Project 2
Parkinsonism and Metal Exposures Among Welders

Parkinsonism is a debilitating, incurable neurodegenerative disorder that affects over several million people in the US. Parkinson's disease is the main type of PS. Parkinsonism is one of the movement disorders whose primary clinical features are slowed movement, difficulty walking and standing, tremor at rest, and muscle rigidity. Metals present in welding fumes have been related to risks for parkinsonism in some previous studies, although there remains some controversy. Of particular concern are exposures to manganese (Mn), although co-occurring metals, notably iron, lead, copper, chromium, and aluminum, may act independently or synergistically to cause signs and symptoms of parkinsonism. This study is being conducted among a group of approximately 1000 professional shipyard welders. The objective of the project is to determine whether the welders' exposure to Mn and other metals increase their risk for parkinsonism. We will also determine whether welding metals is related to the severity and progression of parkinsonism. The study should ultimately provide valuable new scientific information that will shed light on the causes of parkinsonsim and, ideally, lead to the prevention of this disorder.

Recent publications:

Kelada SNP, Checkoway H. Kardia LR, et al. 5’ and 3’ Region variability in the dopamine transporter gene (SLC6A3), pesticide exposure and Parkinson’s disease risk: a hypothesis generating study. Hum Molec Genet 2006;15:3055-62.

Maraganore DM, de Andrade M, Elbaz A, Farrer M, Ionnidis JP, Kruger R, Rocca WA, Schneider NK, Lesnick TG, Lincoln SJ, Hulihan MM, Aasly JO, Ashizawa T, Chartier-Harlin MC, Checkoway H, et al. Collaborative analysis of alpha-synuclein gene promoter variability and Parkinson’s disease. JAMA 2006;296:661-70.

Powers KM, Smith-Weller T, Franklin GM, Longstreth WT Jr., Swanson PD, Checkoway H. Reduced risk of Parkinson’s disease among diabetics. Parkinson Relat Disord 2006;12:185-9.

Ton TG, Heckbert SR, Kukull WA, Longstreth WT Jr., Franklin GM, Swanson PD, Smith-Weller T, Checkoway H. Aspirin, other non-steroidal anti-inflammatory drugs, and risk of Parkinson’s disease. Mov Disord 2006;21:964-9.