Bomb pulse 14C evidence for consistent remodeling rates of cortical femur collagen in middle‐late adulthood

Abstract

AbstractObjectivesBomb pulse (BP) radiocarbon (14C) dating methods are used by forensic anthropologists to estimate the year‐of‐death (YOD) of unidentified individuals. Method resolution and accuracy depend on establishing lag times, or the difference between a tissue's BP 14C‐derived year and the YOD, of various tissue types from known deceased persons. Bone lag times span many years and are thought to increase with age as a function of slowing remodeling rates. However, remodeling rates for various skeletal elements, bone structures and phases are not well known.Materials and MethodsHere a simple method is used to estimate bone remodeling rates from a compilation of published cortical femur bone collagen BP 14C measurements (n = 102). Linear regression models and nonparametric tests are used to detect changes in lag times and remodeling rates with increasing age‐at‐death.ResultsRemodeling rates and lag times of 3.5%/year and 29 years, respectively, are estimated from individuals aged 40–97 years. In contrast to previous work, the analysis yielded modest and negligible changes in remodeling rates and lag times with advancing age. Moreover, statistically significant differences in remodeling rates and lag times were not found between reported females and males.DiscussionImplications for the temporal contexts within an individual's lifetime of biogeochemical data in archaeology and forensic anthropology are discussed, warranting additional BP 14C studies of known individuals and integration with histomorphometric analysis.