Bräuner et al. but the positive trend was less consistent for > 97% of adipose samples, and may therefore sum of chlordanes only (Cantor et al. 2003; oxychlordane. The estimated effect of all three represent a more accurate biomarker of expo- De Roos et al. 2003; McDuffie et al. 2001). compounds was strongest among men. We sure than DDT. Thus, we cannot exclude the We observed no association between NHL observed no clear or consistent evidence of possibility that the observed association with and PCBs, in contrast with previous studies associations between NHL and adipose con- DDT is a false-positive result. that reported associations with PCB concen- centrations of PCB congeners or the other Results for individual chlordanes are trations in blood (Bertrand et al. 2010; De pesticides included in this study. limited, and only four previous studies have Roos et al. 2005; Engel et al. 2007; Hardell These data support the hypothesis of a considered the associations between NHL et al. 2001; Rothman et al. 1997; Spinelli link between DDT and the risk of NHL as and chlordane isomers or the metabolite oxy- et al. 2007). The individual congeners used suggested by some early occupational studies chlordane (De Roos et al. 2005; Hardell et al. when calculating the PCB sum and the actual (Baris et al. 1998; Cantor et al. 1992; Woods 2001; Quintana et al. 2004; Spinelli et al. individual PCB congeners associated with et al. 1987). However, most previous studies 2007). Results are mixed: one group found NHL differed between studies, but three of reported no association (De Roos et al. 2003, an association with oxychlordane but not cis- these studies reported an association between 2005; Hardell and Eriksson 1999; Rothman nonachlor (Spinelli et al. 2007), whereas PCB-180 and NHL (Bertrand et al. 2010; et al. 1997; Spinelli et al. 2007), including another found an association with cis- De Roos et al. 2005; Spinelli et al. 2007). We three with exposures measured in blood sam- nonachlor but not oxychlordane (Hardell detected this congener over LOD in 100% ples. In light of the high level of correlation et al. 2001). Two other groups studied only of our adipose samples but did not observe between DDT measured in adipose and blood oxychlordane; one found results in accord an association with NHL in our study popu- (Archibeque-Engle et al. 1997; Stellman with ours (Quintana et al. 2004), whereas the lation. Three previous studies have reported et al. 1998; Whitcomb et al. 2005), we would other found no association (De Roos et al. no association, in accordance with our find- expect a degree of interchangeability and little 2005). The persistence, bioaccumulation, and ings (Cocco et al. 2008; Laden et al. 2010; discrepancy in health results pertaining to distribution in human tissue as well as toxic Quintana et al. 2004), including one that this compound. We also found no association effects of each individual chlordane depend on measured PCBs in adipose tissue samples between DDE and NHL risk, which could its chemical structure, so we cannot compare (Quintana et al. 2004). The choice of biologi- be expected because DDE is more stable than our results for cis-nonachlor and oxychlordane cal specimen used in exposure quantification DDT, was detected at levels over LOD in with the results of studies that considered the may lead to discrepant human health results Table 2. IRRs of NHL in association with adipose tissue concentrations of organochlorine pesticides. IRR (95% CI) IRR (95% CI) Compound/concentrationa n (cases/ Compound/concentrationa n (cases/ (μg/kg lipids) subcohort) Model 1b Model 2c (μg/kg lipids) subcohort) Model 1b Model 2c p,p´-DDT Oxychlordane 6–15 29/37 1.00 1.00 8–19 30/52 1.00 1.00 15–22 32/32 1.09 (0.54, 2.18) 1.06 (0.52, 2.14) 19–25 38/46 1.31 (0.71, 2.43) 1.33 (0.72, 2.46) 22–36 35/38 1.12 (0.57, 2.19) 1.03 (0.51, 2.09) 25–33 46/39 1.87 (1.00, 3.49) 1.86 (1.00, 3.47) 36–49 23/19 1.25 (0.55, 2.80) 1.21 (0.53, 2.75) 33–41 34/18 2.81 (1.28, 6.14) 2.69 (1.22, 5.96) 49–460 18/11 1.73 (0.72, 4.14) 1.64 (0.68, 3.96) 41–354 21/16 1.95 (0.85, 4.46) 1.92 (0.84, 4.41) Linear estimate per IQRd 137/137 1.36 (1.11, 1.68) 1.35 (1.10, 1.66) Linear estimate per IQRd 169/171 1.13 (0.92, 1.40) 1.11 (0.89, 1.38) p,p´-DDE Dieldrin 68–390 59/58 1.00 1.00 6–13 33/32 1.00 1.00 390–680 53/64 0.82 (0.49, 1.37) 0.83 (0.49, 1.39) 13–20 21/52 0.38 (0.19, 0.76) 0.36 (0.17, 0.73) 680–1,100 63/57 1.03 (0.62, 1.72) 1.04 (0.62, 1.73) 20–29 35/37 0.95 (0.49, 1.85) 0.91 (0.46, 1.79) 1,100–1,700 34/36 0.82 (0.45, 1.50) 0.79 (0.43, 1.46) 29–41 22/12 2.05 (0.92, 4.54) 1.94 (0.87, 4.34) 1,700–8,000 29/22 1.12 (0.58, 2.17) 1.10 (0.57, 2.14) 41–350 18/11 1.42 (0.60, 3.36) 1.27 (0.52, 3.12) Linear estimate per IQRd 238/237 1.03 (0.86, 1.22) 1.02 (0.86, 1.22) Linear estimate per IQRd 140/144 1.03 (0.94, 1.14) 1.03 (0.94, 1.13) β-Hexachlorocyclohexane Hexachlorobenzene 15–45 50/60 1.00 1.00 9–37 47/56 1.00 1.00 45–57 50/54 1.15 (0.67, 1.99) 1.15 (0.66, 2.00) 37–53 50/51 1.08 (0.62, 1.88) 1.07 (0.61, 1.87) 57–77 61/58 1.27 (0.74, 2.17) 1.24 (0.72, 2.15) 53–72 45/56 0.84 (0.48, 1.49) 0.77 (0.42, 1.43) 77–96 38/25 1.59 (0.83, 3.03) 1.49 (0.76, 2.92) 72–98 37/33 1.15 (0.60, 2.18) 1.07 (0.55, 2.09) 96–370 26/23 1.06 (0.53, 2.11) 1.02 (0.50, 2.07) 98–360 25/17 1.25 (0.57, 2.72) 1.16 (0.53, 2.58) Linear estimate per IQRd 225/220 0.99 (0.83, 1.17) 0.96 (0.81, 1.15) Linear estimate per IQRd 204/213 1.00 (0.82, 1.21) 0.98 (0.80, 1.19) cis-Nonachlor ΣChlordanese 3–5 30/50 1.00 1.00 9–37 55/59 1.00 1.00 5–7 35/42 1.23 (0.64, 2.35) 1.19 (0.61, 2.30) 37–58 51/68 0.77 (0.46, 1.30) 0.75 (0.44, 1.27) 7–10 42/32 1.56 (0.82, 2.96) 1.53 (0.80, 2.91) 58–83 64/53 1.18 (0.70, 1.99) 1.10 (0.64, 1.91) 10–15 27/21 1.64 (0.79, 3.41) 1.76 (0.84, 3.67) 83–108 35/35 0.84 (0.45, 1.55) 0.80 (0.43, 1.50) 15–39 21/11 2.60 (1.08, 6.27) 2.52 (1.04, 6.09) 108–439 30/17 1.41 (0.68, 2.94) 1.32 (0.63, 2.79) Linear estimate per IQRd 155/156 1.13 (0.94, 1.36) 1.13 (0.94, 1.36) Linear estimate per IQRf 235/232 1.04 (0.86, 1.26) 1.02 (0.84, 1.24) trans-Nonachlor ΣDDTsg 6–25 47/67 1.00 1.00 76–390 57/56 1.00 1.00 25–33 53/52 1.33 (0.78, 2.28) 1.39 (0.81, 2.39) 390–690 57/67 0.86 (0.51, 1.43) 0.87 (0.52, 1.47) 33–46 65/60 1.40 (0.84, 2.36) 1.43 (0.85, 2.40) 690–1,100 61/56 1.02 (0.61, 1.72) 1.03 (0.61, 1.74) 46–62 41/33 1.37 (0.75, 2.52) 1.38 (0.75, 2.54) 1,100–1,714 36/37 0.86 (0.48, 1.56) 0.83 (0.46, 1.52) 62–290 29/20 1.60 (0.79, 3.24) 1.54 (0.76, 3.14) 1,714–8,041 27/21 1.09 (0.56, 2.15) 1.08 (0.55, 2.14) Linear estimate per IQRd 235/232 1.03 (0.90, 1.18) 1.01 (0.89, 1.16) Linear estimate per IQRh 238/237 1.03 (0.87, 1.23) 1.03 (0.86, 1.23) aThe cutoffs between the exposure groups were the 25th, 50th, 75th, and 90th percentiles. bAge as time scale; model stratified according to sex. cAge as time scale; model stratified according to sex and adjusted for BMI (continuous variable). dLinear estimate per IQR based on pesticide concentrations analyzed as continuous variables. eSum of cis-nonachlor, trans-nonachlor, and oxychlordane. fIQRΣChlordanes = 46.2 μg/kg. gSum of DDT and DDE. hIQRΣDDTs = 710 μg/kg. 108 120 | number 1 | January 2012 • Environmental Health Perspectives ovlume