Ozone Initiated Secondary Emissions of Aldehydesfrom Indoor Surfaces

摘要

Secondary emissions of oxidized organic compounds, primarily aldehydes, from buildingsurfaces in the presence of ozone may contribute significantly to indoor air pollution.Ozone-induced formation of aldehydes was studied to determine how daily use consumerproducts contribute to secondary emissions. A field ready method was developedquantify secondary emission rates on existing surfaces. Four different products, canolacooking oil, a spray cooking oil, bath soap, and a liquid detergent, were evaluated afterbeing coated on a laminated countertop. Upon exposure to 100 ppb O3, nonanal andhexanal were emitted at rates similar to secondary emission rates from carpet. Totalaldehyde emission rates from canola oil, soap, and spray cooking oil were respectively180, 110, 125 μg m-2 h-1. The liquid detergent released small amounts of hexanal, octanal,and nonanal. The aldehyde emission pattern from these products roughly correspondthe anticipated relative aldehyde emission rates due to the proportion of unsaturated fattyacids in vegetable oils and animal fats. If a substantial area of indoor surfaces are coatedwith these products, secondary emission rates of aldehydes (especially nonanal) mayresult in concentrations approaching or exceeding odor thresholds.