Hi Ben, In general you are unlikely to find lead in the shoots of plants, because it is not very soluble and most plants exclude heavy metals. The edible plants that may have Pb would likely be leafy vegetables (grown close to the ground) and root vegetables (as mentioned earlier) because of the associated soil particles containing Pb.
There are some plants that uptake heavy metals into their shoots but few for Pb, and even those may only do so under rare circumstances (such as phosphorous deficiency - Chaney 2007 J. Environ. Qual. 36:14291443). If you are interested in other contaminants you can look into the metal hyperaccumulation literature. Many of these plants are in the mustard family but probably are not normally eaten. best, Judy Judy Che-Castaldo BEES program, Biology Dept. University of Maryland (301)351-8290 http://www.life.umd.edu/grad/BEES/students/che.html
