A Spatial Ecological Study on Hair Selenium Level of Residents in Keshan Disease Endemic and Non-endemic Areas in Heilongjiang Province, China.

This study was aimed to provide, by mapping the spatial distribution of hair selenium levels of residents, visualized evidence for assessment of KD elimination from a perspective of selenium nutrition of the residents living in the KD-endemic and non-endemic areas. Using a spatial ecological research design, 401 male permanent residents in KD-endemic and non-endemic areas participated in this study. Demographic information and hair samples were obtained through a questionnaire survey and sample collection, respectively. Hair selenium was measured using hydride generation atomic fluorescence spectrometry. Thematic maps were created, and spatial analysis was conducted using ArcGIS 9.0. The median of hair selenium of the participants was 0.30 (IQR, 0.23-0.34) mg/kg. The median hair selenium of the residents in the KD-endemic areas was significantly lower than that of the residents of the non-endemic areas. The hair selenium levels of residents were spatially clustered, with cold spots and hot spots located in northwest and southwest regions respectively. Residents living in KD-endemic areas may still have selenium deficiency. Measuring hair selenium levels of residents in KD-endemic areas as a molecular marker of selenium nutritional status as part of KD surveillance could provide visualized evidence for the evaluation of KD elimination from a perspective of selenium nutrition of the residents living in the KD endemic areas.