Methylmercury poisoning in Iraq. An epidemiological study of the 1971-1972 outbreak.

Following the Iraq methylmercury poisoning epidemic in 1971-72, surveys were conducted on selected rural populations to determine the extent of exposure to methylmercury. It was calculated that 40% of those receiving treated grain will have consumed it. Study of death registries in three provincial capitals and their Qada centers reveals that, in the year November 1971 to October 1972, more deaths occurred than in the corresponding period of other years. These deaths were in addition to the 459 deaths which occurred in hospitals. Deaths for the 1-10 and 11-20 year age groups during the year 1971-72 were four-fold higher than the mean of the two preceding and two following years. However, when adjusted for the age distribution of the population, no one age group had a statistically significant higher incidence of poisoning. Registered live births decreased in 1973, the year following the epidemic, but, at the present time, there is not sufficient information to know the significance of this decrease.