I am not a doctor and this post is not intended as advice, medical or otherwise. That being said, the original poster has a legitimate concern and here is what I know. Where I live (Northern NM) there is a useful medicinal plant. It‘s common name is Osha, the scientific name is Ligusticum Porteri. It is a relative of parsley. It is native to the Mountain West and I have personally seen it in my native NM as well as CO, WY, MT, UT, ID and AZ. It is found in the subalpine associated with Engelmann Spruce. It lives near meadows and water and in partial shade. It looks a lot like various types of poision hemlock so be extra careful. It may be distinguished from hemlock by its odor. The smell is strong, similar to parsley, celery or licorice. The root is where the medicine is. Once you pick it, wash it and dry it. But don’t over wash it. I suspect that small bits of soil in contact with the roots have something to do with its medicinal qualities. Store it in dry clean containers once dehydrated. To use it you may boil the roots into tea. But the best method is to chew the dry roots, a small quantity will do as it is potent. Osha protects from disease from viruses and bacteria. It may help you once you are sick but your best bet is to use it before you get sick and take it regularly, especially in winter. It seems to make the body more resistant to contracting colds or flu. For me it prevents illness outright or minimizes the impact of illness dramatically. Again use caution. I would not be surprised if this root would make some people sick or cause an allergy.