title: Epidemiology of organomercury poisoning in Iraq. I. Incidence in a defined area and relationship to the eating of contaminated bread.
abstract: A survey was carried out in a defined area in rural Iraq where there had been many cases of organomercury poisoning following the consumption of bread contaminated by mercury, in order to determine the true incidence of the disorder. The results were compared with those obtained from a similar rural area from which few cases had been reported. A questionnaire was used to determine the amount of contaminated bread eaten and the frequency of symptoms; a simple clinical examination was performed and blood and hair samples were collected for estimation of total mercury concentration. Of 700 people over the age of 5 years in the high-exposure area, 66% admitted to having eaten contaminated bread, while none of the 864 persons in the low exposure area had done so. The mean period during which contaminated bread was eaten was 32 days, but some people had eaten it for as long as 3 months. A mean of 121 loaves was eaten, the maximum being 480 loaves. For the mean number of loaves the intake of methylmercury was likely to have been between 80 mg and 250 mg, but the people who had consumed the largest amount of contaminated bread may have ingested up to 1 000 mg of methylmercury over a 3-month period. Of those with signs of alkylmercury poisoning at the time of the survey, 80% had eaten more than 100 loaves, and 53 (71%) out of 75 persons who had eaten more than 200 loaves showed some evidence of poisoning.The incidence rate for poisoning was estimated at 271 per 1 000; this figure includes a mortality rate of 59 per 1 000, 32 per 1 000 cases with severe disability, 41 per 1 000 cases with mild or moderate disability and 138 per 1 000 cases with only subjective evidence of poisoning at the time of the study.
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D001939:Bread / Q000506:poisoning*; D002648:Child; D002675:Child, Preschool; D002523:Edible Grain; D005260:Female; D005506:Food Contamination; D006801:Humans; D007493:Iraq; D008297:Male; D008630:Mercury Poisoning / Q000453:epidemiology*; D008767:Methylmercury Compounds / Q000506:poisoning*; D008875:Middle Aged; D012424:Rural Population
chemical_list: D008767:Methylmercury Compounds