Gaseous pollutant and acidic rain impacts on crops in the United States: A comparison

Abstract

The effects of gaseous pollutants (O₃, SO₂, NO₂) and acidic rain were assessed and compared for a wide variety of crop cultivars and species. Such a comparison is useful for evaluating the need and the strategy for controlling pollutant emissions. No measurable and consistent crop yield response from the direct effects of simulated acidic rain at ambient levels has been established, although possible interactions with other stresses needs further study. For some local situations, exposures of SO₂ and combinations of SO₂ and NO₂ may reach concentrations and frequencies that could reduce crop productivity, but effects from these pollutants are not significant on a national scale. In contrast, O₃ at ambient levels during the growing season, has been demonstrated to reduce the yield by an average of 5–10% for the majority of crops tested.