Heavy metals can find their way into cannabis through water, soil, fertilizers, and even aging equipment—yet most growers don’t realize how easily contamination can occur. Researchers are just beginning to understand how the plant interacts with metals like arsenic, cadmium, and lead, but cultivators can take practical steps now to minimize risk. From input testing and pH management to smarter irrigation practices, here’s what every grower should know to keep crops compliant and consumers safe.