Purple Staining of Archaeological Human Bone: An Investigation of Probable Cause and Implications for Other Tissues and Artifacts

Table 1

Calculated prevalence values for the presence of colored bone classified according to broad age groups, biological sex where observable, and combined as a whole. The lower and upper levels of the respective 95% confidence intervals for the prevalence values are included to test the null hypothesis that there is no variation of prevalence across the various categories. The 95% confidence intervals for all the subgroups overlap indicating that the null hypothesis holds at the 5% significance level (: number of individuals; CI: confidence interval).

	Infant	Juvenile	Adult	Male	Female	Total
purple	4	10	7	11	6	38
normal	24	43	32	46	26	171
Prevalence%	16.7	23.3	21.9	23.9	23.1	22.2
95% CI	7.6–35.9	13.2–37.7	11.0–38.8	13.9–42.1	11.0–42.1	16.6–29.0