| Acrolein, an unsaturated aldehyde found in both indoor and outdoor air, is considered one of the greatest non-cancer health risks of all hazardous air pollutants. Over the past 20 years, many investigators have measured concentrations of carbonyls in ambient outdoor air, occupational settings, and in residential homes. These studies have employed methods capable of measuring formaldehyde, acetaldehyde, and other aliphatic compounds in air; however they are much less reliable for acrolein and related unsaturated carbonyls and require long sampling periods (12-24 hours). Acrolein levels are either not reported, below the detection limit, or were conflicting and highly variable.; This research resulted in the development of a novel, highly sensitive analytical method that uses a mist chamber to collect carbonyls by forming water-soluble carbonyl-bisulfite adducts. The carbonyls are then liberated from the bisulfite, derivatized, and quantified by gas chromatography/mass spectrometry, The minimum acrolein detection limit for ambient sampling is 0.012 mug/m3, well below that of other published methods, and is obtained using a ten minute sampling period. This makes the new method useful for the detection of temporal fluctuations and variable source contributions. Because the new method can detect a wide range of carbonyl compounds, it may also be useful in establishing source apportionment models for air pollution emissions.; The method was initially used to quantify acrolein concentrations in a variety of outdoor environments, ranging from a pristine coastal site to highly-impacted urban centers. Indoor air was then tested in a number of residential and non-residential settings. The highest indoor levels were 100 times greater than outdoor levels, and were above the acute exposure level of 0.1 ppm set by federal and state regulatory agencies. Acrole emission rates were measured for various cooking activities, and the indoor half-life of acrolein, a value which had not been previously reported in the literature, was experimentally determined to be approximately eight hours.; The data generated by this new method provides valuable information about the concentrations, emission sources, and fate of acrolein in indoor and outdoor air, and will help identify and limit potentially toxic human exposures to this common air pollutant. |
