A new study found nanomaterials in soil hurt crop growth and may contaminate produce. UC Santa Barbara researchers showed nanoscale pollutants in crop soil stunt plant growth and can be taken up by a plant. The study also found that exposures weaken plants by increasing their ability to absorb pollutants and increase fertilizer needs. Such exposures are rising due to increased use by manufacturers. When pollutants were tested on soy plants, zinc oxide made it all the way into soy beans, while cesium oxide remained at root level. Strikingly, cesium oxide strongly interfered with the plants’ ability to fix nitrogen at its roots -- a critical process for plant prosperity. Nanoscale pollutants can come from solids removed from sewage and wastewater, which are applied to crops for their high-nutrient content. Diesel fuel used by tractors also releases tiny pollutants through its exhaust. Other nanopollutant sources include sunscreens and antibiotics that end up in wastewater.