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Advanced Search Abstract The main threats to human health from heavy metals are associated with exposure to lead, cadmium, mercury and arsenic. These metals have been extensively studied and their effects on human health regularly reviewed by international bodies such as the WHO.
Heavy metals have been used by humans for thousands of years. Although several adverse health effects of heavy metals have been known for a long time, exposure to heavy metals continues, and is even increasing in some parts of the world, in particular in less developed countries, though emissions have declined in most developed countries over the last years.
Cadmium compounds are currently mainly used in re-chargeable nickel—cadmium batteries. Cadmium emissions have increased dramatically during the 20th century, one reason being that cadmium-containing products are rarely re-cycled, but often dumped together with household waste.
Cigarette smoking is a major source of cadmium exposure. In non-smokers, food is the most important source of cadmium exposure. Recent data indicate that adverse health effects of cadmium exposure may occur at lower exposure levels than previously anticipated, primarily in the form of kidney damage but possibly also bone effects and fractures.
Many individuals in Europe already exceed these exposure levels and the margin is very narrow for large groups. Therefore, measures should be taken to reduce cadmium exposure in the general population in order to minimize the risk of adverse health effects.
The general population is primarily exposed to mercury via food, fish being a major source of methyl mercury exposure, and dental amalgam. The general population does not face a significant health risk from methyl mercury, although certain groups with high fish consumption may attain blood levels associated with a low risk of neurological damage to adults.
Since there is a risk to the fetus in particular, pregnant women should avoid a high intake of certain fish, such as shark, swordfish and tuna; fish such as pike, walleye and bass taken from polluted fresh waters should especially be avoided. There has been a debate on the safety of dental amalgams and claims have been made that mercury from amalgam may cause a variety of diseases.
However, there are no studies so far that have been able to show any associations between amalgam fillings and ill health. The general population is exposed to lead from air and food in roughly equal proportions. During the last century, lead emissions to ambient air have caused considerable pollution, mainly due to lead emissions from petrol.
Children are particularly susceptible to lead exposure due to high gastrointestinal uptake and the permeable blood—brain barrier. Blood levels in children should be reduced below the levels so far considered acceptable, recent data indicating that there may be neurotoxic effects of lead at lower levels of exposure than previously anticipated.
Although lead in petrol has dramatically decreased over the last decades, thereby reducing environmental exposure, phasing out any remaining uses of lead additives in motor fuels should be encouraged.
The use of lead-based paints should be abandoned, and lead should not be used in food containers.
In particular, the public should be aware of glazed food containers, which may leach lead into food. Exposure to arsenic is mainly via intake of food and drinking water, food being the most important source in most populations.
Long-term exposure to arsenic in drinking-water is mainly related to increased risks of skin cancer, but also some other cancers, as well as other skin lesions such as hyperkeratosis and pigmentation changes. Occupational exposure to arsenic, primarily by inhalation, is causally associated with lung cancer.
Clear exposure—response relationships and high risks have been observed. Introduction Although there is no clear definition of what a heavy metal is, density is in most cases taken to be the defining factor. The main threats to human health from heavy metals are associated with exposure to lead, cadmium, mercury and arsenic arsenic is a metalloid, but is usually classified as a heavy metal.
Heavy metals have been used in many different areas for thousands of years. Lead has been used for at least years, early applications including building materials, pigments for glazing ceramics, and pipes for transporting water.
In ancient Rome, lead acetate was used to sweeten old wine, and some Romans might have consumed as much as a gram of lead a day. Mercury was allegedly used by the Romans as a salve to alleviate teething pain in infants, and was later from the s to the late s employed as a remedy for syphilis.
Although adverse health effects of heavy metals have been known for a long time, exposure to heavy metals continues and is even increasing in some areas.Below is a summary of the most common heavy metals, their sources and the burden they add to the human body as provided by Doctor’s Data webkandii.com’s Data Inc (DDI) is a premier clinical laboratory with over 30 years experience that specializes in essential and toxic elemental testing.
Cadmium is a heavy metal of considerable environmental and occupational concern. It is widely distributed in the earth's crust at an average concentration of about mg/kg. The highest level of cadmium compounds in the environment is accumulated in sedimentary rocks, and marine phosphates contain about 15 mg cadmium/kg [ 88 ].
The most toxic metals to humans and animals are mercury, cadmium and lead, known as heavy metals, all of which naturally occur in the environment.
Mercury, cadmium and lead enter the marine environment from a number of natural, agricultural and industrial processes, such as emissions from coal-fired power stations, via long range transportation. Category Overview. Despite the natural occurrence of heavy metals, human activities are the main driver of heavy metal pollution.
Even trace amounts can harm human health and the environment (Tchounwou, Yedjou, Patlolla, & Sutton, ). Cadmium and sewage sludge This essay concentrates on the heavy metal cadmium, and its occurrence in the environment, its pathways into and out of the human body and its movement into and out of Sewage sludge.
Effects of Cadmium on the environment. Cadmium derives its toxicological properties from its chemical similarity to zinc an essential micronutrient for plants, animals and humans. Cadmium is biopersistent and, once absorbed by an organism, remains resident for many years (over decades for humans) although it is eventually excreted.