High Risk Manganese Occupations

The majority of the population is not at risk for manganese health conditions, but certain industries and communities in the industry specific areas have the risk of suffering serious health conditions when reaching toxic levels of manganese exposure. The National Institute for Occupational Safety and Health (NIOSH) has developed a list of leading work-related diseases and injuries in the United States, and included on that list is high levels of manganese exposure that can produce psychoses and suicidal tendencies, most commonly found in welders. Affecting the central nervous system, high amounts of manganese is linked to conditions such as Parkinson’s disease.

NIOSH stated there is a larger problem than initially assumed regarding occupational neurotoxicity, attributing this to the inability to adequately recognize and diagnose manganese poisoning and because of the similarity manganese poisoning signs have with other common non-occupationally related diseases. The exact risk of manganese health conditions in the workplace is still unknown but the impact it has made on industry specific workers and communities have been devastating.

A psychological test performance completed by the National Institute of Occupational Health in Solna, Sweden in foundry workers exposed to low levels of manganese. The test consisted of 30 manganese exposed foundry workers from two Swedish plants that were examined with a partly computerized psychological test battery. The manganese-exposed workers had 10 performance tests that were compared to a matched control group of 60 workers.

The performance of the manganese-exposed workers was found to be inferior to the control group on simple reaction time, digit span, and finger tapping. The manganese test performance concluded the present workplace limits of manganese were not sufficiently protecting the workers from risks of manganese. Currently, workplace manganese exposure limits are set at:

• OSHA: The legal airborne exposure limit of manganese permissible is 5mg/m3 and cannot be exceeded at any time.
  
  
• ACGIH: The recommended airborne exposure limit of manganese is 5 mg/m3 for dust and compounds and cannot be exceeded at any time. The recommended airborne exposure limit is 1 mg/m3 as manganese for fume averaged over an 8-hour workshift and is 3 mg/m3 for fume as a short-term exposure limit.

Workers in the mining, welding, and factory environment are at the highest risk for manganese exposure. Miners that work with manganese are surrounded by manganese dust and airborne manganese particles. The EPA thinks that the highest risk workers for becoming affected by manganese exposure are factory workers that produce manganese ore or manganese compounds are turned into steel. The towns and communities surrounding the areas of manganese heavy industry can also become affected by exposure to manganese.

Many workplace control and practices are violated in industries with high risk for manganese poisoning.

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