PCDD PCDF INDOOR EXPOSURE IN DAY-CARE-CENTERS AND PCDD/PCDF BLOOD-CONCENTRATIONS OF FEMALE EMPLOYEES/

We determined blood concentrations of polychlorinated dibenzo-p-dioxin s (PCDDs) and polychlorinated dibenzofurans (PCDFs) in 41 female emplo yees with previous exposure to pentachlorophenol-based wood preservati ves from 10 day-care centers in the Hamburg, Germany, area. We compare d the blood concentrations with estimated age-dependent reference valu es and analyzed the correlation between PCDD/PCDF indoor air exposure and blood concentrations. The analyses based on the PCDD congeners 1,2 ,3,4,7,8-, 1,2,3,6,7,8-, and 1,2,3,7,8,9-hexaCDD (hexaCDD), 1,2,3,4,6, 7,8-heptaCDD (heptaCDD), octaCDD, and the 2,3,7,8-tetrachlorodibenzo-p - dioxin toxicity equivalents calculated according to the internationa l NATO-CCMS model (I-TEQ). In comparison to the estimated reference va lues, the blood concentrations of hexaCDD and I-TEQ spread around the mean estimate. Data for octaCDD scattered in some cases distinctly abo ve the upper confidence limit. Reference values for heptaCDD could not be estimated. The correlation between PCDD/PCDF indoor air exposure a nd PCDD/PCDF blood concentrations was examined by linear multiple regr ession analysis considering different exposure variables and taking co nfounders into account. Analyses were carried out with the total study group and with a restricted subgroup. Associations were shown between the PCDD/PCDF indoor air concentrations and blood concentrations for heptaCDD and for the I-TEQ, whereas hexaCDD showed no association. Oct aCDD showed a negative association in the total study group and no ass ociation in the subgroup analysis. In summary, the analyses showed no clear association between PCDD/PCDF indoor air exposure in day-care ce nters and PCDD/PCDF blood levels of female employees previously expose d to wood preservatives. By contrast, the results consistently indicat ed a positive association between PCDD/PCDF blood concentrations and e xposure to wood preservatives in private homes.