Biomarkers of exposure in Monday morning urine samples as a long-term measure of exposure to aromatic diisocyanates

Role of dermal exposure in systemic intake of methylenediphenyl diisocyanate (MDI) among construction and boat building workers

“…In addition to dermal exposure, the urinary levels may also indicate a two-phase elimination pattern of MDA and a longer half-live of a second phase metabolite, as halflives of about 70 h have been reported for MDI (Dalene et al, 1997). Recently, Tinnerberg et al (2014) have reported on another slow elimination pattern of MDI that was concluded to result from inhalation exposure. According to that study Monday morning urine samples may be used as a long-term biomarker of exposure instead of analyzing the protein adducts in the blood.…”

Biomonitoring for Occupational Exposure to Diisocyanates: A Systematic Review

“…Moulding processes have been studied in larger ( n = 18–90) worker populations than for continuous foam production ( n = 4–26) but were only reported in two countries: the UK ( Cocker et al , 2009 ; Keen et al , 2012 ) and Sweden ( Sennbro et al , 2004 ; Tinnerberg et al , 2014 ). If mixed processes (which include some moulding companies but results are not reported separately) are included ( Littorin et al , 2007 ; Säkkinen et al , 2011 ) then three countries are covered (UK, Sweden, and Finland) and maximum results for urinary TDA range from ~3.2 ( Tinnerberg et al , 2014 ) to ~110 µmol mol −1 creatinine ( Sennbro et al , 2004 ).…”

“…Moulding processes have been studied in larger ( n = 18–90) worker populations than for continuous foam production ( n = 4–26) but were only reported in two countries: the UK ( Cocker et al , 2009 ; Keen et al , 2012 ) and Sweden ( Sennbro et al , 2004 ; Tinnerberg et al , 2014 ). If mixed processes (which include some moulding companies but results are not reported separately) are included ( Littorin et al , 2007 ; Säkkinen et al , 2011 ) then three countries are covered (UK, Sweden, and Finland) and maximum results for urinary TDA range from ~3.2 ( Tinnerberg et al , 2014 ) to ~110 µmol mol −1 creatinine ( Sennbro et al , 2004 ). If the Sennbro study (2004) is excluded, the results are more comparable across studies, with maximum urine TDA levels of ~3.2 ( Tinnerberg et al , 2014 ), >6.5 ( Keen et al , 2012 ), only 90th percentile reported, 15.5 ( Cocker et al , 2009 ), ~29.3 ( Littorin et al , 2007 ), and 39 ( Säkkinen et al , 2011 ) being reported; all results in µmol mol −1 creatinine.…”

“… Säkkinen et al (2011) analysed 2,4-TDA (6–270 nmol l −1 ) and 2,6-TDA (3–310 nmol l −1 ) in plasma after acid hydrolysis with sulphuric acid 3 M (100°C for 16 h) and found a very good correlation ( r = 0.91) between the plasma total TDA and the airborne TDI. Sennbro et al (2004) , Littorin et al (2007) , and Tinnerberg et al (2014) used basic hydrolysis with 0.3 M NaOH (24 h) in order to measure plasma concentration of TDA. Similar to Säkkinen et al (2011) , both Sennbro et al (2004) and Littorin et al (2007) found same range levels of plasma TDA as well as good correlations with the air levels of TDI ( r = 0.50 for 2,4-TDA and 0.78 for 2,6-TDA; and r = 0.72 for 2,4-TDA and 0.86 for 2,6-TDA, respectively).…”

“…There were insufficient positive plasma results to investigate correlations between urine and plasma levels of MDA. Tinnerberg et al (2014) reported MDA urine levels of workers ( n = 21) at 0.5–8.4 µg l −1 (~0.2–3.5 µmol mol −1 creatinine) and plasma concentrations of MDA at 0.4–19.4 µg l −1 (2.0–98.0 nmol l −1 ). Significant correlations ( P < 0.01) were seen between plasma MDA and urinary MDA levels ( r = 1.000, 0.988, and 0.986 for unadjusted, specific gravity adjusted, and creatinine adjusted urine, respectively) ( Tinnerberg et al , 2014 ).These results cannot be directly compared with the Säkkinen study as the samples were taken on a Monday morning after a weekend of no exposure.…”