Neuromotor function in a cohort of Danish steel workers.
OBJECTIVE
With a longitudinal design to evaluate possible neuromotor impairment in a cohort of steel workers exposed to metal dust.


METHODS
Ninety-two employees from a steel works were examined in 1989 and 1995. Sixty were re-examined in 2003. A non-matched control group was examined in 1996 (n=19) and in 2003 (n=14). Median blood manganese in 1989, 1995 and 2003 was 149, 171 and 155 nmol/l. Median blood lead in 1989 and 2003 was 0.76 and 0.22 micromol/l. Median air concentration of manganese at the steel works was estimated to be 0.11 mg/m3 in 1970s and was 0.03 mg/m3 in 1990s. Median air concentration of lead was estimated to be 0.13 mg/m3 in 1970s and was 0.01 mg/m3 in 1990s.


METHODS
The Catsys 2000 system developed by Danish Product Development is computer-based device for measuring hand tremor, hand coordination and reaction time.


RESULTS
Over all there were no statistically significant differences in neuromotor function between the participating steel workers, non-participating steel workers and controls in 1995/1996. Only reaction time for the right hand was slower for the participating steel workers. Compared with the control group the steel workers showed a decline in the ability to perform fast precise hand pronation/supination and finger tapping from 1995 to 2005. Correlation analysis showed no associations between test results for fast hand coordination and blood manganese and lead. Only seniority was associated with deterioration of beat regulation of fast pronation/supination of the hands.


CONCLUSIONS
On a group basis the changes were subclinical, but they should none the less be taken seriously.


CONCLUSIONS
Changes of neuromotor function measured as the ability to perform fast precise pronation/supination of the hands and fast precise finger tapping was shown in this cohort of steel workers. No causal relationships could be shown.
Blond
Morten
M
Hilleroed Hospital, Hilleroed, Denmark. blond@dadlnet.dk
Netterstrom
Bo
B
D000328:Adult; D000368:Aged; D000393:Air Pollutants / Q000009:adverse effects* / Q000097:blood; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D015331:Cohort Studies; D003718:Denmark; D004391:Dust; D006801:Humans; D007854:Lead / Q000009:adverse effects* / Q000097:blood; D008137:Longitudinal Studies; D008297:Male; D008345:Manganese / Q000097:blood; D017895:Manganese Compounds / Q000009:adverse effects*; D020149:Manganese Poisoning / Q000097:blood / Q000209:etiology* / Q000523:psychology; D008669:Metallurgy; D008875:Middle Aged; D009043:Motor Activity / Q000187:drug effects*; D009483:Neuropsychological Tests; D009784:Occupational Diseases / Q000097:blood / Q000139:chemically induced* / Q000523:psychology; D016273:Occupational Exposure; D011930:Reaction Time / Q000187:drug effects; D013232:Steel
D000393:Air Pollutants; D015415:Biomarkers; D004391:Dust; D017895:Manganese Compounds; D013232:Steel; D007854:Lead; D008345:Manganese