Review on Heavy Metal Contamination in Vegetables Due to Wastewater
Because of the potential health effects of swallowing tainted food items, heavy metal contamination of soil and vegetative sections of plants as a result of wastewater irrigation is a severe issue. The impacts of trace elements (heavy metals) such as arsenic, cadmium, lead, chromium, nickel, and mercury, which are important environmental pollutants, are assessed in this article particularly in areas with high anthropogenic activities. In addition to these metals, copper, manganese, iron, and zinc are also important trace micronutrients. The presence of trace heavy metals in atmosphere, soil, and water can cause serious problems to living organisms, and the ever-present bioavailability of these heavy metal can result in bioaccumulation in the food chain which especially can be murderous to human health. This study reviews the heavy metal contamination in several areas of Pakistan over the past few years, especially to access heavy metal contamination in water (ground water, surface water, and waste water), soil, sediments, particulate matter, and vegetables. The contaminations affect the drinking water quality, ecological environment, and food chain. Furthermore, the toxicity caused by contaminated water, soil, and vegetables endangers human health. Increased population and high food demand result in the release of many contaminants into the environment, which eventually contaminate the food chain. Edible plants are the primary source of food for humans, and their contamination with toxic metals can have disastrous health consequences. Heavy metals affect the human health directly and/or indirectly; one of the indirect effects is the change in plant nutritional values. Previously, a
Number of review papers have been published on different aspects of heavy metal contamination. However, no related information is available about the effects of heavy metals on the nutritional status of food plants. This review study focuses on heavy metal sources, accumulation, transmission, health risks, and the impact of heavy metals on protein, amino acids, carbohydrates, lipids, and vitamins in plants. According to the research on heavy metals in food plants, both leafy and no leafy vegetables are good heavy metal accumulators. The bioaccumulation pattern in no leafy plants was leaf > root > stem > tuber. Because heavy metals have a considerable impact on nutritional values, plants produced on metal-contaminated soil were nutrient poor, and eating of such vegetables may lead to nutritional insufficiency in the population, particularly in poorer nations where malnutrition is already a problem.