Investigation on Blood and Nail Selenium of Residents in Environment with Different Selenium Levels in Enshi, Hubei Province

Objectives To investigate the level of selenium in blood and nail samples in Enshi with different concentration of selenium in the environment to reflect the absorption and utilization of bio-selenium in local residents.

Methods The blood and nail selenium level of residents living in three sites of each four areas with different levels of selenium(extreme high, high, sufficient and poor selenium) in the environment were examined. Local crops were collected for selenium determination at the same time. Questionnaire was used for the survey of basic situation.

Results The average selenium level inblood and nail was consistent with the trend of selenium in the environment from selenium deficiency to extreme high level of selenium, and a gradient ascent trend of blood and nail selenium with the age was observed. There was a significant correlation between nail selenium and blood selenium level with different selenium level in crops (correlation coefficient r=0.719, bilateral Pearson test P < 0.01). The selenium content of main crop varietiesin the extreme high, high selenium areas in Enshi was significantly higher than that in poor selenium area.

Conclusions The selenium intake in selenium sufficient area and above in Enshi was reasonable, because risk factors for selenium poisoning in extreme high selenium areas had been basically eliminated. There was a significant improvement on selenium intake in poor selenium areas, but an optimal selenium status had not been reached yet. Selenium level in nail sample was also a good indicator for the status of selenium nutrition.