Obesity has been associated with higher total blood mercury levels, based on animal studies; however, studies that focus on children and adolescents are lacking. We aimed to assess the association between total blood mercury levels and the incidence of overweight and abdominal obesity in Korean adolescents.

The study population comprised 1,567 adolescents (793 boys and 774 girls; aged 10–19 years), who participated in the Korea National Health and Nutrition Examination Survey 2010–2013. We analyzed total blood mercury levels according to obesity status in all participants.

The geometric mean of total blood mercury levels was 1.93 µg/L. Participants with overweight (2.20 µg/L) and obesity (2.17 µg/L) had higher levels than those with normal weight (1.86 µg/L, P <0.0001). The prevalence of overweight significantly increased with elevation of the total blood mercury quartile in both sexes. Increased incidence of abdominal obesity corresponding to increased total blood mercury level was observed in boys. After adjusting for covariates, those in the highest total blood mercury quartile were found to be at higher risk of overweight/obesity than those in the lowest quartile in both sexes (odds ratio [95% confidence interval]: boys, 3.27 [1.66–6.41]; girls, 1.90 [1.03–3.49]). The association between total blood mercury quartile and abdominal obesity was significant after controlling for covariates in boys (2.35 [1.05–5.24]).

Our results suggest an association between total blood mercury levels and overweight in Korean adolescents.