Occupational exposures to metals as risk factors for Parkinson's disease

TLDR

The study examined whether long‑term occupational exposure to iron, copper, manganese, mercury, zinc, and lead increases Parkinson’s disease risk. A population‑based case‑control design enrolled 144 PD patients and 464 matched controls from the Henry Ford Health System, who completed detailed work histories that an industrial hygienist blinded to case status scored for metal exposure. After adjusting for sex, race, age, and smoking, >20‑year exposure to copper (OR 2.49) and manganese (OR 10.61) was significantly associated with PD, and combined exposures to lead‑copper, lead‑iron, and iron‑copper produced even higher odds, indicating chronic metal exposure may act alone or synergistically to promote disease. NEUROLOGY 1997;48:650‑658.

Abstract

Article abstract-In a population-based case-control study, we investigated the potential role of occupational exposure to iron, copper, manganese, mercury, zinc, and lead as risk factors for Parkinson9s disease (PD). Concurrently recruited, nondemented patients (n = 144) with idiopathic PD and controls (n = 464) consisting of men and women &gt;or=to50 years of age, frequency-matched for age (within 5 years), race, and sex were enrolled. All had primary medical care at Henry Ford Health System in urban/suburban metropolitan Detroit. Subjects were given an extensive risk-factor questionnaire detailing actual worksite conditions of all jobs held for more than 6 months from age 18 onward. An industrial hygienist, blinded to the case-control status of subjects, rated occupational exposure to each of the metals of interest. When adjusted for sex, race, age, and smoking status, we found in those with more than 20 years9 exposure a significantly increased association with PD for copper (OR = 2.49, 95% CI = 1.06, 5.89) and manganese (OR = 10.61, 95% CI = 1.06, 105.83). For more than 20 years9 exposure to combinations of lead-copper (OR = 5.24, 95% CI = 1.59, 17.21), lead-iron (OR = 2.83, 95% CI = 1.07, 7.50), and iron-copper (OR = 3.69, 95% CI = 1.40, 9.71), there was a greater association with PD than with any of these metals alone. These findings suggest that chronic exposure to these metals is associated with PD, and that they may act alone or together over time to help produce the disease. <b>NEUROLOGY 1997;48: </b> 650-658