Factors influencing the total mercury and methyl mercury in the hair of the fishermen of Kuwait

Total and methyl mercury (MeHg) levels in the hair of fishermen are describ ed anticipating that they represent the critical group for dietary exposure . One-hundred human hair samples were collected from fishermen (Egyptians: age range 25-60), living in Doha Fishing Village, Kuwait. Thirty-five addit ional samples were taken from a control group working in a local constructi on company (age range 26-35). Overall mean concentrations in the hair of th e population of fishermen are 4.181 +/- 3.220 and 4.025 +/- 3.130 mu g g(-1 ) for total and MeHg, respectively. The equivalent values for the control a re 2.617 +/- 1.404 and 2.556 +/- 1.391 mu g g(-1) for total and MeHg, respe ctively. MeHg concentrations are strongly correlated to those of total Hg ( r = 0.999, p < 0.00005) and MeHg concentrations in human hair are unrelated to age and duration of residence in Kuwait but show a positive correlation with the quantity of fish consumed. Levels of Hg in hair also show a tende ncy to increase in those who prefer to eat the entire fish, including the h eads. In general, the concentrations of total and MeHg in fishermens' hair are twice the WHO 'normal' level (2.0 mu g g(-1)) but are still less than t he WHO threshold level (10.0 mu g g(-1)). The results also show that grey h air contains undetectable amounts of Hg and therefore does not reflect indi vidual exposure to this contaminant. (C) 2000 Elsevier Science Ltd. All rig hts reserved.