Examining the use of different sample types following decomposition to estimate year of death using bomb pulse dating

Radiocarbon and bomb pulse dating in the forensic context: A systematic review

Radiocarbon analysis in bones, particularly through Bomb Pulse dating, is an essential tool in forensic investigations for estimating the postmortem interval of human remains. However, there are some limitations related to the interpretation of laboratory data, since this can differ from the Post Mortem Interval by many years, depending on the anatomical district and the bone part sampled, as well as the age of the individual and other parameters, since these elements influence bone turnover. In recent years, many studies have been conducted, but with non-standardized data and on limited samples. Therefore there is a need (experienced by the authors themselves in daily forensic practice when only bones are available) to summarize in a single work the data spread in the literature and try to standardize data, as much as possible, with limitation to forensic case only, in a review that is not only critical, but also systematic, in order to have specific and ready to use information for the interpretation of laboratory results. This work, therefore, not only aims to highlight the complexity and the need for standardized methodologies on multiple types of tissue for future research, but also to be an immediate help to refine the interpretation of the results provided by radiocorabion in order to have a Post Mortem Interval as reliable as possible.

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

OBJECTIVES

Bomb pulse (BP) radiocarbon (14 C) 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 14 C-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 METHODS

Here a simple method is used to estimate bone remodeling rates from a compilation of published cortical femur bone collagen BP 14 C 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.

RESULTS

Remodeling 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.

DISCUSSION

Implications for the temporal contexts within an individual's lifetime of biogeochemical data in archaeology and forensic anthropology are discussed, warranting additional BP 14 C studies of known individuals and integration with histomorphometric analysis.

The effects of diet and beauty products on the uptake and storage of 14C in hair and nails: ramifications for the application of bomb pulse dating to forensic anthropological casework

Radiocarbon dating is a useful tool in the examination of unknown human remains. Recent studies have shown that the analysis of hair and nail samples can provide a highly accurate estimation of the year of death (YOD). However, little research has examined factors that may influence the uptake and storage of 14C in these tissues, such as diet, or the use of beauty products. This study measured the level of 14C in human hair and nail samples collected from living individuals to determine whether diet, and the use of hair dye or nail polish, has a significant impact on the estimation of YOD. The results of this study showed that diet did not appear to impact the radiocarbon content in human hair and nail, and thus should not be considered a limitation when analysing samples obtained from unidentified human remains. The use of nail polish, and in the majority of cases, hair dye, did not significantly impact the 14C concentration in nails and hair. While the results of this study are preliminary, they suggest that in most cases, both hair and nail can be successfully analysed using radiocarbon dating to estimate an individual's YOD. However, best practice should involve the analysis of multiple tissue types, to minimise any error that may be introduced as a result of the decedent's use of beauty products.