Toxicity in food comes from several sources. Toxic influences during the plants’ growth phase include phosphate fertilizer (which has a radioactive component), waste sludge and glyphosate.
Up to 90% of the phosphorous is lost through the supply chain from mining to final fertilizer, and the losses are poorly documented, making it difficult to improve efficiency and prevent losses — which ultimately end up as pollution.
Phosphate contains a radioactive element, polonium-210, which may be taken up by the plant, raising unanswered questions about food safety.
Glyphosate was identified as a probable human carcinogen in 2015 and has been linked to a wide range of possible health problems. Glyphosate is also a phosphate source, adding to the phosphorous loading of soil and water.
Sewage sludge (aka biosolids), used as an inexpensive and readily available fertilizer, contains industrial waste, heavy metals and per- and polyfluoroalkyl substances (PFAS) chemicals linked to cancer and organ damage.