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Manufacturing

NORA Manufacturing Sector Strategic Goals

927Z1LH - Manganese-Associated Parkinsonism in Welders: Feasibility

Start Date: 10/1/2005
End Date: 9/30/2009

Principal Investigator (PI)
Name: Robert Park
Phone: 513-533-8572
E-mail: rhp9@cdc.gov
Organization: NIOSH
Sub-Unit: EID
Funded By: NIOSH

Primary Goal Addressed
9.0

Secondary Goal Addressed
None


Attributed to Manufacturing
50%

Project Description

Short Summary

This project will establish the feasibility of, and a specific plan for, an investigation of manganism in arc welders. Employers with appropriate populations and records will be identified and their cooperation invited for the conduct of a full investigation. The ultimate result of this investigation would be a statistical model for the development of cognitive and Parkinson-like motor neurological deficits resulting from manganese exposure possibly including genetic risk factors, and a risk assessment which will disclose whether new regulatory requirements and production practices are needed.



Description

The goal of this project is to identify and gain access to an appropriate population for meaningful investigation, and to develop a proposal for such an investigation. Enquiries will be made to employers utilizing arc welding on a large scale and to other organizations that have an interest in such forms of production. The target industries will include shipbuilding, bridge construction, and construction in the chemical, petrochemical and power-generation sectors. Organizations will include the US Navy, which contracts with many such employers, and possibly various trade associations that may have an interest in establishing reliable knowledge about risks from manganese. With a small group of willing candidate employers, further investigation will attempt to establish a) the size and demographics of available arc welder and comparison populations, b) the attributes of record systems pertaining to work history, production documentation, retrospective exposure assessment, and medical history (insurance claims, disability), and c) the feasibility of conducting neurobehavioral assessments and further medical evaluations on a sample of the proposed study population. A formal study proposal will be developed for a population appropriate for this investigation and one for which the employer is prepared to cooperate in such an investigation. A proposal will be sought which is acceptable to the employer, interested trade associations and associated workers' organizations.



It is anticipated that travel to up to five sites may be required and a role may be defined for a contractor in soliciting and arranging discussions with various employers. Consultants in occupational medicine specializing in neurological effects and in neurobehavioral clinical evaluation may also be utilized. Site visits would involve inspection of personnel records, productions records, environmental assessment data, and medical information systems. A tentative study design and record access requirements would be shared with prospective employer study candidates as well as numbers of workers that might be required for further evaluation. The ultimate result of this investigation would be a statistical model for the development of cognitive and Parkinson-like neurological deficits resulting from manganese exposure and a risk assessment which will disclose whether new regulatory requirements and production practices are needed.



A pilot study of genetic aspects of the Mn effects will be included in this feasibility effort. Existing blood samples (to be made available by investigators at University of Cincinnati) will be processed to examine DNA polymorphisms at sites known to have relevance to Mn, and some assays of methylation patterns will also be conducted. The blood samples came from a population of 80 adults environmentally-exposed to Mn in SE Ohio. Confidentiality and human subjects reviews have been completed.



Objectives

This project will establish the feasibility of an investigation of parkinsonism in arc welders. Employers with appropriate populations and records will be identified and their cooperation invited for the conduct of a full investigation. The immediate product of this effort will be a formal proposal for a full investigation which is acceptable to the parties involved and which will be peer-reviewed by reviewers from NIOSH and outside NIOSH.



Mission Relevance

This project is intended to address an emerging concern over the development of neurological deficits in relation to exposures to manganese arising from arc welding activities. Although compelling case reports have appeared, very little adequate descriptive or analytical epidemiology exists addressing the actual risks of developing Parkinson-like neurological deficits in relation to levels and durations of prior exposures to manganese. The goal of this project is to identify and gain access to an appropriate population for meaningful investigation, and to develop a proposal for such an investigation. The ultimate goal of the resulting project would be to identify exposure levels and time courses of exposure that lead to clinically significant impairment and that would support a quantitative risk assessment. A secondary goal is assess the importance of genetic variability in Mn-related health effects. The result would indicate whether current welding practices using high-Mn alloys and welding rods are placing workers at unacceptable risk and would support recommendations for further regulation, if needed. This project contributes to the following sectors:

Manufacturing Sector (50%)

Goal 9. Enhance the state of knowledge related to emerging risks to occupational safety and health in manufacturing.

Construction (50%)

Goal 6: Reduce welding fume exposures and related health risks among construction workers by increasing the availability and use of welding fume controls and practices for welding tasks.

IG6.5: Improve understanding of dose-response relationships in welding fume toxicity and develop new approaches for reducing toxic metal exposures from welding fume.

This project also contributes to the Cross-Sector Programs:

Cancer, Reproductive, and Cardiovascular Disease (50%)

09PPCRCSG5

Strategic Goal 5: Reduce the incidence and mortality of other chronic diseases, including (but not limited to), work-related neurologic (cerebrovascular) and renal disease.

Authoritative Recommendations Program (50%)

Goal 1: Reduce and prevent occupational injuries, illnesses and fatalities by supporting NORA sector and cross-sector programs – specifically, this project will contribute to this goal by providing quantitative risk assessment to support development of NIOSH authoritative recommendations documents.



Page last updated: June 3, 2011
Page last reviewed: May 23, 2011
Content Source: National Institute for Occupational Safety and Health (NIOSH) Office of the Director

 

NIOSH Program:

Manufacturing