Sunflowers as a Natural Solution to Detoxify Soil and Air in Los Angeles

Research by Dr. Rahseeda Hawk, Written by Ayana Hawk

At the Seeds of Carver Urban Farm Collective, we spend our time researching bioremediation methods to naturally detoxify the soil and air in Los Angeles. Pollution in urban areas takes a heavy toll on our health that can cause serious issues such as cancer from heavy metals, ADHD/ADD from lead exposure, and hypertension and inflammation caused by tiny particles in the air.

A Los Angeles morning with polluted fog.

Since we are committed to enhancing environmental health and creating vibrant green spaces for our community, our research aims to discover natural and effective methods to reverse this issue within hotspot areas. This work is important as airborne metal contamination is one of the most hazardous pollutants causing premature death after long exposures. 

Insightfully during our research phase, we encountered the process called phytoremediation, which uses plants to extract metals and toxins from the environment. As it proved to be effective in other countries, we chose the drought-resistant native sunflowers to clean up our small ecosystem in South LA.

Understanding Phytoremediation

Let's break down the word Phytoremediation. Phyto means plants, and remediation means to reverse or stop environmental damage. Phytoremediation utilizes plants to clean up contaminated environments by filtering, stabilizing, extracting, degrading, and volatilizing pollutants from soil, water, and air. This natural method leverages specific plants' abilities to transform or remove toxins, making it an effective and eco-friendly remediation strategy.

In the diagram below, you can see the key processes in phytoremediation.

Previous Implementation of Phytoremediation

Countries like India and Ukraine have successfully utilized native plants such as redroots and sunflowers to mitigate environmental contamination. In Ukraine, particularly around areas affected by radioactivity, sunflowers have successfully detoxified soil, water, and air by reducing radioactive contaminants and mines.

This process has not only improved environmental health but also helped in preventing long-term health issues for local communities by mitigating pollution and restoring ecological balance. (Turns)

Sunflowers Phytoremediation of Radiocesium-Contaminated Soil near Chernobyl, Ukraine

Sunflowers and Our Research 

Sunflowers are not only beautiful, but highly effective for phytoremediation due to their adaptability to live in various environments and their capacity to uptake a wide range of pollutants. These hardy plants can bind, extract, and clean up contaminants such as pesticides, petroleum, pollutants from oil spills, and vehicle emissions metals like lead, cadmium, and arsenic.

Our Research

In 2022, with the help of Youth Climate Save, we planted over 100 sunflowers in our garden and along public streets. This initiative aimed to test and collect data on how sunflowers can detoxify soil pollution through phytoremediation.

Sunflowers planted inside the garden in community boxes.

We then tested the soil through a local lab of the 100 sunflowers around the Seeds of Carver garden and on the road verge (green space between the sidewalk and street). Levels in the soil were measured in parts per million (ppm) in October 2022 (initial reading) and December 2023 (one year later).  Measured within a year, lead concentration decreased tremendously. 

Sunflowers planted on the road verge of the garden before data was collected.

The Data

The graph below demonstrates the amount of toxins in particular, lead, that was removed from the soil through the process of phytoremediation using sunflowers. The level of lead in the road verge soil and garden soil decreased by approximately 4x due to the phytoremediation properties of sunflowers. 

As you can see from our approach in applying sunflowers to remediate the soil, we harness the natural abilities to stabilize, extract, degrade, and volatilize contaminants from soil and air.

Conclusion

Conventional remediation methods can be expensive and invasive, making them less feasible for these communities. However, a green and cost-effective alternative exists: phytoremediation using sunflowers. Sunflowers offer a sustainable and cost-effective solution to improving air quality in low-income communities.

By harnessing the natural capabilities of these plants, communities can address environmental pollutants and enhance public health. As awareness and implementation of phytoremediation grow, sunflowers could become a symbol of resilience and renewal in urban landscapes.

Planting sunflowers with your veggies is now proven to clean its soil to have more nutritional value.