Since the steel mills shutdown over 40 years ago, the Youngstown, Ohio area has suffered population decline. This loss of industry and population has resulted in many areas with dilapidated homes lowering property values. One solution has been to remove the structures to prevent harm to people and improve the neighborhood aesthetics. Various groups in the community have acquired these now vacant lots in attempts to either beautify the neighborhood or make the land productive. One such group, Grow Youngstown, has made it their mission to promote local food production by raising urban agricultural skills and available resources. Due to the previous structures, previous land uses (lead based paints batteries, insecticides) and atmospheric deposition originating from the steel industries there is a concern that heavy metal concentrations in these urban gardens may be elevated. The garden for this study was about 8 city lots on the north side of Youngstown near Wick Park. This site was sampled in a grid pattern with 15 foot (4.57 m) squares. Composite samples were taken from each grid square using a 5 spot pattern and separated into two soil layers: from the surface to 6inches deep (15.2 cm) and 6-12 inches (15.2-30.4 cm) deep. The soil was sieved through a 2 mm sieve and analyzed for total metals (EPA Method 3050B) using AES-ICP.
Results/Conclusions
The soil samples were tested for the following metals: arsenic, cadmium, cobalt, copper, chromium, nickel, lead and zinc. Zinc had the highest overall average concentration (242.0 mgkg-1) followed by copper (60.2 mg kg-1), then nickel (35.2 mgkg-1). All these levels were below the Ohio EPA guidance for direct contact with residential soils. The metal that went over the recommended direct contact limit (6.7 mg kg-1) was arsenic which ranged from 12.2-43.0 mg kg-1. There was one area of specific concentration in the garden of lead (396.6 mgkg-1) and arsenic (22.1 mgkg-1). The concentration was located in a raised bed and is the only spot that had a level anywhere close to recommended direct contact limit (400 mgkg-1) for lead. Further analysis will need to be performed to insure that plant available metals do not pose any risk for plant growth and health.