There has been considerable interest in two sector models in which the production of one of the goods is subject to uncertainty. The major papers in this area are by Rothenberg and Smith [13], Batra [1], Britto [3], Diamond [5], Mills [12] and Harford and Park [8]. In the latest of these papers, Harford and Park [8, 41] build on a model in Mills [12] to show that if constant relative risk aversion, R, which is mathematically analogous to the Pratt-Arrow measure, is less than, exceeds, or equal to unity, the direction of efficient resource flow under uncertainty, as compared to certainty, is away from the risky sector, toward the risky sector, or unchanged, respectively. In their model, as in Mills [12], the preferences of consumers are represented by a community expected utility function. In the present two-sector model, the risky sector is an industry that is adversely affected by air pollution, which is a by-product of production in the other industry. Although there is a deterministic relation between the output and emissions of the polluting, stable sector, the damage caused to the other sector as a result of any given level of emissions depends upon random variables such as mixing height and wind velocity and is therefore stochastic. It is not intuitively obvious whether the results of Harford and Park [8] hold if the uncertainty in the risky sector is the consequence of production in the stable sector. In fact, there is substantial dissimilarity in the results. If the measure of risk aversion, R, is less than unity, the efficient direction of resource flow is generally (though not always) toward the risky, polluted sector. If R equals unity, the results also differ with resources shifting, under uncertainty, in the direction of the risky, polluted sector. Only if R exceeds unity are the results always the same in both models, with resources flowing toward the risky sector. This paper presents the marginal condition such that, under uncertainty, the optimal combination of outputs includes less of the stable, polluting good and more of the risky, pollution sensitive good than would be the case if pollution damage were anticipated with certainty. If this marginal condition does not hold, the risk averse community may prefer either more or less of the polluting good. A narrowed interpretation of the marginal condition is then used to predict the special case in which the efficient flow of resources under uncertainty is toward the polluting sector.