In many respects, environmental problems are global problems. People all over the world are threatened by the health effects of air pollution and water pollution. Energy use, overpopulation, and mercury production in one part of the world can affect those who live elsewhere. There are, however, aspects of environmental problems which vary from one region to the next. Latin America presents a unique set of environmental issues.

AIR POLLUTION
In Latin America, levels of urbanization and motor vehicle use are higher than in most other developing regions throughout the world. Almost ¾ of residents of Latin America live in urban areas. For example, Mexico's population numbers almost 100 million, of which three quarters live in cities. Residents of urban areas experience greater exposure to air pollution. In much of Latin America, motor vehicles emit more pollutants than they do in the U.S. whose Clean Air Act has significantly improved air quality. For example, although a large number of industries are located in and around São Paulo, the 7.8 million vehicles in daily use are considered to be the source of most of the air pollution (Fiueredo, 2007). Tetraethyl lead, when added to gasoline, prevents premature explosion (knocking) but unfortunately, it is also a neurotoxin, and its release can affect brain development in children. Since 1976, all new cars and trucks in U.S. run on unleaded on unleaded gasoline and annual lead emissions have dropped dramatically. Unfortunately, unleaded gasoline is a little more expensive than leaded gasoline and some developing nations still use leaded gasoline. Leaded gas is still used in Mexico City, where 85% childhood diseases are blamed on air pollution and 32 tons of lead emissions are released per day. Although the U.S. banned tetraethyl lead since 1975, this country still ships it to other countries.
Throughout the world, asthma is estimated to cause one in every 250 deaths (Singh, 2005). In the following photo, the most commonly used gas "Comun" is leaded (while the Super is unleaded or "sin plomo").

Asthma rates have increased in industrialized nations and urban centers, correlated with the increase in exposure to air pollution (Lily, 2005). More than 100 million people in Latin America reside in areas where air pollution exceeds limits set by the World Health Organization. Every year, respiratory infections cause almost 1.2 million deaths in Mexico, mostly in children under 5 (Berrueta, 2007). Ozone levels in Mexico City are a serious problem for much of the year. Exposure to ozone pollution worsens asthma and increases the number of those admitted to hospitals/emergency rooms for asthma (Curtis, 2006). Significant amounts of dioxins and furans pollute the air of Sao Paulo (Asuncao, 2005). Air pollution in Mexico City and Sao Paulo has been linked to deaths in adults and children, respiratory problems in children (such as asthma), emergency room visits, and other problems (Bell, 2006). Christian, the young man in the picture below, died of asthma at age 22, leaving a wife and daughter.

Many Latin Americans are exposed to significant levels of indoor air pollution. Exposure to smoke from open fires aggravates respiratory problems, especially among women who may breathe smoke while cooking for 2-4 hours a day (and as many as 8 hours a day). Many stoves have been developed to reduce fuel wood usage (up to 74% less) and exposure to smoke (Berrueta, 2007).

Smoking causes almost 5 million premature deaths per year and, due primarily to the increase in tobacco use in developing nations, it is estimated that this number will rise to 10 million per year by the year 2030. Currently, cigarette smoke causes more deaths per year than AIDS, alcohol, violence, accidents, illegal drug use, and obesity combined (Bianco, 2005). It was estimated that Latin America possessed 95 million smokers in 1995, representing 8% of the global total. In Chile and Argentina, smoking rates among adults approach 40% (Bianco, 2005). The primary cause of Chronic Obstructive Pulmonary Disease (COPD) is smoking. Studies indicate that COPD incidence has been underestimated throughout Latin America (Menzes, 2005). The World Health Organization has produced a Framework Convention on Tobacco Control (FCTC) which has been signed and ratified by about half the countries of Latin America and the Caribbean. Although the implementation of the recommended policies would reduce tobacco use, the tobacco industry continues its efforts to undermine such efforts (Bianco, 2005).
Cities such as Santiago, Chile; Mexico City, Mexico; and São Paolo, Brazil, are planting vegetation as part of their strategies to improve air quality. Santiago's air pollution problem is due in part to its physical location in a depression surrounded by tall mountains which restrict air movement (Escobedo, 2007).

WATER
ACCESS TO CLEAN WATER

The average American uses 300 liters of water per day for personal use. Most of the world's population survives with far less. Access to clean water can vary significantly; for example, one area of Chile hasn't received rain in recorded history while one region of India received 72 feet in a year. In many areas throughout the world, water is being extracted from the ground at rates which are causing the levels of underground aquifers to drop dramatically. The main aquifer under Mexico City sinking 11 ft/year and water is now being pumped 1,000 meters high to reach Mexico City.
The northern third of Mexico generates nearly 1/3 of the gross domestic production receives only about 4% of the annual rainfall. Southeastern Mexico, which composes about a fifth of the land area, receives half of Mexico's rainfall. Although Mexico possesses about 2% of the world's population, it receives about 1% of the world's water and many areas suffer water shortages during drought. Mexico City imports water to meet a third of its demand (Wilder, 2006). Recent water reform strategies in Mexico have decentralized the control of water resources. Increased management by private industry (as opposed to government) has had mixed results and has not increased the efficiency or sustainability of water use in Mexico (Wilder, 2006).

Water is not only important for drinking and irrigation but also for recreation. Pollution limits the amount of fresh water which is fit for human activity. Below is a picture of a popular river in Paraguay.

Pollution often limits recreational use. For example, many Paraguayan lakes and rivers have experienced sharp drops in recreational use due to pollution. This applies to both small streams (such as the following one which is polluted by tannery waste and typically has a strong odor, especially in summer) and to the largest lake in the country (Lake Ypacarai), which has lost the majority of its tourism.

The family in the picture below is bathing in a stream in a National Park 4 hours from their house rather than the enormous lake located 10 minutes from their house whose beaches are largely deserted because of pollution.

This situation is not unique to Paraguay. Certain industries (such as tanning industries and slaughterhouses) contaminate water prior to its arrival in Bogota, Colombia and untreated sewage contaminates the water further as it leaves Bogota. Fortunately, Colombian legislation passed in 1993 has caused a decrease in organic waste into watersheds by 87% in some areas (Kathuria, 2006).
EUTROPHICATION
Little oxygen dissolves in water, such as the River Tapiracuai (in Paraguay) below. The amount of oxygen dissolved in water is often a limiting factor for fish communities. As the amount of dissolved oxygen drops, fewer and fewer fish can inhabit the water.

Eutrophication (literally meaning "well nourished") is a type of pollution which adds nutrients to water which were in short supply. This occurs when fertilizers (containing nitrates and phosphates) enter the water through agricultural runoff and when the water is polluted with detergents (which contain phosphates).

The following picture is of women who have brought their clothes to the River Tapiracuai to wash (you can see the clothes drying behind them). Although this will release detergents into the water, obviously they have nowhere near the impact that the runoff from more industrialized areas can have.

Human sewage, animal wastes, and manure cause bacterial blooms (a cow produces 14 lb manure/day). In agricultural regions, large amounts of fertilizer and cattle manure can runoff into streams.
This eutrophication can lead to fish kills because aerobic bacteria (which depend on atmospheric oxygen) which decompose the sewage or the dead plant matter use a good deal of oxygen. As less oxygen is available for fish, species begin to disappear (most commercially desirable species disappear first). When the oxygen is gone, anaerobic bacteria produce foul-smelling and toxic compounds as they decompose the sewage.

DISEASE
A number of diseases can be transmitted through water such as cholera, typhoid fever, giardia, hepatitis, and polio. Five hundred types of pathogenic microbes can be present in feces. According to the UN, dirty water and water-born diseases cause 25,000 deaths daily in the developing nations and about two million children will die annually from diarrhea.
The following picture depicts the backyard of the house where I lived in Paraguay, complete with bathing area, latrine, and well. While I was in Paraguay, cholera broke out in Peru and began to spread to other South American countries. Paraguayans whose water access was comparable to mine were rightly concerned about how cholera might spread should it ever reach Paraguay. The water level in my well was not adequate to filter the water from other households farther up the hill (and I had friends at the bottom of the hill whose well water was often at ground level and thus far less hygienic than mine). If any one at the top of the hill contracted cholera, there was a very real danger that this microbe from the latrines at the top of the hill would contaminate the wells of every one downhill from them.

OCEAN DUMPING AND FISHERIES

The ocean is an important food source: 80 million tons seafood a year provide 16% world's protein. Half the world's population live 100 km from a coast, including those in Rio pictured above. Unfortunately, this resource is being threatened.

Every year, 8 million tons of toxic wastes are dumped in the ocean and 6 million metric tons of litter arrive in the oceans/year. The Petrochemical industries of Colombia and Venezuela represent a significant source of ocean pollution.

It is estimated that all 17 of the world's major fishing areas have reached or have exceeded their natural limits and 9 are in serious decline. Four have been fished out. Ocean fisheries are now harvesting 10% of the levels of fish caught in the 1950s (Kennedy, 2004). Fish have been removed from waterways at unsustainable levels in many areas of Latin America. Many areas lack adequate protection to prevent overharvesting (such as bans on fishing during the seasons in which eggs are being laid).

FUELWOOD
More than three quarters of the world's population lives in developing nations where biomass (such as the burning of fuel wood) can provide between 50% and 90% of primary energy. For example, an estimated 27 million rural people in Mexico cook using fuel wood. In rural Mexico, wood provides 80% of the household energy and half the energy used by the community (Berrueta, 2007). Because of population growth and deforestation, fuel wood shortages exist in many regions.

BIOFUELS
One of the potential ways of decreasing the carbon dioxide emissions responsible for global warming is the increased use of biofuels. The term "biofuel" can be used to include a fuels made from a variety of different processes. Sugar cane, sugar beets, and corn are the primary crops used to generate ethanol. There is little use of these fuels outside Brazil (sugarcane) and the U.S. (corn). Reductions in greenhouse gas emissions can be significant (in Brazil's use of sugarcane) or minimal (in the U.S. use of corn) (IPCC, 2007). Of the existing biofuels, Brazilian fuels made from sugarcane have the greatest net energy yield (Hamelink, 2006).

Because of the price of both cars and gas, buses and motorcycles are popular forms of transport. In the picture on the right, the architecture of the bankallows it to be cooler during summer, thus minimizing energy expenditures.

DEFORESTATION

Throughout large areas of Latin America, forest is burned to create cow pasture. Between 2000 and 2005, deforestation resulted in the loss of 7.3 million hectares per year (which is a decrease from the 8.9 million hectare per year loss during the period of 1990-2000). South America and Africa represent the greatest sites of deforestation. Between 2000 and 2005, South America deforested 4.4 million hectares per year and Africa deforested 4.0 million hectares per year. North America and Central America deforested 0.3 million hectares (with the greatest loss in Central America).

Sixty percent of the tropical forest remaining in Latin America are found in Brazil. Brazil has the highest deforestation rate in Latin America, that of 2.2 million hectares per year (0.4% deforestation rate). Most of the remainder of tropical forest deforestation occurs in Mexico (600,000 hectares per year), Peru (300,000 hectares), Colombia, and Bolivia (both with 200,000 hectares per year) (Barbier, 2004).
More than in any other developing region in the world, increased agricultural yields in Latin America were due to increases in the amount of area dedicated to agriculture. By the year 2050, it is thought that South America will increase its agricultural lands by more than 50%, primarily through deforestation and the draining of wetlands (Barbier, 2004).

As of 2007, the greatest source of carbon dioxide emissions after electricity generation was deforestation, which is responsible for carbon dioxide emissions which are 11 to 28% the amount produced by fossil fuel combustion (IPCC, 2007).

THE OZONE LAYER
The ozone layer is necessary to protect terrestrial life from harmful UV rays which can mutate DNA. The less ozone there is to absorb ultraviolet light, the greater the number of mutations and thus the greater the number of cases of skin cancer. The following two photos of me on a trip to southern Chile in 1991 while I was in the Peace Corps. I was near the city of Puerto Mont, about as far south in Chile as you could get by land without taking a boat headed towards Tierra del Fuego at the tip of South America. The ozone hole has expanded to the point where it affects the southern parts of South America and Australia. The first photo is of myself on a cold, windy beach and the second photo is of the following day with a bad sunburn.

The increased amounts of UV light can also increase the incidence cataracts and blindness, not only in humans, but also in animals. This has already been observed in southern South America. Ultraviolet light can suppress the immune system and result in a greater susceptibility to infectious diseases, cancer, and AIDS. UV radiation has an adverse effect on shrimp, crabs, zooplankton, and fish and it decreases plant and phytoplankton production. Phytoplankton is the ultimate food source for ocean animals and is important in the production of oxygen and removal of CO2. Decreases in phytoplankton of 6-12% have been measured under the Antarctica hole; corals and other invertebrates may suffer as well. Increased ultraviolet radiation is increasing plant damage in southern South America and Antarctica (Day, 1999; Rousseaux, 1999).

Additional factors which worsen the effects of environmental pollutants are the exposure of a large percentage of the population to the chemicals and pesticides used in agriculture, child labor, reduced resistance because of undernutrition, urbanization, and poor access to education and health care.

LOSS OF BIODIVERSITY

As the forests are burned and rivers are overfished, much of Latin America's biodiversity is threatened. Most Paraguayans will never see a wild mammal bigger than an oppossum.

Hunting is not regulated and many species numbers are falling quickly as a result.

POPULATION GROWTH

It has been said that if the population of the planet could be represented by a village of 1,000 people, the following statistics would apply:
Birthrate --28 children will be born this year, 2 of which will die in their first year; 330 (one third) of the village are children and have not yet begun to reproduce
Deathrate --10 people will die this year (including those two children)

Number with Cars 70 (some of which have more than one)
Number with access to clean, safe drinking water 330 (One-third)
Number of adults which are illiterate 335 (of 670; half)
Average Salary per person in the village $3000
Percentage of village budget received by top 20% 75% ($11,250 per person)
Percentage of village budget received by the bottom 20% 2% ($300 per person)

It is estimated that 1.3 billion people live in extreme poverty in which they cannot adequately provide for their needs for food, clothing, and housing. About 800 million people eat less than 80% the amount of food per day considered to represent the basic caloric requirements (Raven, 2001). Much of the population of Latin America lives in conditions closer to the median conditions of the village than to those of the U.S.

Latin America's population is one of the most rapidly growing in the world. Many countries more than doubled their population between 1970 and 2005. Mexico City and Sao Paulo are two of the largest cities in the world. Mexico and Brazil are among the 11 most populated countries in the world.

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