Types Of Pollution And Their Causes Environmental Sciences Essay

suits Of Pollution And Their Ca go fors Environmental Sciences EssayPollutionis the introduction of contaminants into a infixed environment that move overs discomfort to theecosystemi.e. physical systems or biography organisms.Pollution brush off take the form of chemical substancesorenergy, such as noise, heat, or light. Pollutants, the elements of befoulment, rear be foreign substances or energies, or infixedly occurring when naturally occurring, they atomic number 18 carryed contaminants when they exceed natural takes. Pollution is a lot classed aspoint citationornonpoint witness defilement.POINT SOURCE POLLUTIONApoint source of taintis a single identifiablelocalizedsource ofair, piss,thermal,noiseorlightdefilement. Apoint sourcehas negligible extent, distinguishing it from early(a) pollution source geometries. The sources ar calledpoint sourcesbecause in mathematical modeling, they bottom of the inning be approximated as a mathematicalpointto simplify anal ysis. Pollution point sources are identical to otherphysics,engineering,opticsandchemistrypoint sources except that their emissions corroborate been labeledWater pollution from anoil refinerywaste water supplydischarge outletNoise pollution from ajet engineDisruptiveseismicvibration from a localized seismic studyLight pollution from an intrusivestreet light thermal pollution from an industrial physical processoutfallRadioemissions from an interference-producing galvanisingal deviceTypes of air pollution sources which have finite extent areline sources,area sourcesandvolume sources. Air pollution sources are also often categorized as all stationary or mobile.NON POINT SOURCE POLLUTIONNon-point source (NPS) pollutioniswater pollutionaffecting a water body from diffuse sources, such as polluterunofffrom ruralareas draining into a river, or wind-borne debris blowing out to sea. Nonpoint source pollution can be contrasted withpoint sourcepollution, where discharges occur to a body o f water at a single location, such as discharges from a chemical factory,urban runofffrom a roadstorm drain, or from ships at sea.NPS may derive from many different sources with no specific solution to rectify the problem, making it difficult to regulate. It is the leading cause of water pollution in theUnited Statestoday, with contaminated runoff from agriculture the primary cause.Other significant sources of runoff allowhydrologicalandhabitat modification, andsilviculture(forestry).Contaminated stormwater process off ofparking lots,roadsandhighways, andlawns(often containingfertilizersandpesticides) is calledurban runoff. This runoff is often classified as a type of NPS pollution. Some people may also consider it a point source because many eons it is channeled into municipal storm drain systems and discharged through pipes to nearby surface waters. However, not all urban runoff flows through storm drain systems before entering waterbodies. Some may flow tellly into waterbodi es, especially in developing and suburban areas. Also, foreign other types of point sources, such as industrial discharge, wastewater plants and other operations, pollution in urban runoff cannot be attri moreovered to one activity or even group of activities. Therefore, because it is not ca apply by an easily identified and regulated activity, urban runoff pollution sources are also often treated as true nonpoint sources as municipalities work to abate them.MAJOR FORMS OF POLLUTION The major forms of pollution are listed below along with the particular pollutants relevant to each of them way POLLUTIONAir pollutionis the introduction ofchemicals,particulate matter, orbiological naturalsthat cause harm or discomfort to humans or other living organisms, or damages thenatural environmentinto the atmosphere.The atmosphere is a complex dynamic natural gaseous system that is essential to support life on planetEarth.Stratosphericozone depletion repayable to air pollution has long been re cognized as a threat to human health as well as to the Earthsecosystems. illegitimate enterprise POLLUTIONNoise pollution(orenvironmentalnoise) is displeasing human, animal or machine-created sound that disrupts the activity or balance of human or animal life. The enouncenoisecomes from the Latin wordnauseas, meaning seasickness.The source of most outdoor noise world enormous is mainlyconstructionandtranspHYPERLINK http//en.wikipedia.org/wiki/Transportortation systems, includingmotor vehiclenoise,aircraft noiseand school noise.Poorurban planningmay give rise to noise pollution, since side-by-side industrial and residential buildings can result in noise pollution in the residential area.Indoor and outdoor noise pollution sources includecar alarms, emergency servicesirens, mechanical equipment,fireworks, compressedair horns, groundskeeping equipment, barking dogs, appliances,lightinghum, audio entertainment systems, electricmegaphones, and loud people.SOIL CONTAMINATIONSoil contamina tion(soil pollution) is ca apply by the presence ofxenobiotic(human- derive) chemicals or other alteration in the natural soil environment. This type of contamination typically arises from the rupture ofunderground storage tanks, application ofpesticides, percolation of contaminated surface water to subsurface strata, oil and fuel dumping, leaching of wastes fromlandfillsor direct discharge of industrial wastes to the soil. The most common chemicals carryd are petroleumhydro light speeds,solvents, pesticides, lead and otherheavy metals. This occurrence of this phenomenon is correlated with the degree of industrialization and intensities of chemical usage.The concern over soil contamination stems primarily from health risks, from direct contact with the contaminated soil, vapors from the contaminants, and from secondary contamination of water supplies within and be the soil. Mapping of contaminated soil sites and the resulting cleanup are time consuming and expensive tasks, requiri ng extensive amounts ofgeology,hydrology,chemistryandcomputer modelingskills.It is inNorth the StatesandWestern Europethat the extent of contaminated land is most well known, with many of countries in these areas having a legal framework to identify and deal with this environmental problem this however may well be just the tip of the iceberg with developing countries very the likely to be the next generation of radical soil contamination cases.RADIOACTIVE CONTAMINATIONRadioactive contamination, also calledradiological contamination, is radioactive substances on surfaces, or within solids, liquids or gases (including the human body), where their presence is unwitting or undesirable, or the process giving rise to their presence in such places.Also used less formally to refer to a quantity, that is to say theactivityon a surface (or on a unit area of a surface).Contamination does not include residualradioactive materialremaining at a site after the completion ofdecommissioning.The endpoint radioactive contamination may have a connotation that is not intended.The line radioactive contamination refers only to the presence ofradioactivity, and gives no indication of the magnitude of the hazard involved.Radioactive contamination is typically the result of a spill or accident during the production or use ofradionuclides(radioisotopes), an unstable nucleus which has excessive energy. Contamination may occur from radioactive gases, liquids or particles. For example, if a radionuclide used innuclear medicineis accidentally spilled, the material could be spread by people as they walk around. Radioactive contamination may also be an inevitable result of certain processes, such as the release of radioactivexenoninnuclear fuel reprocessing. In cases that radioactive material cannot be contained, it may be diluted to safe concentrations.Nuclear falloutis the distribution of radioactive contamination by anuclear explosion.THERMAL POLLUTIONThermal pollutionis the debaseme nt ofwater feelingby any process that changes ambient watertemperature.A common cause of thermal pollution is the use of water as acoolantbypower plantsand industrial manufacturers. When water used as a coolant is returned to the natural environment at a high temperature, the change in temperature (a) decreasesoxygensupply, and (b) affectsecosystemcomposition.Urban runoffstormwaterdischarged to surface waters fromroadsandparking lotscan also be a source of elevated water temperatures.When a power plant low gear presents or shuts down for repair or other causes, fish and other organisms adapted to particular temperature range can be killed by the abrupt rise in water temperature known as thermal shock.SOURCES AND CAUSESAir pollution comes from both natural and man made sources. Though world-widely man made pollutants from combustion, construction, archeological site, agriculture and warfare are increasingly significant in the air pollution equation.Motor vehicle emissions are o ne of the leading causes of air pollution.China,United States,Russia,Mexico, andJapanare the world leaders in air pollution emissions. Principal stationary pollution sources includechemical plants, coal-firedpower plants,oil refineries,petrochemicalplants,nuclear wastedisposal activity, incinerators, large livestock farms (dairy cows, pigs, poultry, etc.),PVCfactories, metals production factories, bendables factories, and other heavy industry. Agricultural air pollution comes from contemporary practices which include clear felling and burning of natural vegetation as well as spraying of pesticides and herbicidesAbout 400 million metric rafts ofhazardous wastesare generated each year.TheUnited Statesalone produces about(predicate) 250 million metric tons.Americans constitute less than 5% of theworldHYPERLINK http//en.wikipedia.org/wiki/Worlds_populationHYPERLINK http//en.wikipedia.org/wiki/Worlds_populations population, but produce roughly 25% of the worldsCOHYPERLINK http//en.wik ipedia.org/wiki/Carbon_dioxide2,and generate approximately 30% ofworlds waste.In 2007,Chinahas overtaken the United States as the worlds biggest producer of carbonic acid gas.In February 2007, a report by the Intergovernmental Panel on mood Change (IPCC), representing the work of 2,500 scientists from to a greater extent than 130 countries, said that humans have been the primary cause of global warming since 1950. Humans have ways to press cutting babys room gas emissions and avoid the consequences of global warming, a major climate report concluded. But in order to change the climate, the transition from fossil fuels like coal and oil needs to occur within decades, according to the final report this year from the UNs Intergovernmental Panel on Climate Change (IPCC).Some of the more commonsoilcontaminants arechlorinated hydrocarbons(CFH),heavy metals(such as atomic number 24,cadmiumfound in rechargeablebatteries, andleadfound in leadpaint,aviation fueland still in some countries,g asoline),MTBE,zinc, arsenic trioxideandbenzene. In 2001 a series of press reports culminating in a book calledFateful Harvestunveiled a widespread practice of recycling industrial byproducts into fertilizer, resulting in the contamination of the soil with various metals. Ordinary municipallandfillsare the source of many chemical substances entering the soil environment (and often groundwater), emanating from the wide variety of refuse accepted, especially substances illegally discarded there, or from pre-1970 landfills that may have been subject to little control in the U.S. or EU. There have also been some unusual releases ofpolychlorinated dibenzodioxins, commonly calleddioxinsfor simplicity, such asTCDD.Pollution can also be the consequence of a natural disaster. For example,hurricanesoften involve water contamination from sewage, andpetrochemicalspills from rupturedboatsorautomobiles. Larger scale and environmental damage is not uncommon when coastaloil rigsorrefineriesare invol ved. Some sources of pollution, such asnuclear powerplants oroil tankers, can produce widespread and potentially hazardous releases when accidents occur.In the case ofnoise pollutionthe dominant source class is themotor vehicle, producing about ninety percent of all unwanted noise worldwide.EFFECTSHUMAN HEALTHAdverseair qualitycan kill many organisms including humans. Ozone pollution can causerespiratory disease,cardiovascular disease,throatinflammation, chest pain, andcongestion. Water pollution causes approximately 14,000 deaths per day, mostly cod to contamination ofdrinking waterby untreatedsewageindeveloping countries. An estimated 700 millionIndianshave no access to a proper toilet, and 1,000 Indian children die of diarrhoeal sickness every day.Nearly 500 million Chinese lack access to safe drinking water.656,000 people die untimely each year inChinabecause of air pollution. InIndia, air pollution is believed to cause 527,700 fatalities a year.Studies have estimated that the number of people killed annually in the US could be over 50,000.Oil spills can causeskinirritations andrashes. Noise pollution induceshearing loss,high blood pressure,stress, andsleep disturbance.Mercuryhas been conjugated todevelopmental deficitsin children andneurologicsymptoms. Older people are majorly exposed to diseases bring forth by air pollution. Those with heart or lung disorders are under superfluous risk. Children and infants are also at serious risk.Leadand otherheavy metalshave been shown to cause neurological problems. Chemical andradioactivesubstances cancausecancerandas well asbirth defects.ENVIRONMENTPollution has been found to be present widely in theenvironment. There are a number of inwardnesss of thisBiomagnificationdescribes situations where toxins (such asheavy metals) may pass throughtrophic levels, becoming exponentially more concentrated in the process.Carbon dioxideemissions causeocean acidification, the current decrease in the pH of the Earths ocea ns as carbon dioxidebecomes dissolved.The emission ofgreenhouse gasesleads toglobal warmingwhich affects ecosystems in many ways.Invasive speciescan out argue native species and reducebiodiversity. Invasive plants can reach debris and biomolecules (allelopathy) that can alter soil and chemical compositions of an environment, often reducing native speciescompetitiveness.Nitrogen oxidesare removed from the air by rain andfertiliseland which can change the species composition of ecosystems.Smogand haze can reduce the amount of sunshine received by plants to carry outphotosynthesisand leads to the production oftropospheric ozonewhich damages plants.Soil can become infertile and unsuitable for plants. This go forth affect otherorganismsin thefood web.Sulphur dioxideandnitrogen oxidescan causeacid rainwhich lowers thepHvalue of soil.POLLUTION CONTROL Pollution control is a term used inenvironmental management. It means the control ofemissionsandeffluentsinto air, water or soil. Witho ut pollution control, the waste products from consumption, heating, agriculture, mining, manufacturing, transportation and other human activities, whether they accumulate or disperse, will degrade theenvironment. In the hierarchy of controls,pollution preventionandwaste minimizationare more desirable than pollution control.PRACTICESRECYCLING Recyclinginvolves processing usedmaterials(waste) into new products to prevent waste of potentially useful materials, reduce the consumption of impertinent raw materials, reduceenergyusage, reduce air pollution (fromincineration) and water pollution (fromlandfilling) by reducing the need for conventional waste disposal, and lowergreenhouse gasemissions as compared to virgin production.Recycling is a key member of modern waste reduction and is the third component of the Reduce,Reuse, Recyclewaste hierarchy.Recyclable materials include many kinds ofglass,paper,metal, shaping,textiles, andelectronics. Although similar in effect, thecompostingor o ther utilise ofbiodegradable waste such asfoodorgarden waste is not typically considered recycling.Materials to be recycled are either brought to a accruement center or picked up from the curbside, then sorted, cleaned, and reprocessed into new materials bound for manufacturing.In a strict sense, recycling of a material would produce a fresh supply of the same material-for example, used officepaperwould be converted into new office paper, or usedfoamed polystyreneinto new polystyrene. However, this is often difficult or too expensive (compared with producing the same product from raw materials or other sources), so recycling of many products or materials involves theirreusein producing different materials (e.g.,paperboard) instead. other form of recycling is thesalvageof certain materials from complex products, either due to their intrinsic value (e.g.,leadfromcar batteries, orgoldfromcomputercomponents), or due to their hazardous nature (e.g., removal and reuse ofmercuryfrom var ious items). Critics dispute the net economic and environmental benefits of recycling over its costs, and suggest that proponents of recycling often make matters worse and suffer fromconfirmation bias. Specifically, critics argue that the costs and energy used in prayer and transportation detract from (and outweigh) the costs and energy salve in the production process also that the jobs produced by the recycling industry can be a poor trade for the jobs lost in logging, mining, and other industries associated with virgin production and that materials such as paper pulp can only be recycled a a couple of(prenominal) times before material degradation prevents further recycling. Proponents of recycling dispute each of these claims, and the validity of arguments from both sides has led to enduring controversy.PROCESS OFRECYCLINGCollectionA number of different systems have been implemented to collect recyclates from the general waste stream. These systems lie along the spectrum of tr ade-off between public convenience and government ease and expense. The three main categories of collection are drop-off centres, buy-back centres and curbside collection.Drop-off centres require the waste producer to carry the recyclates to a central location, either an installed or mobile collection station or the reprocessing plant itself. They are the easiest type of collection to establish, but suffer from low and unpredictable throughput. Buy-back centres differ in that the cleaned recyclates are purchased, thus providing a clear inducing for use and creating a stable supply. The post-processed material can then be sold on, hopefully creating a profit. Unfortunately government subsidies are necessary to make buy-back centres a viable enterprise, as according to the United States Nation Solid Wastes Management Association it costs on average US$50 to process a ton of material, which can only be resold for US$30.CURBSIDE COLLECTIONCurbside collection encompasses many subtly dif ferent systems, which differ mostly on where in the process the recyclates are sorted and cleaned. The main categories are multiform waste collection, commingled reclaimables and source withdrawal.Awaste collection vehiclegenerally picks up the waste.At one end of the spectrum is mixed waste collection, in which all recyclates are collected mixed in with the rest of the waste, and the desired material is then sorted out and cleaned at a central sorting facility. This results in a large amount of recyclable waste, paper especially, being too soiled to reprocess, but has advantages as well the city need not pay for a specialize collection of recyclates and no public education is needed. Any changes to which materials are recyclable is easy to accommodate as all sorting happens in a central location.In a Commingled orsingle-stream system, all recyclables for collection are mixed but kept separate from other waste. This greatly reduces the need for post-collection cleaning but does r equirepublic educationon what materials are recyclable.Source separation is the other extreme, where each material is cleaned and sorted prior to collection. This method requires the least post-collection sorting and produces the purest recyclates, but incurs additionaloperating costsfor collection of each separate material. An extensive public education program is also required, which mustiness be successful if recyclate contamination is to be avoided.Source separation used to be the like method due to the high sorting costs incurred by commingled collection. Advances in sorting technology (seesortingbelow), however, have lowered this overhead substantially-many areas which had developed source separation programs have since switched to comingled collection.SortingOnce commingled recyclates are collected and delivered to acentral collection facility, the different types of materials must be sorted. This is done in a series of stages, many of which involve machine-controlled proce sses such that a truck-load of material can be fully sorted in less than an hour.Some plants can now sort the materials automatically, known assingle-stream recycling. A 30 percent increase in recycling rates has been seen in the areas where these plants exist.Initially, the commingled recyclates are removed from the collection vehicle and placed on a conveyor belt spread out in a single layer. Large pieces ofcorrugated fiberboardandplastic bagsare removed by hand at this stage, as they can cause later machinery to jam.Next, automated machinery separates the recyclates by weight, splitting lighter paper and plastic from heavier glass and metal. Cardboard is removed from the mixed paper, and the most common types of plastic,PET(1) andHDPE(2), are collected. This separation is usually done by hand, but has become automated in some sorting centers aspectroscopicscanner is used to differentiate between different types of paper and plastic based on the absent wavelengths, and subsequent ly divert each material into the proper collection channel.4Strong magnets are used to separate outferrous metals, such asiron, trade name, andtin-plated steel cans(tin cans).Non-ferrous metalsare ejected bymagnetic eddy currentsin which a rotatingmagnetic fieldinducesan electric current around the aluminium cans, which in turn creates a magnetic eddy current inside the cans. This magnetic eddy current is repulsed by a large magnetic field, and the cans are ejected from the rest of the recyclate stream.4Finally, glass must be sorted by hand based on its color brown, amber, green or clear.GREEN HOUSE GASES AND GLOBAL WARNINGCarbon dioxide, art object vital forphotosynthesis, is sometimes referred to as pollution, because raised levels of the gas in the atmosphere are affecting the Earths climate. Disruption of the environment can also highlight the link between areas of pollution that would normally be classified separately, such as those of water and air. Recent studies have inves tigated the potential for long-term rising levels of atmospheric carbon dioxide to cause slight but criticalincreases in the acidity of ocean waters, and the possible effects of this on marine ecosystems.Global warmingis the increase in theaverage temperatureofEarths near-surface air and oceans since the mid-20th century and its projected continuation. According to the 2007Fourth Assessment Reportby theIntergovernmental Panel on Climate Change(IPCC), global surface temperature increased 0.740.18C(1.330.32F) during the 20th century. Global dimming, a result of increasing concentrations of atmosphericaerosolsthat block sunlight from reaching the surface, has partially countered the effects of warming induced by greenhouse gases.Climate modelprojections summarized in the latest IPCC report indicate that the globalsurface temperatureis likely to rise a further1.1 to 6.4C(2.0 to 11.5F)during the 21st century.The uncertainty in this estimate arises from the use of models with differingsen sitivity to greenhouse gas concentrationsand the use of differingestimates of future greenhouse gas emissions. An increase in global temperature will causesea levels to riseand will change the amount and pattern ofprecipitation, probably including expansion ofsubtropicaldeserts.Warming is expected to bestrongest in the Arcticand would be associated with continuingretreat of glaciers,permafrostandsea ice. Other likely effects include changes in the frequency and intensity ofextreme weatherevents,species extinctions, and changes inagricultural yields. Warming and related changes will vary from region to region around the globe, though the nature of these regional variations is uncertain.As a result of contemporary increases in atmospheric carbon dioxide, the oceans have becomemore acidic a result that is predicted to continue.Thescientific consensusis thatanthropogenicglobal warming is occurring.Nevertheless,politicalandpublic competecontinues. TheKyoto Protocolis aimed at stabilizin g greenhouse gas concentration to prevent a dangerous anthropogenic interference.As of November 2009,187 states had signed and ratifiedthe protocol.Thegreenhouse effectis the process by whichabsorptionandemissionofinfraredradiation by gases in theatmospherewarm aplanets lower atmosphere and surface. It was proposed byJoseph Fourierin 1824 and was first investigated quantitatively bySvante Arrheniusin 1896.The question in terms of global warming is how the strength of the presumed greenhouse effect changes when human activity increases the concentrations of greenhouse gases in the atmosphere.Naturally occurring greenhouse gases have a mean warming effect of about 33C (59F).The major greenhouse gases arewater vapor, which causes about 36-70 percent of the greenhouse effectcarbon dioxide(CO2), which causes 9-26 percentmethane(CH4), which causes 4-9 percent andozone(O3), which causes 3-7 percent.Clouds also affect the radiation balance, but they are composed of liquid water or ice and s o havedifferent effects on radiationfrom water vapor.Human activity since theIndustrial Revolutionhas increased the amount of greenhouse gases in the atmosphere, leading to increasedradiative forcingfrom CO2,methane, troposphericozone,CFCsandnitrous oxide. Theconcentrationsof CO2and methane have increased by 36% and 148% respectively since 1750.These levels are much higher than at any time during the last 650,000 years, the period for which reliable data has been extracted fromice cores.Less direct geological evidence indicates that CO2values higher than this were last seen about 20 million years ago.41Fossil fuelburning has produced about three-quarters of the increase in CO2from human activity over the early(prenominal) 20 years. some of the rest is due to land-use change, particularlydeforestation.Over the last three decades of the 20th century,GDPper capitaandpopulation growthwere the main drivers of increases in greenhouse gas emissions.CO2emissions are continuing to rise due to the burning of fossil fuels and land-use change.Emissions scenarios, estimates of changes in future emission levels of greenhouse gases, have been projected that depend upon uncertain economic,sociological,technological, and natural developments.In most scenarios, emissions continue to rise over the century, while in a few, emissions are reduced.These emission scenarios, combined with carbon cycle modelling, have been used to produce estimates of how atmospheric concentrations of greenhouse gases will change in the future. Using the six IPCCSRESmarker scenarios, models suggest that by the year 2100, the atmospheric concentration of CO2could range between 541 and 970 ppm.This is an increase of 90-250% above the concentration in the year 1750. Fossil fuel reserves are sufficient to reach these levels and continue emissions past 2100 ifcoal,tar sandsormethane clathratesare extensively exploited.The destruction ofstratosphericozone bychlorofluorocarbonsis sometimes mentioned in rela tion to global warming. Although there are a fewareas of linkage, the relationship between the two is not strong. Reduction of stratospheric ozone has a cooling influence.Substantial ozone depletion did not occur until the late 1970s.Ozone in the troposphere(the lowest part of theEarthHYPERLINK http//en.wikipedia.org/wiki/Atmosphere_of_EarthHYPERLINK http//en.wikipedia.org/wiki/Atmosphere_of_Earths atmosphere) does contribute to surface warming.8 most polluted cities in India Sukinda, OrissaNumber of people affected2,600,000Type of pollutantHexavalent chromium and other metalsSource of pollutionChromite mines and processingHexavalent chromium is a nasty heavy metal used for stainless steel production and leather tanning that is carcinogenic if inhaled or ingested.In Sukinda, which contains one of the largest open cast chromite ore mines in the world, 60% of the drinking water contains hexavalent chromium at levels more than double international standards. An Indian health group esti mated that 84.75% of deaths in the mining areas where regulations are nonexistent are due to chromite-related diseases. There has been virtually no attempt to clean up the contamination.Sukinda has been listed in the Top 10 most polluted places in the world by the US-based Blacksmith Institute.Labourers work at a road construction site near VapiVapi, GujaratNumber of people potentially affected71,000Type of pollutantChemicals and heavy metalsSource of pollutionIndustrial estatesIf Indias environment is on the whole healthier than its giant neighbor Chinas, thats because India is developing much more slowly. But thats changing, showtime in towns like Vapi, which sits at the southern end of a 400-km-long belt of industrial estates. For the citizens of Vapi, the cost of growth has been severe levels of mercury in the citys groundwater are reportedly 96 times higher than WHO safety levels, and heavy metals are present in the air and the local produce. Its just a disaster, says Fuller .Vapi has been listed in the Top 10 most polluted places in the world by the US-based Blacksmith Institute.Mandi Gobindgarh, PunjabNumber of people affected155,416Type of pollutantHigh dust and smoke particulateSource of pollutionIndustrial unitsGobindgarh in Punjab, also known as Loha mandi, recorded suspended particulate matter (microscopic particles in the air such as dust and smoke) level of 252 micrograms per cubic metre in 2007, 320 percent higher than the national standard level of 60 micrograms.Known for its iron and steel factories, it is one of the most polluted city in the country. The population in Gobindgarh shows a higher prevalence of symptoms of angina and cardiovascular disease.A ragpicker rows boat in polluted Gomti river in LucknowLucknow, UPNumber of people affected30 lakhType of pollutantHigh dust and smoke particulateSource of pollutionIndustrial units, vehiclesVehicular emissions are the main cause of air pollution in Lucknow. In recent years there has been a rapid rise in vehicular