1/17/03

Dr. Tom Goehl

Editor-in-Chief

Environmental Health Perspectives

Submitted electronically

Dear Dr. Goehl,

Given recent survey data showing that physicians ask their patients about carbon monoxide (CO) less frequently than any other common environmental health hazard (1), I welcome your effort to increase CO awareness by publishing the case report of Devine, Kirkley, Palumbo and White  documenting "MRI and Neuropsychological Correlates of Carbon Monoxide Exposure" (2).  But why include a table purporting to specify "Human responses and approximate ambient CO air levels at various carboxyhemoglobin concentrations" (p.1054)?

Devine et al. report being unable to obtain any CO exposure data and do not even mention their patient’s carboxyhemoglobin (COHb) level, which they apparently saw no need to measure or at least report.   In fact, they give several reasons for not relying on COHb, including (citing Myers) that it is "of little value in diagnosing either acute or chronic CO poisoning" (3).

Certainly no one should rely on their misleading COHb table, which does not specify the duration of CO exposure, air temperature, altitude, the initial COHb level of those exposed, their level of physical exertion, smoking status, blood alcohol level, breathing rate, age or any of the many other variables known to significantly influence the variety and severity of CO symptoms at any COHb level.  

Most misleading is the table’s suggestion that no symptoms of any kind—aside from angina in heart patients upon exertion—should be expected under 10% COHb.   Environmental Health Perspectives is just one of several journals that have recently published large studies of human CO exposure documenting that increases of just 1 to 2 parts per million in average outdoor CO levels—well below those associated with any increase in COHb--are more significantly associated with increasing asthma prevalence (6) and asthma attacks (7) than any other atmospheric pollutant including ozone and particulates.  

Moreover, although Devine et al. reference their COHb table to “data from O’Donoghue” (4), from which it was indeed copied, O’Donoghue’s version does not cite any actual data but merely four other sources.  While three of these contain similar COHb tables, they also do not cite any relevant data, just other published sources. 

I had to check 14 such references before I found what appears to be the original table—itself unreferenced--in a typewritten “Report of Investigations” published by the US Bureau of Mines in 1923, apparently without any external peer review (5).  The table is qualified by the phrase “in general” and clearly not based on any actual human data or study.   Given that the version by published by Devine et al. is thus without any credible foundation, misleading in its content, and irrelevant to their reported case, I urge them to retract it from their otherwise excellent paper. 

Albert Donnay, MHS

Donnay Environmental Health Engineering

508 Westgate Rd

Baltimore MD 21229

410-566-3333

adonnay@jhu.edu

1. Kilpatrick N, Frumkin H, Trowbridge J, Escoffery C, Geller R, Rubin L, Teague G, Nodvin J.  The environmental history in pediatric practice: a study of pediatricians' attitudes, beliefs, and practices. Environ Health Perspect 110(8):823-7 (2002).

2. Devine SA, Kirkley SM, Palumbo CL, White RF.  MRI and neuropsychological correlates of carbon monoxide exposure: a case report.  Environ Health Perspect110(10):1051-5 (2002).

3. Myers RA, DeFazia A, Kelly MP. Chronic carbon monoxide exposure: a clinical syndrome detected by neuropsychological tests.J Clin Psychol 54(5):555-567 (1998).

4. ODonoghue JL Carbon monoxide, inorganic nitrogenous compounds, and phosphorus. In: Neurotoxicity of Industrial and Commercial Chemicals, Vol 1 (O’Donoghue JL, ed). Boca Raton, FL:CRC Press, 1985;193-203.

5.  Sayers RR, Yant WP.  Dangers and treatment of carbon monoxide poisoning.  Reports of Investigations, Department of the Interior, Bureau of Mines, Serial No. 2476 (1923).

6. Guo YL, Lin YC, Sung FC, Huang SL, Ko YC, Lai JS, Su HJ, Shaw CK, Lin RS, Dockery DW.  Climate, traffic-related air pollutants, and asthma prevalence in middle-school children in Taiwan.

Environ Health Perspect 107(12):1001-6 (1999).

7. Yu O, Sheppard L, Lumley T, Koenig JQ, Shapiro GG.  Effects of ambient air pollution on symptoms of asthma in Seattle-area children enrolled in the CAMP study.  Environ Health Perspect 108(12):1209-14 (2000)

NOTES TO EDITOR:

1. I have no financial or other conflicts of interests regarding the issues discussed in this letter.
2. I used COHb as an abbreviation for carboxyhemoglobin because this is the standard form.  The HbCO used by Devine et al. suggests an abbreviation for “hemoglobin carbon monoxide” which is somewhat misleading. 
3. I cited only 2 of the 14 references I checked (the first and the last) because I assumed you would not be willing to print all the others, but I would be happy to provide them upon request if needed.
4. Even if you do not print this letter, I trust you will share it with Devine et al. and give them an opportunity to retract the table in question if they so choose.   (They told me it was not their choice to include the table but that they did so at the request of the editors.)
5. An identical copy of this letter is attached in Word format.