Prenatal pesticides and cognitive development or Hispanic population. Among blacks and Hispanics, the effects of ΣDAP, ΣDEP, and ΣDMP were strongly differential according to PON1 Q192R genotype at 12 months but not 24 months. At 12 months, children of mothers with the PON1 192 QR/RR genotype experi- enced approximately a 5-point decline on the MDI with each log10 unit increase in ΣDAP or ΣDMP biomarker level which was monotonic across tertiles [see Supplemental Material, Figure (doi:10.1289/ehp.1003183)], and a 2-point decline in MDI for each log10 unit increase in ΣDEP biomarker level (Table 3). There was essentially no effect among children of mothers with the QQ genotype. Although in some instances the point estimates among the QQ group were quite elevated in a posi- tive direction, they were always estimated with imprecision and did not follow a monotonic pattern. Results were consistent when we stratified by black and Hispanic ancestry (see Supplemental Material, Table 3), although the sample size was quite small. We found no interaction between the PON1 Q192R polymorphism and organophosphate metabo- lite level on the MDI at 24 months. We also found no interactions (p ≥ 0.20) between organophosphate metabolites and the L55M or –108C > T polymorphisms, or with enzyme activity, on neurodevelopment at any age. Results were similar when we estimated associ- ations according to the child’s PON1 Q192R genotype instead of the mother’s genotype, but child genotype was available for only 57% of the population because cord blood was col- lected for only a subset. Therefore, we report only the maternal gene–organophosphate interactions. Increasing ΣDEP metabolite levels were associated with slight decrements in FSIQ (log10 β = –2.89; 95% CI, –6.15 to 0.36) and Perceptual Reasoning (log10 β = –3.51; 95% CI, –7.31 to 0.30) on the combined psychometric exams, and also with Working Memory (log10 β = –3.48; 95% CI, –7.29 to 0.34) on the 7–9 year WISC-IV examina- tion (Table 4), although the estimated effects were relatively modest and imprecise. These Table 2. Prenatal organophosphate biomarker levels and 12-month BSID-II MDI in the Mount Sinai Children’s Environmental Health Study. Organophosphate biomarker Combined race/ethnicitya (n = 149) Adjusted mean 95% CI Black/Hispanic subjectsb (n = 111) Adjusted mean 95% CI White subjectsb (n = 38) Adjusted mean 95% CI Interaction p-value MDI ΣDAP T3 T2 T1 Log10 β ΣDEP T3 T2 T1 Log10 β ΣDMP T3 T2 T1 Log10 β PDI ΣDAP T3 T2 T1 Log10 β ΣDEP T3 T2 T1 Log10 β ΣDMP T3 T2 T1 Log10 β Biomarker ΣDAP ΣDEP ΣDMP 96.1 95.8 97.0 –1.00 97.5 95.4 95.9 0.03 96.1 96.1 96.8 –1.12 92.5 96.6 95.3 –0.52 93.6 94.5 95.3 –0.20 94.5 93.7 95.1 –0.92 93.1 to 99.0 92.5 to 99.1 93.7 to 100.3 –3.28 to 1.28 94.3 to 100.6 92.3 to 98.6 92.9 to 98.9 –2.23 to 2.29 93.4 to 99.0 92.9 to 99.3 93.5 to 100.0 –3.14 to 0.89 88.5 to 96.6 92.1 to 101.1 90.9 to 99.8 –3.66 to 2.62 89.3 to 98.0 90.1 to 98.9 91.2 to 99.5 –3.28 to 2.87 90.6 to 98.5 89.3 to 98.0 90.7 to 99.5 –3.68 to 1.85 91.5 94.4 96.2 –3.29 95.2 93.8 94.3 –0.33 92.1 94.2 96.3 –3.35 94.2 97.5 97.7 –1.52 95.6 95.9 97.7 –0.48 96.4 94.5 97.8 –1.81 88.3 to 94.7 91.2 to 97.5 92.9 to 99.4 –5.88 to –0.70 91.9 to 98.6 90.4 to 97.1 90.9 to 97.6 –3.00 to 2.35 89.0 to 95.2 91.0 to 97.4 93.0 to 99.5 –5.64 to –1.06 89.5 to 98.9 93.0 to 102.1 93.1 to 102.4 –5.21 to 2.16 91.0 to 100.2 91.2 to 100.6 93.1 to 102.4 –4.11 to 3.16 92.0 to 100.8 90.1 to 99.0 93.2 to 102.4 –5.07 to 1.45 103.7 95.9 92.0 4.77 100.6 96.8 97.3 0.86 103.3 97.2 92.2 4.45 90.8 97.0 90.0 2.07 91.7 94.4 92.1 0.46 92.5 94.4 89.5 1.36 T, tertile. aGeneral linear model adjusted for race/ethnicity, maternal age at enrollment, child sex, examiner, maternal PON1 enzyme activity, season of urine collection, laboratory batch, HOME score, alcohol consumption during pregnancy, and urinary creatinine. bGeneral linear model adjusted for maternal age at enrollment, child sex, examiner, maternal PON1 enzyme activity, season of urine collection, laboratory batch, HOME score, alcohol consumption during pregnancy, and urinary creatinine and including a biomarker–race interaction term. Table 3. PON1 Q192R interaction with ΣDAP, ΣDEP, and ΣDMP levels on the BSID-II MDI in the Mount Sinai Children’s Environmental Health Study. 12-month BSID-II: black/Hispanic subjects (n = 110)a 24-month BSID-II: total population (n = 197) PON1 192 QQ (slow; n = 28) log10 β 95% CI 5.72 –0.48 to 11.92 3.69 –0.97 to 8.36 2.76 –2.44 to 7.97 PON1 192 QR/RR (fast;b n = 82) log10 β –4.94 –1.95 –4.47 95% CI –7.81 to –2.07 –5.36 to 1.47 –7.05 to –1.89 Interaction p-value < 0.01 0.06 0.02 PON1 192 QQ (slow; n = 57) log10 β 95% CI –1.04 –6.06 to 3.99 –0.55 –4.79 to 3.70 0.12 –4.17 to 4.42 PON1 192 QR/RR (fast; n = 140) log10 β 95% CI –1.27 –4.40 to 1.84 –0.15 –3.51 to 3.21 –0.48 –3.27 to 2.30 Data are for a general linear model adjusted for maternal age at enrollment, child sex, examiner, HOME score, alcohol consumption during pregnancy, laboratory batch, season of urine collection, urinary creatinine, and including a biomarker–PON1 Q192R genotype interaction. The 24-month model was additionally adjusted for maternal race/ethnicity. aOne subject identified mixed ethnicity. bIn this category, seven were black and the remainder Hispanic. Environmental Health Perspectives • volume 119 | number 8 | August 2011 98.5 to 108.8 90.6 to 101.3 85.4 to 98.7 0.69 to 8.86 94.6 to 106.5 90.8 to 102.9 91.8 to 102.7 –3.16 to 4.87 97.9 to 108.7 91.1 to 102.6 85.6 to 98.7 0.82 to 8.08 83.3 to 98.2 89.2 to 104.7 80.5 to 99.6 –3.83 to 7.96 83.5 to 99.9 86.0 to 102.7 84.6 to 99.6 –5.12 to 6.03 84.9 to 100.2 86.7 to 102.1 80.2 to 98.8 –3.83 to 6.56 < 0.001 0.001 0.82 0.62 < 0.01 < 0.001 0.65 0.31 0.25 0.78 0.83 0.31 Interaction p-value 0.93 0.88 0.81 1185