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

Abstract

Total and methyl mercury (MeHg) levels in the hair of fishermen are described 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 additional samples were taken from a control group working in a local construction company (age range 26–35). Overall mean concentrations in the hair of the population of fishermen are 4.181±3.220 and 4.025±3.130 μg g −1 for total and MeHg, respectively. The equivalent values for the control are 2.617±1.404 and 2.556±1.391 μg g −1 for total and MeHg, respectively. 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 tendency to increase in those who prefer to eat the entire fish, including the heads. In general, the concentrations of total and MeHg in fishermens' hair are twice the WHO ‘normal’ level (2.0 μg g −1) but are still less than the WHO threshold level (10.0 μg g −1). The results also show that grey hair contains undetectable amounts of Hg and therefore does not reflect individual exposure to this contaminant.