| Genetic polymorphisms | Candidate genotype | Exposure† | Multiplicative interaction | p Value |
| Low vs high | Odds ratio (95% CI) | |||
| CYP2D6 | *4*4 | Solvents | 1.65 (0.37 to 7.36) | 0.51 |
| CYP1B1 | *3*3 | Solvents | 1.15 (0.49 to 2.69) | 0.75 |
| GSTM1 | Null | Solvents | 1.76 (0.91 to 3.41) | 0.09 |
| GSTT1 | Null | Solvents | 0.81 (0.35 to 1.89) | 0.63 |
| GSTM3 | AB/BB | Solvents | 0.93 (0.45 to 1.91) | 0.84 |
| GSTP1 haplotype | AB, AC, AD, BB, BC,CC | Solvents | 1.53 (0.79 to 2.96) | 0.21 |
| NQO1 | *1*2/*2*2 | Solvents | 0.54 (0.27 to 1.11) | 0.09 |
| SOD2 Val9Ala | AV | Solvents | 1.74 (0.72 to 4.23) | 0.46** |
| VV | Solvents | 1.60 (0.60 to 4.24) | ||
| NAT2 | FS/SS | Solvents | 2.31 (0.61 to 8.77) | 0.22 |
| CYP2D6 | *4*4 | Pesticides | 1.61 (0.40 to 6.46) | 0.50 |
| PON1 L55M | LM/LL | Pesticides | 4.43 (0.88 to 22.31) | 0.07 |
| PON1 Q192R | QR/RR | Pesticides | 1.56 (0.70 to 3.44) | 0.27 |
| GSTM1 | Null | Pesticides | 0.65 (0.29 to 1.43) | 0.28 |
| GSTT1 | Null | Pesticides | 1.29 (0.42 to 3.94) | 0.65 |
| GSTM3 | AB/BB | Pesticides | 1.41 (0.60 to 3.30) | 0.43 |
| GSTP1 haplotype | AC/AD/BC/CC | Pesticides | 2.47 (0.63 to 9.73) | 0.20 |
| NQO1 | *1*2/*2*2 | Pesticides | 1.20 (0.54 to 2.66) | 0.66 |
| CYP1B1 | *3*3 | Pesticides | 0.57 (0.18 to 1.91) | 0.37 |
| NAT2 | FS/SS | Pesticides | 1.70 (0.48 to 6.07) | 0.42 |
| GSTM1 | Null | Iron | 0.94 (0.48 to 1.83) | 0.85 |
| CYP1B1 | *3*3 | Iron | 1.53 (0.61 to 3.83) | 0.37 |
| SOD2 Val9Ala | AV | Iron | 0.67 (0.29 to 1.55) | 0.64** |
| VV | Iron | 0.75 (0.31 to 1.84) | ||
| NAT2 | FS/SS | Iron | 1.45 (0.39 to 5.40) | 0.58 |
| SOD2 Val9Ala | AV | Copper | 0.78 (0.30 to 2.04) | 0.66** |
| VV | Copper | 1.20 (0.40 to 3.55) | ||
| CYP2D6 | *4*4 | Manganese | 1.27 (0.28 to 5.80) | 0.76 |
| NQO1 | *1*2/*2*2 | Manganese | 1.09 (0.53 to 2.22) | 0.82 |
| CYP1B1 | *3*3 | Manganese | 1.75 (0.68 to 4.52) | 0.25 |
| SOD2 Val9Ala | AV | Manganese | 0.75 (0.31 to 1.82) | 0.60** |
| VV | Manganese | 1.13 (0.44 to 2.92). |
*Logistic regression adjusting for age, sex, country, ever used tobacco containing product, ever knocked unconscious and first degree family history of Parkinson’s disease. MAO-A and MAO-B are not adjusted for sex but are presented for males and females separately.
**For three category factors p value for trend derived from logistic regression coding genetic factors as 0, 1 and 2 variable.
†Cut-offs for low/high exposure: solvents/iron/manganese: 20% of an OEL (AAI); pesticides/copper: 2% of an OEL (AAI).