Dietary homogenization and spatial distributions of carbon, nitrogen, and sulfur isotope ratios in human hair in South Korea

Dietary homogenization has progressed worldwide due to westernization and the globalization of food production systems. We investigated dietary heterogeneity in South Korea by examining the spatial distribution of carbon (C), nitrogen (N), and sulfur (S) isotope ratios using 264 human hair samples. Overall, variation in isotope values was small, indicating low dietary heterogeneity. We detected differences in δ(13)C, δ(15)N, and δ(34)S values between administrative provinces and metropolitan cities; inter-regional differences were typically < 1 ‰. Values of δ(34)S were significantly lower in hair samples from inland regions relative to those from coastal locations, and a similar pattern was observed in δ(15)N values. Understanding geographic variation in δ(34)S and δ(15)N values in human hair is useful for provenancing humans in South Korea.