Soil pollution results from the build up ofcontaminants, toxic compounds, radioactivematerials, salts, chemicals and cancer-causing agents. The most common soilpollutants are hydrocarbons, heavy metals(cadmium, lead, chromium, copper, zinc,mercury and arsenic), herbicides, pesticides,oils, tars, PCBs and dioxins.
Until the 1970s, there was little talk of soilpollution and its devastating effects. In the1980s, the U.S. Superfund was created to setguidelines for the handling of hazardousmaterial and soil contamination cleanup.Today there are more than 200,000 sitesawaiting EPA soil cleanup, which is veryexpensive and labor-intensive work. Even asmall cleanup project can cost $10,000, whilelarger areas require millions of dollars toclean it up for future use.
Following WWII and Vietnam, scientists discoveredhigh incidences of mutation, miscarriage, mentaldefects, cancer and sickness in areas where nuclearwarheads had been dropped. Food shortages alsoalerted officials that something was seriously wrongwith the local soil. DDT and Dioxin were two of theworst pollutants from war aftermath.
In some cases, agricultural processes causesoil pollution. High levels of radionuclideslike nitrogen and phosphorus can be foundsurrounding farm centers containing highpopulation densities of livestock. Pesticidesapplied to plants can also seep into theground, leaving lasting effects. Heavy metalscan arrive in the soil by using polluted waterto wet crops and by using mineral fertilizers.
Industry is to blame for some of the biggest soil- pollution disasters. Heavy metals come from iron, steel, power and chemical manufacturing plants that recklessly use the Earth as a dumping ground for their refuse. Plants that burn their waste on-site are guilty of releasing heavy metals into the atmosphere, which come to settle in the soil, thus leaving behind lasting effects for years to come. Even companies that try to dispose of their waste properly contribute to the problem when faulty landfills and bursting underground bins leach undesirable toxins into the soil.
Mining leaves a tremendous impact on thesurrounding communities. The 2001 WestVirginia Geological and Economic Survey foundthat people living near mines have a 70 percenthigher risk of kidney disease, 64 percent higherrisk for chronic obstructive pulmonary diseaseand a 30 percent higher risk of high bloodpressure. "People in coal-mining communitiesneed better access to health care, cleaner air,cleaner water, and stricter enforcement ofenvironmental standards," concluded MichaelHendryx, Ph.D., associate director of the WVUInstitute for Health Policy Research.
Before purchasing land for development or inhabiting, itsimportant to have a soil test performed to ensure a soundinvestment. A soil test can reveal the presence of nitrogen,phosphorus, potassium, sulphur, calcium, magnesium,iron, manganese, copper, zinc, boron, molybdenum andaluminum. It can also analyze soil acidity, electricalconductivity, organic matter, moisture content, andidentify dangerous soil contaminants like benzene,petroleum hydrocarbons, xylene and toulene. Even if thesoil is in fine condition for planting, landowners can usetheir soil tests to make more informed decisions regardingfertilizers and crop growing. Most people call in a localprofessional to do the job, although stores like HomeDepot and Lowes are now selling do-it-yourself mail-inkits as well.
Love Canal is perhaps the most famous case study ofsoil pollution. In the snowy winter of 1976, chemicalwaste began to seep above ground in schoolplaygrounds and communities in Niagara Falls, NewYork. The area suffered high incidences of stillbornbirths, miscarriages and birth defects. Officials soonrealized that there were over 400 toxic substances inthe air, water and soil -- many of them cancerous. Asit turns out, the area had been used as a chemicaldumping ground for more than 22,000 tons of toxicwaste at the turn-of-the-century, when no one wasaware of the hazardous impact it could have decadeslater.
Another one of the most infamous cases of soilpollution happened in Chernobyl, a small town inRussia. A nuclear power plant exploded in Aprilof 1986, which caused a sevenfold increase inbirth defects, a marked increase in cancer thatwas passed down to future generations, livestockdeath and mutation and tainted agriculture. Itsestimated that 40 percent of Chernobyl is stilluninhabitable due to radiation contaminationthat is ten times the normal level in some places.
Ethiopia is filled with both air and soil pollution.The worst area is in Somalias Ayaha valley nearHargeysa. To boost their economy, many farmersbegan using chemical fertilizers and pesticides toincrease productivity without understanding thefull ramifications. Over their war-torn years,metal drums holding 14,200 liters of chemicalslike fenitrothion, malathion, diazionon anddurban were punctured. As a result, landpollution has caused widespread famine andsickness.
China is a nation that is developing rapidly --perhaps faster than safety permits. "It isestimated that nationwide 12 million tons ofgrain are polluted each year by heavy metals thathave found their way into soil," Zhou Shengxian,director of the State Environmental ProtectionAdministration, announced in July 2006. "Directeconomic losses exceed 20 billion yuan (about2.5 billion U.S. dollars). Soil pollution hasworsened. According to incomplete statistics,about 150 million mu (10 million hectares) ofarable land in China has been polluted."
"When old factories are relocated, they justdismantle the houses, carry away themachines and nothing else is left to be done.The land that used to be a production siteeither is turned into farmland or real estate.Few understand that this land has becomesick," explains Zhao Qiguo of the ChineseAcademy of Sciences Institute of Soil Science.
People living near polluted land have higherincidences of migraines, nausea, fatigue,miscarriage and skin disorders. Long-termeffects of pollution include cancer, leukemia,reproductive disorders, kidney and liverdamage, as well as central nervous systemfailure. Children often suffer fromdevelopmental problems and weakenedimmune systems.
In addition to direct health effects, soilpollution also harms plants that feedAmericans. Chemicals can sometimes absorbinto food like lettuce and be ingested. Othertimes, the pollutants simply kill the plants,which has created widespread cropdestruction and famine in other parts of theworld. The entire ecosystem changes whennew materials are added to the soil, asmicroorganisms die off or move away fromcontaminants.
Predators who feed off the microorganisms andworms in the polluted soil will also be affected.Researchers found that some species of birds --like the Peregrine Falcon, the Brown Pelican andthe Bald Eagle -- fell prey to DDT poisoning,which caused egg shells of future generations tothin. Mother birds would arrive home to omeletsin their nests, as the thin shells could notsupport the weight of the incubating offspring.Mortality rates increased, nearly sending thebirds to extinction.
If nothing is done to clean up soil pollution,water supplies could become contaminated,threatening the human species. Sudden firesor explosions will occur from undergroundlandfill gases, pipelines and buildingstructures may corrode and once beautifulregions will turn into cesspools, expertswarn.
The conventional methods of soil pollution are verytime-consuming and very costly. EPA officialsexcavate the soil to dispose of it elsewhere -- aband-aid for the problem, no doubt, but essential fortoxic disasters in highly populated places. Soils canbe aerated, heated up in a process called thermalremediation, contained with pavement or caps,extracted with an active electromechanical system orpropagating the soil with microbes that will digestorganic pollutants.
New processes are being developed tocombat the problem in a natural, lesslaborious way. By studying plants that grewnaturally in toxic mines, scientist ChenTongbin discovered that certain plants lovedto eat heavy metals like arsenic, bronze, lead,zinc, cobalt and cadmium. The contaminantscan then be retrieved from the plants leavesand used in industrial materials. This safeand effective method isnt perfect, but its astart.
Naturally, prevention is the best cure for soilpollution. Most states have enacted tougherlegislation to stop illegal dumping. For instance, onecan expect five years in jail and a fine of $100,000 forsoil pollution in Texas.
Educating consumers about the dangers oflittering, while encouraging recyclingprograms, is a good way to ensure everyonedoes their part to keep debris where itbelongs. Consumers can also make aconcerted effort to buy organic foods todemand that chemical pesticides arent usedon their foods.
People who grow their own food can keep excessnitrogen and phosphorus out of the soil bychoosing crops that do not need as manynutrients from the soil, by applying fertilizerduring the growing season to replenish the soil,by shortening the grazing season / cattledensity, by using organic compost, by keepingthe surface moist and mulched, and by choosingfruiting crops like tomatoes, squash, peas andcorn. Gardens should be situated away from oldpainted buildings and roadways. Outer leaves oflettuce should be discarded and all vegetablesshould be washed before eating.
Over the years, stronger and moreindestructible bins were created to storehazardous materials. Researchers willcontinue to look for ways to improvemanufacturing and agricultural processes toavoid the need for toxic byproducts. Businessleaders, miners and community officials willwork together to reduce wastefulness andcontaminants to keep the world a clean placefor future generations.
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