周周-Sophia
空气污染是英语作文的`一个常见话题。以下是我为大家整理的关于空气污染的英语作文，仅供大家参考!
In the past few decades, our Earth has changed a lot, but to the bad direction. Among these changes, the air pollutions resulting from a huge number of automobiles and coal-burning is almost the severest. The severe air pollution alarms humans of the heavy load we have exerted on Earth by our insatiable production and usage of automobiles. However, with the deepening of urbanization, more cars are needed, which will make the air pollution worse. Therefore, the following actions should be taken.
First, we should apply the most cutting-edge technologies in order to adopt new forms of energy as substitutes for fossil fuels. Second, try hard to develop possible transportation means, which are enviromental friendly. So that the citizens can reduce the dependence on cars. In short, our humans should take responsibilities for the air pollution and have to find ways to solve this problem.
Air pollution is one of the major problems of the modern world. A great deal of energy is needed to run the factories of modern industrial nations. Automobile, trains, planes and busses need energy, too. Nearly all of this energy is produced by burning fuels. The burning produces wastes, some of which remain in the air, causing air pollution.
Scientists are finding ways to stop air pollution especially in big industrial areas and densely-populated cities. They are studying new ways of generating electricity that may be less damaging to the environment. In the meantime, many power plants are being modernized to give off less polluted material. Also, engineers try to design and locate new power plants to do minimum damage to the environment.
However, it may be that we still have a long way to go before we have a "clean" world. Nearly all of the countries are trying hard to prevent and control air pollution. There indeed seems to be no end to tasks that environmentalists will be required to do. People will continually find new ways to control pollution.
Air pollution comes from factories, power stations and cars. Chemicals in the smoke from power stations cause a lot of damage. They can travel hundreds of miles in the wind before falling to the ground in the rain. But this "chemical rain" gradually destroys trees in the forests and kills fish in the lakes. In Germany, over 50% of the country's trees had been damaged by the year 1986.
Time and time again there are serious accidents that pollute the air. In 1986 there was a bad accident at a nuclear power station in Russia. A cloud of radiation crossed the whole of Europe. It is said that 125,000 people died in Russia as a result of illnesses caused by this accident.
In 1984 there was a serious accident at a factory in India and a cloud of dangerous gas covered the town of Bhopal. Over 2,500 people were killed that night, and hundreds of thousands of people were injured. Many of the injured lost their sight.
We all know that clean air is important to good health. Wherever you go and whatever you do, you are always surrounded by a sea of gases that we call air. If there are impurities in the air, they may be absorbed by our bodies and make us ill. We need clean air, but unfortunately , air pollution is globally present , especially in cities.
Many large cities are anything but pollution-free. Our cities have many factories, which we need to make food, clothing and other things. Every year these factories pour millions upon millions of tons of smog into air. Power plants and houses that burn coal add greatly to air pollution. Besides , there are more cars in cities now. Once out on the streets, they will take in fresh air and replace it with poisonous gases.
Our country is trying hard to prevent and control air pollution. As long as every citizen also realizes its importance and makes join efforts, the day will come soon when people will take in only clean air. Then , the sunlight will no longer be blackened out by smoke and soot.
Pollution is becoming more and more serious all over the world. As is shown in the cartoon, two cars are giving off waste gas and three people are trying to avoid breathing in the poisonous gas by masking their face with their hands. The poisonous gas sent off by factories, domestic appliances and automobiles has made the air unhealthy for people to breathe.
There is no denying that automobiles are indications of civilization, progress and development; nevertheless , automobiles cause the serious problem of air pollution. Scientists have warned that unless effective measures are taken, the problem of pollution will eventually get out of hand. Actually, people are showing a real concern over the problem. For example, there is an increasingly loud voice from the public for firm action against pollution from automobiles.
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RISK FACTORS Many cancers are related to specific environmental and lifestyle factors that predispose a person to develop cancer. Accumulating data suggest that some of these risk factors initiate carcinogenesis, other risk factors act as promoters, and some risk factors both initiate and promote the disease process. Air pollution Air pollution has been linked to the development of cancer, particularly lung cancer. Persons living near industries that release toxic chemicals have a documented increased risk of cancer. Many outdoor air pollutants ¡ª such as arsenic, benzene, hydrocarbons, polyvinyl chlorides, and other industrial emissions as well as vehicle exhaust ¡ª have been studied for their carcinogenic properties. Indoor air pollution, such as from cigarette smoke and radon, also poses an increased risk of cancer. In fact, indoor air pollution is considered to be more carcinogenic than outdoor air pollution. Tobacco Cigarette smoking increases the risk of lung cancer more than tenfold over that of nonsmokers by late middle age. Tobacco smoke contains nitrosamines and polycyclic hydrocarbons, two carcinogens that are known to cause mutations. The risk of lung cancer from cigarette smoking correlates directly with the duration of smoking and the number of cigarettes smoked per day. Tobacco smoke is also associated with laryngeal cancer and is considered a contributing factor in cancer of the bladder, pancreas, kidney, and cervix. Research also shows that a person who stops smoking decreases his or her risk of lung cancer. Although the risk associated with pipe and cigar smoking is similar to that of cigarette smoking, some evidence suggests that the effects are less severe. Smoke from cigars and pipes is more alkaline. This alkalinity decreases nicotine absorption in the lungs and also is more irritating to the lungs, so that the smoker doesn't inhale as readily. Inhalation of "secondhand" smoke, or passive smoking, by nonsmokers also increases the risk of lung and other cancers. Plus use of smokeless tobacco, in which the oral tissue directly absorbs nicotine and other carcinogens, is linked to an increase in oral cancers that seldom occur in persons who don't use the product. Alcohol Alcohol consumption, especially in conjunction with cigarette smoking, is commonly associated with cirrhosis of the liver, a precursor to hepatocellular cancer. The risk of breast and colorectal cancers also increases with alcohol consumption. Possible mechanisms for breast cancer development include impaired removal of carcinogens by the liver, impaired immune response, and interference with cell membrane permeability of the breast tissue. Alcohol stimulates rectal cell proliferation in rats, an observation that may help explain the increased incidence of colorectal cancer in humans. Heavy use of alcohol and cigarette smoking synergistically increases the incidence of cancers of the mouth, larynx, pharynx, and esophagus. It's likely that alcohol acts as a solvent for the carcinogenic substances found in smoke, enhancing their absorption. Sexual and reproductive behavior Sexual practices have been linked to specific types of cancer. The age of first sexual intercourse and the number of sexual partners are positively correlated with a woman's risk of cervical cancer. Furthermore, a woman who has had only one sexual partner is at higher risk if that partner has had multiple partners. The suspected underlying mechanism here involves virus transmission, most likely human papilloma virus (HPV). HPV types 6 and 11 are associated with genital warts. HPV is the most common cause of abnormal Papanicolaou (Pap) smears, and cervical dysplasia is a direct precursor to squamous cell carcinoma of the cervix, both of which have been linked to HPV (especially types 16 and 31). Occupation Certain occupations, because of exposure to specific substances, increase the risk of cancer. Persons exposed to asbestos, such as insulation installers and miners, are at risk of a specific type of lung cancer. Asbestos also may act as a promoter for other carcinogens. Workers involved in the production of dyes, rubber, paint, and beta-naphthylamine are at increased risk of bladder cancer. Ultraviolet radiation Exposure to ultraviolet radiation, or sunlight, causes genetic mutation in the P53 control gene. Sunlight also releases tumor necrosis factor alpha in exposed skin, possibly diminishing the immune response. Ultraviolet sunlight is a direct cause of basal and squamous cell cancers of the skin. The amount of exposure to ultraviolet radiation also correlates with the type of cancer that develops. For example, cumulative exposure to ultraviolet sunlight is associated with basal and squamous cell skin cancer, and severe episodes of burning and blistering at a young age are associated with melanoma. Ionizing radiation Ionizing radiation (such as X-rays) is associated with acute leukemia, thyroid, breast, lung, stomach, colon, and urinary tract cancers as well as multiple myeloma. Low doses can cause DNA mutations and chromosomal abnormalities, and large doses can inhibit cell division. This damage can directly affect carbohydrate, protein, lipid, and nucleic acids (macromolecules), or it can act on intracellular water to produce free radicals that damage the macromolecules. Ionizing radiation also can enhance the effects of genetic abnormalities. For example, it increases the risk of cancer in persons with a genetic abnormality that affects DNA repair mechanisms. Other compounding variables include the part and percentage of the body exposed, the person's age, hormonal balance, prescribed drugs and preexisting or concurrent conditions. Hormones Hormones ¡ª specifically the sex steroid hormones estrogen, progesterone, and testosterone ¡ª have been implicated as promoters of breast, endometrial, ovarian, or prostate cancer. Estrogen, which stimulates the proliferation of breast and endometrial cells, is considered a promoter for breast and endometrial cancers. Prolonged exposure to estrogen, as in women with early menarche and late menopause, increases the risk of breast cancer. Likewise, long-term use of estrogen replacement without progesterone supplementation for menopausal symptoms increases a woman's risk of endometrial cancer. Progesterone may play a protective role, counteracting estrogen's stimulatory effects. The male sex hormones stimulate the growth of prostatic tissue. However, research fails to show an increased risk of prostatic cancer in men who take exogenous androgens. Diet Numerous aspects of diet are linked to an increase in cancer, including: obesity (in women only, possibly related to production of estrogen by fatty tissue), which is linked to a suspected increased risk of endometrial cancer high consumption of dietary fat (due to an increase in free radical formation), which is linked to endometrial, breast, prostatic, ovarian, and rectal cancers high consumption of smoked foods and salted fish or meats and foods containing nitrites, which may be linked to gastric cancer naturally occurring carcinogens (such as hydrazines and aflatoxin) in foods, which are linked to liver cancer carcinogens produced by microorganisms stored in foods, which are linked to stomach cancer diet low in fiber (which slows transport through the gut), which is linked to colorectal cancer. ACS GUIDELINES: DIET, NUTRITION, AND CANCER PREVENTION -------------------------------------------------------------------------------- Because of the numerous aspects of diet and nutrition that may contribute to the development of cancer, the American Cancer Society (ACS) has developed a list of guidelines to reduce cancer risk in persons ages 2 years and older. Choose most of the foods you eat from plant sources. ¨C Eat 5 or more servings of fruits and vegetables each day. ¨C Eat other foods from plant sources such as breads, cereals, grain products, rice, pasta, or beans several times each day. Limit your intake of high-fat foods, particularly from animal sources. ¨C Choose foods low in fat. ¨C Limit consumption of meats, especially high-fat meats. Be physically active and achieve and maintain a healthy weight. ¨C Be at least moderately active for 30 minutes or more on most days of the week. ¨C Stay within your healthy weight range. Limit your consumption of alcoholic beverages, if you drink at all. The American Cancer Society (ACS) has developed specific nutritional guidelines for cancer prevention.
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