This article is an open access article distributed under the terms and conditions of the Creative Commons by Attribution CC-BY license http: Abstract The use of aquatic plants for phytoremediation is an important method for restoring polluted ecosystems. We sought to analyze the capacity of different aquatic plant species to absorb heavy metals and to summarize available relevant scientific data on this topic. We present a meta-analysis of Cu, Zn, and Cd absorption capacities of aquatic plants to provide a scientific basis for the selection of aquatic plants suitable for remediation of heavy-metal pollution.
Mercury in fish The first emperor of unified China, Qin Shi Huangit is reported, died of ingesting mercury pills that were intended to give him eternal life. The best-known instances were in Minamata and Niigata.
In Minamata alone, more than people died due to what became known as Minamata disease. More than 21, people filed claims with the Japanese government, of which almost became certified as having the disease. In 22 documented cases, pregnant women who consumed contaminated fish showed mild or no symptoms but gave birth to infants with severe developmental disabilities.
Lead[ edit ] The adverse effects of lead were known to the ancients. In the 2nd century BC the Greek botanist Nicander described the colic and paralysis seen in lead-poisoned people.
For it seems to be made injurious by lead, because white lead is produced by it, and this is said to be harmful to the human body. Inthe World Health Organization estimated that lead poisoning resulted indeaths, and "contribute[d] tonew cases of children with intellectual disabilities", each year.
The source of the contamination has been attributed to "corrosion in the lead and iron pipes that distribute water to city residents".
The source of the contamination was attributed to "a combination of dilapidated drinking water infrastructure, including lead jointed pipelines, end-of-life polyvinyl chloride pipes and household plumbing".
Chromium III compounds and chromium metal are not considered a health hazard, while the toxicity and carcinogenic properties of chromium VI have been known since at least the late 19th century. The workers had been wet-sanding chromate-based primer paint that had been applied to car bodies.
Up to 20 workers at the plant were exposed as were 70 nearby homes in Stockton.
The town was only notified three days after the release and the accident sparked a major public controversy, with Orica criticised for playing down the extent and possible risks of the leak, and the state Government attacked for their slow response to the incident.
Cadmium[ edit ] Cadmium exposure is a phenomenon of the early 20th century, and onwards. In Japan inthe Mitsui Mining and Smelting Company began discharging cadmium into the Jinzugawa river, as a byproduct of mining operations. Residents in the surrounding area subsequently consumed rice grown in cadmium-contaminated irrigation water.
They experienced softening of the bones and kidney failure. The origin of these symptoms was not clear; possibilities raised at the time included "a regional or bacterial disease or lead poisoning".
Wal-Mart continued to sell the jewelry until May, when covert testing organised by Associated Press confirmed the original results. Chelates are not without side effects and can also remove beneficial metals from the body.There is evidence that plants can accumulate heavy metals in their tissues such as Sebera acuminate and Thlaspi caerulescens (Cunningham and Ow ), Arabidopsis thaliana (Delhaize ), Typha latifolia, and Phragmites australis (Ye et al.
). the heavy metal uptake inside the shoot plays at least as important a role in hyperaccumulation as do the root mechanism s. Clearly, the major ligands for both Cd and Zn in hyperaccumulator plants.
While accumulated metal ions are detoxified by phytochelatins, which are synthesized from glutathione in plants during their exposure to heavy metals.
Phytochelatins form complex with metal ions and sequestered them into the vacuole. This mechanism of heavy metal tolerance in plants has strongly suggested that glutathione should not be . Apr 04, · Heavy metals in plants and factors affecting metal uptake by plants It is well known that concentrations of Cd in edible vegetables range from to μg g −1 (DW: dry weight) and leafy plants such as lettuce, cabbage, spinach contain relatively higher Cd than grain or fruit plants such as apple, barley, corn, oat and rice [ 20 ].
heavy metals uptake mechanisms by plant, to give some description about the performance of several types of plants to uptake heavy metals.
2. Effects of Heavy Metals on Human Health The heavy metals hazardous to humans include lead, mercury, cadmium, arsenic, copper, zinc, and chromium. While this review draws particular attention to metal accumulation in edible plants, researched studies of certain wild plants and their consumers are included.
Furthermore, this review focuses on plant uptake of the toxic elements arsenic, cadmium, chromium, mercury, and lead and their possible transfer to the food chain.