Table 3

Bivariate analyses of the effects of selected demographic, lifestyle, and occupational variables on serum prolactin concentrations

		Serum PRL, mean (SEM), ng/ml	p value*
*Independent samples t test for dichotomous comparisons, one way analysis of variance for multi-group comparisons, Pearson correlation for comparison of two continuous variables.
†African American, Asian, and American Indian.
‡Weight in kg divided by height in m².
Gender	Male	10.4 (0.4)	0.026
Gender	Female	12.7 (1.0)	0.026
Industry	Bathtub	8.5 (0.6)	0.254
	Boat build	10.0 (0.5)
	Pipe, tank	11.7 (0.9)
	Truck, RV	11.2 (0.5)
	Boat repair	11.0 (3.2)
Respirator use	No	10.7 (0.4)	0.576
Respirator use	Yes	11.2 (0.8)	0.576
Glove use	No	11.0 (0.4)	0.517
Glove use	Yes	10.5 (0.6)	0.517
Working in a confined space	No	10.6 (0.4)	0.551
Working in a confined space	Yes	11.1 (0.8)	0.551
Recreational drug use	No	10.9 (0.4)	0.532
Recreational drug use	Yes	10.3 (0.7)	0.532
Non-prescription drug use	No	10.8 (0.5)	0.873
Non-prescription drug use	Yes	10.7 (0.5)	0.873
Prescription drug use	No	10.9 (0.4)	0.502
Prescription drug use	Yes	10.3 (0.7)	0.502
Styrofoam food or drink containers	No	11.1 (0.5)	0.457
Styrofoam food or drink containers	Yes	10.6 (0.5)	0.457
Current no. of cigarettes per day	<1	11.7 (0.5)	0.015
	1–10	10.2 (0.9)
	11–20	9.1 (0.6)
	>20	8.6 (0.8)
Current no. of alcoholic beverages per week	<1	10.8 (0.5)	0.155
	1–7	10.7 (0.6)
	8–21	11.6 (1.3)
	>21	6.9 (0.6)
Ethnicity	Caucasian	10.3 (0.5)	0.111
	Hispanic	12.2 (0.7)
	Other†	11.1 (1.2)
Season	Dec–Feb	11.3 (0.6)	0.516
	Mar–May	10.2 (0.8)
	June–Aug	10.1 (0.5)
	Sep–Nov	11.2 (0.9)
Time of day	21:00–4:59	12.5 (1.3)	0.245
	13:00–16:59	10.5 (0.4)
	17:00–20:59	10.8 (0.7)
		Correlation coefficient
Age		−0.114	0.085
Body mass index‡		−0.022	0.736
Income		−0.163	0.013
Air styrene		0.123	0.063
Blood styrene		0.168	0.016