Lec 11 Global Water Crisis#2 PDF

Global Water Crisis 2 Case Study: Arsenic – “The Largest Mass Poisoning in History” Arsenic “is becoming the key environmental health problem of the twenty-first century.” The reason for this statement is apparent in some parts of Bangladesh, West Bengal, India, Vietnam, and other Asian c...

Global Water Crisis 2 Case Study: Arsenic – “The Largest Mass Poisoning in History” Arsenic “is becoming the key environmental health problem of the twenty-first century.” The reason for this statement is apparent in some parts of Bangladesh, West Bengal, India, Vietnam, and other Asian countries. The World Health Organization (WHO) advises a maximum permissible level for arsenic in drinking water of 50 μg/l, and recommends 10 μg/l. But in Bangladesh, more than 100 million people drink water containing more than 50 μg/l. In some Asian wells, arsenic levels exceed 3000 μg/l. Case Study: Arsenic – “The Largest Mass Poisoning in History” Surface water in Bangladesh and in many other impoverished countries is too polluted with pathogens, and sometimes industrial chemicals, to serve as drinking water. So, 30 years ago the UN International Children’s Emergency Fund (UNICEF) funded the drilling of wells to provide clean drinking water. When well water became available, infant mortality from diarrheal diseases dropped dramatically. The wells seemed a major success. Case Study: Arsenic – “The Largest Mass Poisoning in History” However, in moist tropical environments, there is much organic matter buried in the sediments into which the wells were drilled. As this material decays it leads to chemical events that result in arsenic release into groundwater, and thus into wells. Arsenic levels in Bangladeshi wells are high, but not high enough to be acutely toxic. Chronic toxicity is the problem. This meant that awareness of the poisoning was slow in coming. People began showing symptoms after they had drunk the water for 5 to 10 years. In Bangladesh, nearly one-quarter of the villagers examined in regions served by these wells had skin lesions  Case Study: Arsenic – “The Largest Mass Poisoning in History” People began showing symptoms after they had drunk the water for 5 to 10 years. In Bangladesh, nearly one-quarter of the villagers examined in regions served by these wells had skin lesions, in a region where 59% of nearly 11 000 well water samples contained more than 50 μg/l arsenic. Early symptoms are changes in skin coloration or many hard corns on the palms, soles, and torso. Drinking water with arsenic levels greater than about 300 μg/l resulted in skin lesions. Case Study: Arsenic – “The Largest Mass Poisoning in History” Later, after the lesions were first observed, skin cancers began appearing. Later still, as people continued drinking the water for decades, lung, liver, and bladder cancers developed. Other major toxic effects also appeared, sometimes gangrene because arsenic is toxic to the nervous system, including the long nerve fibers in the limbs. Case Study: Arsenic – “The Largest Mass Poisoning in History” People who eat nutritious diets are less susceptible to poisoning. In well-fed people, even drinking water with arsenic levels of 400 μg/l may not cause lesions. In contrast, lesions occur in people who have poor nutrition, drink large quantities of contaminated water, or drink it over a long period. At the earliest stages of the poisoning, skin changes can be reversed by drinking clean water and eating nutritious food. Unfortunately, a great many poisoned people are poor and do not have access to either. In Bangladesh alone, 85 million people are at risk of developing cancer. This poisoning is a stunning tragedy. Case Study: Arsenic – “The Largest Mass Poisoning in History” An intense effort is under way to find ways to remove arsenic from water cheaply. Technologies already exist, but are too costly for impoverished countries. Techniques used to remove arsenic, or else to avoid water that contains it, include sand filters, harvesting rainwater or, in some cases, drilling deeper wells. In addition to choosing appropriate technologies, the WHO must closely oversee those that install them because corruption is so prevalent. Meanwhile, because wells with lower arsenic levels may be located far from their homes, many people continue to drink from arsenic- contaminated wells even though they are marked as unsafe. Case Study: China’s Water Pollution Reports from the UN Food and Agriculture Organization, the World Bank, the World Resources Institute, and China’s State Environmental Protection Administration (SEPA) stress the gravity of China’s environmental degradation. Water pollution is severe; 80% of 50 000 km along its seven major rivers are so badly polluted that they no longer support fish life. Some fish species have become extinct, taking with them a valuable food source. Case Study: China’s Water Pollution Pollution is especially severe in the industrial north. In substantial portions of the rivers, pollution has been so bad that it is unsuitable even for industrial use. Many river sections are classified as unsuitable for human contact. A drought has worsened the pollution in recent years because the same amount of pollution enters the rivers, but there is less water to dilute it. Case Study: China’s Water Pollution Pollution is especially severe in the industrial north. In substantial portions of the rivers, pollution has been so bad that it is unsuitable even for industrial use. Many river sections are classified as unsuitable for human contact. A drought has worsened the pollution in recent years because the same amount of pollution enters the rivers, but there is less water to dilute it. Case Study: China’s Water Pollution Lakes and coastal areas are also badly polluted. Water pollutants include hazardous metals and organic solvents from oil refineries, chemical plants, paper mills, and other facilities. Agricultural runoff, untreated human sewage, and animal waste lead to excessive nutrients, excessive BOD, excessive suspended solids, and microbial contamination in rivers. Water pollution reports use terms such as ‘‘ever-deteriorating conditions” and ‘‘unsuitable for human contact.” Diseases from bacterial pathogen contamination are ‘‘epidemic.” Case Study: China’s Water Pollution One Chinese observer said, ‘‘You cannot find a single river that is clean these days in China.” In addition, more than half of the groundwater is severely contaminated. Coastal waters are rated as poor or, in some places, worse. Case Study: China’s Water Pollution China’s population is about 1.3 billion, and continues to grow along with increasing industrialization and urbanization. China’s economic growth rate in 2000 was 7%. The government is struggling to at least stabilize its environmental problems including water pollution. In 1995, China produced 37 billion tons (34 billion tonnes) of municipal and industrial wastewater. Although 77% of the industrial wastewater was treated, half failed to meet government standards. For regulated industries, wastewater volumes may be leveling off. However, pollution continues unabated from about 7 million small village businesses, which release largely untreated wastewater. China has shut down many thousands of the worst of these, but even as it did so, water pollution from agriculture and domestic water use was increasing. Farmers use inappropriately large amounts of pesticides and fertilizers, much of which runs off into surface water or seeps into groundwater. Case Study: China’s Water Pollution One of the major reasons is that China’s population is about 1.3 billion, and continues to grow along with increasing industrialization and urbanization. China’s economic growth rate in 2000 was 7%. In 1995, China produced 37 billion tons of municipal and industrial wastewater. Although 77% of the industrial wastewater was treated, half failed to meet government standards. China had only 100 modern municipal wastewater-treatment plants. These treated only 1 billion of the 30 billion tons of urban sewage produced. Case Study: China’s Water Pollution Not surprisingly, about 700 million of China’s 1.3 billion people drink water that does not meet health-based standards for microorganisms and industrial chemicals. High incidences of human diseases are reported along some of China’s rivers. Moreover, farmers continue the historical practice of using human sewage on their crops. They use irrigation water containing high levels of industrial chemicals, such as lead and chromium, leading to high metal levels in some crops. Case Study: The Songhua River Spill: China's Pollution Crisis On November 13, 2005, two fuel towers exploded at PetroChina's facility in Jilin City, China, a petrochemical factory constructed in the mid-1950s. Although the explosions at the plant killed five people, triggered the evacuation of an estimated 10,000 people, and resulted in the spill of approximately 100 tons of benzene and related compounds into the Songhua River, approximately ten days passed before Chinese government officials issued the first public reports of the spill. Case Study: The Songhua River Spill: China's Pollution Crisis During that, local bureaucrats reportedly told the people of Harbin, China (a downstream city of nearly four million) that it was suspending water distribution to perform routine waterworks maintenance. All the while, the spill continued to migrate downstream through multiple population centers and towards the Amur River in Russia. Fishermen continued to fish (and people presumably continued to drink from) the stretch of river between Jilin City and Harbin having had no information to suggest they should do otherwise. Case Study: Oxygen Depletion in the Northern Gulf of Mexico The world’s third largest oxygen-depleted zone forms every spring and summer in a narrow stretch of the northern Gulf of Mexico off the mouth of the Mississippi River. This area includes the coastal waters of the U.S. states of Mississippi, Louisiana, and Texas. The low oxygen levels suffocate fish, crabs, and shrimp that cannot move to less polluted areas. Case Study: Oxygen Depletion in the Northern Gulf of Mexico In recent years, this oxygen-depleted zone has covered an area almost as large as the U.S. state of New Jersey. Because of the size and agricultural importance of the Mississippi River basin, there are no easy solutions to the severe cultural eutrophication of this and other overfertilized coastal zones around the world. Case Study: Oxygen Depletion in the Northern Gulf of Mexico Each year, excess nutrients from cities, farms and other sources in upland watersheds drain into the Gulf and stimulate algal growth during the spring and summer. The algae eventually die, sink and decompose. Throughout this process, oxygen-consuming bacteria decay the algae. The resulting low oxygen levels near the bottom are insufficient to support most marine life, rendering the habitat unusable and forcing species to move to other areas to survive. Exposure to hypoxic waters has been found to alter fish diets, growth rates, reproduction rates, habitat use, and availability of commercially harvested species like shrimps. Case Study: Oxygen Depletion in the Northern Gulf of Mexico Preventive measures include: Applying less fertilizer; Injecting fertilizer below the soil surface; Using controlled-release fertilizers that have water-insoluble coatings; Planting strips of forests and grasslands along waterways to soak up excess nitrogen; Restoring and creating wetlands between crop fields and streams emptying into the Mississippi River; Reducing government subsidies for using corn to make ethanol when other more energy efficient options are available. Case Study: Oxygen Depletion in the Northern Gulf of Mexico Improving flood control to prevent the release of nitrogen from floodplains during major floods Upgrading sewage treatment to reduce discharges of nitrates into waterways. Deposition of nitrogen compounds from the atmosphere could be reduced by requiring lower emissions of nitrogen oxides from motor vehicles and by phasing in forms of renewable energy to replace the burning of fossil fuels. Some scientists who have studied this problem fear that it could reach an ecological tipping point where most of the organisms living in this part of the Gulf of Mexico simply can no longer move far enough away to avoid the oxygen-depletion or to enable their populations to recover. Case Study: The Love Canal Love Canal is a notorious site located in Niagara Falls, New York, that symbolizes one of the most devastating environmental disasters in American history. Its story begins in the early 20th century when the canal was dug as part of an ambitious hydroelectric power project that was never completed. The Love Canal area was initially designed as a dream project by entrepreneur William T. Love, who envisioned a canal connecting the Niagara River with Lake Ontario to create a Utopian industrial city. However, the project failed due to financial difficulties, leaving behind a partially constructed canal. Case Study: The Love Canal The canal was eventually turned into a chemical dumpsite by the Hooker Chemical Company in the 1940s and 1950s, burying thousands of tons of toxic waste underground. Case Study: The Love Canal Hooker Chemical Company disposed of 22 000 tons of hazardous waste there, including halogenated organic chemicals and pesticides; some of this waste was contaminated with dioxin. In 1953, Hooker sold the land to the Niagara Falls School Board for just $1, warning that the site contained dangerous chemical waste. Hooker included a clause in the sales contract that both described the land use (filled with chemical waste) and absolved them from any future damage claims from the buried waste. Case Study: The Love Canal The city later said that Hooker had not informed it of the hazards of the wastes. Despite these warnings, the land was developed, and a school and hundreds of homes were built in the area. New York Officials and School Board members knew of the dangers, but instead chose to publicly hide them because of the cheap cost of the land In 1954, the Board of Education built one school next to the landfill and another directly over it. It sold some of the land to a developer, who put up hundreds of houses, some directly around the landfill. Case Study: The Love Canal Case Study: The Love Canal In the 1960s, a highway bordering the development was built. As it was built, roads and sewers were constructed over and also directly through the Hooker site, and its protective clay cap was partially excavated, allowing rainwater to seep into the waste. It was this highway that created the greatest problem, as the highway and accompanying roads and sewers were built, they were laid over and directly through the site, which contained toxic waste. This construction process inadvertently compromised the protective clay cap that covered the waste, leading to serious environmental consequences. Case Study: The Love Canal The excavation of the clay cap allowed rainwater to infiltrate the buried hazardous materials, resulting in leachate—contaminated water that can carry harmful chemicals into the surrounding soil and groundwater. The result was that the waste, and an increasing amount of groundwater and rainwater, became trapped in a clay “bathtub” (the canal). Case Study: The Love Canal This began overflowing – along with its contaminants – into the basements and back yards of homeowners living near the canal. People complained of odors in the 1960s, and the complaints increased in the 1970s as the water table continued rising. In the 1970s, Love Canal gained national attention when residents of the nearby housing development, built on top of the buried toxic waste, began experiencing alarming health issues. They started noticing strange environmental and health problems. Children playing in the area experienced burns from contact with the soil, and foul odors permeated homes. Case Study: The Love Canal These health problems included birth defects, miscarriages, and a range of serious illnesses such as leukemia and asthma. The residents also noticed foul odors and strange substances oozing from the ground, raising concerns about the safety of their community. The situation at Love Canal sparked a public health crisis and became a focal point for the emerging environmental justice movement. Case Study: The Love Canal Residents organized protests and demanded government action to address the contamination and relocate affected families. After years of pressure, scientific studies confirmed the severe contamination of the area, linking the health problems experienced by residents to the toxic chemicals seeping into their homes. In 1978, President Jimmy Carter declared a federal state of emergency, marking the first time in U.S. history that such action had been taken in response to an environmental disaster. Case Study: The Love Canal Over 800 families were evacuated from the Love Canal neighborhood, and the government undertook extensive efforts to relocate affected residents. Homes closest to the canal were destroyed, and the rest were sealed off. A Superfund program by the Environmental Protection Agency (EPA) was implemented to clean up hazardous waste sites across the country. The disaster gained national attention, and the media coverage made Love Canal a symbol of the dangers of industrial pollution. Case Study: The Love Canal The status in 1993: Love Canal’s 40-acre cap had been repaired and sealed with a thick layer of clay plus a high-density plastic membrane. Contaminated soil had been removed. Around 2.4 m fencing had been built around the site. A drainage system directing leachate to a treatment system had been built. The site’s bottom rests on low-permeability clay, which greatly retards downward movement of leachate. Case Study: The Love Canal Despite the cleanup efforts, Love Canal remains a deeply scarred area. The environmental remediation process included the construction of a containment system to prevent further leakage of chemicals, and parts of the neighborhood have since been declared habitable again. Officials believed that it no longer threatened human health or the environment. They decided to redevelop the area and sell, at reduced prices, the homes that had not been destroyed. Case Study: The Love Canal The new inhabitants as well as the former ones who had never moved are of two minds: Some, especially those who had refused to leave their homes, believe the risks were greatly overstated and blame the city and state for disrupting the canal; Others, believe the site still poses unacceptable risks. Many court cases are still pending filed by people who believe the contamination caused their illnesses. An ongoing study examines the health of local people, but there is no way of measuring the psychological effects on those involved. Case Study: The Love Canal The legal battle following the Love Canal disaster was lengthy. Hooker Chemical was sued by both the state and federal governments, and the company eventually paid millions in settlements. While Hooker argued that it had disclosed the waste and warned the school board, the courts held the company responsible for the resulting contamination. Case Study: The Love Canal Today, Love Canal serves as a sobering reminder of the lasting consequences of environmental negligence and the importance of community activism in holding polluters and policymakers accountable for protecting public health and the environment. While significant strides have been made in cleaning up the site and addressing its legacy, the lessons of Love Canal continue to inform environmental policy and inspire grassroots movements for a more sustainable and just future. https://www.youtube.com/watch?v=FSVzUTS zwrE Good video