Determination of ergosterol on mouldy building materials using isotope dilution and gas chromatography-tandem mass spectrometry.

Ergosterol content of building materials was quantified using gas chromatography-tandem mass spectrometry (GC-MS-MS) in an ion trap with external ionisation. Hydrolysing the samples by classic extraction at 85 degrees C for 90 min in vials was faster, more precise and safer than microwave assisted extraction. [4-2H2]ergosterol was synthesised and used as internal standard, giving method standard deviation of 5-10% from 10 to 30 ng to 10-15 microg ergosterol in the sample. The use of GC-MS-MS meant that no solid-phase extraction clean-up was needed, so one person could easily prepare 40-80 samples per day.

Residential exposure to plasticizers and its possible role in the pathogenesis of asthma.

The plasticizer di(2-ethylhexyl) phthalate (DEHP) is widely used in building materials. DEHP is identified as the major plasticizer exposure in dwellings. We provide evidence that inhalation exposure to DEHP as aerosols adsorbed to particulate matter is as important, or more important, than vapor phase exposure. The particulate inhalation exposure to DEHP is considered to be significant due to its low clearance and extensive penetration into the pulmonary region. DEHP is capable of creating high local concentrations in the airways at the deposition site with subsequent local effects. The proposed mechanism of effect states that mono(2-ethylhexyl) phthalate (MEHP), the primary hydrolysis product of DEHP, mimics the inducing prostaglandins (PG) PGD(2), 9alpha,11betaPGF2, and PGF2alpha, and thromboxanes in the lungs, thereby increasing the risk of inducing inflammation in the airways, which is a characteristic of asthma.