Current ozone air quality standards are set using data from previous studies on human health and from common tree species. However, it was unknown whether current ozone standards harm herbaceous species, especially species important to the Forest County Potawatomi Community. A Northern Research Station scientist tested varying ozone levels on 12 herbaceous plants that are common in the Great Lakes Region and are culturally important to the Forest County Potawatomi Community.

In the first step of the study, elders of the Forest County (Wisconsin) Potawatomi Community were surveyed to select 12 species of cultural importance to include in the study. The experiment consisted of germinating and growing the selected species in a greenhouse before transferring them to two different environmental chambers that can control light, air temperature, and soil moisture. Ozone was generated at known levels and pumped into one of the environmental chambers, while the other chamber remained as a control. Plants were exposed to ozone for 5 weeks, which lasted most of their life cycle. Researchers measured plant photosynthesis and growth over the 5-week trial. After each 5-week trial, a new set of plants was grown and retested at a different ozone level. Results indicate that the species were unharmed in any of the ozone testing, which means current ozone air quality standards are not resulting in harm to the 12 species tested: Canadian horseweed, nodding bur-marigold, common milkweed, white sage, wild bergamot, hoary vervain, lamb's quarters, tall bellflower, fireweed, cup plant, pearly everlasting, and bristly buttercup. The research was funded by the U.S. Environmental Protection Agency and was developed in cooperation with the Forest County Potawatomi Community.