i keep hearing the allegation that all imported herbs are irradiated and i am not so sure about that. i called up mountain rose herbs and asked about this issue. we talked specifically about their black walnut, which is imported from hungary. they told me that irradiation is expensive and many countries dont even have the technology to do it in place. they also said that they knew exactly where their black walnut came from and could trace its entire transit path and could tell me for sure it was not irradiated.
i am sure that many herbs are irradiated, but i dont think its quite as many as some have alleged.
as far as turmeric goes, i have not looked into it.