Environmental Problems, Their Causes, and Sustainability 1

2,000400Grain production(millions of tons)1,5001,00050001950 19601970 1980 1990 2000 2010YearTotal World Grain ProductionPer capita grain production(kilograms per person)3503002502001501950 19601970 1980 1990 2000 2010YearWorld Grain Production per CapitaFigure 14-16 Total worldwide grain production of wheat, corn, and rice (left), and per capita grain production(right), 1950–2003. In order, the world’s three largest grain-producing countries are China, the United States,and India. (U.S. Department of Agriculture, Worldwatch Institute, UN Food and Agriculture Organization, andEarth Policy Institute)occurs because of differences in soil, climate, politicaland economic power, and average per capita income.Most agricultural experts agree that the root causesof hunger and malnutrition are and will continue to bepoverty and inequality, which prevent poor people fromgrowing or buying enough food regardless of howmuch is available. Other factors are war, corruption,and tariffs and subsidies that make it hard for poorpeople to see excess food they produce.How Serious Are Undernutrition andMalnutrition? Some ProgressSome people cannot grow or buy enough food to meettheir basic energy needs, and others do not getenough protein and other key nutrients.To maintain good health and resist disease, we needfairly large amounts of macronutrients (such as protein,carbohydrates, and fats), and smaller amounts ofmicronutrients consisting of various vitamins (such asA, C, and E) and minerals (such as iron, iodine, andcalcium).People who cannot grow or buy enough food tomeet their basic energy needs suffer from chronic undernutrition.Chronically undernourished childrenare likely to suffer from mental retardation andstunted growth. They are also susceptible to infectiousdiseases such as diarrhea and measles that rarely killchildren in developed countries.Many of the world’s poor can only afford to liveon a low-protein, high-carbohydrate diet consisting ofgrains such as wheat, rice, or corn. Many suffer frommalnutrition resulting from deficiencies of proteinand other key nutrients.The two most common nutritional deficiency diseasesare marasmus and kwashiorkor. Marasmus (fromthe Greek word marasmos, “to waste away”) occurswhen a diet is low in both calories and protein. Mostvictims are either nursing infants of malnourishedmothers or children who do not get enough food afterbeing weaned from breast-feeding. A child sufferingfrom severe marasmus is usually very thin and shriveledand looks like a very old miniature starving person(Figure 1-12, p. 13). Good news. If the child istreated in time with a balanced diet, most of these effectscan be reversed.Kwashiorkor (meaning “displaced child” in a WestAfrican dialect) is a severe protein deficiency occurringin infants and children ages 1–3, usually after thearrival of a new baby deprives them of breast milk.The displaced child’s diet changes to grain or sweetpotatoes, which provide enough calories but notenough protein. Such children typically have a bloatedbelly, reddish-orange hair, and discolored and puffyskin. Good news. If caught soon enough, most of theharmful effects can be cured with a balanced diet. Otherwise,children who survive their first year or twosuffer from stunted growth and mental retardation.Good news. According to the UN Food and AgricultureOrganization (FAO), the average daily foodintake in calories per person in the world and in developingcountries rose sharply between 1961 and 2003,and is projected to continue rising through 2030 (Figure14-17). Also, the estimated number of chronicallyundernourished or malnourished people fell from 918million in 1970 to 825 million in 2001, about 95% ofthem in developing countries.Bad news. About one of every six people in developingcountries (including about one of every threechildren below age 5) is chronically undernourished ormalnourished. The FAO estimates that at least 5.5 millionpeople die prematurely from a combination ofpoverty, undernutrition, malnutrition, and increasedsusceptibility to normally nonfatal infectious diseaseshttp://biology.brookscole.com/miller14287