Earthworms vs Nicotine

Our group was interested in the impact of nicotine on soil and organisms, like pigeons, who might consume cigarette butts in New York. We wondered what negative effects might this introduced nicotine might cause. We focused on one essential organism that lives in soil: earthworms, specifically Red Wigglers, Eisenia fetida. Burrowing is when earthworms dig down into soil, circulating oxygen within the soil and releasing carbon dioxide (Avant, 2017). However, if their soil was contaminated with a foreign substance, would the worms still burrow? Would the worms take longer to burrow within unhealthy soil? Would nicotine make the soil unhealthy to begin with?