Analysis on Carbon and Nitrogen Stable Isotope Ratios of Residents’ Hair from Different Cities

Abstract

Stable isotope ratios of carbon, nitrogen, hydrogen and oxygen act as “nature’s recorder”. As a carrier for individual human information, human hair can be measured by isotope ratio mass spectrometry (IRMS) to translate into information about people’s dietary habits, health condition and life track. The basic principle behind establishing dietary lifestyle using isotopic profiles of human hair is the fact that the body’s only source of C, N is a person’s staple diet. It may have significant differences in carbon, nitrogen isotopic compositions of human hair that are living at different regions. The aim of the study was to analyze the discrepancy of 15N and 13C stable isotope ratios in human hair collected from different cities, and explore the relationship between carbon and nitrogen isotope ratios and human groups, such as gender and age. The carbon and nitrogen isotope ratios in the human hair of 247 local residents from 8 different cities were investigated by IRMS. The results showed that there were significant difference in carbon and nitrogen stable isotope ratios of human hair from different cities. The value of δ13C was negatively correlated with vegetable consumption per capita. The value of δ15N was positively correlated with meat consumption per capita, and might be increased by high intake of fish. The relationship between δ13C, δ15N and the factors of gender and age demonstrated that there were no significant difference between males and females, but the age of females showed a weakly negative correlation with δ13C. By comparing the data of this paper and other literatures, the carbon and nitrogen stable isotopes in the hair of residents in China were different from other countries, which implied that there were various dietary habits in different countries.

Keywords

• human hair
• carbon and nitrogen stable isotope
• ratio characteristics