Table 7

Summary of previous case-control studies of total PCBs in serum

ReferenceCountry/United States regionPeriod samples collectedNo. cases/controlInterval between blood sample and diagnosis% of cases postmenopausalMean PCB concentration in seruma,bORs by tertile (Q1–Q3), quartile (Q1–Q4), or quintile (Q1–Q5)a
ControlsCasesQ1Q2Q3Q4Q5
Wolff et al., (1) 1993Northeast1985–199158/171<6 mo58.66.7 ppb8.0 ppb1.05.27.04.14.3
Krieger et al., (5) 1994Northern California1964–1969150/150>6 mo Mean: 14.2 yr74.64.8 ppb4.4 ppb1.01.20.9
Hunter et al., (6) 199711 States1989–1990240/240None required; diagnosis <6/1/9268.05.16 ppb5.08 ppb1.00.60.50.50.7
Moysich et al., (10) 1998Western New York1986–1991154/192Within 3 mo after diagnosis1004.12 ng/g4.29 ng/g1.00.71.1
Høyer et al., (7) 1998Denmark1976240/477None required; dx. <12/31/9370.08.7 ng/ml8.6 ng/ml1.00.90.81.1
Dorgan et al., (11) 1999Missouri1977–1987105/208None required; mean 2.7 yr79.02.8a ng/mlNRd1.00.71.10.7
Helzlsouer et al., (9) 1999Maryland1974, 1979,1974: 235/2351974: 2 yr1974: 55.3% >504.7 ng/ml4.9 ng/ml1.01.10.80.70.7
or both1989: 105/1051989: no minimum1989: 75.2% >502.2 ng/ml2.1 ng/ml1.00.60.7
Høyer et al., (13) 2000Denmark1976–1978 1981–1983155/274Diagnosed after 2nd blood sample68% 1st exam, 84% 2nd examNRNR1.00.80.81.6
Wolff et al., (15) 2000Northeast United States1985–1990148/2956 mo63.55.0 ng/ml5.0 ng/ml1.01.51.22.0
  • a If the reference cited included both unadjusted and adjusted means and ORs, adjusted values were selected for the summary.

  • b Some papers report concentrations in units of ppb, others in units of ng/ml, and others in units of ng/g. These units are essentially equivalent because ppb is equivalent to ng/g and 1 ml serum = 1.026 grams.

  • c Median concentrations.

  • d NR, not reported.