Concentration Levels of Essential Metals

Concentration Levels of Essential Metals Comparative Distribution of Selected Essential Metals in Drinking Water by Atomic Absorption Spectrophotometric Method Tanzeel ur Rehman and Misbah Zahid ABSTRACT This study reports the concentration levels of selected essential metals; Ca, Mg, Na, K, Fe and Zn in the drinking water collected from different areas of Islamabad. The levels of these metals present in the drinking ground water were compared with standards reported worldwide. The analysis was carried out using atomic absorption spectrophotometry. The mean metal concentration for Na was far less than those reported worldwide, while the average concentrations of K and Zn were also less than those reported worldwide. The mean concentration of Fe was equal to those reported worldwide standards. Sodium showed maximum concentration while Fe was estimated to be the lowest among the selected metals. Key Words: Essential Metals; Ground water; Atomic Absorption Spectrophotometry INTRODUCTION Environmental pollution especially in the metropolitan cities is generally expected to deteriorate the quality of drinking water. One of the important parameters of the quality of water is represented by the concentration of major, minor and trace elements. In industrial areas, some of the metals may be expected to present at considerably elevated level as a result of excessive industrial effluents which might find their way to the underground drinking water reservoir1. Contrary to such theory, one may suggest that, the underground drinking water resources may still be out of reach to the surface pollutants. In any of such cases, regular monitoring of trace metals is always recommended especially in the drinking water2. In Pakistan, only limited population has access to the purified public water supply while the rest of population is dependent upon direct withdrawal of water from both surface and underground sources. Most of the quality problems in Pakistan are due to lack of waste disposal regulations non-availability of treatment facilities and due to lack of public awareness about water quality3. Atomic absorption spectrophotometry is most commonly used for the determination of metal levels in the groundwater and soil4. In addition, few other techniques, such as X-ray fluorescence, ICPMS, ICPES, flame photometry, emission spectrography and voltammetry have been used for metal analysis on limited scale. Atomic absorption method is preferably used because it is more sensitive, and reproducible, relatively free of interferences and convenient to use than most of the other methods of analysis. For the quantitative measurements of trace metal levels, calibration line method has been most widely applied. The most selective light sources in the form of hollow cathode lamps have been in use since a long in atomic absorption spectroscopy5. Drinking water used in Rawalpindi and Islamabad is contributed by two main sources. First is the surface water, mainly in the form of dams and the other is groundwater which is drained off after proper boring. Water supplied to twin cities of Rawalpindi and Islamabad is mostly a run-off collected from the watershed of Murree hills. The contamination is due to the anthropogenic emissions and geological structure of the area bearing unhealthy minerals affecting the taste and characteristics of water6. The pathogenic organism is also responsible for health hazard, apart from the inorganic chemical7. The present study was carried out to estimate the concentration of selected essential metals Ca, Mg, Na, K, Fe and Zn in the drinking water and then to compare these metal levels with the international standards in order to evaluate their health effects. EXPERIMENTAL Water samples were collected from the residential areas of Islamabad. These samples were collected in plastic bottles and stored in proper place before analysis. Before filling, the sample bottles were first rinsed with the sample water and were then filled to overflow so that no air bubble was left trapped in the sample. The samples were collected during day time, mostly on a shiny day. Care was taken to collect the representative samples. For calibration line, working standards of the metals were prepared. The stock solutions of 100 ppm of all these metals were prepared from pure metal salts, or metal salt having fixed H2O molecules. The working standards were prepared by appropriately diluting 100 ppm stock solutions of these metals. All equipments used, were properly calibrated prior to experimental measurement. Atomic absorption spectrophotometer (Hitachi, 170-10, Japan) equipped with laminar flow burner. Air-acetylene flame was used for the determination of these metals under optimum analytical conditions shown in Table-1. Each metal was analyzed at its optimum wavelength under stipulated flow rate of oxidant and fuel, as recommended by the manufacturer of the instrument. Every care was taken to reduce the contamination during the analysis. RESULTS AND DISCUSSION The analysis of selected essential metals was performed under the optimum analytical conditions as shown in Table-1. The absorption wavelength used for Ca was 422.7 nm, for Mg 285.2 nm, for Na 589.0 nm, for K 766.5 nm, for Fe 248.3 nm, Zn 213.8 nm. The lamp currents were properly adjusted as recommended by the manufacturer and oxidant and fuel flow rates were also controlled for maximum absorption signal (Table-1). The distributed parameters for the selected essential metals in the drinking water are shown in Table-2. Minimum levels for Ca, Mg, Na, K, Fe, and Zn were 1.15, 9.00, 11.21, 0.70, 0.20 and 0.23 ppm, while their maximum values were 32.43, 25.64, 25.95, 4.43, 0.63 and 0.56 ppm respectively. Ca, Mg and Na were present at dominant levels while K, Fe, and Zn showed relatively low concentrations. Mean and median values were found to be comparable in each case. Overall, the metal levels were quite divergent as manifested by relative high standard deviation values as well as appreciably large coefficient of variance. In water, trace amounts of metals are common, and normally, these are not harmful to health. In fact, some metals are essential for the sustainability of life. Ca, Mg, K and Na must be present at relatively higher levels for normal body functions. Co, Cu, Fe, Mn, Mo, Se and Zn are needed as catalysts for enzyme activities at low levels. Drinking water containing high levels of these extremely important metals or poisonous metals such as Al, As, Ba, Cd, Cr, Pb, Hg. Se and Ag may be dangerous to health8. The presence of metals in water supply may be natural or may be the result of contamination. Natural presence of these metals is the result of dissolution of metals due to the connection of water with soil or rocks9. Corroded material i.e corrosion of pipes and waste disposal leakage are the major sources of contamination of water. Metals present at high enough level than threshold limit value should be removed to be out of risk factor. Comparison of present metal levels with the international standards is shown in Table-3. Ca is important in controlling nerve impulse conduction and muscle contraction in living organisms. It has very important role in blood clotting. It converts fibrinogen to fibrin during blood clotting10. Ca is very important for good health. Most of the required portion of Ca for human body is provided by the drinking water containing Ca. This particular amount of Ca prevents ailments as hypertension, osteoporosis and cardiovascular disorders. The calcium level was found in the range of 1.15 to 32.43 ppm. The WS-1, WS-2, WS-3 has approximately equal amount of Ca while the WS-6 has a maximum amount of Ca. The median of all these samples were 18.64 ppm. The WS-5 was found to have the minimum amount of Ca. All the observation shows that Ca has the low amount than the WHO standards. The standard deviation is 8.02 and the co–efficient of variance is 40.8 which is maximum than all the other elem ents. Magnesium is driven out from the bodies of healthy persons. People may suffer from increase in blood pressure, muscle weakness and even coma if they have kidney disease. Mg is for signaling the nervous system and it also participates in osmotic and electrolyte balance. It is essentially required in photosynthesis. In human, it can cause genetic disorder11. In the present work the Mg mean value was found 18.04 ppm. The concentration of Mg ranges from 9.00–25.64 ppm. The lowest value was found in WS-6D and the highest was found in WS-2C. The median was found 16.36 ppm .All the values were found to be below the international standards of WHO. The maximum difference was found in WS-1 samples which is 15.93–25.23. The median was lower than the mean which shows asymmetry in its distribution. The standard deviation is 4.59 ppm and co-efficient of variance is 23.21 which is lower than all other elements. Sodium is beneficial to healthy adults at normal intake levels. But people having hypertension or heart problem should reduce Na intake to lower the danger of heart diseases and blood pressure. Na has serious effects on both human life and crop yield. Water high in Na is considered soft and generable for irrigation12. In present study, the result showed the mean value of Na was 19.80 ppm which was higher than Ca and Mg but this level was not the toxic level, so it has no bad effects. Na levels range from 11.21 to 35 ppm. The least Na levels were found in WS-6D and the highest was found in WS-4E. The median was higher than the mean value which showed the negative asymmetry in the data. The spread of the data is found in form standards deviation and was 6.02 ppm and the co-efficient of variance was 33.39 %. In comparison with the international standards, the Na levels found in the samples were low than WHO, EU, UK and Japan, but are just equivalent to USEPA standards. In natural water, K is found in far smallest concentration than other metals. It acts in water as Na does, although it occurs in small concentration but plays an important role in metabolism of the fresh water environment and is regarded to be the vital macro-nutrients. It has an important role in maintenance of osmotic and electrolytic balance. It is important in proper rhythm of heart beat. It is important for creation of nerve impulse and its transmission13. In our analysis the K ranges from 0.70 to 4.43 ppm and mean value was 3.06 ppm. The lowest level was found in WS-6A and the highest in WS-3A. The median is 3.53 ppm which showed the negative asymmetry and standard deviation is 1.19 and co-efficient of variance is 39%. K values in present study were much lower than EU and UK standards. Iron in water has not hazardous for health by itself but it may be responsible for increasing the hazard of pathogenic organisms, because many of these organisms need Fe to grow. Iron is one of the most abundant metals in the earth crust and is essential for plants, animals and human being. The permissible limit placed on this metal has no health significance14. In our study the mean value found for the Fe was 0.39 ppm. The minimum value was found at 0.2 ppm in the WS-4B, and the maximum was 0.63 ppm in WS-1A. The median found for Fe was 0.40 which is greater than the mean and show asymmetry in the data. The standard deviation was 0.13 which showed small spread of the data. The co-efficient of variance value was 33.79%, in comparison with the international standards of WHO, EU, USEPA, UK, Russia and Japan present levels were almost same. The iron present in the sample seems to be ferrous iron since no discoloration of water was observed when collected. Zinc is very important constituent in our diet. Zn has hazardous effects if we increase its amount 10-15 times higher than the amount required for good health. Large doses of Zn taken orally even for a short period of time can cause nausea, stomach cramps and vomiting. Its intake for longer time results in anemia and in decreasing the levels of good cholesterol. Metal fume fever, a short term disease, may be the result of inhaling Zn as dust or fumes of zinc. Breathing high levels of Zn for long time, no doubt, has long-term effects but these are still unknown. Zinc is essential element for plants and exists in water and soil as an organic complexes and inorganic salts. Zinc is required for growth, sexual development, wound healing infection, sense of taste and night vision in human15-17. The mean value found in water samples was 0.42 ppm which ranged from 0.23 to 0.56 ppm. The median of the data reading was 0.48 which showed negative asymmetry in the data. The standard deviation sho wn was 0.12 ppm and co-efficient of variance was 27.49 %. When these values are compared with international standards the Zn level was found lower than WHO, US EPA, Russia, but was higher than EU. CONCLUSION It was observed during the present study that mean concentrations of Ca, Mg, Na, K, Fe, and Zn in the drinking water of Islamabad were found to be 19.65, 18.04, 19.80, 3.06, 0.39, and 0.42 ppm respectively. For Na, K, Ca, Mg and Zn, these values are far less in comparison to the concentrations reported worldwide, whereas for Fe present value is nearly equal to the reported values. Ca, Mg and Na were in high concentrations as they are macronutrients while K, Fe and Zn being the micronutrients were present in low concentrations. Over all, the selected metals revealed asymmetric distribution in their concentration duly reported by standard deviation and co-efficient of variation. Table-1: Optimum analytical conditions on FAAS for selected essential metals Table-2: Distribution of selected essential metal levels (ppm) in the drinking water BDL = Below Detection Limits Table-3: Comparison of selected essential metal levels (ppm) with the international standards reported world-wide18 REFERENCES Manahan, S. E. (1997). Environmental Science and Technology, Lewis Publishers, New York, pp. 339-340. Khan, M. J.; Sarwar, S. and Khattak, R. A. (2004). Evaluation of river Jehlum water for heavy metals (Zn, Cu, Fe, Mn, Ni, Cd, Pb, and Cr) and its suitability for irrigation and drinking purposes at district Muzaffarabad (AK), Journal of the Chemical Society of Pakistan, 26, 436-442. InamUllah, E. and A. Alam, (2014). Assessment of drinking water quality in Peshawar, Pakistan. Bulg. J.Agric. Sci., 20: 595-600 Robinson, J. W. (1995). Undergraduate Instrumental Analysis, 5th Edition, Marcel Dekker, New York, pp. 7-8, 316-318. Mendham, J.; Denney, R. C.; Barnes, J. D. and M. Thomas, (2000). Quantitative Chemical Analysis, 6th Edition, Addison Wesley Longman Singapore. pp. 60-64 Manzoor, S.; M. H Shah, M. H; Shaheen, N.; Khalique, A. and Jaffar, M. (2006). Characterization distribution and comparison of selected metals in textile effluents, adjoining soil and groundwater, Journal of the Chemical Society of Pakistan, 28, 10-13. Rauf, M. A.; Ikram, M. and Shaukat, S. (2002). Water analysis of Rawal lake and its surrounding areas, Journal of the Chemical Society of Pakistan, 24, 271-281. Paul B Tchounwou, Clement G Yedjou, Anita K Patlolla, and Dwayne J Sutton, Heavy Metals Toxicity and the Environment, EXS. (2012); 101: pp. 133–164 Kumar, A. (1989) Environmental Chemistry, 2nd Edition, Wiley Eastern Limited, New Delhi, pp. 60-64. Tahir, M. A.; Chaudary, M.; Rasool, M. R.; Naeen, T. M.; Chughtai, I. R. and Dhami, M. S. I. (1999). Quality of drinking water samples of Sialkot and Gujranwala, Proceedings of Tenth National Chemistry Conference, pp. 62-69. Konrad M, Weber S. Recent advances in molecular genetics of hereditary magnesium-losing disorders. Journal of American Society, Nephrol. (2003);14:249–260. Dr. James Robbins, Irrigation Water For Greenhouses And Nurseries Agriculture And Natural Resources , FSA6061. Hodgkin AL, Huxley AF (1952). Currents carried by sodium and potassium ions through the membrane of the giant axon of Loligo. Journal of Physiology 116 (4): 449–472. Afzal Shah,Abdul Niaz,Nazeef Ullah,Ali Rehman,Muhammad Akhlaq,Muhammad Zakir,andMuhammad Suleman Khan; Comparative Study of Heavy Metals in Soil and Selected Medicinal Plants; Journal of Chemistry, Volume20137. Simmer K, Thompson RP. Zinc in the fetus and newborn. Acta Paediatr Scand Suppl (1985); 319:158-63. Fabris N, Mocchegiani E. Zinc, human diseases and aging. Aging (Milano) (1995); 7:77-93. Maret W, Sandstead HH. Zinc requirements and the risks and benefits of zinc supplementation. J Trace Elem Med Biol (2006); 20:3-18. Radojevic, M. and Bashkin, V. N. (1999). Practical Environmental Analysis, Royal Society of Chemistry, Cambridge, UK. 1

John Constable :: Biography Biographical Painter Artist Essays

John Constable John Constable was born on June 11, 1776, in East Bergholt, Suffolk. As a young man he worked for his father in the family business at a flour mill. In 1799, Constable decided to leave the flour mill so that he could study at the Royal Academy School. His first landscape painting was in 1802 and after that he studied painting and English Rural life on his own. Constable developed a distinctly individual style. His paintings were "executed in the open air rather than in a studio, as was customary, was an innovation in English art. Constable departed from the traditions of Dutch and English painting by discarding the usual brown under painting and achieving more luminous lighting effects through the use of broken bits of color applied with a palette knife. The Dedham Vale, The Cornfield, The Leaping Horse, and The Hay Wain are great examples of Constable's individual style and how he was a Romantic Painter. One of Constable's first important paintings was Dedham Vale of 1802 and the Dedham Vale of 1828. These paintings "repeat intrinsically the composition of that compact gem - like scene" (Reynolds,21). The Dedham Vale of 1828 was painted from a topographical point of view. "The painting shows a view from the hill bordering the Stour Valley. Constable loved the view from the Stour Valley so much, that he drew from almost the same spot in several sketches and painted at least three versions in oil." Constable described the Dedham Vale as, "perhaps my best." Because Constable painted in the open air rather than in a studio, his attention to detail is almost unmatched. The way "he catches the sunlight in blobs of pure white and yellow." Maybe Constable sums it up well when he says; "I should paint my own places best - painting is but another word for feeling. I associate my "careless boyhood" to all that lies on the banks of Stour. They made me a painter and I am grateful" (Reynolds, 31). Constable's next painting is a good example of his Romantic style. The Cornfield, painted in 1826, shows his Romantic vision of the countryside. The landscape is of the Suffolk countryside with "lovely valleys and peaceful farmhouses." As a young boy Constable would travel down that lane from East Bergholt to the Vale at Dedham on his way to school. There are a number of elements in the Cornfield that Constable focused on.

A Narrative of the Captivity and Restoration of Mrs. Mary Rowlandson Essay

On June 20, 1675, Metacomet, also known as Philip by the early American colonist, led a series of attacks on colonial settlements that lasted for more than a year. These attacks became known as â€Å"King Philips War.† It was a desperate attempt by the Natives to retain their land as their culture and resources dwindled before them. Mary Rowlandson, a famous victim of these Indian attacks, recounts her eleven-week captivity in her published book, A Narrative of the Captivity and Restoration of Mrs. Mary Rowlandson. The book describes her experience as a captive of the Wampanoags in great detail, and combines high adventure, heroism, and exemplary piety, which made it a popular piece in the seventeenth century. Throughout the narrative Mary Rowlandson portrays her skills as a writer with the delineation of her character. In her captivity, Mary Rowland realizes that life is short and nothing is certain. The common theme of uncertainty teaches Rowlandson that she can take nothing for grated. In a single day the seeming stability of life disappears without warning as portrayed in the opening scene when the town of Lancaster is burned down and she is separated from her two elder children. Rowlandson transitions from a wife of a wealthy minister with three children to a captive prisoner with a single wounded daughter in one day. Another instance of uncertainty is between The Twelfth Remove, where she is approved by her master to be sold to her husband, but the next day in The Thirteenth Remove she writes, â€Å"instead of going toward the Bay, which was that I desired, I must go with them five or six miles down the river into the mighty thicket of brush; where we abode almost a fortnight (271).† In addition to the uncertainty nothing in her captivity was consistent either. One day the Indians treat her respectfully, while the next day they give her no food. This inconsistency can be seen between The Eighth Remove and The Ninth Remove. In The Eighth Remove, Rowlandson is asked to make various garments in return for a shilling and different types  foods; however, in The Ninth Remove, Rowland was asked to make a shirt, but receives nothing in return (267-268). The inconsistency stems from the uncertain future, which plants fear in Rowlandson’s character. The only light she can see in her dark captivity is the light of her God. As a Puritan, Rowlandson believes that God’s will shapes the events in her life, and that each event serves a purpose. The common Puritan belief that humans have no choice, but to accept God’s will and make sense of it is portrayed throughout her narrative. This belief in God produces values of fortitude and determination Rowlandson uses to survive the eleven-week captivity. This is can be seen in The Second Remove as she is about to collapse from fatigue and injury, â€Å"but the Lord renewed my strength still, and carried me along, that I might see more of his power (260).† Rowlandson often creates parallels between her own situation and biblical verses about the Israelites because the Puritans thought they were the descendants of the Israelites in the new world. This is portrayed in the closing scene when Rowlandson is reunited with her family and she quotes Moses speaking to the Israelites, †stand still and see the salvation of the Lord (288).† Moses said this to the Israelites at their arrival to the promise land after forty days of wandering in the desert. Rowlandson compares her captivity to the forty days in the desert, and her reunion with her family to the arrival at the promise land. In Rowlandson’s captivity, her perspective of the Native Indians evolves from savagery to aspects of civility. The more time she spent with the Natives the more relations she made with them that culminate into respect and appreciation for their culture. Initially Rowlandson considered the Natives â€Å"barbarous creatures† who â€Å"made the place a lively resemblance of hell† after the burning of Lancaster (259). As a result she speculates the Natives as violent savages. She was also disgusted with the various foods they ate such as ground nuts, tree bark, and horse liver; nevertheless, after three weeks of starvation she acquired a taste for the irregular foods. This is depicted in The Fifth Remove, â€Å"but the third week†¦ I could starve and die before I could eat such things, yet they were sweet and savory to my taste (265).† This expresses a minor change of heart Rowlandson  has for the Natives as she finds herself eating the same foods and enjoying them. In addition to the acquired taste of the Native foods, more similarities become apparent such as â€Å"praying Indians† who claim to have converted to Christianity and some instances where the Natives are wearing colonists’ clothing (279). The once distinct difference in civility and savagery becomes blurred in the similarities Rowland notices between the colonist and the Natives. Rowlandson explores the fearful hesitation most colonists feel in the face of the new world. The new world is the unknown environments outside the colonies, mainly toward the west. This includes the forest and wooded areas that are associated with the Natives. It is where the Natives live, where they take their captives, and a place of unknown to the colonist, which made it fearful. Rowlandson described it as a place of â€Å"deep dungeon† and â€Å"high and steep hill (266).† In Rowlandson’s captivity, she is pushed into the forest where her experience brings her further away from civilization. Her and other captives, such as Robert Pepper, gain practical knowledge about the natural world during their time spent with the Indians. Although this knowledge is key to her survival, it brings her anxiety and guilt because she feels as though she is being pushed from civilization. The delineated characterization of Mary Rowlandson in her published book, A Narrative of the Captivity and Restoration of Mrs. Mary Rowlandson, depicts the way Puritans approached life with religious concepts and beliefs, but the influence of the Native culture is what separates her work as the first captivity narrative. In her captivity she loses her original physiological security through eleven weeks of uncertainty and inconsistency. This forces her to think outside her Puritan ideology into the new world of different environments and experiences. Her new experiences allow her to grow and appreciate the differences of the new world, and in her reflection Rowlandson closes the gap between the Natives and Puritans by identifying the similarities between the two cultures.

The Things They Carried By Tim O Brien - 1809 Words

SOLDIER! Grab a helmet and buckle up immediately there is no more room for fatuous behavior because it is a matter of life and death. Soldier, adhere to this warning: the draft brings young men into the action of war but the wretched war surely chews them up and spits them back out as a diabolic mutant grieved with woes. A former marine, Tim O’Brien, wrote The Things They Carried in order to demonstrate this aforementioned warning as well the cryptic reality of Vietnam. By implementing a cataloging technique, O’Brien truly brings the horrifying stories of Vietnam to life further roping in his readers so much that they feel themselves carrying the characters burdens of the Alpha Company. Ultimately O’Brien’s book The Things They Carried,†¦show more content†¦Browker seems to look up to his father, who served in WWII and decides to go to Vietnam in hopes of returning as a hero with medals which would make his father proud. On the contrary, there are those who feel the government has infringed upon their First Amendment right (freedom of speech) by drafting them into a war. O’Brien has similar feelings which he expresses, â€Å"If you support the war, if you think it’s worth the price, that’s fine, but you have to put your own precious blood on the line,† (O’Brien 45). O’Brien then proceeds to share his personal story; he testifies of the radical measures he takes under the burden of the draft. The war is asking too much of him, he has a full-ride scholarship to Harvard! His whole life still lies ahead of him but now the door of death is unlocked and beginning to creak open. Like a thief in the night he attempts to steal away to Canada as his way of coping with this hardship of uncertainty that looms before him. O’Brien even turns this scenario over to his readers asking them what they would feel or do as their fragile life dangles by a thread. In the end O’Brien relents and bowing to the draft he goes because he is afraid of being called a coward for the rest of his life. Now for a moment imagine the feeling of humidity so thick one can cut it, surreptitious jungle vines that grab at ones ankles, sounds that chill the bones, sites and the stink of