Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

NIH-funded twin study finds occupational chemical exposure may be linked to Parkinson's risk

14.11.2011
A new research report contributes to the increasing evidence that repeated occupational exposure to certain chemical solvents raises the risk for Parkinson's disease.

Researchers analyzed the occupational histories of twins in which one of the pair developed the neurodegenerative disorder, and assessed that twin's likelihood of exposure to six chemicals previously linked to Parkinson's.

Of the six chemicals investigated, researchers concluded that two common chemical solvents, trichloroethylene (TCE) and perchloroethylene (PERC), are significantly linked to development of this disease. This study, supported in part by the National Institute of Neurological Disorders and Stroke (NINDS), a part of the National Institutes of Health, appears in the Nov. 14, 2011 issue of Annals of Neurology.

Parkinson's disease is a movement disorder caused by the loss of brain cells that produce a molecule called dopamine. The primary symptoms of Parkinson's are tremor, stiffness, slowed movement and impaired balance, and as these symptoms progress, patients may also develop difficulty walking, speaking or completing other activities of daily living. Genes play a role in Parkinson's disease, but fewer than 10 percent of cases are due to a single gene mutation, and not all people with these mutations develop Parkinson's, suggesting that environmental factors also contribute to the likelihood of developing the disease.

The researchers, led by Samuel Goldman, M.D., M.P.H. and Caroline Tanner, M.D., Ph.D. at the Parkinson's Institute in Sunnyvale, Calif., collected the histories of 99 pairs of twins in which one of the pair developed Parkinson's and the other twin did not. Since twins are so genetically similar, twin studies are especially useful in identifying environmental influences in disease. The twins were identified through the National Academy of Sciences/National Research Council World War II Veteran Twins Registry. Of the 99 pairs, half were genetically identical twins, and half were fraternal twins.

The study team assessed the twins' lifetime work and hobby activities, specifically inquiring about occupational tasks such as electrical work, industrial machinery repair, and dry cleaning, which would potentially expose people to chemicals previously linked to Parkinson's. The researchers also collected information on head injuries, which are suspected to increase Parkinson's risk, and smoking history, which is reported to decrease Parkinson's risk. Expert evaluators, unaware of which study subjects had Parkinson's, reviewed this information and calculated lifelong exposure to six chemicals: TCE, PERC, carbon tetrachloride, n-hexane, xylene and toluene. Of these, TCE and PERC posed a notable risk for developing Parkinson's.

"The potential importance is great, since both solvents persist in the environment and are commonly used," said Dr. Goldman, "Parkinson's was sixfold more common in twins exposed to TCE, and ninefold more common in twins exposed to TCE or PERC." There was also a trend toward a tenfold increase in Parkinson's disease in twins exposed to PERC alone.

In this study researchers looked only at occupational chemical exposure, and the association with job categories tended toward significance only for the industrial machinery repairer and industrial worker categories. However, the chemicals evaluated here are found outside industrial settings as well. PERC is the leading chemical used in garment dry cleaning. TCE is the most frequently reported organic groundwater contaminant, was once used as general anesthetic and coffee decaffeinating agent, and is still used widely as a metal degreasing agent.

TCE has also been linked to Parkinson's by other research groups. Researchers at the University of Kentucky, Lexington, and the Kangwon National University in South Korea have reported an association between TCE and Parkinson's in highly-exposed industrial workers, and have also demonstrated that TCE causes neurodegeneration in animal models.

The analysis described in this report expands on preliminary findings presented at the 2010 American Academy of Neurology meeting. The new paper quantifies the individuals' exposures to the chemicals in terms of successive years and cumulative exposure over their lifetime.

Dr. Tanner notes that while the association between chemical exposure and Parkinson's is strong, one limitation of the research is the small number of individuals studied. "It will be important to replicate these results in additional populations with well-characterized exposure histories," she commented.

Wendy Galpern, M.D., Ph.D., program director at NINDS, agreed that replication of these results is necessary. "This epidemiologic study is a noteworthy addition to our growing understanding of the association between environmental exposures and Parkinson's disease," Dr. Galpern said. "The identification of specific chemicals linked to this neurodegenerative disorder may have implications for disease prevention and an improved understanding of how Parkinson's develops."

The research was supported by NINDS/NIH, The Michael J. Fox Foundation for Parkinson's Research, New York, Parkinson's Unity Walk, Kingston, N.J., The Valley Foundation, Los Gatos, Calif., and James and Sharron Clark.

Reference: Goldman SM et al. "Solvent Exposures and Parkinson Disease Risk in Twins" Annals of Neurology, published online Nov. 14, 2011

For more information about Parkinson's Disease, visit the Parkinson's Disease fact sheet on the NINDS website: http://www.ninds.nih.gov/PD

NINDS (http://www.ninds.nih.gov) is the nation's leading funder of research on the brain and nervous system. The NINDS mission is to reduce the burden of neurological disease – a burden borne by every age group, by every segment of society, by people all over the world.

About the National Institutes of Health (NIH): NIH, the nation's medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit http://www.nih.gov.

Nicole Garbarini | EurekAlert!
Further information:
http://www.nih.gov

More articles from Studies and Analyses:

nachricht ECG procedure indicates whether an implantable defibrillator will extend a patient's life
02.09.2019 | Technische Universität München

nachricht Fracking prompts global spike in atmospheric methane
14.08.2019 | European Geosciences Union

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Solving the mystery of quantum light in thin layers

A very special kind of light is emitted by tungsten diselenide layers. The reason for this has been unclear. Now an explanation has been found at TU Wien (Vienna)

It is an exotic phenomenon that nobody was able to explain for years: when energy is supplied to a thin layer of the material tungsten diselenide, it begins to...

Im Focus: An ultrafast glimpse of the photochemistry of the atmosphere

Researchers at Ludwig-Maximilians-Universitaet (LMU) in Munich have explored the initial consequences of the interaction of light with molecules on the surface of nanoscopic aerosols.

The nanocosmos is constantly in motion. All natural processes are ultimately determined by the interplay between radiation and matter. Light strikes particles...

Im Focus: Shaping nanoparticles for improved quantum information technology

Particles that are mere nanometers in size are at the forefront of scientific research today. They come in many different shapes: rods, spheres, cubes, vesicles, S-shaped worms and even donut-like rings. What makes them worthy of scientific study is that, being so tiny, they exhibit quantum mechanical properties not possible with larger objects.

Researchers at the Center for Nanoscale Materials (CNM), a U.S. Department of Energy (DOE) Office of Science User Facility located at DOE's Argonne National...

Im Focus: Novel Material for Shipbuilding

A new research project at the TH Mittelhessen focusses on the development of a novel light weight design concept for leisure boats and yachts. Professor Stephan Marzi from the THM Institute of Mechanics and Materials collaborates with Krake Catamarane, which is a shipyard located in Apolda, Thuringia.

The project is set up in an international cooperation with Professor Anders Biel from Karlstad University in Sweden and the Swedish company Lamera from...

Im Focus: Controlling superconducting regions within an exotic metal

Superconductivity has fascinated scientists for many years since it offers the potential to revolutionize current technologies. Materials only become superconductors - meaning that electrons can travel in them with no resistance - at very low temperatures. These days, this unique zero resistance superconductivity is commonly found in a number of technologies, such as magnetic resonance imaging (MRI).

Future technologies, however, will harness the total synchrony of electronic behavior in superconductors - a property called the phase. There is currently a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International Symposium on Functional Materials for Electrolysis, Fuel Cells and Metal-Air Batteries

02.10.2019 | Event News

NEXUS 2020: Relationships Between Architecture and Mathematics

02.10.2019 | Event News

Optical Technologies: International Symposium „Future Optics“ in Hannover

19.09.2019 | Event News

 
Latest News

Energy Flow in the Nano Range

18.10.2019 | Power and Electrical Engineering

MR-compatible Ultrasound System for the Therapeutic Application of Ultrasound

18.10.2019 | Medical Engineering

Double layer of graphene helps to control spin currents

18.10.2019 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>