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BEST IELTS General Reading Test – 257
IELTS GENERAL READING TEST – PASSAGE – 3
IELTS GENERAL READING TEST
READING PASSAGE – 3
Bioremediation
A Global energy need; will probably increase by 30% over the next ten years and at present, 40% of the world’s energy is consumed by buildings. One way to make buildings more energy efficient is to insulate them and minimise fresh air exchange. However, reduced air circulation causes a phenomenon known as Sick Building Syndrome when combined with the volatile organic compounds (VOCs) emitted by modem materials used in of blocks, furnishings and high-tech equipment, along with human bio-effluents.
Eye irritations, skin rashes, sinus and respiratory problems, headaches and drowsiness are common symptoms. The VOCs are not only noxious but carcinogenic, with long-term exposure heightening one’s risk of cancer.
B An environmental scientist, Dr Bill Wolverton, working for The National Aeronautics Space Administration (NASA), came up with a solution: “if man is to move into closed environments, on Earth or in space, he must take along nature’s life support system”. In other words, plants. Early experiments were conducted in the BioHome, an airtight habitat constructed entirely of synthetic materials, designed for one person to live in. Before Wolverton introduced houseplants into the environment, it was uninhabitable because of the poor air quality – anyone entering suffered burning eves and breathing difficulties.
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C Wolverton found that, apart from absorbing carbon dioxide and releasing oxygen as all plants do, some plants are able to remove considerable amounts of VOCs. They do this by absorption through tiny openings (stomata) on their leaves, but roots and microorganisms living in the potting soil or other growing medium are also important in the removal of toxins from the air.
Most of the plants used by Wolverton originated in the understory of subtropical or tropical forests, with their particular leaf composition enabling them to photosynthesise in reduced sunlight. This ability is what allows them to thrive indoors away from direct sunshine. One largish plant for approximately every ten square metres of home or office space is suggested as an operational ratio.
D The strategy of using indoor plants as air purifiers has not been widely endorsed because of a lack of quantifiable outcomes. This could be changing, however. Recent studies at the University of Technology in Sydney have shown that certain plants on Wolverton’s list, namely Dracaena deremensis ‘Janet Craig’ and the peace lily Spathiphyllum wallisii, reduced pollution levels to negligible levels when placed in offices with high quantities of VOC’s.
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E Building on the NASA experiments and with the help of the Indian Institutes of Technology and The Energy and Resources Institute, Kamal Meattle of New Delhi has trialed several of Wolverton’s recommended plant species at his workplace. He used 1,200 plants for 300 occupants (four waist – to shoulder-high plants per person) in a twenty years old building measuring some 4,600 square metres.
Results of this experiment showed elevated blood oxygen levels in the occupants and reduced incidences of eye irritation as well as a marked reduction in respiratory system disorders and headaches. Since the installation of the plants, the labour force has increased productivity by over 20% and energy requirements for the building have been reduced by 15 per cent. For his study, he used the areca palm, the snake plant (or mother-in-law’s tongue) and the money plant (golden pathos).
F The areca palm (Chrysandocarpus lutescens), native to the island of Madagascar, has a smooth silver-green trunk and feathery-shaped fronds. A sensitive plant, it needs year round care with the right amount of bright but indirect light. The soil should be kept a little moist in spring and summer but allowed to thy slightly in autumn and winter. The areca favours a snug container – the crowded root system will limit the size of the palm, if unrestricted, it may grow as tall as six metres. The areca palm has been proven effective in the removal of toluene (in new carpet, paints and varnishes) and xylem (a potent neurotoxin found in marker pens, paints and varnishes).
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G The snake plant (Sansevieria trsfasciata) is an evergreen perennial species, originally a resident of tropical West Africa. Its stiff vertical leaves extend up to a metre in length. It is more tolerant of irregular watering and low light levels than the areca palm. Meattle notes that it would be ideally placed in bedrooms because it is a nocturnal oxygenator.
It also does a good job of absorbing benzene (a commonly used solvent in oils, paints, plastics and rubber), trichloroeihylene (a commercial product with a wide variety of uses including inks, paints, adhesives) and formaldehyde. in addition to toluene and xylem. Formaldehyde is a pervasive and abundant chemical found in numerous paper products, particleboard, plywood synthetic fabrics, carpet, cigarette smoke and heating and cooking fuels.
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H The money plant (Eppreinnum aureson), is indigenous to French Polynesia. This evergreen vine is a very hardy plant, but highly invasive if it takes root out of doors. It is an easy and undemanding plant to care for, equally comfortable in bright or low light, nutrient-poor or nutrient-rich soil – it can even be grown in a jar of water. Unfortunately, its leaves are poisonous to cats, dogs and children and even the sap from the plant may cause a rash in people with sensitive skin. However, it is extremely efficient at filtering all the same pollutants as the snake plant, except for trichloroethylene.
I Popular minimalist architecture mostly did away with indoor plants but, as a result of research by Dr Wolverton and others, they are making a comeback. After all, in the words of Margaret Burchett of the University of Technology in Sydney: “Potted plants can provide an efficient, self-regulating, low-cost, sustainable bioremediation system for indoor air pollution”. Plants have even more in their favour: they balance indoor humidity, are pleasing on the eye and, according to a recently published article: “plants relieve physiological stress and negative psychological symptoms”.
IELTS General Reading Test
Questions 28-32
The text has nine paragraphs A-I. Which paragraph mentions the following?
28. measurable effects of bioremediation on workers
29. how plants cleanse the air
30. research which tested the bioremediation effects of two different plant species
31. an experimental facility that was initially unfit to live in
32. a condition affecting office workers
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Questions 33-39
Look at the following statements and list of plant species below. Match each statement with the correct plant.
33. it is robust
34. it prefers a tight-fitting pot
35. it easily overruns other plants in an outside environment
36. it releases oxygen at night
37. it is delicate
38. it is harmful to infants and some adults
39. it has leaves that grow straight up
A Areca plant
B Snake plant
C Money plant
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Question 40
Choose the correct letter A, B, C or D.
40. Which of the following is NOT mentioned in the last paragraph of the passage?
A indoor plants improve air quality
B indoor plants need regular care
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ANSWERS ARE BELOW
IELTS General Reading Test
ANSWERS
28. E
29. C
30. D
31. B
32. A
33. C
34. A
35. C
36. B
37. A
38. C
39. B
40. B