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