Are there safety issues involved in urban farming?

Are there safety issues involved in urban farming? 

Yes. One major safety concern is the risk of contaminants, lead or other heavy metals in the soil. It is important to investigate the history of the land where produce may be grown, especially if the land is near a former industrial site. Soil tests are recommended for all new gardening sites. In areas with soil health issues, using raised beds or planting in imported soil may reduce the chances of contamination.