Occurrence of mental illness following prenatal and early childhood exposure to tetrachloroethylene (PCE)-contaminated drinking water: a retrospective cohort study

Table 1 Selection, enrollment, and initial and final exposure status of study subjects

	Initial Exposure Status
	Index Subject		Older Sibling
	Exposed	Unexposed	Unexposed	Total
Selected	1910	1928	1202	5040
Excluded during enrollment
Deceased	35	40	36	111
Parent refused participation	199	148	80	427
Never located	113	149	70	332
No response	871	887	536	2294
Refused	73	78	36	187
Returned questionnaire	619	626	444	1689
Percent of selected	32.4%	32.5%	36.9%	33.5%
Percent of located	39.6%	39.3%	43.7%	40.5%
Excluded during exposure assessment
Inadequate residential history	15	37	29	81
Off-Cape address in town with VL/AC pipes	19	27	50	96
Available for analysis	585	562	365	1512
Percent of selected	30.6%	29.1%	30.4%	30.0%
Final exposure status
Both prenatal and early childhood exposure	561	160	110	831
Only early childhood exposure	7	42	85	134
Unexposed	17	360	170	547
Total	585	562	365	1512

ISSN: 1476-069X