Mercury poisoning in Iraq

Bakir F, Damluji SE, Amin-Zaki L, et al. (1973) Methyl-mercury poisoning in Iraq. Science 181 230-241. 

Organic Mercury. Extremely limited information was also obtained regarding the hepatic effects of organic mercury exposure. An autopsy of four adults and four infants who died as the result of methyl-mercury poisoning in Iraq in 1972 reported fatty changes in the liver occurred in most cases (Al-Saleem... 

Amin-Zaki L, Elhassani S, Majeed MA, et al. 1974. Intra-uterine methyl mercury poisoning in Iraq. Pediatrics 84 587-595. 

Rustam H, Hamdi T Methyl mercury poisoning in Iraq. Brain 97 499-510, 1974... 

Greenwood MR (1985) Methyl mercury poisoning in Iraq. An epidemiological study of the 1971 — 1972 outbreak. J Appl Toxicol 5 148 — 159. 

Rustam H and Hamdi T (1974) Methyl mercury poisoning in Iraq. A neurological study. Brain 97 500-510. 

Parathion poisoning in Columbia, Egypt, Iran, Malaysia, Mexico Organic mercury poisoning in seed grains (Iraq, 1972)... 

Iraq Organic mercury poisoning in seed grains ... 

Organic Mercury. Limited information was located regarding respiratory effects in humans after oral exposure to organic mercury. Two boys who died after eating meat from a hog that had eaten seed treated with ethylmercuric chloride developed bronchopneumonia and edematous alveolitis, and required artificial ventilation (Cinca et al. 1979). Bronchopneumonia was also identified as the cause of death in four adults and one infant who died as the result of methylmercury poisoning in Iraq during 1972 (Al-Saleem and the Clinical Committee on Mercury Poisoning 1976). It is unclear whether these respiratory effects were the result of direct effects on the respiratory system or were secondary to other effects. 

Methylmercury compounds undergo extensive enterohepatic recirculation therefore, introduction of a nonabsorbable mercury-binding substance into the intestinal tract should facilitate their removal from the body. A polythiol resin has been used for this purpose in humans and appears to be effective. The resin has certain advantages over penicillamine. It does not cause redistribution of mercury in the body with a subsequent increase in the concentration of mercury in blood, and it has fewer adverse effects than do sulfhydryl agents that are absorbed. Clinical experience with various treatments for methylmercury poisoning in Iraq indicates that penicillamine, N-acetylpenicillamine, and an oral nonabsorbable thiol resin all can reduce blood concentrations of mercury however, clinical improvement was not clearly related to reduction of the body burden of methylmercury. 

In mercury poisoning in children, it is to be differentiated between pre- and postnatal exposure. On the basis of animal experiments it is known that organic and metallic mercury are transferred via the placenta into the embryo or foetus. Accordingly, teratogenic effects in both Minamata and in the mass poisonings in Iraq occurred. 

In the poisonings in Iraq, the mercury concentrations in the blood were measured, in spite of the fact that due to pharmaco-kinetic reasons this method of measurement of mercury levels is more suited to the determination of acute exposure rather than for long term exposures. In persons who were over 9 years of age, the levels amounted to as much as 5 ppm (Bakir et al., 1973). Phelps et al. (1980) ascertained in the case of exposed Americans a relation between the concentrations in hair and blood of 300 1. Correspondingly, levels of up to 700 ppm mercury in hair were measured in Iraq. In the case of breast feeding mothers, the milk contained 5 to 6% of the mercury concentration in the blood. The blood concentrations in the breast fed children were the same or lower, if they had not been exposed in utero. These children did not display any symptoms of poisoning. In contrast, the blood levels of breast fed children who had been exposed in utero amounted to 2.5 ppm that is almost threefold the levels of their mothers. Some of these children showed severe damage of the central nervous system. Thus we can assume that newborn babies of chronically exposed mothers are subjected to a higher burden than the mothers themselves. 

Fungicides have caused a number of human health disasters. In the late 1950s, approximately 4000 people in Turkey were poisoned by hexachlorobenzene that had been applied to seed grain to protect against soil fungus. Adults and particularly children developed diseases of the skin and bone. In Iraq, a similar incident occurred when people consumed grain coated with a mercury compound. 

Many human tragedies have been caused by organomercury compounds in food. In the twentieth century, mercury compounds, usually the most toxic types, were applied as fungicides to seeds. Large-scale poisoning occurred in Iraq in 1971-1972 as a result of an appalling error, when seeds contaminated with Hg compounds were sold for consumption. After that event, the application of Hg compounds in farming practice declined, but a fair amount of the element remains in the soil. 

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