Table 1.

Characteristics of lead (Pb) concentration in CIN subjects and controls (n = 133)

Research group	Pb concentration (μg/dL)
	Median	Interquartile range
CIN (N = 40)	5.5	4.7–6.4
CIN I (N = 6)	6.6	6.4–7.0
CIN II (N = 6)	5.0	4.7–5.8
CIN III (N = 28)	5.4	4.7–6.2
Control (N = 93)	4.7	4.3–5.8
Non-cancerous/HPV infected (N = 50)	4.7	4.2–8.7
Non-cancerous/non-HPV infected (N = 43)	4.7	4.5–5.4
Comparisons	P value
CIN versus overall controls	< 0.01a
CIN versus HPV infected control	0.080a
CIN versus non-HPV infected control	< 0.01a
Comparison between CIN grades	0.019b

Abbreviations: CIN, cervical intraepithelial neoplasia; HPV, human papillomavirus; Pb, lead

^aThe P value comparison between two indicated groups by the Mann-Whitney U test

^bThe P value comparison between three groups by the Kruskal-Wallis test