Chris Robertson, Technical Environmental Services
Objectives
3. Past and Present Exposure Limits;
4. Health Effects;
6. Sampling Data; and,
Born in New Orleans;
CIH and CSP;
Practicing EH&S for 14 years, most of it in Chemical, Paper Industries and Consulting;
Current Past President of AIHA DSS;
I am one of the owners of TES; and,
My favorite hobby is free style, jet skiing.
What is Manganese A naturally occurring metal that is found in many
rocks;
Pure manganese is sliver-colored; - not found in pure form naturally;
The metal will be found naturally combined with oxygen, chlorine, or sulfur;
Elemental symbol is Mn.
Most common forms are metallic, and compounds where Mn exists in the Mn(II), Mn(III), Mn(IV) forms (chiefly as MnCl2, MnSO4, MnPO4, MnO2, and MnO3)
What is Manganese Ubiquitous in the environment, found in low levels in water, air,
soil and food;
Average manganese levels found are:
0.004 ppm in water, 0.02 ug/m3 in air, 400 to 900 ppm in soil, daily intake from food is 1-5 mg/day;
Biological ½ life of approximately 40 days;
It primary excreted through the feces, very little is excreted through the urine.
It is an essential element in the nutrition of humans:
It’s role in the body: formation of connective tissue and bone, in carbohydrate and lipid metabolism, and as a catalyst in several metabolic pathways;
Both Mn deficiencies and Mn excess cases are very rare;
Uses of Manganese Metallic manganese is used in the steel industry to improve
hardness, stiffness and strength; It is used in carbon steel, stainless steel, high temperature
steel, cast iron and superalloys.
Manganese dioxide (MnO2) is used in the production of dry-cell batteries, fireworks, and matches; MnO2 is used as a flux agent in the coatings of shielded arc
electrodes and as an alloying element in electrodes;
Manganese chloride (MnCl2) is used as a catalyst in the
chlorination of organic compounds, in animal feed;
Manganese sulfate (MnSO4) is used as a fertilizer, livestock nutritional supplement, in glazes and varnishes and in ceramics.
Present Exposure Limits OSHA
0.1 mg/m3 (TWA – inhalable, >4 um)
NIOSH 1 mg/m3 (TWA)
all workers may be repeatedly exposed without adverse health effects.
The TLVs should not be considered fine lines between safe and unsafe conditions.
Additive effect when one is exposed to lead, iron oxide, and Mn (NOx, Ozone);
When two or more substances effect the same organ/system, then their combined effect should be evaluated ;
C1/T1 + Cn/Tn, if >1 concern, if <1 may not be a concern;
Health Effects *How important are chemical exposures in our workplace?
*90% of known work related mortality is chronic diseases arising from long term chemical exposures; *Injury: 6,200 per year; *Illness: 49,000 per year;
Listed as an A4 by ACGIH – Not classified as a human carcinogen due to lack of data;
^One widely cited study of 20,000 welders found the incidence of Parkinson’s disease to be ten times higher then a similar population of non-welders.
^According to an ASSE practice specialty article on welding fumes, approximately 10,000 welders nationwide have filed suit on grounds that welding fume exposure have caused them to suffer from manganese-induced parkinsonism.
*Dr. Mirer presentation of choosing PEL’s to Update, 12/2014, CUNY School ^ Article from Bill Walsh with Galson written in June 2011
Health Effects Chronic exposure to Mn causes a CNS disease known as
Manganism; Manganism was first described in the 19th century; Manganism disorder clinically resembles Parkinson’s
Disease (PA);
Manganism differs from PA disease because of where Mn accumulates in the brain, among other factors: Mn primarily accumulates in the globus pallidus, as in
contrast with PA first site of degradation is in the pars compacta
Mn is paramagnetic in nature; therefore, is detectable via MRI.
globus pallidus vs pars compacta
Health Effects Mn induced neurological damage can persist and progress
for many years after exposure to Mn stops;
Chronic exposures, Early symptoms include fatigue, sleepiness, and weakness in the legs, uncontrolled laughing, spastic gait, and a tendency to fall backwards easily (mining exposures); Sexual disfunction, hand-eye coordination, ability to comprehend and retain (Welding exposures)
Acute high exposures (100-900 mg/m3) can cause pneumonia.
Information Behind the 2013 TLV Mn Change
Info. Behind the TLV Change Route of Entry
Inhalation is the primary source of entry into the body
Some uptake can occur via absorption through the olfactory nerve and transported to the CNS;
Particularly respirable fraction;
Info. Behind the TLV Change Route of Entry
Virtually all Mn is absorbed from particles deposited in the fine, gas-exchange regions of the lungs. Thus, the particles of greatest concern are the fine respirable fraction (mostly <4 um, 0.02 mg/m3).
Info. Behind the TLV Change Route of Entry
0.1 mg Mn/m3 is recommended for particles >4 um (inhalable fraction) to limit the secondary absorption via the intestinal tract, and possible absorption of soluble (MnCl2, MnSO4) Mn particles via nasopharynx.
Info. Behind the TLV Change Evolution of the Studies of Health Effects
1. WHO, in 1981, clincial Mn disease occurs at 2-5 mg/m3 (total dust);
2. Roels and coworkers, in 1992, found neurotoxic effects, suggested a 0.036 mg/m3 (respirable aerosol) 8-hour TWA to protect workers from CNS effects
3. Megler and co-workers, in 1994, followed 14 workers exposed to median level of 0.032 mg/m3 Mn (respirable aerosol), Still found Mn-related neurobehavioral effects;
5. Lucchini et al., in 1999, observed exposed workers after 11.5 years: Derived a lowest-observed-adverse-effect level (LOAEL)
of 0.1 mg/m3 (average total dust), 0.038 mg/m3 (geometric mean respirable aerosol);
6. Bast-Petterson et al., in 2004, showed an increase tremor in workers exposed to: A level of 0.036 mg/m3 (geometric mean respirable
aerosol);
7. Young and colleagues, in 2005, demonstrate increase neurobehavioral changes among workers exposed to: 0.01 – 0.04 mg/m3 Mn;
Info. Behind the TLV Change Evolution of the Studies of Health Effects
ACGIH considered all the studies previously mentioned to determine:
0.02 mg Mn/m3 TLV-TWA, respirable;
0.1 mg Mn/m3 TLV-TWA, inhalable;
They note these levels are recommended to reduce the potential for preclinical, adverse, neurophysiological and neuropsychlogical effects
Info. Behind the TLV Change TLV Rationale
Info. Behind the TLV Change Air Sampling Data
Mines, airborne levels of Mn ranged from:
1 to 450 mg/m3 (EPA 1984);
Ferroalloy foundries, airborne levels of Mn ranged from:
0.3 to 2 mg/m3 (Saric and Lucic-Palaic, 1977);
Dry cell battery manufacturing, airborne levels of Mn ranged from:
3 to 18 mg/m3 (Emara et al, 1971);
Info. Behind the TLV Change Air Sampling Data
Welding operations, airborne levels of Mn ranged from:
1 to 4 mg/m3 (Sjogren et al. 1990);
High as 14 mg/m3 when welding with Mn wire (WHO, 1999)
0.01 to 4.93 mg/m3 (total aersol) in 42 Canadian workers (Korcynski, 2000)
In confined space operations;
0.11 to 0.46 mg/m3 (respirable aerosol) personnel exposures (Bowler et al., 2007);
Inside welding helmets, >0.1 to as high as 1 mg/m3, even with 2,000 cfm general ventilation per welder (Harris et al. 2005)
Air Sampling Data My Results
The next few slides covers data that my team has collected over the years;
The focus of my Mn data is on welding fumes as respirable faction;
The data is organized by key variables which effect exposures;
Activity, welding technique, substrate metal, consumable, environment, # of personnel in the space working, ventilation, painted, and field or shop
Total of 76 Mn samples collected
Total Mn Samples per Year by Activity
Results of Data Evaluation I used the AIHA IHStat Tool to determine the 95% concentration for a
couple scenarios.
All sample results had some level of Mn and Iron Oxide – additive effect should be considered
All common welding techniques, TIG, MIG, Flux core and Stick have the potential to exceed the TLV of 0.02 mg/m3
Controls Engineering controls such as LEV, general dilution,
booth are effective in reducing exposures to Mn;
Based on my data, one can reduce an average Mn exposure of 0.379 mg/m3 to 0.048 mg/m3 using LEVs.
Training employees to be aware of their body positioning while generating welding fumes will reduce exposures.
Controls and Conclusion In addition to the engineering and administrative
controls, one may still need respiratory protection.
You will need to gather your own data to determine what controls are needed.
While you are gathering data, a minimum of a half face P-100 respirator should be used.
If one has proper data management (identifying the key variables), the data can be used to predict exposures, possible savings your company money while protecting employees.
Questions and Answers…