Ever-use of pesticides and hyperthyroidism risk
| Pesticide | Overall sample (n=35 150)* | Stricter case definition (n=34 463)† | ||
| Exposed cases | HR (95% CI)‡ | Exposed cases | HR (95% CI)§ | |
| Organochlorine insecticide | ||||
| Aldrin | 43 | 0.82 (0.57 to 1.16) | 8 | 0.73 (0.33 to 1.60) |
| Chlordane | 68 | 0.92 (0.69 to 1.24) | 13 | 0.73 (0.39 to 1.39) |
| DDT | 73 | 0.98 (0.71 to 1.34) | 12 | 0.80 (0.40 to 1.60) |
| Dieldrin | 18 | 0.99 (0.60 to 1.62) | – | – |
| Heptachlor | 39 | 0.94 (0.65 to 1.36) | – | – |
| Lindane | 45 | 0.93 (0.67 to 1.30) | – | – |
| Toxaphene | 31 | 0.74 (0.50 to 1.09) | 7 | 0.70 (0.31 to 1.58) |
| Carbamate insecticide | ||||
| Aldicarb | 26 | 0.84 (0.54 to 1.30) | 5 | 0.61 (0.23 to 1.60) |
| Carbaryl (overall) | 143 | 0.81 (0.62 to 1.07) | – | – |
| ≤62 years¶ | – | – | 27 | 0.96 (0.51 to 1.79) |
| >62 years¶ | – | – | 7 | 0.43 (0.15 to 1.23) |
| Carbofuran | 58 | 0.79 (0.59 to 1.07) | 10 | 0.51 (0.26 to1.01) |
| Organophosphate insecticide | ||||
| Chlorpyrifos | 98 | 0.85 (0.66 to 1.09) | 26 | 0.85 (0.52 to 1.39) |
| Coumaphos | 17 | 0.79 (0.48 to 1.29) | – | – |
| Diazinon | 88 | 1.05 (0.80 to 1.39) | – | – |
| Dichlorvos | 23 | 0.96 (0.62 to 1.49) | 5 | 0.76 (0.30 to 1.93) |
| Fonofos | 52 | 1.13 (0.82 to 1.57) | 11 | 0.86 (0.43 to 1.70) |
| Malathion | 158 | 0.68 (0.52 to 0.88) | 37 | 0.56 (0.33 to 0.94) |
| Parathion | 39 | 0.94 (0.66 to 1.34) | 9 | 0.87 (0.42 to 1.81) |
| Phorate | 63 | 0.75 (0.56 to 1.02) | 13 | 0.56 (0.30 to 1.07) |
| Terbufos | 84 | 0.91 (0.69 to 1.20) | 16 | 0.54 (0.30 to 0.98) |
| Pyrethroid insecticide | ||||
| Permethrin (animals) | 31 | 1.09 (0.74 to 1.61) | 6 | 0.67 (0.28 to 1.60) |
| Permethrin (crops) | 24 | 0.73 (0.48 to 1.12) | 8 | 0.95 (0.45 to 2.01) |
| Fumigant | ||||
| Carbon tetrachloride/ carbon disulfide 80/20 mix | 14 | 0.96 (0.56 to 1.66) | – | – |
| Aluminium phosphide | 11 | 0.97 (0.53 to 1.78) | – | – |
| Ethylene dibromide | 11 | 1.14 (0.62 to 2.11) | – | – |
| Methyl bromide | 50 | 0.91 (0.64 to 1.30) | 12 | 0.85 (0.41 to 1.73) |
| Fungicide | ||||
| Benomyl | 21 | 0.63 (0.40 to 1.02) | 6 | 0.75 (0.31 to 1.85) |
| Captan ≤62 years¶ | 11 | 0.62 (0.33 to 1.15) | – | – |
| >62 years¶ | 10 | 1.08 (0.56 to 2.10) | – | – |
| Chlorothalonil | 16 | 0.61 (0.36 to 1.03) | 5 | 0.76 (0.29 to 1.97) |
| Maneb/mancozeb | 17 | 0.50 (0.30 to 0.83) | 6 | 0.77 (0.31 to 1.91) |
| Metalaxyl | 64 | 0.92 (0.67 to 1.27) | 15 | 0.92 (0.47 to 1.79) |
| Herbicide | ||||
| Alachlor | 120 | 0.88 (0.68 to 1.14) | 32 | 1.03 (0.61 to 1.75) |
| Butylate | 62 | 0.76 (0.56 to 1.02) | 14 | 0.59 (0.32 to 1.08) |
| Chlorimuron ethyl (overall) | – | – | 19 | 0.80 (0.46 to 1.40) |
| ≤62 years¶ | 44 | 0.70 (0.49 to1.00) | – | – |
| >62 years¶ | 30 | 1.16 (0.75 to 1.80) | – | – |
| Dicamba | 100 | 0.74 (0.55 to1.00) | – | – |
| EPTC | 37 | 0.84 (0.59 to 1.21) | 7 | 0.55 (0.25 to 1.23) |
| Glyphosate | 210 | 1.06 (0.79 to 1.43) | 59 | 1.81 (0.89 to 3.70) |
| Imazethapyr (overall) | – | 26 | 1.23 (0.66 to 2.29) | |
| ≤62 years¶ | 56 | 0.89 (0.61 to 1.29) | – | – |
| >62 years¶ | 38 | 1.43 (0.91 to 2.24) | – | – |
| Metolachlor | 88 | 0.75 (0.57 to0.99) | 22 | 0.68 (0.39 to 1.16) |
| Paraquat | 50 | 0.75 (0.54 to 1.05) | 12 | 0.67 (0.34 to 1.32) |
| Pendimethalin | 102 | 0.97 (0.75 to 1.26) | 26 | 0.94 (0.56 to 1.57) |
| Petroleum oil | 102 | 0.89 (0.68 to 1.16) | 31 | 1.20 (0.71 to 2.03) |
| Trifluralin | 123 | 1.05 (0.80 to 1.38) | 34 | 1.21 (0.70 to 2.10) |
| 2,4-D (overall) | 188 | 0.86 (0.65 to 1.14) | – | – |
| ≤62 years¶ | – | – | 40 | 1.09 (0.56 to 2.11) |
| >62 years¶ | – | – | 8 | 0.31 (0.11 to 0.83) |
| 2,4,5 T | 56 | 1.01 (0.74 to 1.38) | 9 | 0.62 (0.30 to 1.29) |
| 2,4,5 T P | 22 | 0.93 (0.60 to 1.45) | – | – |
| Atrazine | 170 | 0.77 (0.59 to1.00) | 45 | 0.82 (0.48 to 1.39) |
| Cyanazine | 87 | 0.86 (0.64 to 1.16) | 20 | 0.70 (0.39 to 1.27) |
| Metribuzin | 101 | 0.96 (0.73 to 1.27) | 22 | 0.66 (0.38 to 1.16) |
Bold-face indicates p value≤0.05.
*Analysis with overall sample
†Analysis with cases restricted to those confirmed by a validation questionnaire or medical records or who reported having hyperthyroidism at least two times in surveys.
‡Adjusted for sex, education, state and smoking.
§Adjusted for education, state and smoking (as there were no female cases of hyperthyroidism).
¶HR allowed to vary by the median age (ie, 62 years) for pesticides for which proportional hazards assumptions were not met (p≤0.10)
DDT, dichlorodiphenyltrichloroethane; EPTC, S-ethyl dipropylthiocarbamate; 2,4-D, 2,4-Dichlorophenoxyacetic acid; 2,4,5-T, 2,4,5-Trichlorophenoxyacetic acid; 2,4,5 T,P, 2-(2,4,5-trichlorophenoxy) propionic acid.