Formic and acetic acids in the atmosphere of the southwest U.S.A.

Gaseous formate and acetate have been detected at ground level both within and near Tucson, Arizona, and at relatively remote sites. Concentrations downwind of the city were several parts per billion. At the more remote sites, concentrations were usually less than 1 ppb. In view of the reactivity of these compounds, their contribution to tropospheric photochemistry, specifically OH loss and O3 production, could be significant.