Urine vanadium concentrations in workers overhauling an oil-fired boiler.
Since fuel oil ash contains vanadium (V), the measurement of urinary levels of V may provide a biological marker in workers exposed to fuel oil ash. The usefulness of urine V samples as a biological monitoring tool ultimately depends on determining the appropriate time of sampling relative to when exposure occurs. Twenty boilermakers were studied during the overhaul of a large oil-fired boiler. A total of 117 urine samples were collected, 65 start-of-shift (S-O-S) and 52 end-of-shift (E-O-S) samples. Air V exposures were estimated with personal sampling devices and work history diaries. Air V concentrations ranged from 0.36 to 32.19 micrograms V/m3, with a mean +/- SD of 19.1 +/- 10.7, and a median of 18.5. On the first day of work on the overhaul, the V urine levels at the E-O-S (mean +/- SD were 1.53 +/- 0.53, median was 1.52 mg V/g creatinine) were significantly higher than those at the S-O-S (0.87 +/- 0.32, median was 0.83), P = 0.004. However, the V concentrations of the S-O-S urine samples on the last Monday of the study were not significantly different from the S-O-S urine levels on the previous Saturday, a time interval of about 38 hr between the end of exposure and sample collection. The Spearman correlation coefficient (r) between the S-O-S urine V and the workplace concentration of V dust during the previous day was r = 0.35. In summary, the results suggest a rapid initial clearance of V (elevating the E-O-S V concentration on the first day of work relative to the S-O-S concentration), followed by a slow clearance that is not complete 38 hr after the end of exposure, as evidenced by the Monday morning urine V concentrations. The Spearman correlations suggest that the S-O-S urine is preferred to the E-O-S urine for across-shift biological monitoring of V exposure.
Hauser
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R
Department of Environmental Health (Occupational Health and Environmental Science and Engineering Programs), Harvard School of Public Health, Boston, Massachusetts 02115, USA.
Elreedy
S
S
Ryan
P B
PB
Christiani
D C
DC
D000328:Adult; D000395:Air Pollutants, Occupational / Q000633:toxicity; D005648:Fuel Oils; D006801:Humans; D007509:Irritants / Q000652:urine*; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure / Q000009:adverse effects*; D014639:Vanadium / Q000633:toxicity* / Q000652:urine*
D000395:Air Pollutants, Occupational; D005648:Fuel Oils; D007509:Irritants; D014639:Vanadium