Introduction:
In recent years it has become clear that some environmental chemicals can cause risks to the developing embryo and fetus. Evaluating the developmental toxicity of environmental chemicals is now a prominent public health concern. The suspected association between TCE and congenital cardiac malformations warrants special attention because TCE is a common drinking water contaminant that is detected in water supplies throughout the U.S. and the world. There is a lot of concern about the clean up of toxic pollutants from the environment.
Traditional methods for cleaning up contaminated sites such as dig and haul, pump and treat, soil venting, air sparging and others are generally harmful to habitats. Some methods strip the soil of vital nutrients and microorganisms, so nothing can grow on the site, even if it has been decontaminated. Typically these mechanical methods are also very expensive. Most of the remediation technologies that are currently in use are very expensive, relatively inefficient and generate a lot of waste, to be disposed of.
Cleaning up contamination:
Phytoremediation is a novel, efficient, environmentally friendly, low-cost technology, which uses plants and trees to clean up soil and water contaminated with heavy metals and/or organic contaminants such as solvents, crude oil, polyaromatic hydrocarbons and other toxic compounds from contaminated environments. This technology is useful for soil and water remediation.
Mechanisms:
Phytoremediation uses one basic concept: the plant takes the pollutant through the roots. The pollutant can be stored in the plant (phytoextraction), volatized by the plant (phytovolatization), metabolized by the plant (phytodegradation), or any combination of the above.
Phytoextraction is the uptake and storage of pollutants in the plants stem or leaves. Some plants, called hyperaccumulators, draw pollutants through the roots. After the pollutants accumulate in the stem and leaves the plants are harvested. Then plants can be either burned or sold. Even if the plants cannot be used, incineration and disposal of the plants is still cheaper than traditional remediation methods. As a comparison, it is estimated a site containing 5000 tons of contaminated soil will produce only 20-30 tons of ash (Black, 1995). This method is particularly useful when remediating metals. Some metals are also being recycled from the ash.
Phytovolatization is the uptake and vaporization of pollutants by a plant. This mechanism takes a solid or liquid contaminant and transforms it to an airborne vapor. The vapor can either be the pure pollutant, or the plant can metabolize the pollutant before it is vaporized, as in the case of mercury, lead and selenium (Boyajian and Carriera, 1997; Black, 1995; Wantanbe, 1997).
The word “remediate” means to solve a problem, so the word “bioremediation” refers to the use of biological organisms to solve an environmental problem. Bacteria, fungi, protists and other microorganisms in a non-polluted environment are constantly breaking down organic matter, and when the soil is polluted, some of the organisms may die, but others will still be able to break down the pollutants. Bioremediation provides organisms that can consume the pollutants with fertilizer, oxygen, and other conditions to encourage the rapid growth of these organisms. They then would be able to break down the organic pollutants at a correspondingly faster rate. There are two general ways in which bioremediation functions. One way is where specific survival conditions of a microorganism living in the soil are enhanced to increase the rate of a pollutant’s degradation. The second way is when specialized microbes are added to degrade the contaminant. This way is less common. For many types of polluted soil, bioremediation provides an excellent method of clean-up, but in some cases the pollutant is toxic even for the microbes. These pollutants include metals such as cadmium or lead, and salts such as sodium chloride. Although it may not work in all cases, bioremediation is considerably easier than other methods because it enhances the functions that the microbes already carry out in the soil. Along with being easier, it can be much less expensive because the soil does not have to be pumped out of the ground for treatment (Environmental Inquiry-Bioremediation). Serratia Marcescens is a bacterium that is commonly used for bioremediation.
DEQ. (2013). Environmental Cleanup. Retrieved from Oregon Department of Envriornmental Quality: natural bioremediation; soil vapour and water extraction; activated carbon treatment of emissions
“[…] a treatability technology that uses biological activity to reduce the concentration or toxicity of a pollutant. It commonly uses processes by which microorganisms transform or degrade substances hazardous to human health or the environment.” This statement is often used to describe the fundamental aim of bioremediation around the world. Richard Raymond, who is thought by some the father of bioremediation, foresaw that “adding acclimated microorganisms to contaminated sites could become a common practice” thus benefiting society by attacking the pollutants and converting them into harmless products to humanity and animal habitat. Bioremediation technologies can be generally classified as ex situ in which treatments involve the physical removal of the contaminated material for treatment process and in situ techniques that involve treatment of the contaminated material in place. Although the use of living systems to make a product has an established history, bioremediation have generated many social and ethical controversies to the foreground. The idea promoted by Richard Raymond illustrates a direct connection between bioremediation and its potential to restore contaminated environments inexpensively yet effectively.
Not mentioned in the report is a technique called bioremediation, which uses microbes to clean up the hazardous waste. Some small natural organisms, such as bacteria, can eat, digest and gain energy from contaminants, converting them into small amounts of water or innocuous gases. Specific conditions must be present for bioremediation to be successful. Natural amendments can be added if ideal conditions are not present, or contaminated soil can be treated ex situ. Traditionally, it takes anywhere between a few months and several years for bioremediation to fully clean a Superfund site, depending on the size of the site and extent of contamination. Bioremediation is currently being used to clean up contaminated groundwater at the Iceland Coin Laundry Superfund Site in New Jersey (EPA, n.d.). Additionally, experiments are currently underway to determine if fungi can help remediate some of the contamination at the Newtown Creek Superfund Site in New York City (Parry, 2012). As an all-natural alternative, bioremediation is a particularly appealing clean up method. If ideal conditions for microbial growth are not present at the Portland Harbor Superfund site, bioremediation could be a good ex situ treatment
During recent years, numerous newspaper and magazine articles have suggested that humans may be at risk because small amounts of well known environmental contaminants, such as dioxin, PCBs and DDT, can affect hormone levels. Hormones are produced by the endocrine system as regulators of biological function in target organs. Because hormones play a critical role in early development, toxicological effects on the endocrine system often have an impact on the reproductive system. The term endocrine disruptor is used to describe chemicals that can mimic hormones and may either enhance or counteract their effects. It has been suggested that these hormone changes can, in turn, lead to a variety of health problems including cancer, decreased fertility, and abnormalities in newborns.
There are many factors that are integrated into the successful development of a child from Prenatal growth into toddlerhood. Teratogens (outside factors) have a great impact on the babies’ inutero development. Some outside factors like second-hand smoke, smog, or fumes from cleaning chemicals can cause negative effects on the child inside the womb. A few major affects from teratogens could result in low birth weight, head circumference, slow physical growth as well as an effect on mental, behavioral and motor skills (Berk, 2003). The environment around the mother provides many of these outside factors affecting the baby’s growth. But the main link to teratogens during the gestation period is most likely the mother. Daniel S. Messinger and the National Institute on Drug Abuse found that 2.8% of pregnant women admitted to using illicit drugs during their pregnancy (1996). Through illicit drug use, tobacco use and alcohol use, the mother disrupts her baby’s growth with possibly permanent damage.
Pesticides and Fertilizer run off from farms causes an overwhelming negative effects on the environment. Pesticides contaminate the water and poison fish both killing them and causing biological magnification in the fish that are higher up in the food chain. When humans eat these fish the risk of being harmed by pesticides is increased. Tobacco plants were engineered to express a gene that detoxifies 2,4-dichlorophenoxyacetate ( 2,4-D), one of the most commonly used pesticides world wide, and removes it from the soil.
Pesticides and herbicides are toxins that are used to kill of unwanted animals and plants. These may be collected by rainwater runoff and carried into steams, rivers, lakes, and e...
pollutant before materials are used, removed the pollutant after it is formed, or altered the
Not only does pollution destroy plants but it also affects the health of animals and humans. The affects of pollution on living organisms maybe short and long term. As a child growing I had a friend who was form India, and he would visit every few
Different pollutants cause different things to happen to plants. Sometimes, water pollution causes an explosion of new plant growth by providing necessary nutrients and food. If there is too much of one species, this can harm or kill plants by changing their growing conditions, such as raising or lowering the environment’s acidity. Plants must take in nutrients from the surrounding environment in order to grow. Nitrogen and phosphorus, in particular, help a plant’s growth because they are important in photosynthesis. This is why they are common ingredients in plant fertilizers. When runoff from farms pollute waterways with nitrogen and fertilizers rich with phosphorus, the water enriched with nutrients often have stunts of growth. Sometimes too much growth can be harmful, as when plant-like algae bloom in polluted waters and create oxygen-depleted dead zones. One solution to this issue is planting seaweed farms in areas that get alot of runoff from farms. This is because seaweed can soak up the excess nutrients and be harvested for people to eat. Marine debris is garbage that ends up in the ocean. Plastic debris that builds up at or near the water’s surface blocks sunlight from fully reaching plants that rely on sunlight to move along the photosynthesis process. By blocking sunlight, marine debris prevent plants from creating glucose at full capacity, which stunts their growth. When chemical pollutants
Pharmaceutical waste seems to be one of the dominant elements that are prevalent in our waters, and other aspects of the environment. These aforementioned elements are largely becoming a concern in today’s society because its effects have proven to be harmful towards our environment, and all of its existing forms of life. Through various ways, whether controllable or uncontrollable, pharmaceutical waste slowly and increasingly multiplies its presence within the environment. Additionally, it eventually trickles down into our waterways and causes a large array of damages. Some of the most common ways that this waste gets into the water includes: disposal through the drainage systems, farming fertilization methods and the maintenance of treatment plants. These methods are self-explanatory through their brief discussions, but it helps decipher whether the disposal of these dangerous wastes are intentional or not.
Professional audience: Toxicology is a multidisciplinary, scientific field, which studies the hazards and adverse effects of xenobiotic agents on biotic components of the ecosystem. These biotic components include, but are not limited to the following: humans, animals, and plants. More importantly, the field of toxicology is also used to construct preventative measures, treatment, and other amelioration strategies relative to the adverse health effects and the agent(s) being analyzed. The field of toxicology has evolved from a science focused on poisons
As a result of this process, the mine sites "do not develop normal soil structure or support the establishment of a plant cover". Many mine sites have...
...or lakes (Weber 2). When people just dump waste products instead of recycling, it is a misuse of the soil and can contribute to serious health conditions in animals, plants and humans.