Study type: Epidemiological study (observational study)

Severe cognitive dysfunction and occupational extremely low frequency magnetic field exposure among elderly Mexican Americans. epidem.

Published in: Br J Med Med Res 2014; 4 (8): 1641-1662

Aim of study (acc. to author)

A population-based cohort study was conducted in the USA to investigate the association between severe cognitive dysfunction and occupational extremely low frequency magnetic field exposure among elderly Mexican Americans.

Further details

A Mini-Mental State Exam score below 10 was used to define cognitive dysfunction.

Endpoint/type of risk estimation

Type of risk estimation: (odds ratio (OR))

Exposure

Assessment

Exposure groups

Group Description
Reference group 1 average occupational magnetic field exposure < 0.2 or intermittently < 1 µT: low
Group 2 average occupational magnetic field exposure between 0.2 and 1 µT or intermittently > 1 µT: medium
Group 3 average occupational magnetic field exposure > 1 µT or intermittently > 10 µT: high

Population

Study size

Type Value
Participants 3,050
Participation rate 85 %
Evaluable 2,844
Statistical analysis method:

Conclusion (acc. to author)

Overall 91.8% of the study participants hat a low occupational magnetic field exposure, 4.7% a medium exposure and 3.5% a high exposure. About 1.7% of 2873 subjects with a Mini-Mental State Exam had a MMSE score below 10.
Significant increased risks for severe cognitive dysfunction were observed for high (group 2: OR 3.4, CI 1.3-8.9) and for 'medium or high' occupational magnetic field exposure (groups 2 + 3: OR 1.7, CI 0.7-4.1). Interaction between occupational magnetic field exposure and other possible risk factors were investigated. The results showed that the interactions between 'medium or high' or high occupational MF exposure and smoking history or age group were statistically significant, depending upon whether two (65-74, 75+) or three (65-74, 75-84, 85+) age groups were considered, respectively.
The authors conclude that working in an occupation with high or 'medium or high' magnetic field exposure may increase the risk of severe cognitive dysfunction. Smoking and older age may increase the deleterious effect of occupational magnetic field exposure.

Study funded by

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