Question: Mary Ochsenhirt Amdur studied the effects of which historic air inversion that killed 20 people?

full_context: Document 1: Doñana disaster: The Doñana Disaster, also known as the Aznalcollar Disaster or Guadiamar Disaster (Sp: "Desastre de Aznalcóllar", "Desastre del Guadiamar"), was an industrial accident in Andalusia, southern Spain. On 25 April 1998, a holding dam burst at the Los Frailes mine, near Aznalcóllar, Seville Province, releasing 4–5 million cubic metres of mine tailings. The acidic tailings, which contained dangerous levels of several heavy metals, quickly reached the nearby River Agrio, and then its affluent the River Guadiamar, travelling about 40 kilometres along these waterways before they could be stopped. The Guadiamar is the main water source for the Doñana National Park, a UNESCO World Heritage Site and one of the largest national parks in Europe. The cleanup operation took three years, at an estimated cost of €240 million.
Document 2: Cancer Wars: Cancer Wars was a six-part documentary that aired on PBS in May 25, 1998. The first episode discussed the history of cancer research such as contributions of epidemiologists at the University of Jena which were the first to document the link between cancer and smoking. The documentary discusses how US government tobacco interests prevented this evidence from coming to surface since tobacco was such an important US export. Cancer Wars delved into the pioneering work of Rachel Carson, whose book "Silent Spring" radically changed the world's thinking about chemicals and their effects on human health and the environment. Other episodes in this series discussed various topics ranging from the history of the advances in cancer therapy to the influence of Margaret Thatcher's neoliberal policies which cut funding to Anti-smoking campaigns in Britain because of interests in protecting British tobacco companies.
Document 3: Monster Study: The Monster Study was a stuttering experiment performed on 22 orphan children in Davenport, Iowa in 1939. It was conducted by Wendell Johnson at the University of Iowa. Graduate student Mary Tudor conducted the experiment under Johnson's supervision. Half of the children received positive speech therapy, praising the fluency of their speech, and the other half, negative speech therapy, belittling the children for speech imperfections. Many of the normal speaking orphan children who received negative therapy in the experiment suffered negative psychological effects and some retained speech problems for the rest of their lives.
Document 4: 1948 Donora smog: The 1948 Donora smog was a historic air inversion that resulted in a wall of smog that killed 20 people and sickened 7,000 more in Donora, Pennsylvania, a mill town on the Monongahela River, 24 mi southeast of Pittsburgh. The event is commemorated by the Donora Smog Museum.
Document 5: Marylyn D. Ritchie: Marylyn D. Ritchie is a professor of Biochemistry and Molecular Biology and the director of the Center for Systems Genomics at Penn State University. She has published many papers in peer-reviewed journals such as the American Journal of Human Genetics, the Journal of Biological Chemistry, Human Molecular Genetics, Bioinformatics, and PLOS Genetics. Previously, she was an associate professor at Vanderbilt University in the Department of Molecular Physiology and Biophysics and the Department of Biomedical Informatics. She has also served as a consultant for Boehringer-Ingelheim, one of the world's leading pharmaceutical companies.
Document 6: Kingston Fossil Plant coal fly ash slurry spill: The TVA Kingston Fossil Plant coal fly ash slurry spill occurred just before 1 a.m. on Monday December 22, 2008, when an ash dike ruptured at an 84 acre solid waste containment area at the Tennessee Valley Authority's Kingston Fossil Plant in Roane County, Tennessee. 1.1 e9USgal of coal fly ash slurry was released. The coal-fired power plant, located across the Clinch River from the city of Kingston, uses ponds to dewater the fly ash, a byproduct of coal combustion, which is then stored in wet form in dredge cells. The slurry (a mixture of fly ash and water) traveled across the Emory River and its Swan Pond embayment, on to the opposite shore, covering up to 300 acre of the surrounding land, damaging homes and flowing up and down stream in nearby waterways such as the Emory River and Clinch River (tributaries of the Tennessee River). It was the largest fly ash release in United States history.
Document 7: Amy Wetherby: Amy M. Wetherby, Ph.D., CCC-SLP, is a distinguished research professor in the Department of Clinical Sciences and director of the Autism Institute in the College of Medicine and the Laurel Schendel Professor of Communication Disorders at Florida State University. She has thirty years of clinical experience and is a fellow of the American Speech-Language-Hearing Association. Wetherby has published extensively and presents regularly at national conventions on early detection of children with autism spectrum disorders and intervention for children with autism spectrum disorders using the SCERTS model. She is the project director of a Doctoral Leadership Training Grant specializing in autism funded by the U.S. Department of Education. She served on the National Academy of Sciences Committee for Educational Interventions for Children with Autism and is the executive director of the Florida State University Center for Autism and Related Disabilities. Wetherby is the project director of the FIRST WORDS Project, a longitudinal research investigation on early detection of autism spectrum and other communication disorders, funded by the U.S. Department of Education, National Institutes of Health, and Centers for Disease Control and Prevention. She is also the principal investigator of the Early Social Interaction Project, an early treatment study teaching parents of toddlers with autism spectrum disorders how to support social communication and play in everyday activities funded by Autism Speaks and the National Institutes of Mental Health.
Document 8: Donora Smog Museum: Donora Smog Museum features a collection of archival materials documenting the Donora Smog of 1948, an air inversion of smog containing fluorine that killed 20 people in Donora, Pennsylvania, United States, a mill town 20 miles south of Pittsburgh on the Monongahela River.
Document 9: Nakdong River Battle Museum: Nakdong River Battle Museum is a small museum built inside the Apsan Park to commemorate the soldiers and civilians killed during the Korean War at a battle that raged near the Nakdong River. The grounds around the museum are scattered with vintage tanks and airplanes from the Korean War. Built in 1979 the museum has two floors with exhibits from the Korean War and other significant eras in Korea's past. Other areas within the museum pay tribute to those that died in both natural and man-made disasters in Korea's past.
Document 10: Camelford water pollution incident: The Camelford water pollution incident involved the accidental contamination of the drinking water supply to the town of Camelford, Cornwall, in July 1988. Twenty tonnes of aluminium sulphate was inadvertently added to the water supply, raising the concentration to 3,000 times the admissible level. As the aluminium sulphate broke down it produced several tonnes of sulphuric acid which "stripped a cocktail of chemicals from the pipe networks as well as lead and copper piping in people’s homes." Many people who came into contact with the contaminated water experienced a range of short-term health effects, and many victims suffered long-term effects whose implications remained unclear as of 2012 . There has been no rigorous examination or monitoring of the health of the victims since the incident, which is Britain's worst mass poisoning event. Inquests on people who died many years later found very high levels of aluminium in the brain. Dame Barbara Clayton led a Royal Commission on Environmental Pollution enquiry into the incident.
Document 11: Duquesne City School District: Duquesne City School District is a tiny, suburban public school district in the state of Pennsylvania. It is located in the east hills of Allegheny County, and serves the City of Duquesne (upwards of 7,000 residents), a former mill town on the banks of the Monongahela River. Duquesne City School District encompasses approximately 2 square miles. Per 2000 federal census data, it served a resident population of 7,352. According to 2010 federal census data, the resident population declined sharply to 5,566 people. The educational attainment levels for the Duquesne City School District population (25 years old and over) were 89.5% high school graduates and 9.2% college graduates.
Document 12: Kimberly Renee Dunbar: Kimberly R. Dunbar received her B.S. in Chemistry at Westminster College in 1980, followed by her Ph.D. in Inorganic Chemistry in 1984 at Purdue University studying with professor Richard Walton. Dunbar then became a Postdoctoral Research Associate in Inorganic Chemistry with F. Albert Cotton in 1985-1986 at Texas A&M University, before going on to spend the next twelve years conducting research and teaching at Michigan State University, where she moved through the ranks ultimately becoming a Distinguished Professor in 1998. She was recruited back to Texas A&M University in 1999, where she currently holds a Davidson Chair of Science and the Distinguished Professorship of Chemistry. Notably, Dunbar is the first female chair holder of the College of Science at TAMU.
Document 13: Exide lead contamination: The Exide lead contamination, in southeast Los Angeles County, California, United States, came from a battery recycling plant that emitted lead, arsenic and other dangerous pollutants over decades that contaminated as many as 10,000 homes in half a dozen working-class, Latino communities near the plant. Exide Technologies, owner of the lead-acid battery smelter located in Vernon, agreed in 2015 to close the facility while the massive cleanup of the contaminated soil will take years and cost hundreds of millions of dollars. The residents have expressed outrage over the failure of state regulators to act as the plant was allowed to operate without a full permit while documented violations were occurring. The Department of Toxic Substances Control, which allowed the plant to operate, is in charge of the cleanup and is finding that the many residents do not trust them. The residents must give them permission to test the soil around their home yet many feel betrayed by this government agency.
Document 14: Soma mine disaster: On 13 May 2014, an explosion at a coal mine in Soma, Manisa, Turkey, caused an underground mine fire, which burned until 15 May. In total, 301 people were killed in what was the worst mine disaster in Turkey's history. The mine, operated by coal producer Soma Kömür İşletmeleri A.Ş., suffered an explosion, the cause of which is still under investigation. The fire occurred at the mine's shift change, and 787 workers were underground at the time of the explosion. After the final bodies were pulled from the mine on May 17, 2014, four days after the fire, the Minister of Energy and Natural Resources Taner Yıldız confirmed the number of dead was 301. Disaster and Emergency Management Presidency (AFAD) announced the names of 301 workers who died in the mine disaster and 486 people who survived but some politicians claimed that the number of dead is more than 340.
Document 15: Mary Amdur: Mary Ochsenhirt Amdur (February 18, 1921 – February 16, 1998) was an American toxicologist and public health researcher who worked primarily on pollution. She was charged with studying the effects of the 1948 Donora smog, so she specifically looked into the effects of inhaling Sulfuric acid by experimenting on guinea pigs. Her findings on the respiratory effects related to sulfuric acid led to her being threatened, to her funding being pulled, and to her losing her job at the Harvard School of Public Health in 1953. Undeterred by the setback, she carried on her research in a different role at Harvard, and subsequently at MIT and New York University. Despite the early controversy related to her work, it was used in the creation of standards in air pollution, and towards the end of her life she received numerous awards and accolades.
ground_truth: 1948 Donora smog