SOIL LEAD DETERMINATIONS IN THREE URBAN COMMUNITY GARDENS, LEWISTON, ME

Elevated lead levels in urban soils are a major source for increased blood lead levels in residents via hand-to-mouth ingestion and dust inhalation. Children are particularly susceptible to the adverse developmental affects associated with high blood lead levels. Lead in urban soils has accumulated significantly during past century from the use of leaded gasoline, and leaded paint. Lewiston, Maine is a city with a very old housing stock; only 2% of homes in the downtown residential neighborhood were built after 1978 when the use of leaded paint on the exteriors and interiors of homes became illegal.

The community has recently initiated an urban gardening program. Community gardens provide a plethora of benefits to residents, including improved physical and psychological well being and individual leadership opportunities within neighborhoods. These gardens however have not been systematically analyzed for lead concentrations. This study is the first to assess the total lead concentrations in the community gardens as a means to assess the potential hazard of soil lead to the Lewiston community.

Soil and vegetation samples were collected in August, 2003, from three urban lots in Lewiston, to evaluate the extent of lead contamination at the sites. These lots have been community gardens for varying periods of time (Knox Street garden, 4 summers; Blake Street garden, 1 summer, and Pierce Street lot, to become a garden in the 2004 season). Soil samples were collected from depths of 3 cm and 26 cm and the total exchangeable lead concentrations were measured using an ICP-OES. Preliminary data on soil lead concentrations indicate that lead levels in the Knox Street garden are within native levels and levels in the Blake Street garden are in excess of EPA recommended levels. Total lead concentrations of the garden soils and vegetation will be interpreted in light of the soil loss-on-ignition, pH and grain size distribution.