Welcome Sadhbh!
Thank you for introducing yourself. Those forests in Ireland are so special too! Indeed, the concept of foraging being illegal can feel so alien when arriving here. I have had a lot of fun using that feeling of being an outsider, looking at rules and regs through different eyes, to try to make a few steps in green directions.
If the soil all around you is really not good, then I would seek out nut trees (sounds simplistic but plant parts further from the soil, and most linked to plants reproduction, are usually the cleanest). And also, look out for raised beds, or even place some plant pots with safe soil near home / work (if possible at all), maybe with a plant in, so they are left alone, and leave plenty of bare soil showing. The “weeds” will move in there in no time, choosing their home and giving you a good crop or at least something green and interesting to try to ID! And spread your foraging, just a touch from here and there, that will also help a lot to reduce risk.