Showing posts with label waterpipe. Show all posts
Showing posts with label waterpipe. Show all posts

Wednesday, September 16, 2015

E-Cigarettes – Gateway to Fatally Flawed, Federally Funded Research



The latest addition to a flood of biased, federally-funded e-cigarette research is a JAMA Pediatrics article (here) claiming that e-cig use leads to smoking among teens and young adults. 

First author Dr. Brian Primack (University of Pittsburgh) and colleagues analyzed a Dartmouth-based survey of 16-26 year olds.  As a baseline, they asked never smokers if they had “ever” used an e-cigarette; 16 said yes and 678 said no. 

A year later, Dr. Primack asked: “If one of your friends offered you a cigarette, would you try it?” and “Do you think you will smoke a cigarette sometime in the next year?”  Possible answers for both questions were “Definitely yes, probably yes, probably not or definitely not.”  Participants were at risk for smoking if they gave any of the first three answers – including probably not (see my blog post about probably not meaning yes).  Primack also asked if participants had “smoked at least1 puff of a cigarette in her or his lifetime.”  He did not ask about current smoking (in the past 30 days).  Of 16 people who had ever used an e-cig at baseline, five were “at risk” for smoking one year later, and six had smoked at least a puff. 

As Dr. Michael Siegel observed (here), the authors’ media campaign grossly distorted their data.  Their statements to the press were based on tiny numbers, distorted by “ever” e-cigarette use refashioned as “use”, and “thinking about smoking” or ever having taken a puff repositioned as “regular smoking”. 

In this analysis Primack et al. claimed to include “characteristics that have been previously associated with cigarette smoking and could also be associated with e-cigarette use.”  However, they omitted characteristics that they had previously claimed were important predictors of smoking: use of snus and waterpipes.  Three of the authors – Primack, Samir Soneji and James Sargent – published a study earlier this year from the same survey in the same journal (here), dubiously claiming that snus use and waterpipe smoking are gateways to cigarette smoking. (As I wrote just last week, “If you have ever used one tobacco product, you are likely to have ever used another.”)  This omission is inexplicable.

In addition to Dr. Siegel’s critique, the Primack claims have been questioned by a thoughtful article at FiveThirtyEight aptly entitled, “Ignore The Headlines: We Don’t Know If E-Cigs Lead Kids To Real Cigs.  We do know that omitting important information is a fatal flaw in this study.    

Friday, October 11, 2013

The Hazards of Waterpipe Smoking



One of the hot trends in tobacco use is waterpipe smoking (the terms hookah, narghile or shisha are also used)(description here). Hookah bars are located throughout the U.S., especially near college campuses. 

While waterpipes vary in design, they all allow for charcoal-heated air to pass through a tobacco mixture and then through a water-filled chamber before being inhaled through a flexible hose. Owing to the use of charcoal, the resulting smoke contains toxic by-products of combustion. 

A study published last year in Food and Chemical Toxicology (abstract here) by researchers at the American University of Beirut and the Virginia Commonwealth University compared the smoke from a waterpipe with that from a conventional tobacco cigarette.  The lead author was Alan Shihadeh and the senior author was Thomas Eissenberg, a member of the FDA Tobacco Products Advisory Committee.
Dr. Shihadeh and colleagues first observed the smoking behavior of 31 waterpipe smokers during a 45- minute period.  They then programmed a smoking machine to puff on a waterpipe to produce a representative session; the mainstream smoke was analyzed for various by-products of combustion.  The results for a 45-minute waterpipe session are seen in the table below, compared with the emissions from a single cigarette.



Mainstream Smoke Emissions From a 45-minute Waterpipe Session Compared with a Single Cigarette
Agent (amount)WaterpipeCigarette
Nicotine (mg)1.040.73
Carbon Monoxide (mg)15512
Nitric Oxide (ug)437218
Tar (mg)4649.4
Benzo(a)pyrene (ng)526.6
Volatile Aldehydes (ug)
Formaldehyde5921
Acetaldehyde383587
Acetone118270
Methacrolein122--



mg = milligrams
ug = micrograms
ng = nanograms

The waterpipe smoke contained considerable quantities of toxic by-products of combustion, in addition to nicotine.  Although there are clear differences between a 45-minute waterpipe session and smoking 10 to 30 individual cigarettes daily, the “results were unambiguous,” as the researchers commented. 

Waterpipe smoking produces unacceptable levels of toxic contaminants.  Don’t be snookered by hookah.