No abstract

Hydrocarbon and nonhydrocarbon components dissolving in water from fresh diesel and field samples of highly weathered diesel (spilled up to 50 years ago) from two sites were investigated. The fresh and weathered diesels were equilibrated with water using a slow‐stirring method, and the product and equilibrated aqueous water samples analyzed by a range of analytical procedures. The water phase equilibrated with weathered diesels had higher total dissolved organics concentrations (96 and 8.6 mg/L at the two sites) compared to the water phase equilibrated with fresh diesel (average of 3.4 mg/L). Compound class characterization of dissolved organics in water from the weathered diesel showed that polar components were a significant compound class (98% and 42% at the two sites) and appeared largely as an unresolved complex mixture (UCM) in the total ion chromatograms (TICs). Identification of 1‐adamantanol in the polar fraction of both weathered diesel samples (3.6 and 0.3 μg/L at the two sites) suggested that at least some of the associated polar components are from a petroleum source. The analysis of total petroleum hydrocarbons (TPH) is aimed at measuring only dissolved carbon and hydrogen‐containing compounds, and dissolved polar compounds present as a UCM are often assumed to be from natural organic matter (NOM) and removed. This may result in a gross underestimation of the total soluble organic material in water associated with weathered diesels. In addition, the risk posed by these fuel‐derived polar compounds is unknown.

A speech intelligibility pilot study is being conducted in primary school classrooms in Seattle. The properties of a number of unoccupied, conventional classrooms have been determined [e.g., EDT, RT60, and background noise levels without and with operating mechanical (HVAC) systems]. Intelligibility tests have been conducted in one room using four groups of children, two from grades 1–3 and the others from grades 3–5. The tests employed prerecorded AUDITEC words lists and Test of Auditory Comprehension short paragraphs and picture images. The test conditions used prerecorded tapes played through a loudspeaker placed at the front of the class. These tapes were played back at levels 15 dB(A) above background noise levels. Four playback conditions served as the major variable for these tests: with the HVAC system ‘‘off;’’ with HVAC system ‘‘on;’’ through an FM system; and a repeat of the first condition. Other test variables are student grade levels and student’s location versus the loudspeaker. An additional variable arises from the ethnic diversity of the school population: 46 distinct ethnic groups are present in the student body. Data analysis is presently underway. [Work supported by University of Washington Royalty Research Fund.]