IELTS Academic Reading Practice Test 34

For thousands of years, smallpox was among the most feared diseases on Earth. Caused by the variola virus and spread from person to person, it began with fever and aching, followed by a rash that developed into deep, fluid-filled blisters across the face and body. In its most common severe form it killed roughly three in every ten people it infected, and many survivors were left with deep scars or, in some cases, blindness. The disease struck rich and poor alike, and it is estimated to have caused hundreds of millions of deaths in the twentieth century alone. Its eventual disappearance is therefore one of the greatest achievements in the history of medicine.

Long before scientists understood viruses, people noticed that those who survived smallpox never caught it again. In several parts of the world this observation led to a practice known as variolation. In China, powdered scabs from smallpox patients were blown into the nose, while in India, parts of Africa and the Ottoman Empire material from a patient's blisters was scratched into the skin of a healthy person. Variolation usually produced a milder illness than natural infection, but it was not without danger: a small proportion of those treated died, and they could pass the disease on to others. The practice was introduced to Britain by Lady Mary Wortley Montagu, the wife of the British ambassador in Constantinople, who had her son treated there in 1718 and promoted the method after her return to London. Variolation became fairly common in Britain during the following decades, although it was never without its critics.

Meanwhile, in the English countryside, a different observation was circulating. Dairy workers who had caught cowpox, a mild disease that produced sores on the udders of cows and on the hands of those who milked them, seemed to be protected from smallpox. At least one farmer, Benjamin Jesty of Dorset, acted on this belief in 1774, deliberately infecting his wife and sons with material from cowpox sores. It was a country doctor from Gloucestershire, Edward Jenner, however, who investigated the idea systematically and made it known to the world.

On 14 May 1796 Jenner took material from cowpox sores on the hand of a milkmaid named Sarah Nelmes and inserted it into small cuts on the arm of James Phipps, an eight-year-old boy. The boy developed a mild fever but soon recovered. Some weeks later Jenner exposed him to material taken from a smallpox patient, and no illness followed. By modern standards the experiment would be considered unethical, since a healthy child was deliberately exposed to a deadly disease, but its result was clear.

Jenner's first account of his work was rejected by the Royal Society, whose president advised him not to damage his reputation by publishing ideas so far removed from accepted knowledge. Undeterred, he carried out further cases and in 1798 published a short book at his own expense describing his findings. He called the cowpox material 'variolae vaccinae', from the Latin word vacca, meaning cow, and the term vaccination soon came into general use. Within a few years the technique had spread across Europe and beyond. The main practical problem was keeping the vaccine active, since there was no way to store it for long. One solution was to pass it from one person to the next: material from the sores of a recently vaccinated person was used to vaccinate another, a method known as arm-to-arm vaccination.

The most ambitious use of this method was an expedition organised by the Spanish crown in 1803 and led by the physician Francisco Xavier de Balmis. To carry the vaccine across the Atlantic, Balmis took with him around twenty orphan boys who had never had smallpox. During the voyage the boys were vaccinated in pairs, one pair after another, so that fresh material was always available. The expedition reached Spain's territories in the Americas and later crossed the Pacific to the Philippines, vaccinating many thousands of people on its way.

Vaccination was not universally welcomed. When Britain made it compulsory for infants in 1853, opposition grew rapidly. Some objectors distrusted the medical profession or feared that the procedure itself spread other infections, while others regarded compulsion as an unacceptable intrusion by the state into family life. Anti-vaccination leagues organised large demonstrations, and later legislation eventually allowed parents to refuse on grounds of conscience.

Even so, the disease gradually disappeared from Europe and North America, and in 1967 the World Health Organization launched an intensified campaign to eliminate it from the rest of the world. Two technical improvements helped. A freeze-dried vaccine remained effective in tropical heat, and a simple two-pronged instrument called the bifurcated needle held exactly the right dose and could be used after very little training. Equally important was a change of strategy.

Rather than attempting to vaccinate entire populations, teams concentrated on finding every new case and vaccinating the people around it, a method known as surveillance and containment. Smallpox was well suited to this approach, because the virus had no animal host in which it could survive and its distinctive rash made cases relatively easy to recognise. The last naturally occurring case was recorded in a hospital cook in Merca, Somalia, in October 1977. In May 1980 the World Health Assembly formally declared smallpox eradicated, and it remains the only human disease ever to have been eliminated worldwide.

For almost all of human history, a clear night revealed thousands of stars and the pale band of the Milky Way stretching across the sky. Today that sight has become a rarity for most people. In 2016 an international team led by the Italian scientist Fabio Falchi published a world atlas of artificial sky brightness, combining satellite data with thousands of measurements taken on the ground. It concluded that more than eighty per cent of the world's population, and more than ninety-nine per cent of people in the United States and Europe, live under skies polluted by artificial light. The Milky Way is now hidden from more than a third of humanity, including about sixty per cent of Europeans and nearly eighty per cent of North Americans.

Light pollution takes several forms. The most widespread is skyglow, the brightening of the night sky over populated areas, which occurs when light directed upwards or sideways is scattered by molecules and particles in the atmosphere. Skyglow from a large city can be seen from more than a hundred kilometres away. Glare is excessive brightness that causes visual discomfort and can dazzle drivers, while light trespass refers to unwanted light falling where it is not needed, such as through a neighbour's bedroom window. Much of this light serves no purpose at all. It comes from badly designed or badly aimed fixtures that send light into the sky instead of onto the ground they are meant to illuminate.

Measuring how quickly the problem is growing has proved surprisingly difficult. Satellite observations suggested that the brightness of the Earth at night was increasing by about two per cent a year. In 2023, however, a study published in the journal Science by Christopher Kyba and colleagues reached a very different conclusion. It used more than 50,000 observations made between 2011 and 2022 by members of the public taking part in a project called Globe at Night, who recorded the faintest stars they could see from their location. The results indicated that the sky had been growing brighter by almost ten per cent a year, a rate at which the brightness would double in about eight years. The researchers suggested that satellites had missed much of the increase because their sensors cannot detect the blue light produced by many modern lamps, and because they record mainly light travelling upwards rather than the light emitted horizontally from signs and windows, which contributes heavily to skyglow.

Ironically, part of the problem lies in a technology that was expected to reduce the waste of energy. Light-emitting diodes, or LEDs, use far less electricity than older street lamps, but because they are cheap to run, they have encouraged towns and businesses to install more lighting and to leave it on for longer. This is an example of what economists call a rebound effect. In addition, many early LED installations produced cold, bluish-white light, which is scattered more readily in the atmosphere than light of longer wavelengths and has stronger effects on living organisms.

The consequences for wildlife can be severe. Sea turtle hatchlings, which emerge from their nests on beaches at night, instinctively crawl towards the brightest horizon, which under natural conditions lies over the sea. Lights from hotels and roads can draw them inland instead, where many are taken by predators or crushed by vehicles. Many species of migratory birds travel at night, and brightly lit buildings can attract them and lead to fatal collisions, which is why several North American cities now encourage owners of tall buildings to switch off unnecessary lights during migration seasons. Insects are drawn to lamps in vast numbers and often circle them until they die of exhaustion or are eaten, and scientists consider artificial light to be one of the factors contributing to declines in insect populations. Even plants respond: a study in Britain found that trees growing near bright street lighting came into leaf earlier in spring than trees in darker locations.

Human beings are not immune. Our bodies regulate sleep and many other processes according to a daily cycle, which is set partly by exposure to light. Special light-sensitive cells in the eye, which play no part in forming images, help to send this timing signal to the brain. In darkness, the body produces a hormone called melatonin, which helps to prepare it for sleep, and light at night, especially blue light, suppresses its production. Researchers are investigating possible links between night-time light exposure and various health problems, although for most of these conditions a direct causal connection has not yet been established.

Unlike most forms of pollution, however, light pollution can be reduced almost immediately and at little cost. Fixtures fitted with shields that direct light downwards, lamps with a warmer colour, lower brightness and timers that switch lights off when they are not needed can all make a large difference without compromising safety. Some towns have also installed motion sensors, so that paths and car parks are lit only when someone is actually using them. The city of Flagstaff in Arizona, home to an important astronomical observatory, introduced its first lighting regulation as early as 1958, when it banned advertising searchlights, and in 2001 it became the world's first International Dark Sky City. Since then, many parks and communities around the world have been certified for the quality of their night skies.

Fast fashion, the business of producing large quantities of inexpensive clothing that follow the latest trends, has transformed the way people dress. The model was pioneered in the late twentieth century by retailers such as the Spanish chain Zara, whose first shop opened in A Coruña in 1975 and which became famous for moving new designs from the drawing board to its stores in a matter of weeks. Online retailers have since accelerated the cycle further, adding thousands of new items to their websites every day. Shoppers are frequently urged to feel guilty about their part in this system. In my view, however, placing the burden on individual consumers is both unfair and ineffective; the problem lies primarily in the design of the industry itself.

The scale of the industry's growth is difficult to overstate. According to a widely cited report published by the Ellen MacArthur Foundation in 2017, global clothing sales more than doubled in the first fifteen years of this century, while the average number of times a garment was worn before being discarded fell substantially. The same report estimated that the equivalent of one rubbish truck full of textiles was landfilled or burned every second, and that less than one per cent of the material used to make clothing was recycled into new clothing. Low labour costs in producing countries, combined with highly efficient supply chains, have allowed prices to remain low even as volumes have risen.

The environmental consequences are wide-ranging. Growing cotton requires large amounts of water and, in many regions, heavy use of pesticides. Polyester, now the most widely used fibre, is made from oil, and garments made from it shed tiny plastic fibres when they are washed, some of which pass through treatment plants and reach rivers and the sea. Spinning, weaving and dyeing also consume large amounts of energy, much of it generated from fossil fuels in the main manufacturing countries. Dyeing and finishing fabrics can release chemicals into waterways in producing countries. Estimates of the industry's contribution to global greenhouse gas emissions vary considerably according to the methods used, but even the lower figures are substantial.

The human costs became impossible to ignore in April 2013, when the Rana Plaza building near Dhaka in Bangladesh, which housed several garment factories, collapsed and killed 1,134 people. Cracks had been noticed in the structure the day before, yet many workers were required to return. The disaster led to a legally binding agreement between international brands and trade unions under which factories were subjected to independent safety inspections, and conditions in many Bangladeshi factories have since improved. Low wages and long hours nevertheless remain common across the industry's supply chains.

Many consumers believe that donating unwanted clothes solves the problem of waste. In reality, charity shops in wealthy countries can sell only a fraction of what they receive, and much of the remainder is exported in compressed bales to second-hand markets in Africa, Asia and elsewhere. As the quality of fast-fashion garments has declined, an increasing proportion of these exports cannot be resold at all, and they end up in dumps in the importing countries. Reports from Accra, the capital of Ghana and the site of one of West Africa's largest second-hand clothing markets, have described unsold garments piling up in landfill sites and washing up on nearby beaches.

Faced with such facts, campaigners often advise shoppers to buy less, choose better and keep their clothes for longer. This advice is sensible, and I do not dismiss it. But its effect is limited. Consumers rarely have reliable information about how or where a garment was made, and the price of fast fashion is precisely what makes it attractive to people on low incomes. Surveys repeatedly show that shoppers say they care about sustainability, yet their purchases do not change accordingly. A system that depends on millions of individuals continually resisting cheap prices and constant marketing is unlikely to change very much.

Regulation offers a more promising route, and governments have begun to act. France passed a law in 2020 prohibiting companies from destroying unsold non-food products, including clothing, and it requires clothing producers to contribute to the cost of collecting and recycling used textiles, a principle known as extended producer responsibility. The European Union has followed with rules preventing large companies from destroying unsold clothing and footwear. Such measures matter because they place the cost of waste on those who decide how much is produced, rather than on taxpayers or on the countries that receive discarded goods.

Technology alone will not solve the problem. Recycling old garments into new fibre remains difficult and expensive, partly because many fabrics are blends of natural and synthetic materials that are hard to separate. The most effective change would therefore be for the industry to produce fewer, more durable garments and to earn more of its income from repair, resale and rental. Some brands have already launched their own resale and repair services, and rental companies now offer clothing for occasions when a garment might otherwise be worn only once, but these initiatives remain small compared with the volume of new clothing sold each year. Companies will make this shift only when the rules of the market reward them for doing so. Shoppers have a part to play, but it is governments that must change those rules.