Nonfire carbon monoxide-related deaths: a survey in Tehran, Iran (2002-2006)

To depict the epidemiology of deaths due to carbon monoxide (CO) poisoning in Tehran, distinguishing those at greatest risk for acute poisoning resulting in death.

A retrospective survey was carried out with regularly collected information set in Tehran's Legal Medicine Organization, with a population of 11.1 million. The data included 666 deaths due to CO poisoning from January 2002 through December 2006. The principal consequence measures were age and sex standardized incidence rates for unintentional, suicidal, and undetermined poisonings for legal authorities.

The overall rate of unintentional poisonings over the 5-year period was 7.5 per 100,000, with an annual rate of 1.5 per 100,000. The 5-year rates were highest in people aged 25 to 34 years: men, 16.4 per 100,000; women, 7.8 per 100,000. For suicides, the 5-year rate was 0.1 per 100,000; annual rate, 0.02 per 100,000. The suicidal 5-year rates were highest in men aged 35 to 44 years, that is, 0.9 per 100,000; there was no case for women. Unintentional poisonings displayed a powerfully seasonal variation with the highest rates being documented in the months October to March. Over the 5-year period, increasing rates of death from CO poisoning were found annually to be approximately 20%.

In this study, middle-age people, young adults, and elderly people were at the greatest risk for unintentional CO poisoning, and rates were highest in the winter months. Death from suicidal CO poisoning was very rare in this study; on the other hand, unintentional CO poisoning deaths are increasing in Tehran. Health authorities require to consider all populations in any prevention plan.