Abstract No:
1710
Abstract Type:
Student Poster
Authors:
N Shin1, J Park1, U Dydak1
Institutions:
1Purdue University, West Lafayette, IN
Presenter:
Nara Shin
Purdue University
Faculty Advisor(s):
Jae Hong Park, Ph.D., C.I.H.
Purdue University
Ulrike Dydak
Purdue University
Description:
Welders are exposed to metal-containing aerosols with manganese (Mn) linked to motor function deficits, such as Parkinsonism. We developed refined short-term and long-term cumulative exposure indices (CEIs) using personal air sampling during a work shift and a work history questionnaire. In this study, we examine how this exposure metrics affect measurable motor impairments and provide new insights into Mn effects on the nervous system while advancing methods to assess risk in occupational settings.
Situation/Problem:
Workers in welding occupations are routinely exposed to metal-containing aerosols including Mn which can accumulate in the brain and cause motor function impairment resembling Parkinsonism. These impairments are clinically measure using the Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) – Part III. Accurately quantifying Mn exposure is critical, yet past studies utilized the years of welding, which fail to capture variations across tasks, departments, and prior jobs. Linking exposure to motor outcomes is further complicated by aging, which independently increases UPDRS scores.
Methods:
This study compared nine exposure metrics including years-of-welding (YW), respirable particle (RP) concentrations, Mn, and Fe air levels, CEI for the past three months (CEI3M) and cumulative CEI (CEIcumul) for both Mn and Fe. These metrics were evaluated 1) to determine group differences between welders (W), non-welding factory controls (FC), and university controls (UC) and 2) to explore relations with a total UPDRS score for each of these exposure metrics. A total of 72 subjects (34 W, 23 FCs, and 12 UCs) was recruited from a trailer manufacturing facility. Personal air sampling was conducted following NIOSH Method 0600 and the metals collected on the filters were analyzed using inductively coupled plasma–optical emission spectroscopy (ICP-OES). CEIs were calculated by combining personal air sampling with detailed work histories, accounting for department changes and prior welding jobs. The UPDRS-III was assessed by a trained specialist. Spearman correlations were used for variable comparisons, and linear regression models including age as covariates were run to predict UPRDS-III as a dependent variable for each of the exposure metrics for its independent association.
Results / Conclusions:
The three groups did not differ significantly in age but had different variances in all variables. UPDRS-III scores were 7.0±4.3 (W), 4.9±3.9 (FC), and 1.9±1.6 (UC) and were only significantly different between W and UC. Mean Mn air levels for the three groups were 220±232 µg/m3 (W), 8.0±10.3 µg/m3 (FC), and 0.07±0.06 µg/m3 (UC). The nine-exposure metrics, YW, air levels, and CEIs, found a significantly higher exposure to both Mn and Fe in welders. In the linear mixed models for UPDRS-III, age was considered as a significant predictor for all models. In welders, RP CEI cumul and Mn CEI cumul were only significant predictors of the UPDRS across all groups. This suggests that chronic Mn or Mn containing respirable particle exposure contributed to motor impairment independently of aging. FC showed no significant independent relationship between CEIcumul and UPDRS but observed R2 (0.22-0.29) suggest possible bystander co-exposure to ambient industrial fume.
Core Competencies:
Exposure Assessment
Secondary Core Competencies:
Biostatistics and Epidemiology
Toxicology / Human Disease
Choose at least one (1), and up to five, (5) keywords from the following list. These selections will optimize your presentation's search results for attendees.
Aerosol and airborne particulate monitoring
Exposure Assessment
Labs – Health & Safety, Testing
Risk assessment and management
Toxicology
Based on the information that will be presented during your proposed session, please indicate the targeted audience practice level: (select one)
Professional: Professional is a job title given to persons who have obtained a baccalaureate or graduate degree in IH/OH, public health, safety, environmental sciences, biology, chemistry, physics, or engineering or who have a degree in another area that meets the standards set forth in the next section, Knowledge and Skill Sets of IH/OH Practice Levels, and has had 4 or more years of practice. One significant way of demonstrating professional competence is to achieve certification by a 3rd party whose certification scheme is recognized by the International Occupational Hygiene Association (IOHA) such as the Board of Global EHS Credentialing (BGC).
Was this session organized by an AIHA Technical Committee, Special Interest Group, Working Group, Advisory Group or other AIHA project Team?
No
Are worker exposure data and/or results of worker exposure data analysis presented?
Yes
If yes, i.e., If worker exposure data and/or results of worker exposure data analysis are to be presented please describe the statistical methods and tools (e.g. IHSTAT, Expostats, IHSTAT_Bayes, IHDA-AIHA, or other statistical tool, please specify) used for analysis of the data.
Benjamini-Hochberg method using SPSS
How will this help advance the science of IH/OH?
The primary implication of this study is the validation of CEIs as a sophisticated estimate for exposure assessment. While years-of-welding has been widely used in predicting exposure level, CEIcumul demonstrated the chorionic exposure of metal particles. Additionally, the use of UPDRS combined with exposure assessment improves industrial hygiene (IH) and occupational health (OH) by providing a detailed and targeted monitoring approach. Under the IH perspective, the study links exposure level and duration to specific motor performance. Differentiating between short-term and long-term exposure allows these motor test results to serve as a rapid check of the work environment. In practical application, implementing specific subtests in routine occupational exposure assessment can provide an early warning system for workers exposed to Mn. The findings also help IH professionals distinguish between natural aging and work-related neurological changes, which is especially important for older workers to receive an accurate evaluation. By adding these targeted motor tests to the monitoring program, IH professionals can take proactive measures to prevent further exposure and mitigate health risk. This approach can protect welders’ health long term neurological health and increase awareness of occupational hazards. It supports evidence-based interventions and improves worker safety.
Have you presented this information before?
Yes
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2017 - Seattle, WA
2018 - Philadelphia, PA
2019 - Minneapolis, MN
2025 – Kansas City, MO
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