TABLE 1.

Number of workers recruited in different trimellitic anhydride (TMA) exposure areas according to their antibody responses. Ten of 18 actively exposure workers in L4 areas developed sIgG; two subjects with sIgG (marked with asterisk) transiently produced borderline sIgE (sIgE 0.11 kU/L to 0.27 kU/L). Only 2 of 18 workers in L3 exposure developed sIgG. In contrast, 11 of 13 removed workers in an L4 exposure area developed sIgG and sIgE and two developed sIgG only

	Active workers (N = 77)				Removed workers (N = 15)
	L1	L2	L3	L4	L1	L2	L3	L4	Total number
No TMA-specific Ab	22	19	16	6	0	2	0	0	65
With only slgG	0	0	2	10	0	0	0	2	14
With slgG + slgE	0	0	0	2*	0	0	0	11	11
Total number of workers recruited	22	19	18	18	0	2	0	13	92