Letter to the editor: Avoid harvesting plants from urban waterways
Last updated 10/14/2020 at 11:29am
The other evening while walking near Fowler Pear Tree Park in Mukilteo, my wife and I noticed women collecting wild watercress (Nasturtium spp.) from an adjacent drainage ditch that receives runoff from the road, railroad yard, and adjacent homes.
Animal waste is also carried to the ditch via a nearby stormwater grate. We've seen ducks and rabbits using the drainage ditch and often see dog feces in the surrounding area.
Wild watercress can bioaccumulate some metals, such as arsenic, from the environment, as well as carry some parasitic diseases attributable to animal wastes entering the environment. Organic chemical contamination is also possible due to pesticide application in adjacent areas.
I would strongly recommend against harvesting and consuming wild watercress from this ditch or any urban waterway that has the potential of receiving contaminated stormwater runoff. While washing the watercress may remove any potential external parasites, it will be ineffective in removing contaminants incorporated into the plant tissue.
Whenever harvesting any kind of wild plant for human consumption, know what you are harvesting and the environment within which it grows. Harvesting plants and animals for human consumption from urban waterways is generally not a good idea and should be avoided. Contact your local health department to inquire about consumption advisories for specific urban waterways or lakes before harvesting.