Your Leafy Greens May Have More Heavy Metals Than Allowed

Spinach, lettuce, and pumpkin leaves all had heavy metal levels above WHO safety limits. The soil they grew in was contaminated, and the plants pulled those metals right into the leaves you eat.

Five Vegetables, Multiple Metals Over the Limit

Researchers tested five types of leafy greens and the soil they were grown in for a range of metals. The vegetables had elevated levels of calcium, iron, silicon, aluminum, and strontium. Spinach had especially high sodium concentrations, according to a 2026 study in Int J Environ Res Public Health.

The target hazard quotient flagged potential health risks from boron, silicon, vanadium, aluminum, chromium, manganese, iron, nickel, zinc, and lead. Metal concentrations in the vegetables exceeded permissible limits set by both the WHO and FAO.

The Soil Tells the Story

The soil was loaded with metals. Lettuce, spinach, and pumpkin leaves were especially efficient at pulling chromium, cobalt, manganese, and nickel from the ground into the plant. The more contaminated the soil, the more metals in your salad.

What You Can Do

Buy organic greens or grow your own in tested, clean soil. Wash all leafy vegetables thoroughly. Rotate your greens so you're not overloading on one source. And explore non-toxic kitchen alternatives for safer food prep.

Also see glass food containers for safer alternatives.

Source: Kola E, Munyai LF, Munyai C, et al. (2026). Int J Environ Res Public Health.