Lead Contaminants
As of 2022, over 54% of the US population had a blood lead level above the 5-µg/dL threshold for “safe” exposure as children. This is primarily due to the presence of leaded paint in homes built before the 1970s, contaminated soils from man-made and natural sources, and exhaust from automobiles pre 1996 when leaded gasoline was used. To this day, runoff from leaded gasoline has left high amounts of lead in soil adjacent to roadways since lead does not biodegrade, or disappear over time, but remains in soils for thousands of years.
Remediation
In modern day, we typically deal with lead remediation by removing and relocating the contaminated soil. Not a great solution, especially considering that so much of our lands are now contaminated and that you need a place to store all the contaminated soil. Some hopeful studies have demonstrated the ability of plants to absorb lead as a form of remediation with a variety of efficacy depending on the plant (see study) and taking decades to complete. While this may be great for decontaminating the soil, it is not great if you are trying to eat the plants being grown in that soil because they are now absorbing the risidual lead as well as arsenic from our modern day gasoline breaking down into the soil.
Pesticides, Herbicides, Fungicides OH MY
The active ingredient most widely used on residential lawns in the United States is a chemical mixture called 2,4-dichlorophenoxyacetic acid, or 2,4-D, which is sold in differing formulations under a variety of trade names. Another common herbicide is glyphosate. Studies of occupational exposure to agricultural pesticides (including 2,4-D and glyphosate) have found a positive correlation with certain cancers.
Nurseries and public park management often spray their plants or soil with pesticides as a protective measure against pests. Just because a plant is an edible species, doesn't mean it's safe to eat if it is soaked in pesticides from it's previous life at a nursery or public park. This is less of a concern in the wild, but in the city it is something to be aware of. Pesticides can be absorbed into the plants and remain in and on their tissues for years.
To minimize exposure, don't spray your land with these chemicals and don't interact with land that has been sprayed for at least three days after, espicially for children or pets. These chemicals are also leaching into the below ground waterways, polluting drinking water, killing animals and important pollinators, and disrupting natural habitats. Grow or forage your own foods or support organic farms to avoid consuming these chemicals in your food.
Dog waste in Urban Envoronments
Dog urine and fecal matter can carry bacteria, parasites, viruses, and fungi to whatever person comes in contact with it. In urban environments especially, people are less likely to have big backyards for their pup to get exercise in and are more likely to walk their dog down the sidewalk or in the city greenspaces. Keep an eye out for which trails are heavily trafficked by dogs and avoid exposing yourself to unnecessary risk. Thouroughly washing and cooking your food helps to kill off any unwanted guests that might make you sick.
So how do we avoid exposure?
Observe the proximity of gardening or foraging grounds to roadways and buildings built before the 1970s. Would the flow of rain runoff from roadways or near old buildings flow to your site? You may be reasonably far from the road or old building, but it if you are at a lower elevation, it is likely that those pollutants will be carried there by rain water.
Observe - Is your garden or foraging ground sprayed with herbicides, pesticides, or fungicides? Is the adjacent land sprayed such that it just runs into your yard when it rains?
If you currently spray your yard, look for safer alternatives such as planting repelling herbs or using safer oils.
Test your soil if possible. UGA and other labs offer soil, plant tissue, and water testing services that measure contaminants and nutrients.
Wash your food thoroughly as residual contaminants are found in highest quantity on the surface and roots of plants.
If you discover that you do have contaminated soil, consider building a raised bed with potting soil approved by the EPA or with verified ingredients that are sufficiently low in heavy metals. This will lift the plants up above the contaminated soil. Just make sure to make your raised bed tall enough such that the roots aren't reaching into the contaminated soil.
Don't forage along highly trafficked paths, where dog urine and fecal matter is likely to be present. If you have a pet and home garden, consider building raised beds that are higher than the dog to prevent them from getting waste on your food.
Comentarios