Table 5

Exposure to specific active ingredients and Parkinson disease risk: crop-exposure matrix

Cases
n (%)
Controls
n (%)
Crude
OR (95% CI)
Model 1*
OR (95% CI)
Model 2†
OR (95% CI)
Paraquat‡
 Never411 (92.6)818 (93.4)11
 >0–3.8018 (4.1)29 (3.3)1.27 (0.68 to 2.35)1.33 (0.68 to 2.60)1.42 (0.71 to 2.85)
 >3.8015 (3.4)29 (3.3)1.03 (0.54 to 1.95)0.91 (0.45 to 1.84)1.01 (0.48 to 2.12)
Maneb‡
 Never419 (94.4)835 (95.3)111
 >0–1.3812 (2.7)21 (2.4)1.16 (0.56 to 2.42)1.33 (0.60 to 2.93)1.42 (0.63 to 3.21)
 >1.3813 (2.9)20 (2.3)1.28 (0.64 to 2.57)1.16 (0.55 to 2.45)1.31 (0.60 to 2.85)
Atrazine‡
 Never423 (95.3)845 (96.5)111
 >0–0.359 (2.0)14 (1.6)1.30 (0.56 to 3.00)1.03 (0.42 to 2.52)1.05 (0.42 to 2.61)
 >0.3512 (2.7)17 (1.9)1.40 (0.66 to 2.98)1.08 (0.48 to 2.43)1.15 (0.50 to 2.65)
Benomyl‡
 Never420 (94.6)841 (96.0)111
 >0–0.277 (1.6)20 (2.3)0.69 (0.29 to 1.66)0.80 (0.31 to 2.05)0.88 (0.34 to 2.27)
 >0.2717 (3.8)15 (1.7)2.46 (1.16 to 5.22)2.23 (1.01 to 4.82)2.47 (1.05 to 5.78)
Dinoseb‡
 Never422844 (96.3)111
 >0–3.4611 (2.5)16 (1.8)1.38 (0.64 to 2.96)1.34 (0.60 to 3.03)1.41 (0.61 to 3.26)
 >3.4611 (2.5)16 (1.8)1.36 (0.62 to 2.97)0.91 (0.38 to 2.18)0.98 (0.39 to 2.46)
Dichlorvos‡
 Never430 (96.8)850 (97.0)111
 >0–9.67 (1.6)12 (1.4)1.18 (0.45 to 3.07)2.04 (0.73 to 5.72)2.06 (0.72 to 5.90)
 >9.67 (1.6)14 (1.6)0.97 (0.38 to 2.46)0.87 (0.32 to 2.37)0.96 (0.34 to 2.66)
Lindane‡
 Never407 (91.7)810 (92.5)111
 >0–0.3517 (3.8)35 (4.0)0.95 (0.52 to 1.74)0.85 (0.45 to 1.60)0.89 (0.46 to 1.73)
 >0.3520 (4.5)31 (3.5)1.29 (0.72 to 2.31)1.26 (0.67 to 2.38)1.39 (0.70 to 2.75)
Parathion‡
 Never404 (91.0)796 (90.9)111
 >0–1.5317 (3.8)41 (4.7)0.81 (0.45 to 1.44)0.85 (0.46 to 1.57)0.85 (0.45 to 1.63)
 >1.5323 (5.2)39 (4.5)1.16 (0.68 to 1.99)1.09 (0.60 to 1.98)1.22 (0.64 to 2.31)
Permethrin‡
 Never427 (96.2)852 (97.3)111
 >0–1.037 (1.6)12 (1.4)1.18 (0.45 to 3.07)1.32 (0.47 to 3.74)1.37 (0.47 to 3.99)
 >1.0310 (2.3)12 (1.4)1.62 (0.70 to 3.75)1.44 (0.57 to 3.67)1.60 (0.60 to 4.30)
2,4-D‡
 Never415 (93.5)832 (95.0)111
 >0–0.2511 (2.5)22 (2.5)1.02 (0.48 to 2.18)1.05 (0.46 to 2.38)1.13 (0.49 to 2.64)
 >0.2518 (4.1)22 (2.5)1.68 (0.87 to 3.24)1.51 (0.74 to 3.08)1.68 (0.81 to 3.49)
  • *The first adjusted model includes cigarette smoking (5 categories), coffee consumption (4 categories) and occupational skill and status (4 categories).

  • †The second adjusted model additionally includes endotoxin exposure (4 categories). Since information on coffee consumption was missing for one control, this participant was excluded from adjusted analyses.

  • ‡Conditional logistic regression analyses of exposure to specific active ingredients as assessed based on self-reported crops and applying the crop-exposure matrix. Exposure was calculated by summing the estimated chance of use at the farm times the frequency of use, summed for all years working on farms. Exposed were divided based on the median of the exposure distribution among the controls. No exposure was assigned to a farm job when on that farm according to the participant no insecticides, herbicides, or fungicides were applied.