PCB in serum and hand wipes from exposed residents living in contaminated high-rise apartment buildings and a reference group.

Exposure to polychlorinated biphenyls (PCB) in buildings constructed with PCB-containing materials can lead to increased body burden of PCB for building users. Exposure to PCB from building related sources was assessed by measuring PCB in serum and hand wipes in two groups of tenants living in the same building estate in apartments constructed with and without PCB. The median serum levels of the sum of 19 PCB congeners was 777 ng/g lw (5-95th percentile: 219-2576 ng/g lw) for the exposed group and 282 ng/g lw (5-95th percentile: 49.8-797 ng/g lw) for the reference group. The congener pattern in serum of the exposed was shifted towards lower chlorinated congeners and was dominated by tri- and tetrachlorinated congeners. The largest difference in serum levels between the groups was observed for PCB-28, with median levels of the exposed being 70 times higher than in the reference group. For very persistent lower chlorinated congeners, like PCB-28, 66 and 74, an increase with residence times was observed as a result of accumulation over time. Less persistent congeners such as PCB-44 and 70 were also elevated in the exposed group -but independent of residence time. The less persistent congeners can therefore be used as markers of recent exposure to original PCB sources. The hand wipes also showed a large exposure contrast, e.g. PCB-28 being more than 60 times higher in the exposed group compared to the reference group (medians 14.4 and 0.23 ng/wipe, respectively) and no overlap between the groups. All measured di- to pentaPCB congeners were significantly higher in hand wipes from the exposed group compared with the reference group. Thus hand wipes seem to be a good, non-invasive screening tool for ongoing indoor exposure to PCB. Furthermore, the measured level of PCB on hand wipes was significantly correlated to PCB in blood for almost all congeners. In conclusion, PCB exposure in contaminated buildings can contribute significantly to the exposure and total body burden of PCB and the lower chlorinated congeners can make up the majority of the total PCB body burden.

Associations between plasma concentrations of PCB 28 and possible indoor exposure sources in Danish school children and mothers.

BACKGROUND: Polychlorinated biphenyls (PCBs) are ubiquitously present in the environment and are suspected of carcinogenic, neurotoxic and immunotoxic effects. Significantly higher plasma concentrations of the congener PCB 28 occur in children compared to adults. Exposure in schools may contribute to this difference. OBJECTIVE: To determine whether increased blood plasma concentrations of PCB 28 in Danish school children and mothers are associated with living in homes or attending schools constructed in the PCB period (1959-1977). METHODS: PCB 28 was analyzed in plasma samples from 116 children aged 6-11years and 143 mothers living in an urban and a rural area in Denmark and participating in the European pilot project DEMOCOPHES (Demonstration of a study to COordinate and Perform Human Biomonitoring on a European Scale). In Denmark, PCBs were used in construction in the period 1950-1977, and year of construction or renovation of the homes and schools was used as a proxy for indoor PCB exposure. Linear regression models were used to assess the association between potential PCB exposure from building materials and lipid adjusted concentrations of PCB 28 in plasma, with and without adjustment for potential confounders. RESULTS: Among the 116 children and 143 mothers, we were able to specify home construction period in all but 4 children and 5 mothers leaving 111 children and 138 mothers for our analyses. The median lipid adjusted plasma PCB 28 concentration was 3 (range: 1-28) ng/g lipid in the children and 2 (range: 1-8) ng/g lipid in the mothers. Children living in homes built in the PCB period had significantly higher lipid adjusted plasma PCB 28 concentrations compared to children living in homes built before or after the PCB period. Following adjustment for covariates, PCB 28 concentrations in children were 40 (95% CI: 13; 68) percent higher than concentrations of children living in homes constructed at other times. Furthermore, children attending schools built or substantially refurbished in the PCB period also had significantly higher (46%, 95% CI: 22; 70) PCB 28 concentrations compared to children attending schools constructed before or after the PCB period, while their mothers had similar concentrations. Adjustment for the most prevalent congener, PCB 153, did not change this effect of home or school construction. When both home and school construction year were included in the models, the increase in lipid adjusted plasma PCB 28 for children living in or attending schools from the PCB period was no longer statistically significant. The individual effect of home and school construction periods could not be evaluated further with the available data. CONCLUSION: Our results suggest that PCB exposure in the indoor environment in schools and homes constructed during the PCB period may contribute significantly to children's plasma PCB 28 concentration. Efforts to minimize PCB exposure in indoor environments should be considered.

Interplay between patient global assessment, pain, and fatigue and influence of other clinical disease activity measures in patients with active rheumatoid arthritis.

The interplay between patient-reported outcome measures in rheumatology is not well clarified. The objective of the study was to examine associations on the group level and concordance on the individual patient level between patient global assessment (PaGl), pain, and fatigue as scored on visual analog scales (VAS) in the daily clinic by patients with active rheumatoid arthritis (RA). Associations with other measures of disease activity were also examined. Traditional disease activity data on 221 RA patients with active disease planned to initiate biological treatment were extracted from the Danish DANBIO registry. Associations between VAS PaGl, pain, and fatigue (0-100) were examined using multiple regression analysis. Concordance between the VAS scores was expressed as the bias (mean difference between intra-individual scores) and the 95% lower and upper limits of agreement (LLoA; ULoA) according to the Bland-Altman method. Mean age was 57 ± 14 years, mean Disease Activity Score (DAS28-CRP4) 5.0 ± 0.9, and mean PaGl 63.6 ± 22.6. PaGl was most strongly predicted by pain and fatigue, pain by PaGl and fatigue, and fatigue by PaGl and pain (beta ranging from 0.17 to 0.69, p < 0.01-0.0001). More objective measures were not or far less predictive. LLoA;ULoA [bias] for PaGl vs. pain was -19.1; 29.5 [5.2], for PaGl vs. fatigue -22.8; 28.6 [2.9], and for fatigue vs. pain -29.2; 33.8 [2.3]. In conclusion, PaGl, pain, and fatigue were most strongly explained by each other, not by more objective clinical measures of disease activity and were nearly identical on the group level. On the individual patient level, however, differences between the scores varied considerably. The findings highlight the challenge of understanding and dealing with traditional patient-reported VAS measures when it comes to individual RA patients in the daily clinic.

FRAX fracture risk in women with a recent fracture of the distal forearm: agreement between assessments with and without bone mineral density and impact of measurement side in the individual patient.

The Fracture Risk Assessment Tool (FRAX) has been developed by the World Health Organization to evaluate the 10-year risk of a hip fracture and a major osteoporotic fracture. We examined the agreement between fracture risk calculated with and without femoral neck bone mineral density (BMD) in individual patients and the impact of BMD measurement side. Bilateral femoral neck BMD results obtained by dual-energy X-ray absorptiometry and clinical risk factor data from 140 women (age 66 ± 8 years) with a recent distal forearm fracture were used for FRAX analyses. Discrepancies between pairs of risk assessments were analysed by the Bland-Altman method. Agreement on the individual level was expressed as 95% limits of agreement (LoA) and on the group level as the mean (or median) of intra-individual differences (the bias). The femoral neck T-score was -1.69 ± 0.87 (hip with lowest BMD value). The risk of a major fracture and a hip fracture based on the lowest femoral neck BMD value was 23.8 ± 21.4% and 7.6 ± 8.3%, respectively. For major fracture risk assessed without versus with the lowest BMD value, lower and upper LoA were -12.3 and 21.1 percentage points (pp) (bias 4.4 pp, p < 0.0001). The corresponding LoA for hip fracture risk were -11.6 and18.6 pp (bias 3.5 pp, p < 0.0001). LoA for major fracture risk assessed with the lowest versus the highest BMD value were 0.0 and 9.5 pp (bias 2.0, p < 0.0001), and correspondingly for hip fracture risk 0.0 and 9.5 pp (bias 1.0 pp, p < 0.0001). Intra-individual differences increased with increasing fracture risk. In conclusion, the 10-year fracture risk calculated without BMD was on the average slightly overestimated compared to calculations with BMD. On the individual patient level differences between fracture risk assessments with and without BMD were pronounced. The side of BMD measurement may also significantly influence the risk assessment result in individual patients.