A concise review on cadmium in fertilizers: Soil-plant interactions, health risks, and solutions

Abstract

Cadmium (Cd) is a toxic heavy metal that can cause serious health issues, such as kidney problems and Itai-Itai disease, mainly due to contaminated crops. The primary source of Cd intake occurs primarily through consuming crops that accumulate Cd, which have a bioconcentration factor (BCF) exceeding 10, indicating their ability to accumulate Cd. Using fertilizer inputs contributes to Cd pollution, especially fertilizers made from phosphate rock and power plant ash, because these fertilizer sources will contain high concentrations of Cd. Phosphorus fertilizers lower soil pH and increase Cd absorption, while ash fertilizers raise soil pH and decrease Cd bioavailability. However, overapplication of both types of fertilizers can significantly increase Cd levels in the soil. Therefore, necessitating mitigation strategies such as reducing Cd content in raw materials by leaching methods. Hyperaccumulators favor phytoextraction of Cd, such as intercropping, crop rotation, and selective breeding of low-Cd varieties, which are crucial for food safety. Effective regulatory soil amendments can further enhance Cd removal from agriculture.