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Non-invasive in vivo neutron activation analysis (NAA) was used to measure the fluorine concentration in 35 people in Hamilton, Ontario, Canada. Measurement and precision data of this second generation NAA system were determined in 2013, and the results were compared with the performance of a first generation system used in a pilot study of 33 participants from the Hamilton area in 2008. Improvements in precision in line with those predicted by phantom studies were observed, but the use of fewer technicians during measurement seemed adversely to affect performance. We compared the levels of fluorine observed in people between the two studies and found them to be comparable. The average fluorine concentration in bone was found to be 3  ±  0.3 mg and 3.5  ±  0.4 mg F/g Ca for 2013 and 2008 measurements respectively. Ten people were measured in both studies; the observed average change in bone fluorine in this subgroup was consistent with that predicted by the observation of the relationship between bone fluorine and age in the wider group. In addition, we observed differences in the relationship between bone fluorine level and age between men and women, which may be attributable either to sex or gender differences. The rate of increase in fluorine content for men was found to be 0.096  ±  0.022 mg F/g Ca per year while the rate of increase for women was found to be slightly less than half that of men, 0.041  ±  0.017 mg F/g Ca per year. A discontinuity in the rate of increase in fluorine content with age was observed in women at around age 50. Bone fluorine content was significantly lower ([Formula: see text]) in women age 50 to 59 than in women age 40 to 49, which we suggest may be attributable to bone metabolism changes associated with menopause. We also observed increased fluorine levels in tea drinkers as compared to non-tea drinkers, suggesting tea may be a significant source of exposure in Canada. The rate of increase in fluorine content of the tea drinkers and the non-tea drinkers were found to be 0.127 (± 0.029) and 0.050 (± 0.009) mg F/g Ca per year respectively. Finally, we also obtained twelve bone samples from cadavers' skulls. Neutron activation analysis was used to determine the fluorine levels in these ex vivo samples. The rate of increase of fluorine content versus age for in vivo and ex vivo measurements were found to be 0.078  ±  0.014 and 0.078  ±  0.050 mg F/g Ca per year respectively. Excellent agreement was found between the fluorine levels determined in vivo and ex vivo using the two separate systems, providing confidence in the fluorine concentration data being measured in vivo.

Ochre is a red mineral pigment that was a key element of social and ceremonial practices among cultures of the Pacific Northwest Coast. It is recovered routinely from archaeological excavations, is visible as pigment for pictographs, and is described in the historical record as a trade item and component of ceremonial practices. Despite its ubiquity in the archaeological record, it is difficult to interpret its significance without first understanding the nature of its procurement and distribution. As a step towards identifying procurement practices, trade and resource use, it is necessary to thoroughly characterize ochre outcrops with regard to their intra-source and regional variability. We analysed ochre from three outcrops using INAA to determine their elemental chemistry. The purpose of this study is threefold: to provide an example of the range of elemental variability within and between outcrops, to illustrate the effect of scale and geomorphological processes on elemental compositions and statistical interpretation, and to create a database of known deposits in southern British Columbia. The results demonstrate that ochre deposits may be differentiated on the basis of their chemistry, and that conservative statistical interpretation needs to be employed to assess true elemental variability within and between ochre deposits and regions.

Fifty‐three ceramic samples were collected in the area of the colonial city of Riobamba, Ecuador (today Sicalpa/Cajabamba). Neutron activation analysis was used to attempt to establish elemental compositions, and from these gain information on the manufacturing locations of these samples. Colonial samples imported from Panama were separable by their high Cs contents, and can be sorted into glazed and unglazed industries based on As and Cs. High As concentrations in several sherds indicate an origin near Cuenca, in the Southern Highlands of Ecuador, for both colonial and Inca samples. Inca and colonial Quito samples from the north of the country are identifiable through high Na combined with low Sc and Cr concentrations. Locally produced Puruhá, unglazed colonial and majolica samples form a group indicative of local Riobamba elemental composition.