title: Solvent exposures and Parkinson disease risk in twins.
abstract: OBJECTIVE
  Several case reports have linked solvent exposure to Parkinson disease (PD), but few studies have assessed associations with specific agents using an analytic epidemiologic design. We tested the hypothesis that exposure to specific solvents is associated with PD risk using a discordant twin pair design.
  
  
  METHODS
  Ninety-nine twin pairs discordant for PD ascertained from the National Academy of Sciences/National Research Council World War II Veteran Twins Cohort were interviewed regarding lifetime occupations and hobbies using detailed job task-specific questionnaires. Exposures to 6 specific solvents selected a priori were estimated by expert raters unaware of case status.
  
  
  RESULTS
  Ever exposure to trichloroethylene (TCE) was associated with significantly increased risk of PD (odds ratio [OR], 6.1; 95% confidence interval [CI] 1.2-33; p = 0.034), and exposure to perchloroethylene (PERC) and carbon tetrachloride (CCl(4) ) tended toward significance (respectively: OR, 10.5; 95% CI, 0.97-113; p = 0.053; OR, 2.3; 95% CI, 0.9-6.1; p = 0.088). Results were similar for estimates of exposure duration and cumulative lifetime exposure.
  
  
  CONCLUSIONS
  Exposure to specific solvents may increase risk of PD. TCE is the most common organic contaminant in groundwater, and PERC and CCl(4) are also ubiquitous in the environment. Our findings require replication in other populations with well-characterized exposures, but the potential public health implications are substantial.
authors.affiliation: The Parkinson's Institute, 675 Almanor Avenue, Sunnyvale, CA 94085, USA. sgoldman@thepi.org
authors.forename: Samuel M
authors.initials: SM
authors.lastname: Goldman
authors.forename: Patricia J
authors.initials: PJ
authors.lastname: Quinlan
authors.forename: G Webster
authors.initials: GW
authors.lastname: Ross
authors.forename: Connie
authors.initials: C
authors.lastname: Marras
authors.forename: Cheryl
authors.initials: C
authors.lastname: Meng
authors.forename: Grace S
authors.initials: GS
authors.lastname: Bhudhikanok
authors.forename: Kathleen
authors.initials: K
authors.lastname: Comyns
authors.forename: Monica
authors.initials: M
authors.lastname: Korell
authors.forename: Anabel R
authors.initials: AR
authors.lastname: Chade
authors.forename: Meike
authors.initials: M
authors.lastname: Kasten
authors.forename: Benjamin
authors.initials: B
authors.lastname: Priestley
authors.forename: Kelvin L
authors.initials: KL
authors.lastname: Chou
authors.forename: Hubert H
authors.initials: HH
authors.lastname: Fernandez
authors.forename: Franca
authors.initials: F
authors.lastname: Cambi
authors.forename: J William
authors.initials: JW
authors.lastname: Langston
authors.forename: Caroline M
authors.initials: CM
authors.lastname: Tanner
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002251:Carbon Tetrachloride / Q000633:toxicity; D015331:Cohort Studies; D004200:Diseases in Twins / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure / Q000009:adverse effects*; D016017:Odds Ratio; D010300:Parkinson Disease / Q000453:epidemiology* / Q000209:etiology*; D012307:Risk Factors; D012997:Solvents / Q000633:toxicity*; D013750:Tetrachloroethylene / Q000633:toxicity; D014427:Twins
chemical_list: D012997:Solvents; D002251:Carbon Tetrachloride; D013750:Tetrachloroethylene
references.citation: Occup Environ Med. 2006 Apr;63(4):267-72
references.pmid: 16556747
references.citation: Am J Ind Med. 1990;18(3):285-93
references.pmid: 2220833
references.citation: Pharmacol Rev. 2001 Jun;53(2):177-208
references.pmid: 11356983
references.citation: Psychol Med. 1995 Nov;25(6):1211-9
references.pmid: 8637951
references.citation: Am J Ind Med. 2005 Jul;48(1):63-77
references.pmid: 15940722
references.citation: Neurobiol Aging. 2003 Mar-Apr;24(2):197-211
references.pmid: 12498954
references.citation: Scand J Work Environ Health. 1996 Dec;22(6):405-14
references.pmid: 9000307
references.citation: J Environ Sci Health C Environ Carcinog Ecotoxicol Rev. 2007 Jul-Sep;25(3):185-209
references.pmid: 17763046
references.citation: Cancer Res. 2010 Aug 15;70(16):6527-36
references.pmid: 20663906
references.citation: J Neural Transm Suppl. 1997;50:107-11
references.pmid: 9120411
references.citation: Ann Neurol. 1994 May;35(5):616-9
references.pmid: 8179306
references.citation: Mol Chem Neuropathol. 1993 Apr;18(3):313-28
references.pmid: 8507307
references.citation: Am J Ind Med. 1994 Jul;26(1):1-11
references.pmid: 8074117
references.citation: Am J Ind Med. 1989;16(5):547-67
references.pmid: 2556028
references.citation: J Neurochem. 2010 Feb;112(3):773-83
references.pmid: 19922440
references.citation: Ann Neurol. 2008 Feb;63(2):184-92
references.pmid: 18157908
references.citation: Arch Neurol. 1999 Jan;56(1):33-9
references.pmid: 9923759
references.citation: IARC Monogr Eval Carcinog Risks Hum. 1991;52:1-544
references.pmid: 1683674
references.citation: Occup Environ Med. 2011 Jun;68(6):391-9
references.pmid: 20833760
references.citation: Toxicol Sci. 2003 May;73(1):90-7
references.pmid: 12657742
references.citation: Acta Neuropathol. 2010 Apr;119(4):435-45
references.pmid: 20300918
references.citation: Neurology. 2002 Feb 26;58(4):581-8
references.pmid: 11865136
references.citation: Adv Exp Med Biol. 2003;527:253-63
references.pmid: 15206739
references.citation: Toxicol Appl Pharmacol. 2002 Mar 15;179(3):163-71
references.pmid: 11906246
references.citation: Toxicol Lett. 1983 Aug;18(1-2):163-6
references.pmid: 6623542
references.citation: Neurotoxicology. 2008 Sep;29(5):871-82
references.pmid: 18582500
references.citation: Arch Neurol. 1995 Aug;52(8):763-71
references.pmid: 7639628
references.citation: Neurology. 2003 Sep 9;61(5):716-7
references.pmid: 12963777
references.citation: Am J Ind Med. 1997 Mar;31(3):280-6
references.pmid: 9055950
references.citation: J Neural Transm Suppl. 1995;46:235-44
references.pmid: 8821060
references.citation: Am J Ind Med. 1994 Sep;26(3):297-312
references.pmid: 7977404
references.citation: Am J Ind Med. 2003 May;43(5):519-22
references.pmid: 12704624
references.citation: Crit Rev Toxicol. 2003;33(2):105-36
references.pmid: 12708612
references.citation: Am J Hum Genet. 1967 Mar;19(2):133-61
references.pmid: 6067093
references.citation: JAMA. 1999 Jan 27;281(4):341-6
references.pmid: 9929087
references.citation: Neurology. 1994 Jun;44(6):1051-4
references.pmid: 8208398
references.citation: Environ Health Perspect. 2000 May;108 Suppl 2:359-63
references.pmid: 10807565
references.citation: Am J Ind Med. 2010 Mar;53(3):217-23
references.pmid: 20025075
references.citation: J Neurol Neurosurg Psychiatry. 1992 Mar;55(3):181-4
references.pmid: 1564476
references.citation: Occup Environ Med. 2007 Oct;64(10):666-72
references.pmid: 17332139
references.citation: Toxicol Lett. 1995 Oct;80(1-3):39-48
references.pmid: 7482590
references.citation: IARC Sci Publ. 1990;(97):29-42
references.pmid: 2164501
references.citation: Eur J Pharmacol. 2005 Apr 11;512(2-3):181-7
references.pmid: 15840403
references.citation: J Neurochem. 2007 Mar;100(6):1469-79
references.pmid: 17241123
references.citation: Biochem Pharmacol. 1994 Feb 11;47(4):651-7
references.pmid: 7907472
references.citation: Lancet. 2001 Jun 23;357(9273):1997-2001
references.pmid: 11438130
references.citation: Brain Res Bull. 2009 Aug 28;80(1-2):75-8
references.pmid: 19406217
references.citation: Int J Epidemiol. 1996 Aug;25(4):744-52
references.pmid: 8921451
references.citation: Eur J Pharmacol. 2002 May 3;442(1-2):1-16
references.pmid: 12020676
references.citation: Toxicology. 2009 Jun 16;260(1-3):97-103
references.pmid: 19464574
references.citation: Eur J Neurol. 1999 Sep;6(5):609-11
references.pmid: 10457397
references.citation: Environ Health Perspect. 2000 May;108 Suppl 2:177-200
references.pmid: 10807551
references.citation: Can J Psychiatry. 1989 Dec;34(9):934-6
references.pmid: 2611760
references.citation: Appl Occup Environ Hyg. 2002 Jun;17(6):444-53
references.pmid: 12049435
references.citation: Arch Neurol. 2009 Sep;66(9):1106-13
references.pmid: 19752299
references.citation: Annu Rev Public Health. 1998;19:35-53
references.pmid: 9611611
references.citation: Mov Disord. 1992;7(1):2-13
references.pmid: 1557062
references.citation: Ann Neurol. 2006 Jul;60(1):65-72
references.pmid: 16718702
references.citation: Arch Neurol. 1971 Jun;24(6):550-4
references.pmid: 5089901
references.citation: Br J Ind Med. 1987 Nov;44(11):721-3
references.pmid: 3318914
references.citation: Lancet. 1989 Oct 7;2(8667):874
references.pmid: 2571809
references.citation: Neurology. 1991 May;41(5 Suppl 2):38-42; discussion 42-3
references.pmid: 1904141