismoking sources funding those grants they have to promise and deliver the "right" results and interpretations ... or else those grants will quickly dry up. You can sometimes actually see those promises being made, in slightly subdued language for form's sake, in their research proposals. For a good example, see my commentary under Jacob Grier's article at:

http://www.jacobgrier.com/blog/archives/2210.html

That's the "Money" end of the story. But it's also important to realize how that sort of thing grew and why it's grown so strong: basically the researchers believe that smoking is "bad" and that virtually ANYTHING that might cause people to stop smoking is "good." The fear of secondhand smoke drives the limitations on and the stigmatization and denormalization of smokers -- and acts like electric shocks given to rats to guide them into the "desired" behavior patterns.

The thing that's wrong with this is simple: People are not rats, and it is wrong, *very* wrong, that organizations wielding such huge amounts of money and power have given the keys to use that sort of behavioral conditioning on *people*!

I'd like to thank Raedwald for illustrating the scam so clearly in his article and giving me the inspiration to properly describe what went on in this study and is going on in so many others. Remove the money, keep the idealism. If ASH et al can't survive on their own, working from that idealism, then they don't deserve to exist. And they most certainly don't deserve to continue treating people like rats to be conditioned by their tricks.

Michael J. McFadden
Author of "Dissecting Antismokers' Brains"