Partitioning of PCBs from air to clothing materials in a Danish apartment.

Polychlorinated biphenyl (PCB) contamination of buildings continues to pose an exposure threat, even decades after their application in the form of calks and other building materials. In this research, we investigate the ability of clothing to sorb PCBs from contaminated air and thereby influence exposure. The equilibrium concentration of PCB-28 and PCB-52 was quantified for nine used clothing fabrics exposed for 56 days to air in a Danish apartment contaminated with PCBs. Fabric materials included pure materials such as cotton and polyester, or blends of polyester, cotton, viscose/rayon, and/or elastane. Air concentrations were fairly stable over the experimental period, with PCB-28 ranging from 350 to 430 ng/m3 and PCB-52 ranging from 460 to 550 ng/m3 . Mass accumulated in fabric ranged from below detection limits to 4.5 mg/g of fabric. Cotton or materials containing elastane sorbed more than polyester materials on a mass basis. Mass-normalized partition coefficients above detection limits ranged from 105.7 to 107.0  L/kg. Clothing acts as a reservoir for PCBs that extends dermal exposure, even when outside or in uncontaminated buildings.

Studies on the diagnosis of Tyzzer's disease in laboratory rat colonies with antibodies against Bacillus piliformis (Clostridium piliforme).

To develop a system to be used for confirming diagnosis of Tyzzer's disease in seropositive rat colonies, 38 Mol:SPRD, BB/Wor/Mol-BB, and Stroke-Prone rats suffering from megaloileitis were examined. All affected rats had been found by a systematic examination of 5-week-old male rats from barrier-protected colonies, sero-positive to Bacillus piliformis, the agent of Tyzzer's disease. The rats were evaluated by serologic testing, histologic examination of the ileum, liver, and heart (hematoxylin and eosin and Warthin-Starry staining), and immunofluorescence staining of tissue smears of the ileum and liver. The presence of B. piliformis was verified in 24 of the rats. All animals that had the agent in the liver or heart also had it in the ileum. The sensitivity of immunofluorescence staining for identification of the agent was higher than that for Warthin-Starry staining. Thirty-seven rats had histologic changes indicative of Tyzzer's disease in the liver, and 23 had histologic changes in the myocardium. All rats had a high titer of antibodies against B. piliformis. Having verified the presence of the agent, germ-free sentinels were placed in one of the colonies. These also became infected, as did germ-free sentinels caged with the infected rats outside the barrier unit. The number of sentinels infected increased with the age of the sentinels at introduction. To prove the absence of Tyzzer's disease in a seropositive colony, it is considered necessary to examine approximately 3,000 5-week-old rats for abdominal distension and demonstrate negative staining of the ileum for B. piliformis.