The US study about CO contains a striking conflict of interest on behalf of the co-author, Katharine Hammond [1]. -On the one hand, the latter is a member of WHO TobReg, the group of experts who have “peer-reviewed” and validated the WHO flawed report [2]. -On the other, the co-author should have disclosed that she actually is an “Exposure Assessment Research investigator” for the UCSF FAMRI Center because FAMRI officially funds research on diseases caused by ETS (Environmental Tobacco Smoke). Such an affiliation has obviously influenced the paper that she not only supervised but also co-authored, particularly the concluding sentence: “the high levels of exhaled CO found in this study indicate a possibly significant health hazard from use of waterpipes that requires further study"[3]. _____________ [1] El-Nachef WN, Hammond SK. Exhaled carbon monoxide with waterpipe use in US students. JAMA 2008 (Jan 2);299(1):36-8. [2] Chaouachi K. A Critique of the WHO's TobReg "Advisory Note" entitled: "Waterpipe Tobacco Smoking: Health Effects, Research Needs and Recommended Actions by Regulators. Journal of Negative Results in Biomedicine 2006 (17 Nov); 5:17. doi:10.1186/1477-5751-5-17 http://www.jnrbm.com/content/5/1/17 [3] FAMRI Bland Lane Center of Excellence on Second Hand Smoke at UCSF: “supported by the National Flight Attendant Medical Research Institute (FAMRI) program. FAMRI is funded through a settlement from a class action lawsuit against tobacco companies on behalf of flight attendants who sustained health problems due to exposure to second hand smoke in their job”. http://tobacco.ucsf.edu/index.cfm?ucsfaction=... FAMRI: http://www.famri.org/researchers/awards_histo... http://www.famri.org/about_famri/mission_stat...

Several errors can be found in El-Nachef and Hammond’s paper on hookah (shisha, narghile) smoking [1]. First, the 84-hour abstention condition, which may be useful for cotinine measurements, is not relevant for CO. For some reason, only 10 g of the smoking product were used for a whole 60 min session. This is not in agreement with values retained in most reliable studies of the Middle East where 20 grams are generally used: see cited studies by Shafagoj et al (Jordan) and Bacha et al (Lebanon). Then, the use of 30 g of charcoal is surprisingly high. Shihadeh himself used only one disk of 5.8 g for a whole session of a similar duration. He found that 5 g of the charcoal were consumed [2].

The authors state that mean exhaled CO in Lebanese smokers was 22 ppm whereas the referred to study (Bacha et al.) actually reported 38.5 ppm. In fact, levels vary tremendously because they also depend on ventilation. 10 years ago in France, we measured CO levels fluctuating between 10 and 60 ppm [3]. We immediately issued public health recommendations recently renewed in the light of the epidemic [4].

As a conclusion, we have now enough data to draw practical public health consequences from all the available existing studies: from Jordan to the USA [1] and from Lebanon to France [4]. One clear first step could be to deter hookah users to smoke in ill-ventilated places as the smoker is, let us not forget it, the first victim of environmental smoke.

Dr Kamal T. Chaouachi

_________ References:

[1] El-Nachef WN, Hammond SK. Exhaled carbon monoxide with waterpipe use in US students. JAMA 2008 (Jan 2);299(1):36-8.

[2] Shihadeh A. Investigation of mainstream smoke aerosol of the argileh water pipe. Food and Chemical Toxicology 2003;41: 143-152.

[3] Chaouachi K. Tabacologie du narguilé [Tobaccology of Narghile]. Alcoologie. 1999;21(1/83):88-9.

[4] Chaouachi K. The Medical Consequences of Narghile (Hookah, Shisha) Use in the World. Revue d’Epidemiologie et de Sante Publique (Epidemiology and Public Health) 2007;55(3):165-70.