Heavy metal uptake and stress in food crops: A Review

Abstract

Abstract. Heavy metal (HM) food contamination is detrimental to food safety and human health. Water scarcity, food shortage, illiteracy, failure to enforce environmental protection laws, and food quality regulations account for human HM contamination. Understanding their uptake pattern in food crops and how the crops behave under excessive concentration of these hazardous chemicals will guide farmers, researchers, and policymakers in devising appropriate control measures that will ensure the production and consumption of safer food crops. Relevant texts published by Science Direct, Springer Nature, and Wiley between January 2018 and December 2020 were cited in this article. The article discussed major factors affecting HM accumulation and the effects of HM stress on yield, physiology, and chemical properties of food crops. Wastewater irrigation, production in contaminated soil, and atmospheric deposit contributed to the contamination. Factors that influence HM uptake are those related to soil and irrigation water qualities and plant properties. The presence of other HMs and chemicals, growing season, crop age, planting method, and food crop type also affect HM uptake in food crops. HM stress affects anatomy, physiology including antioxidant defense mechanisms, nutrient availability and uptake, germination, seedlings development, growth, yield, leaf geometry, root and shoot length, plant genetics, pollination, and chemical composition including moisture content, soluble protein, and pigment content and characteristics.