Chronic occupational exposure to hexavalent chromium causes DNA damage in electroplating workers

BMC Public Health

Table 1 Demographic information of the electroplating workers and control subjects.

variables	exposed workers	control subjects	Pvalue^a
	n = 157	n = 93
gender			0.47
male	101	64
female	56	29
age (years, mean ± sd)	39.7 ± 8.3	38.8 ± 9.6	0.47
smoking status^b			0.18
yes	64	46
no	93	47
alcohol consumption^c			0.18
yes	78	38
no	79	55
years of chromium exposure (median (min-max))	5.3(0.5-23)	--

^a P values were calculated from Pearson's χ² test for categorical variables (gender, smoking status, alcohol consumption) and Student's t-test for age.
^b Smoking status was defined as: ≧one cigarette per day for more than one year or quit smoking for less than one year.
^c Alcohol consumption was defined as: at least once a week for more than six months.

ISSN: 1471-2458