Carbon and Nitrogen Isotope Composition of Australasian Hair and Fingernails in a Global Context

Global supply chains and industrial fertilizer use have reduced the range δ¹³C and nitrogen δ¹⁵N values in the samples in this study, as has been the case globally. The range of values observed reflects the ability of consumers to access local produce from supermarkets or local markets. The Australasian data tend to lower δ¹³C values than the global average, indicating a dominance of carbon assimilated by C₃ photosynthesis in the diet. While similar to some European and Asian populations, δ¹³C values are lower than from regions with a high reliance on carbon assimilated by C₄ photosynthesis, including the Americas and parts of Africa.