A SURVEY OF LEAD AND CADMIUM CONTENT OF SOILS FROM URBAN GARDENS IN THE CITY OF ONEONTA, NEW YORK

Heavy metals are one the most complex and persistent pollutants in the environment. Cadmium and lead are highly toxic trace elements found in Earth’s crust that occur naturally as well as a result of pollution. Though heavy metals are necessary for functioning of all organisms, they become harmful when their concentrations exceed the non-toxic levels. Potential health risks for animals and humans from cadmium and lead exposure vary, but include damage to the kidneys, liver, testes, bones, and the cardiovascular, endocrine, and circulatory systems. The increase in economic development and growth of agriculture and industry in urban areas has led to heavy metal contamination in soils. The purpose of this project was to assess the lead and cadmium concentrations in urban gardens within the City of Oneonta, New York. Three soil cores were collected from the gardens of the volunteered city residents using a 2-inch diameter hand-auger to the depth of the human refusal limit, typically about 20 to 25 cm. The soil cores were separated into horizons based on color changes. Lead and cadmium content was determined using a standard sequential extraction process that separated water soluble, exchangeable, easily reducible, and oxidizable fractions leaving the residual and silicate bound fraction behind. Each extract was analyzed for lead and cadmium concentrations using either flame or graphite furnace atomic absorption spectroscopy. The preliminary results show that the soils in the City of Oneonta contain less than 400 ppm lead, which is the EPA defined soil lead hazard level. Cadmium levels are found to be lower than 0.8 ppm, which is the recommended safe limit by the WHO for soils. Based on the results of this study thus far, residents of the City of Oneonta do not need to worry about the levels of lead and cadmium in their garden and can safely grow food crops for consumption.