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Abandoned mines Areaswhere operations toextract minerals and metals from the earth are nowdefunct. They are no longer active because they ceasedto be valuable enterprises and so were permanentlyabandoned, or because they were shut down by thegovernment due to environmental concerns. This isdistinct from inactive mines, which have only closedtemporarily due to financial or market reasons.1 Abandonedmines exist in virtually every area where significantmining has been undertaken over past decades,and evencenturies. They still pose major environmental,safety and health problems in many countries.
Abandoned mines represent a legacy of outdatedmining and mineral processing practices, and ofinadequate mine closure. The environmental impacts fromabandoned mines include loss of productive land,degradation of waterways by sediment or salts, airpollution from contaminated dust; and, decrepit anddangerous structures including shafts and pits. Particularproblems often arise from the large quantitiesof waste rock which have been moved to allow accessto the valuable ore.
Unless these heaps have beenproperly contained and covered, they pose an ongoingthreat of release of toxic materials and of landslides. • A related, and sometimes greater problem is “tailings”.Tailings are the finely ground waste rock that is producedby the initial ore processing that usually happensat or near a mine site. • The tailings are often releasedas a mud-like slurry which can contaminate and clogrivers. Where the tailings are contained in a pond,behind a dam, the problem is temporarily resolved butabandoned tailings ponds are a major hazard, withrisks of flooding and mud-slides.
Sites of abandoned mines can : - pose publicsafety hazards, especially when children explore orplay around the area of an old mine. - pollute the water through acid drainage, whichoccurs when rain or groundwater mixes with exposedmetal sulfide minerals to create sulfuric acid and dissolvedheavy metals which then acidify and contaminate local waterways.
Ideally, all of the these hazards are resolved as part ofa mine closure process but there many cases wherethis work has been incomplete or just ignored, mainlyfor financial reasons. • Unfortunately, the high cost ofrehabilitation and lack of clearly assigned responsibilityand standards, also undermine efforts for remediationof contamination. Occasionally the problems of abandonedmines are even complicated by cross contaminationwith other nearby industrial activities. • Abandoned mines present other economic issues.Communities that once depended on the mines for jobsand services are often still there, without alternativesources of employment.
Agrotoxins and POPs Agrochemicals were initially developed to stimulate andimprove agricultural output, through synthetic growthenhancers, and killing pests that damaged crops. However, such chemicals were often too effective, killingother organisms besides the intended pests, andpolluting the environment. Now, the practice of intensepesticide and fertilizer application is recognized as hazardousto environmental and human health. Due to theserious negative impacts of some of these substances, they are often known as agrotoxins.
Agrotoxins are typically harmful pesticides includingorganochlorinesand organophosphates such as Lindane, Dicofol, Heptachlor, endosulfan, Chlordane, Mirex, pentachlorophenol, toxaphene, DDT, etc. Other pesticides which are known to have serious healtheffects include glyphosate, methyl bromide, Metadof,Duron, Novafate and Novaquat. In addition, overuse ofsome agricultural fertilizers can also release quantitiesof urea, nitrogen, phosphates, and heavy metals, whichcan have harmful effects at high levels. Persistent Organic Pollutants (POPs) are chemicals that bioaccumulate in human and animal tissue andpersist in the environment. POPs are used for range ofpurposes. Here we discuss their use as agrochemicals.
The use of agrotoxins has skyrocketed since its introduction for agricultural purposes in the 1940s.Roughly 2.3 million tons (2.5 million imperial tons) ofindustrial pesticides are now used annually, a 50-foldincrease since 1950. • Out of the millions of tons ofagrochemicals applied to soils every year, a significantportion ends up being washed away to the surroundingsurface and ground waters, or absorbed by organismswhich were not the original targets. • At an extreme, onestudy found that over 98% of sprayed insecticides and95% of herbicides reach a destination other than theirintended target species, including non-target species,air, water, bottom sediments, and food.Since agrotoxinsare also harmful to humans, their over-use poses a serious threat.
After recognizing the human health risks associatedwith agrochemicals, many older, more noxious agrotoxins,particularly organochlorines, are now bannedin most developed countries. • However, these olderpesticides are highly effective in dealing with the targetpests and are often the cheapest to produce. Thereforemany developing countries are still using someof the more toxic agricultural chemical agents. • Forexample, a study in 2003 estimated that about 36% ofthe pesticides restricted in use by the WHO have beenused in the TienGiang province of rural Vietnam.’
Chemical pesticides, especially those made of chlorinatedcompounds, can be highly toxic, persistent andmay bio-accumulate. Fertilizers may also be hazardousto the environment and human health, especially whereinorganic fertilizers, such as phosphate andmicronutrientfertilizers, are blended locally with fillers such as recycledindustrial wastes (e.g., steel mill flue dust, minetailings), and therefore can contain the heavy metals.’
ARSENIC Arsenic is a naturally occurring, semi-metallic elementthat is odorless and tasteless. When combined withoxygen, chlorine, and sulfur, it forms inorganic arseniccompounds. In general, arsenic is considered a heavy metal, and can be very toxic to the environment and human health.
The toxicity of arsenic for humans is well documentedand even famous as a method of poisoning used infiction and in real life. • Arsenic poisoned Napoleon,Francesco I de’ Medici (the Grand Duke of Tuscany),George the III of Great Britain, and various impressionistpainters that inadvertently ingested paints containingarsenic. • However, both organic and inorganicforms of arsenic are frequently used for industrial andagricultural purposes. Organic arsenic compoundsare typically used as pesticides while inorganic arseniccompounds are primarily used to preserve wood. • Arsenicis also a common byproduct of copper smelting,mining and coal burning, and can also be released intothe environment through the manufacturing of pesticides,burning fossil fuels, and cigarette smoke.2 Watersources become tainted with arsenic through the dissolutionof minerals and ores, industrial effluents, and atmospheric deposition.
Arsenic contamination of groundwater is becoming acommon problem for many places in the developingworld. • While arsenic is a naturally occurring element ingroundwater, higher concentrations of the element are being drawn into underground water supplies mainlydue to over-pumping during agricultural irrigation. • Bangladeshis experiencing this problem with the numberof people drinking arsenic-rich water having increaseddramatically since the 1970s due to increased welldrilling and population growth. • One estimate points toat least 100,000 cases of skin lesions, which occurredin Bangladesh due to increased arsenic exposure.5Studies found more than a fifth of the nation’s contaminateddrinking water to have 50 parts per billion ofarsenic, which is significantly over the WHO’s recommended limit of 10 ppb.
Arsenic-contaminated food crops are a major problemin many developing countries straining their naturalresources when attempting to boost agricultural cropproduction. • Using arsenic-rich waters to irrigateagricultural crops normally results in food uptake of theelement and human ingestion of arsenic. Young childrenand babies are particularly susceptible to arsenicpoisoning from foods, such as rice due to lower tolerances to the element.
Arsenic is also released into the environment and canimpact human health during the process of coppersmelting. Arsenic is a common by-product during theprocess and enters the environment as arsenic-laden dust. • Arsenic is also found in “pressure-treatedlumber,since it is used to treat lumber to make the woodresistant to rotting, fungus and insects. The treatedwood often releases arsenic and arsine gas into the environment, especially when burned.
CADMIUM Cadmium is a natural element commonly found in allsoil and rocks and typically extracted during the productionof other metals such as zinc, lead or copper.About 75 percent of all cadmium in the world is usedin batteries. The other 25 percent of cadmium isused in many other products such as pigments, metalcoatings, and plastics.2 Cadmium does not corrode easily, and can be used in equipment for the control of nuclear fission.
Since cadmium is a by-product from mining, smelting,and refining zinc, lead or copper mineral ores,these industrial activities can release cadmium intothe environment through waste streams. • Once inthe environment, cadmium does not break down andbinds strongly to soil particles. It is toxic at even lowconcentrations and will bioaccumulate in fish, plantsand animals. Cadmium is a commonly found pollutant in groundwater and rivers.
Cadmium enters the environment in several ways. Primarysources of airborne cadmium come from fossilfuel combustion, burning of municipal waste, smeltingor refining other metals, as well as through cigarette smoke. • Waterways become polluted when cadmium is releasedvia waste streams of factories that processcadmium and other metals. Cadmium can also pollutewater and soil as a result of poor waste disposal, spillsor leaks at hazardous waste sites.
In addition, cadmium can enter the food chain when agriculturalfields are irrigated with contaminated waterand when phosphate-based fertilizers or sewage sludgecontaining cadmium are used as nutrients during agricultural production in various countries.
CHROMIUM Chromium (Cr) is a metallic element whose principalore is chromite. These are found mainly in Russia,South Africa, Albania, and Zimbabwe. Chromium is produced when the chromite is smelted with aluminumor silicon. The metal has a number of uses, includingsteel making, metal planning and tanning. Chromiumin the environment can be found in several forms, of which the trivalent ion (chromium+3) and the hexavalention (chromium+6) are of most concern. The latter(hexavalent) is the most toxic form.
Elemental chromium is primarily used as a componentof steel and other alloys. Trivalent chromium isused to make other metals and alloys, but is also usedin refractory bricks and other chemical compounds. • Chromium compounds in both trivalent and hexavalentforms are used for chrome plating, dyes and pigments,leather tanning and wood preserving. • Chromitemining, can release chromium compoundsinto the environment, particularly into water. Furtherprocessing of the ore, particularly for use in tanning,produces wastes that can be highly polluting if not properly managed.
Elemental chromium and hexavalent chromium aretypically produced by industrial processes, while trivalentchromium can be naturally occurring as well as a by-product of industry. • When chromium compounds are used for electroplating,a thin layer of chromium is coated onto anothermetal such as nickel or iron, using an electriccharge. Electroplating operations tend to producelarge amounts of wastewater containing heavy metals, including chromium.
The leather industry uses chromium compounds in theprocess of tanning animal hides and skins, both to preservethem and to produce a tough, supple texture thatis resistant to biodegradation, and ready to be furtherdyed. • The methods employed by tanneries often producelarge amounts of residues that can be harmfulto the environment, including chromium wastes, hair,salts, and fleshing residues. • In small scale or uncontrolledtanneries, these residues and the wastewaterfrom the process are sometimes dumped into thesurrounding area. For reasons of logistics, tanneriesare often located in clusters, which can include largenumber of individual operations and which can havea serious cumulative impact on the environment.
Coal-fired power plants are the leading source ofelectricity for the world, and is the primary sourceof electric power for many countries.An estimated 4050 million tons of coal are consumed worldwideeach year, and almost 40 percent of the world’s electricityis supplied by coal.As a result , coal plants are one of the biggest sources of air pollution formany areas of the world, releasing particulates, nitrogen oxides, sulfur dioxide, mercury and carbon dioxide into the atmosphere.Because of its widespread, andinadequately regulated proliferation, this dependenceon coal is a growing hazard to human health and the environment.
Coal is an abundant and cheap source of energy. Accordingto the OECD “World Energy Outlook, 2006”,coal is the world’s most abundant fossil fuel withglobal reserves at around 909 billion tons. • The constructionof coal plants for mass power generation isalso significantly cheaper than other types of powerplants, and there are constant improvements in costefficiency through new technologies and mining productivity.
These factors have resulted in a dominance ofcoal in electric power generation throughout the world.Cheap energy is particularly desirable for developingcountries, as they strive for rapid industrialization. • Therefore the problem of polluting coal plants is moresevere in these areas of the world. For example, Polanduses coal for 94 percent of all its electricity, and Chinarelies on coal to supply 77 percent of its total electricity.
Garbage Dumps Across the planet each person on average, producessomewhere between 0.2 and 1 kilogram of solid waste(garbage) per day, depending on a wide range of factors,not counting industry and construction activities,which produce even larger quantities. Much of the solid waste in developing countries is dumped into piles ofvarying size. From mounds along roadways, to dumpsacres wide, these areas are unlined, and completelyexposed to the elements , leading to contamination of the surrounding environment as materials degrade.
As communities grow larger, denser and often economicallybetter off, more goods are consumed andmore material is thrown away. In every city there aregroups of people who will take waste from households,either for a small fee or for the value of what can bescavenged. • Despite these collection activities, most ofthe waste is dumped in drainage ditches or any patchof wasteland. Eventually, by varying circumstances, large dumps appear.
These dumps can be several hectares in size and 20meters or more high. They typically burn and smoke(due to the gas released as the material rots), andseep large quantities of corrosive liquid (“leachate”),which pollutes both ground and surface water. • Oftenthese dumps are colonized by poor families that extracta modest living from scavenging activities on the dumpsite.
These dumps are generally noxious and although theymainly pose an acute health hazard to the residents,they also contaminate the local atmosphere, supportvarious kinds of vermin, and can pollute local waterwaysto a dangerous degree. • Dumps are often usedas open toilets and fecal contamination of the land andnearby waterways is common. Actions to improve theconditions of dumps are needed, but the problems areoften too massive for developing country governmentsto fully address at present.
Industrialestates, known under many other names, are large areas of land (often hundreds of hectares) which are designated for general or specific industrial activity.
There are nearly 10-12,000 industrial estatesworldwide, with an estimated 4,500 or so inAsia. They can contain anything from a handfulof firms up to several hundred, of all types fromhigh tech to basic industrial production. • Whenwell run, the estate provides environmentalservices for all the firms, but in the worst casesthey can represent a large collection of highlpolluting sources. • Serious air pollution, heavycontamination of waterways and illegal dumpingof hazardous wastes are consequences ofestates where industrial growth is put before environmental management.
Industrial estates often operate under special regulatoryregimes, intended to attract and promote industry,sometimes with specific incentives for export activities. • They can range from very modern “IT City” complexesto clusters of small ad medium enterprises in profitablebut dirty sectors such as tanning or textiles. Many“estates” resemble small industrial cities with numerous problems.
OIL REFINERIES AND PETROCHEMICAL PLANTS An oil refinery is a major chemical processing plantthat converts crude oil into commercial products suchas fuels, lubricants, and feedstock for other downstreamprocesses. There are over 2,500 productsthat refineries produce including petrochemicals, asphalt, diesel fuel, fuel oils, gasoline, kerosene, liquefied petroleum gas, lubricating oils, paraffin wax, and tar.
The many and complicated processes and equipment,employed at oil refineries can allow the escape (ordeliberate release) of various volatile chemicals intothe atmosphere, resulting sometimes in high levels ofair pollution emissions, and often a foul odor in communitiessurrounding the refinery. • Oil refineries also cancause pollution problems by releasing of inadequatelytreated wastewater to rivers, improperly managedspills infiltrating into groundwater, and consequencesof industrial accidents. • Typically, processing one ton ofcrude oil, refineries can produce up to 3.5 to 5 cubicmeters of wastewater, and 3 to 5 tons of solid waste and sludge.
The world consumes approximately 82 million barrelsper day of refined petroleum products. Raw or unprocessed(“crude”) oil is not useful in its natural state andgenerally requires refining into a myriad of products foreveryday use. • Processing of crude oil for fuel resultsin losses to the environment and creates highly toxic wastes .
Chemical weapons are classified as arms that utilizetoxic chemical substances to harm or kill an enemyduring warfare. According to the international ChemicalWeapons Convention, there are over 50 differentchemicals that have been produced specifically for useas weapons during warfare (also known as chemicalweapons agents or CWA). Most chemical weaponsproduced have either been used on the battlefields ofWWI (more than hundred thousand metric tons), seadumpedin one of the many oceans during the 50s and 60s (several hundred thousand metric tons) or are stillstored in stockpiles worldwide (about 70’000 metrictons). These stockpiles are extremely dangerous if theywould not be adequately maintained and guarded.
Old and abandoned chemical weapons (OCW/ACW)stockpiles can be found in nearly every country thatproduced or stored chemical weapons or wherechemical weapons were deployed during war. • Themost common methods of OCW disposal historicallyhave been sea-dumping, burial or open-air incineration. • During the large weapons destruction campaigns afterWWII, hundreds of thousands of tons of OCW weretransported to the nearest ocean port, loaded on boatsand then dumped into the sea.
Weapons not suitable for long distance transport were often buried (resultingin leaking of the shells after long term corrosion),burned in open pits or the chemical agent waspoured into lakes. • As a result, traces of un-destroyedchemical agent or products of its destruction (dioxines,furanes, arsenic, acids, etc.) are leaching today intothe surrounding environment. • Buried shells areoften discovered by chance (e.g. during constructionprojects), the long term corrosion making identificationof the contents difficult and the shells dangerous to handle.
While the destruction of military deployable chemicalweapons is under way globally under the auspicesof the Chemical Weapons Convention, OCW/ACWremain a difficult issue. • A major challenge is thatalmost no archive data exists about the location ofOCW/ACW sites and most findings are chancediscoveries. • The number of OCW/ACW sites is notwell known. • The locations of OCW/ACW types andsites has been as diverse as unexploded shells onWWI battlefields in Europe, shells sunk in Japaneseports, Japanese shells left in Northern China, or shellsincinerated or buried in Russia and the U.S. • Numberscan also vary from a few shells up to burial sites withthousands of shells. The U.S. Army has defined morethan two hundred sites with OCW in the U.S. In Russiaexperts estimate the existence of some dozens of OCW sites.
PCBs Polychlorinated biphenyls, also known as PCBs, are agroup of man-made chemicals which are very resistantto decay and natural breakdown. PCBs typically exist asyellow, oily liquids or white, solid resins that do not buror degrade easily. In the past, PCBs were used in a varietyof products, including coolants in electrical equipment, surface coatings, inks, dyes, adhesives, flameretardants and even carbonless copy paper. Howeveras it became widely realized PCBs are persistent in the environment and hazardous to humans, production and use of PCBs has been banned in many countries.
Although PCB production was banned, PCBs continueto pose human health risks. It is estimated that 30-70percent of all PCBs produced remain in use and someproduction still goes on. • Nearly 30 percent of all PCBs(about a thousand tons) are now located in landfills,in storage, or in the sediments of lakes, rivers, and estuaries.
PCBs are released into the environment in many ways,including illegal or improper dumping of wastes from industries; leakage from electrical transformers con-taining PCBs; poorly maintained hazardous waste sitescontain PCBs; and waste incineration. • Once PCBs enter the environment, they do not readilybreak down and can be carried long distances inthe air and waterways.3 They tend to bioaccumulateandbioconcentrate in the fatty tissues of humans and animals.
Ocean and Seas • Oceans, seas and coastal areas form an integrated and essentialcomponent of the Earth’s ecosystem and are critical to sustaining it and that international lawas reflected in United Nations Convention on the Law of the Sea (UNCLOS), provides thelegal framework for the conservation and the sustainable use of the oceans and theirresources. • The importance of the conservation and sustainable use of the oceans andseas and of their resources for sustainable development have to be concerned, including through the contributions to : - poverty eradication, - sustained economic growth, - food security, - creation of sustainablelivelihoods and decent work, - protect biodiversity and the marineenvironment and - address the impacts of climate change.
Therefore it is important : (1) to protectand restore : - the health, - productivity and resilience of oceans and marine ecosystems, and (2) tomaintain its biodiversity, enabling their conservation and sustainable use for present andfuture generations, and (3) to effectively apply anecosystem approach and the precautionaryapproach in the management Those should be done in accordance with international law, of activities impacting onthe marine environment, to deliver on all three dimensions of sustainable development.
The health of oceans and marine biodiversity are negativelyaffected by marine pollution, including marine debris, especially plastic, persistent organicpollutants, heavy metals, and nitrogen-based compounds, from a number of marine and landbasedsources, including shipping and land runoff. It is important to take action to reduce theincidence and impacts of such pollution on marine ecosystems, including through theeffective implementation of relevant conventions adopted in the framework of theInternational Maritime Organization (IMO), and the follow up of the relevant initiatives suchas the Global Programme of Action for the Protection of the Marine Environment from LandbasedActivities, as well as the adoption of coordinated strategies to this end. Some further action should be taken by 2025, based on collected scientific data, achieve significantreductions in marine debris to prevent harm to the coastal and marine environment.
There is a significant threat alien invasive species (bioinvander or non-indigenous aquatic species) pose to marine ecosystems andresources and commit to implement measures to prevent the introduction of, and manage theadverse environmental impacts of, alien invasive species including, as appropriate, thoseadopted in the framework of the IMO.
Examples of Marine Bioinvaders • Chinese Mitten Crab • Red Lionfish • European Oyster • European Green Crab • Colonial Tunicates (e.g. Didemnum sp.)
Sea level rise and coastal erosion are serious threats for many coastalregions and islands particularly in developing countries and, in this regard, we call on theinternational community to enhance its efforts to address these challenges.
