How might Flint’s water contamination affect garden soils? Part 1
With the news of lead contamination in the City of Flint’s water supply, people who farm and garden in the city are questioning the safety of growing in soil that has been irrigated with contaminated water.
January 26, 2016 - Author: Terry McLean, Michigan State University Extension
Much has been reported recently about lead contamination of the drinking water in the City of Flint, Michigan, and the danger that represents to its residents. Lead is a neurotoxin when ingested or inhaled, with potentially serious, harmful health effects. With this city’s vibrant culture of community gardens, residential gardens and urban farms, Flint gardeners and farmers have become concerned with the safety of growing food in soil that has been irrigated with lead contaminated water. While it is clearly recognized that drinking lead contaminated water is a direct health concern, affected residents are now worried about every possible pathway to potential lead exposure.
New concerns about using contaminated water for irrigation over the last two growing seasons has gardeners and farmers asking questions, even as we’ve learned that a healthy diet, such as those grown in Flint’s food gardens, is one of the strategies to prevent lead poisoning. Foods rich in iron, calcium and vitamin C, such as grean leafy vegetables, tomatoes and peppers are particularly effective. An additional blow to the community’s health in the past year was the closure of the three remaining chain grocery stores, further reducing food access for those most vulnerable, requiring innovative ideas for access to healthy food, information, and resources.
There are several pathways for lead to accumulate in garden soils. People are more commonly exposed to soil lead when in direct contact with contaminated soil or from the very fine soil particles carried into houses as airborne dust on shoes, clothing or pets, rather than from irrigation water. A past article from a Michigan State University Extension colleague, described the dangers of lead exposure and steps to minimize your risk. The typical sources of elevated lead in our soils are lead-based house paint (chips, dust) used before the mid 1970’s; soils adjacent to major roads existing before the mid 1980’s when leaded gasoline was used; soils on sites that were old fruit orchards where lead arsenate was used as a pesticide until the 1950’s, or soils where the previous land use included certain types of manufacturing.
If you are concerned about the level of lead found in the soils you wish to garden in, we routinely recommend soil testing - including testing for environmental contaminants such as lead - for all new food gardens, as well as researching the site’s previous uses.
For more information on how lead contamination can affect your farm or garden read part two of this series.