Summary of “Effect of Chronic Low Level Manganese
Exposure on Postural Balance”
A study was conducted on residents in Marietta, Ohio; home to the only ferromanganese alloy refinery is located, to determine the effect of non-occupational exposure to manganese (Mn). Manganese is a chemical element naturally found in nature and is required in small amounts for the human body. Inhaling excessive amounts of manganese can lead to symptoms that resemble Parkinson’s disease. Symptoms include; postural tremors, difficulties with speech, balance, or gait. Unlike ingestion, inhalation of manganese particles bypasses the liver allowing for a relatively greater dose to reach the central nervous system. Postural balance testing has proven to be useful in identifying subtle balance problems. Postural balance is ...view middle of the document...
These four test conditions included; standing on a platform with eyes open and eyes closed. Then a foam pad was placed on the platform then the subjects stood on the foam pad with eyes open and eyes closed. Before testing, each resident was instructed to stand in a standardized position on the center of the platform where there feet were traced to serve as a guide for consistent foot placement for each test. The test was then reversed and repeated for each subject. They measured distance traveled in each direction to get an accurate measurement of postural balance for each resident. The study was a voluntary study and with a study using a voluntary nonrandom participant selection has potential for bias.
Following the testing each resident was measured for manganese levels in whole blood and hair samples taken. The results of the study showed a significant relationship between manganese levels in the subject’s hair and the postural balance results. Blood manganese did not demonstrate a consistent connection association with the postural balance results. Using blood has been identified as a suitable marker for group-based but isn’t always as reliable as hair. The subject results were compared to the results of a control group. The study results were compared to two other studies and were generally consistent with the results of the other non-occupational studies. The results of the residents were significantly larger in five of the eight postural balance outcomes when compared to the control group’s results.
In conclusion the results suggest impairment in postural balance among the residents who were regularly exposed to ambient manganese. The study was done with a small sample size of the residents that live around the refinery and it is suggested that a larger study should be done to be able to infer accurately the causation of the ambient exposure to manganese.