Discipline: Ecology Environmental and Earth Sciences
Sania Rose - University of the District of Columbia
Co-Author(s): Trinh Vu, Yacov Assa, Sebhat Tefera, and Tolessa Deksissa, University of the District of Columbia
Many studies have indicated that soil in urban areas is contaminated with trace metals such as lead, arsenic, and copper. These trace metals are known to be toxic and can have adverse effect on human health if one uses urban soils for urban gardening. However, due to population increases in urban areas, urban agriculture continues to thrive in food production. Therefore, people are at greater risk of direct exposure to soil contaminated with heavy metals from food ingestion, as well as, the inhalation of these trace metals. Soil analysis is very important to determine the levels and types of soil contamination of heavy metals so that the soil can be treated to prevent consumption of these metals. The purpose of this study was to analyze trace metals such as arsenic, copper, and lead contamination in urban gardens in the District of Columbia. Our hypothesis is that soil samples from home gardens would have a higher level of lead, arsenic, and copper than community gardens, due to the garden being closer to homes with lead paint and plumbing. Soil samples were collected from private homes and community gardens and analyzed in the University of the District of Colombia (UDC) laboratory were extracted using Mehlich 1, spike solution, 10 times dilution with 2% HNO3 acid, then analyzed with the 300 D Perkin Elmer Inductive Couple Mass Spectrophotometer. The results revealed that the average extractable Arsenic exceeded the EPA guidelines level in home gardens by 37% and 32% in community gardens. Copper and lead did not exceed the EPA guidelines level in any of the samples, because they were below that level. Based on the research conducted the results showed that there were higher levels for the mean, median and standard deviation for arsenic and lead in home garden soil than community garden soil. However, copper was only higher in home garden for the median, but higher for the mean and standard deviation in the community garden soil. Therefore, if heavy metals are too high in the soil the gardens can be remediated, using raised beds with compost and soils that are non-contaminated for gardening. In conclusion, the results show the usefulness of soil analysis for trace metals in urban gardens, before doing any project that includes food production.
Funder Acknowledgement(s): USDA grant
Faculty Advisor: Tolessa Deksissa,