Deterioration in the natural form of water is caused by mixing unwanted elements more than the specific limit. Use of such water causes various water-borne diseases. Pollutants deforming water enter from different sources on account of human activities and they cause harmful effects on man. Other creatures on earth and in water are also affected by it.
Effects of water pollution can be described from the following view points:
Effects on Man:
Water is a natural gift which has no alternative existing on earth. Hence, water has been termed as life. As per latest surveys, per capita requirement of water is 140 litre.
Man needs water for drinking, cooking, cleaning, irrigation etc., which should be fresh. Polluted water causes the following diseases:
1. Water-borne diseases:
Water polluted by human and animal excreta, if drunk or used otherwise, causes plague, typhoid and other diseases.
2. Diseases caused by contact with water:
Taking bath with polluted water affects eyes and causes skin diseases and diarrhea.
3. Diseases based on water:
Many types of micro organisms exist in polluted water, the use of which spread infectious diseases.
Some disease bearing micro organisms and diseases caused by them are described below:
Infectious diseases like hepatitis, jaundice and polio diseases are caused by virus. About 2000 persons suffered from jaundice due to polluted water in 1978.
Bacteria cause typhoid, paratyphoid, plague, diarrhea, gastroenteris, dysentery and other diseases.
Stomach and intestine related different diseases are caused by presence of protozoa in drinking water. Main diseases among them are thrombosis, giardiasis, dysentery, amoebic, hepatitis, apses etc.
Parasites enter intestines in the body through drinking water and give birth to various kind of worms including round worms, hip worms, thread worms, tape worms, escarps etc. these cause many diseases.
Apart from the above, wells disease in leptospiral diseases and systosamiasis in snail supported diseases cause adverse effect on human health.
4. Diseases related to water:
When water polluted from various sources is accumulated at a certain place, many mosquitoes, flies and insects are produced which cause malaria, philaria, dengue, yellow fever encephalitis and many other infectious diseases.
5. Diseases caused by chemical substances mixed with water:
Many chemical substances like Fluorides, nitrates and mercury etc. exist in water in liquid form. They can prove harmful if their quantity increases due to human interference. Fluorides affect teeth and bones. Nitrates after joining with hemoglobin, reduce the oxygen carrying capacity of blood, and mercury causes constipation.
A World Health Organization (WHO) report of 1982 had indicated effect of water pollution on man as under:
1. Every year 2,500 persons die in the world due to use of polluted water.
2. Every year 2,500 persons and one crore children die in the world due to non-availability of sufficient water.
3. In the world, 200 crore persons do not get pure and perfect drinking water.
4. In developing countries, four out of every five children die because of water-borne diseases.
5. Every year 50 crore persons suffer from water-borne diseases.
6. 30 per cent population of the world suffers from dysentery.
7. 40 per cent persons suffer from diseases caused by water-borne worms.
Thus man, the main creator of water-borne diseases, suffers most from it and its treatment is also in his hands. There is no other alternative of water on earth. Hence, man can secure his future only by keeping water fresh.
Effects on Animals:
Polluted water affects creatures living in water as well as those using such water. They include fish, tortoises, water birds etc. which live in water and others which move on land, but are affected by use of polluted water. Sea creatures are affected more by thermal, oily, mercury and radioactive pollutants. Fish and other creatures die due to non-availability of sufficient oxygen.
Due to pollution, 40 per cent sea creatures have reduced during the last 50 years. Iraq had burnt oil wells of Kuwait during the Gulf War, due to which biotic life had deteriorated to a large extent. Apart from this, creatures on the earth are also affected by polluted water, which occur when industrial, urban and agricultural effluents mix in drinking water sources.
For example in Lucknow, many fish are dying due to sewage of urban areas mixing in river Gomti. Cows, buffaloes and other animals also die by drinking polluted water. In May 1999, 500 cows had died because of drinking polluted water. Agricultural effluents are also equally harmful. Many poisonous chemicals mix in water and cause diseases. Materials flowing from domestic effluent destroy micro organisms. Thermal pollution kills fish existing in lakes, tanks and seas.
Effects on Plants
Like human beings and other creatures, water pollution affects plants also. Nitrates and phosphate produced by agricultural effluent after mixing with water, result in developing many types of harmful algae which do not allow sunshine to pass. Many useless vegetation grow and harm water plants.
Due to thermal pollution many algae and fungus develop which reduce the quantity of oxygen by causing decay. Vegetation is destroyed by this sewage by polluting water and it support the fast development of algae, fungus and bacteria.
Excreta fungus mainly bacteria, spherotilas, netais, carkesium, polypinum, leptomitus etc. remain spread over water surface. Due to increasing lichens in polluted water, absence of transparency of sunshine is caused and the process of photosynthesis is hindered. This prevents growth of plants.
Thus, water pollution not only affects creatures but also the trees and plants which affect man. Vegetables are being grown by establishing sewerage farms near urban effluents. By consuming them, the food cycle of man is affected.
Effects on Agriculture:
Crops are destroyed by irrigation with polluted water. Soils are also polluted in the process. Harmful elements found in polluted water enter into the soil and reduce its productivity. Apart from this, crops grown with polluted water are not beneficial for the health of human beings.
Water is the basis of the ecological system. Trees and plants as well as other biotic organisms develop according to it. A water deposit is a complete ecological unit and all the living organisms found in it remain in a balance and a food chain is formed. This chain remains healthy till the water remains fresh in the natural form. Food chain becomes imbalanced as soon as water becomes polluted.
Danger is created for the biotic community and many organisms, specially sea creatures become extinct. As Patrick has said, “Water pollution reduces aquatic biodiversity which causes destruction of life in river”. Similarly, due to weeds like water hyacinth and water ferns etc. found in water, vegetation having roots in water and algae are destroyed. Photosynthesis is not possible due to water pollution and it also destroys vegetation in the water.
Grave effect of water pollution is caused on sea creatures. In the absence of availability of proper geographical conditions to planktons, many species of fish are on the brink of extinction. Similarly on the earth, every element of ecological system is being affected by water pollution. Its effect would be worldwide rather than being at the micro level.
Uharibifu katika fomu ya asili ya maji husababishwa na kuchanganya vipengele visivyotakiwa zaidi ya kikomo maalum. Matumizi ya maji hayo husababisha magonjwa mbalimbali yanayopitishwa na maji. Machafuko yanayobadili umbo la maji huingia kutoka vyanzo mbalimbali kwa sababu ya shughuli za kibinadamu na husababisha athari mbaya kwa mwanadamu. Viumbe wengine walio duniani na katika maji pia huathiriwa na ugonjwa huo. Matokeo ya uchafuzi wa maji yanaweza kuelezwa kutoka kwa maoni yafuatayo: Matokeo kwa Mwanadamu: Maji ni zawadi ya asili ambayo haina mbadala iliyopo duniani. Kwa hiyo, maji yameitwa uhai. Kulingana na uchunguzi wa hivi karibuni, mahitaji ya maji kwa kila mtu ni lita 140 kwa mwaka. Mtu anahitaji maji kwa ajili ya kunywa, kupika, kusafisha, umwagiliaji maji nk, ambayo yanapaswa kuwa safi. Maji machafu husababisha magonjwa yafuatayo: 1. Madhara yanayopitishwa na maji: Maji yaliyochafuliwa na uchafu wa binadamu na wanyama, ikiwa yanakunywa au kutumiwa kwa njia nyingine, husababisha tauni, homa ya kawaida na magonjwa mengine. 2. Uwezekano wa kupata Ugonjwa unaosababishwa na kuwasiliana na maji: Kuoga kwa maji machafu huathiri macho na kusababisha magonjwa ya ngozi na kuhara. 3. Uwe na mtazamo wa kweli Ugonjwa wa maji: Kuna aina nyingi za viumbe wadogo katika maji machafu, ambayo hutumia kueneza magonjwa ya kuambukiza. Baadhi ya magonjwa yanayohusisha viumbe wadogo na magonjwa yanayosababishwa na wao yanaelezwa hapa chini: Magonjwa ya kuambukiza kama vile hepatitis, jaundice na polio husababishwa na virusi. Watu 2,000 waliugua ugonjwa wa kichefuchefu mwaka 1978 kutokana na maji machafu. Bakteria husababisha ugonjwa wa kifafa, paratyphoid, tauni, kuhara, gastroenteris, dysentery na magonjwa mengine. Magonjwa mbalimbali yanayohusiana na tumbo na matumbo husababishwa na uwepo wa protozoa katika maji ya kunywa. Magonjwa makuu miongoni mwao ni thrombosis, giardiasis, dysentery, amoebic, hepatitis, abses nk. Vimelea huingia ndani ya matumbo kupitia maji ya kunywa na kuzaa aina mbalimbali za minyoo, ikiwa ni pamoja na minyoo ya mviringo, minyoo ya kiuno, minyoo ya kamba, minyoo ya mkanda, minyoo ya escarpment, na mengineyo. hizo husababisha magonjwa mengi. Mbali na hayo yaliyotajwa hapo juu, ugonjwa wa Wells katika magonjwa ya leptospiral na systosamiasis katika magonjwa yanayoungwa mkono na konokono husababisha athari mbaya kwa afya ya binadamu. 4. Uwe na uhakika "Ugonjwa unaohusiana na maji: Wakati maji machafu kutoka vyanzo mbalimbali yanapokusanyika mahali fulani, mbu, nzi na wadudu wengi hutokezwa ambao husababisha malaria, philaria, dengue, homa ya manjano, encephalitis na magonjwa mengine mengi ya kuambukiza.""" 5. Uwe na mtazamo mzuri. Magonjwa yanayosababishwa na kemikali zilizochanganywa na maji: Vitu vingi vya kemikali kama vile Fluorides, nitrates na mercury nk. Zipo katika maji katika hali ya kioevu. Zinaweza kuwa zenye kudhuru ikiwa idadi yao huongezeka kwa sababu ya kuingiliwa na wanadamu. Fluoridi huathiri meno na mifupa. Nitrati baada ya kuungana na hemoglobini, hupunguza uwezo wa damu wa kubeba oksijeni, na zebaki husababisha upungufu wa damu. Ripoti ya Shirika la Afya Duniani (WHO) ya mwaka 1982 ilionyesha athari za uchafuzi wa maji kwa binadamu kama ifuatavyo: Kila mwaka watu 2,500 hufa duniani kutokana na matumizi ya maji machafu. 2. Uwezekano wa kupata Kila mwaka watu 2,500 na watoto milioni moja hufa duniani kote kutokana na ukosefu wa maji ya kutosha. 3. Uwe na mtazamo wa kweli Katika nchi za Asia, watu milioni 200 hawana maji safi ya kunywa. 4. Uwe na uhakika Katika nchi zinazoendelea, watoto wanne kati ya watano hufa kutokana na magonjwa yanayopitishwa na maji. 5. Uwe na mtazamo mzuri. Kila mwaka watu milioni 50 wanakabiliwa na magonjwa yanayotokana na maji. 6. Uwe na uhakika Asilimia 30 ya watu duniani wanaugua ugonjwa wa dysentery. 7. Uwe na mtazamo gani? Asilimia 40 ya watu wanaugua magonjwa yanayosababishwa na minyoo inayosambazwa na maji. Kwa hiyo, mwanadamu, ambaye ndiye chanzo kikuu cha magonjwa yanayotokana na maji, ndiye anayesumbuliwa zaidi na magonjwa hayo, na matibabu yake pia yako mikononi mwake. Hakuna mbadala mwingine wa maji duniani. Kwa hiyo, mwanadamu aweza kuhakikisha wakati wake ujao tu kwa kudumisha maji safi. Matokeo kwa Wanyama: Maji machafu huathiri viumbe wanaoishi majini na vilevile wale wanaotumia maji hayo. Hizi ni pamoja na samaki, kasa, ndege wa maji nk. Kuna aina ya wanyama wanaoishi majini na wengine wanaotembea kwenye nchi kavu lakini wanaathiriwa na matumizi ya maji machafu. Viumbe wa baharini huathiriwa zaidi na uchafuzi wa joto, mafuta, zebaki na mnururisho. Samaki na viumbe wengine hufa kwa sababu ya kutokuwa na oksijeni ya kutosha. Kwa sababu ya uchafuzi wa mazingira, idadi ya viumbe wa baharini imepungua kwa asilimia 40 katika miaka 50 iliyopita. Iraq ilichoma visima vya mafuta vya Kuwait wakati wa Vita vya Ghuba, na kwa sababu hiyo maisha ya viumbe yalipungua kwa kiasi kikubwa. Kwa kuongezea, viumbe duniani pia huathiriwa na maji machafu, ambayo hutokea wakati maji machafu ya viwanda, mijini na kilimo yanapochanganyika katika vyanzo vya maji ya kunywa. Kwa mfano huko Lucknow, samaki wengi wanakufa kwa sababu ya maji machafu ya maeneo ya mijini yanayochanganyika katika mto Gomti. Ng'ombe, nyati na wanyama wengine pia hufa kwa kunywa maji machafu. Mnamo Mei 1999, ng'ombe 500 walifariki kutokana na kunywa maji machafu. Maji ya kilimo pia ni yenye kudhuru. Kemikali nyingi zenye sumu huchanganyika na maji na kusababisha magonjwa. Vifaa vinavyotiririka kutoka kwa maji machafu ya nyumbani huharibu viumbe wadogo. Uchafuzi wa joto huua samaki walio katika maziwa, matangi na bahari. Uchafuzi wa maji huathiri mimea kama vile wanadamu na viumbe wengine. Nitrates na phosphate zinazozalishwa na maji machafu ya kilimo baada ya kuchanganywa na maji, husababisha kuendeleza aina nyingi za mwani hatari ambao hauruhusu jua kupita. Mimea mingi isiyofaa hukua na kuharibu mimea ya majini. Kwa sababu ya uchafuzi wa joto mwani na kuvu nyingi huendelea ambazo hupunguza kiasi cha oksijeni kwa kusababisha kuoza. Mimea huangamizwa na maji machafu haya kwa kuchafua maji na huunga mkono maendeleo ya haraka ya mwani, kuvu na bakteria. Excreta fungi hasa bakteria, spherotilas, netais, carkesium, polypinum, leptomitus nk. kubaki kuenea juu ya uso wa maji. Kwa sababu ya kuongezeka kwa lichens katika maji machafu, kutokuwa na uwazi wa jua husababishwa na mchakato wa photosynthesis unazuiwa. Hilo huzuia ukuzi wa mimea. Kwa hiyo, uchafuzi wa maji hauathiri viumbe tu bali pia miti na mimea ambayo huathiri mwanadamu. Mboga zinakuzwa kwa kuanzisha mashamba ya mifereji ya maji machafu karibu na maji machafu ya mijini. Kwa kuzitumia, mzunguko wa chakula wa mwanadamu huathiriwa. Athari kwa Kilimo: Mazao huharibiwa kwa umwagiliaji maji wenye uchafuzi. Udongo pia huchafuliwa katika mchakato huo. Vitu vyenye kudhuru vinavyopatikana katika maji machafu huingia ndani ya udongo na kupunguza uzalishaji wake. Mbali na hayo, mazao yanayokuzwa kwa maji machafu hayana faida kwa afya ya wanadamu. Maji ndiyo msingi wa mfumo wa ikolojia. Miti na mimea na pia viumbe wengine wa kibiolojia huendelea kulingana nayo. Maji ni kitengo kamili cha ikolojia na viumbe vyote vilivyomo huendelea kuwa na usawa na mnyororo wa chakula. Mnyororo huu unabaki kuwa na afya mpaka maji yaendelee kuwa safi katika hali ya asili. Mnyororo wa chakula unaharibika mara tu maji yanapochafuliwa. Hatari huundwa kwa jamii ya viumbe na viumbe wengi, hasa viumbe wa baharini, huangamia. Kama Patrick alivyosema, "Uchafuzi wa maji hupunguza utofauti wa viumbe wa majini ambao husababisha uharibifu wa maisha katika mto". Vivyo hivyo, kwa sababu ya magugu kama hyacinth ya maji na ferns za maji nk. Katika maji, mimea ambayo imepata mizizi katika maji na mwani huangamizwa. Photosynthesis haiwezekani kwa sababu ya uchafuzi wa maji na pia huharibu mimea katika maji. Uchafuzi wa maji husababisha madhara makubwa kwa viumbe wa baharini. Kwa sababu ya ukosefu wa hali nzuri za kijiografia kwa plankton, spishi nyingi za samaki ziko karibu kutoweka. Vivyo hivyo duniani, kila sehemu ya mfumo wa ikolojia huathiriwa na uchafuzi wa maji. Athari yake ingekuwa ulimwenguni pote badala ya kuwa katika ngazi ya micro.