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#1 Posted : 07 June 2021 16:16:24(UTC)
Rank: New forum user

Hi, I did medical surveillance for a welder recently. His urine Manganese came back as 1200ng/L followed by 2500ng/L one month later, however Lab minimum threshold (LOR) was 1000ng/L. (Guidance HSE UK urine manganese = 19ng/L)

Meanwhile, Blood manganese = 0.212mg/L
BEI or guidance HSE UK = 7.1 -10.4mg/L

Any idea why the discrepancy in results. Does it warrant in reporting it as occupational disease or medically remove him temporarily? 

FYI he doesn't have any sign and symptom of poisoning. No PPE was provided at work. 

peter gotch  
#2 Posted : 07 June 2021 16:55:02(UTC)
Rank: Super forum user
peter gotch


A quick google suggests that it is normal for the level of manganese in blood to exceed that in urine.

So, google says that the usual range is 4-15 micrograms per L in blood, but 1-8 micrograms per L in urine.

If you are saying that you are getting 1200-2500 nanograms per L in urine then that would be in the normal range, viz 1.2-2.5 micrograms per L.

Not sure where you found the HSE guidance. Are you saying that it says 7.1 times 10 to the minus 4 @ mg/L? This would be 7.1 times 10 to the minus 7 which would be a very odd way of expressing things since SI units assume that generally one works in powers of 3 i.e. 10 to the minus 3 (milligrams) or minus 6 (micrograms) or minus 9 (nanograms).

The key concern would be the chronic condition of manganism otherwise called Parkinson's syndrome as the effects are similar to Parkinson's Disease. [Something I learned mostly from a Medical Director in Ukraine].

Hence, even if urine and blood levels were elevated you might not expect that to translate into systems of poisoning in the short term.

HSE guidance would suggest that in general monitoring of airborne exposure in preference to post exposure biological monitoring (though of course that would not pick up any exposure by other routes). So HSE guidance EH40 sets workplace exposure limits for manganese and its inorganic compounds.

#3 Posted : 07 June 2021 17:44:07(UTC)
Rank: Super forum user

Firstly you cannot report it as you do not have an diagnosis you have a test result and it needs to be interpreted by an occuptional health doc to provide diagnosis.

Normal human background levels are around 1.19 mcg/l...we need to get our micrograms (mcg) and milligrams (mg) right here... his exposure is 2500 mcg/l = 2.5 mg/l, and 1200mcg/l = 1.2 mg/l...again not sure of your limits from....Slight disorders of the lung functions, such as coughing and bronchitis, after exposure to an average value of 1.33 mg/m3 and a medium exposure duration of 7.1 years are still described in current studies.

The picture of ‘manganism’, a disease with a clinical picture similar to Parkinson’s disease , has often been observed after chronic inhalation of high Mn concentrations of up to 450 mg/m3. 

The half life of it in the blood is fairly short but long in the tissues (8-9 years)...but as I say you don't have a lot to go on at the moment...smoker vaper?

if in doubt remove temporarily and test before re-entry and then test after first shift...observe him for his good and bad work practices..there is a NOAEL of 0.040 mg/m³ (respirable) maybe test the respiratory exposure?

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