Determination of volatile organic compound emissions and ozone formation from spraying solvent-based pesticides.

Large-scale agricultural activities have come under scrutiny for possible contributions to the emission of ozone precursors. The San Joaquin Valley (SJV) of California is an area with intense agricultural activity that exceeds the federal ozone standards for more than 30 to 40 d yr(-1) and the more stringent state standards for more than 100 d yr(-1). Pesticides are used widely in both agricultural and residential subregions of the SJV, but the largest use, by weight of "active ingredient," is in agriculture.

Direct measurements of the ozone formation potential from livestock and poultry waste emissions.

The global pattern of expanding urban centers and increasing agricultural intensity is leading to more frequent interactions between air pollution emissions from urban and agricultural sources. The confluence of these emissions that traditionally have been separated by hundreds of kilometers is creating new air quality challenges in numerous regions across the United States. An area of particular interest is California's San Joaquin Valley (SJV), which has an agricultural output higher than many countries, a rapidly expanding human population, and ozone concentrations that are already higher than many dense urban areas.

Reactive organic gas emissions from livestock feed contribute significantly to ozone production in central California.

The San Joaquin Valley (SJV) in California currently experiences some of the highest surface ozone (O(3)) concentrations in the United States even though it has a population density that is an order of magnitude lower than many urban areas with similar ozone problems. Previously unrecognized agricultural emissions may explain why O(3) concentrations in the SJV have not responded to traditional emissions control programs. In the present study, the ozone formation potentials (OFP) of livestock feed emissions were measured on representative field samples using a transportable smog chamber.

Analysis of aerosol particles and coarse particulate matter concentrations in Chillán, Chile, 2001-2003.

Daily particle samples were collected in Chillán, Chile, at six urban locations from September 1, 2001, through September 30, 2003. Aerosol samples were collected using monitors equipped with a Sierra Andersen 246-b cyclone inlet on Teflon filters. Average concentrations of coarse particulate matter (PM10) for the 2001-2003 period ranged from 43.

The application of thermal desorption GC/MS with simultaneous olfactory evaluation for the characterization and quantification of odor compounds from a dairy.

Few analytical methods exist that combine chemical and sensory analysis of odorous compounds in whole air. Volatile organic compounds were collected by sampling air downwind from a small dairy through sorbent tubes of Tenax TA and Carboxen 569. Samples were analyzed by thermal desorption into a cryotrap and subsequent gas chromatographic separation, followed by simultaneous olfactometry and mass spectrometry.