Top 10 of anthropogenic and natural environmental disasters
Note: The division in the top 10 is dependent upon death toll, injuries, (lasting) damage and media exposure of the environmental disasters in question. It does not imply that one specific disaster is worse than another.
1. Bhopal: the Union Carbide gas leak
December 3, 1984 has become a memorable day for the city of Bhopal in Madya Pradesh county, India. Shortly after midnight, a poisonous gas cloud escaped from the Union Carbide India Limited (UCIL) pesticide factory. The cloud contained 15 metric tons of methyl isocyanate (MIC), covering an area of more than 30 square miles. The gas leak killed at least 4.000 local residents instantly and caused health problems such as oedema for at least 50.000 to perhaps 500.000 people. These health problems killed around 15.000 more victims in the years that followed. Approximately 100.000 people still suffer from chronic disease consequential to gas exposure, today. Research conducted by the BBC in 2004 pointed out that this pollution still causes people to fall ill, and ten more die every year. This event is now known as the worst industrial environmental disaster to ever have occurred.
(Note that the numbers of victims are not absolute, as they are different for every organization that describes the accident in books or on their websites. Particularly the Union Carbide company states a much lower total number of victims.)
Union Carbide was accused of deliberate evasion of regular safety procedures. During lawsuits where victims demanded compensation, documents were revealed which proved that Union Carbide regularly used untested technology in the Bhopal factory. When the gas leak occurred doctors were not informed of the nature of the gas. This caused the correct treatment and emergency measures to be held off.
On April 26, 1986 tests were conducted in nuclear reactor 4 of the Chernobyl nuclear power plant in Ukraine, located 80 miles from Kiev. These tests required part of the security system to be shut down. Errors in the reactor design and errors in judgment of the personnel of the power plant caused cooling water to start boiling. This caused reactor stress, resulting in energy production increases to ten times the normal level. Temperatures reached more than 2000 °C, causing fuel rod melting and further cooling water boiling.
The people that have lived in the Chernobyl area during the accident suffer from various health problems. Immediately following the accident, hundreds of people were diagnosed with radiation sickness. Particularly in Belarus, there has been a dramatic increase in the number of thyroid cancers (2.400%) and leukaemia (100%).
The extraordinary increase in the number of these illnesses can be associated with the exposure of the population to the aggressive radioactive particles released by the Chernobyl explosion. Four dangerous substances were released, which are not identified as such by our bodies:
Governments in the region estimate that up to seven million people were affected by the accident. Four years after the accident, 627.000 Soviets were already under permanent observation for symptoms and effects of radiation poisoning. The number of individuals that will ultimately be affected by the Chernobyl disaster has been estimated as high as 11 times that of the cancer deaths expected from the combined 1945 bombings of Hiroshima and Nagasaki. Today it is believed that over 4 million people in the Ukraine, Belarus and western Russia still live on contaminated ground.
After the Chernobyl disaster international organizations pressured the Ukrainian government to close the remaining reactors. This was disadvantageous for the country, because it derived 5% of its power supply from the power plant. Eventually, it was decided that the power plant would be closed in winter of the year 2000. The Ukrainian government tried to obtain a postponement, but the reactor was nevertheless closed in December 2000.
Dangerous chemicals emitted by the nuclear power plant after the explosion continue to spread by bush fires and weather conditions, re-contaminating soil, air and water. New radiation hot spots are still being discovered today in Belarus and Ukraine and evacuations will need to continue well into the 21st century. Plans have now been made to build a 20.000 ton steel shell to replace the failed sarcophagus around reactor 4. If construction is successful, this will be ready by 2007.
On midday of July 10, 1976 an explosion occurred in a TCP (2,4,5-trichlorophenol) reactor in the ICMESA chemical company in Meda, Italy. A toxic cloud escaped into the atmosphere containing high concentrations of TCDD, a highly toxic form of dioxin. Downwind from the factory the dioxin cloud polluted a densely populated area of six kilometres long and one kilometre wide, immediately killing many animals. A neighbouring municipality that was highly affected is called Seveso. The accident was named after this village. The dioxin cloud affected a total of 11 communities.
The Seveso accident and the immediate reaction of authorities led to the introduction of European regulation for the prevention and control of heavy accidents involving toxic substances. This regulation is now known as the Seveso Directive. This Directive was a central guideline for European countries for managing industrial safety.
The most remarkable feature of the Seveso accident was that local and regional authorities had no idea the plant was a source of risk. The factory existed for more than 30 years and the public had no idea of the possibility of an accident as it occurred in 1976. The European Directive was created to prevent such ignorance in the future and to enhance industrial safety. The Council of Ministers of The European Committee adopted the Directive in 1982. It obligates appropriate safety measures, and also public information on major industrial hazards, which is now known as the ‘need to know’ principle.
"Direr visions, worse foreboding
December 1952 brought an episode of heavy smog to London, which lasted until March 1953. Light winds and a high moisture content created ideal conditions for smog formation. The unusual cold in London in the winter of 1952-1953 caused additional coal combustion and many people travelled only by car, which caused the occurrence of a combination of black soot, sticky particles of tar and gaseous sulphur dioxide. This resulted in the heaviest winter smog episode known to men.
The smog episode killed approximately 12.000 people, mainly children, elderly people and people suffering from chronic respiratory or cardiac disease. The number of deaths during the smog disaster was three or four times that on a normal day. They could be attributed to lung disease, tuberculosis and heart failure. Mortality from bronchitis and pneumonia increased more than sevenfold.
Peaks of smoke and sulphur dioxide were in line with peaks in deaths. However, most deaths occurred because of breathing in acid aerosols, which irritates or inflames the bronchial tubes. Acidity was not measured, but estimates show that the pH probably fell to 2 during the peaks in the smog episode.
At the end of the 20th century and the beginning of the 21st century there have been oil spills all over the world, caused either by naval accidents or during major wars. It is impossible to determine which of these oil spills had the most severe consequences for its environment. Consequently, we will sum up a number of oil spills in this environmental disaster top 10. First, we will describe some events that obtained a lot of media attention.
In 1978 on March 16 the Liberian super tanker Amoco Cadiz stranded on Portsall Rocks off the coast of Brittany, France because of failure of the steering mechanism at 9:15. Although Captain Pasquale Bandari hoisted the international signal for "Not Under Command" almost immediately, he did not request assistance until 11:20, when his engineer determined that the damage was irreparable. The Amoco Cadiz started drifting to shore where touching the bottom ripped open the hull and storage tanks.
On July 6, 1988 an explosion occurred on the oil and gas production platform Piper Alpha of Occidental Petroleum Ltd. and Texaco in the North Sea. Piper Alpha was located on the Piper Oilfield, about 190 kilometres from Aberdeen in 144 metres of water. There were about 240 people working on the platform. The explosion and resulting fire killed 167 of them. It is now said that evacuation plans were inadequate and therefore failed preventing any of the deaths. By the time rescue helicopters arrived, flames over 100 metres in height prevented safe approach. Only 62 workers were pulled from the sea alive.
In 1989 the American oil tanker Exxon Valdez clashed with the Bligh Reef, causing a major oil leakage. The tanker had left the Valdez terminal in Alaska, navigating through Prince William Sound. Captain Joseph Hazelwood informed the coast guard they would change course to avoid collision with some small icebergs present in the region. The coast guard instructed the captain to sail north.
In August 1990 Iraqi forces invaded Kuwait, starting the Gulf War in which an allegiance of 34 nations worldwide was involved. In January 1991 of the Gulf War, Iraqi forces committed two environmental disasters. The first was a major oil spill 16 kilometres off the shore of Kuwait by dumping oil from several tankers and opening the valves of an offshore terminal. The second was the setting fire to 650 oil wells in Kuwait.
The apparent strategic goal of the action was to prevent a potential landing by US Marines. American air strikes on January 26 destroyed pipelines to prevent further spillage into the Gulf. This however seemed to make little difference. Approximately one million tons of crude oil was already lost to the environment, making this the largest oil spill of human history. In the spring of 1991, as many as 500 oil wells were still burning and the last oil well was not extinguished until a few months later, in November.
The oil spills did considerable damage to life in the Persian Gulf (see picture). Several months after the spill, the poisoned waters killed 20.000 seabirds and had caused severe damage to local marine flora and fauna. The fires in the oil wells caused immense amounts of soot and toxic fumes to enter the atmosphere. This had great effects on the health of the local population and biota for several years. The pollution also had a possible impact on local weather patterns.
In the early hours of December 14, 2002 the Norwegian ship Tricolor collided with the Bahama container ship Kariba in the French Channel. The accident was caused by fog and human errors. The Kariba was heavily damaged, but managed to reach the Antwerp harbour. The crew of Tricolor was rescued by emergency teams, which experienced low visibility that made the rescue operation very hard. Fortunately, nobody was hurt.
In January 2003 the oil tanker Vicky collided with the Tricolor, causing some oil from the Vicky to flow into sea and reach French and Belgium shores. Fortunately damages were limited and the Tricolor did not leak any oil.
There have been many other accidents involving oil spills throughout the years. Many received not nearly as much media attention as the ones mentioned above. Some more examples of oil spills:
- 1967 Liberian tanker Torrey Canyon spills 120.000 ton oil near Cornwall
In 1920 Hooker Chemical had turned an area in Niagara Falls into a municipal and chemical disposal site. In 1953 the site was filled and relatively modern methods were applied to cover it. A thick layer of impermeable red clay sealed the dump, preventing chemicals from leaking out of the landfill.
Lois Gibbs, an activist, noticed the high occurrence of illness and birth defects in the area and started documenting it. In 1978 newspapers revealed the existence of the chemical waste dump in the Love Canal area and Lois Gibbs started petitioning for closing the school. In August 1978, the claim succeeded and the NYS Health Department ordered closing of the school when a child suffered from chemical poisoning.
The chemicals had entered homes, sewers, yards and creeks and Gibbs decided it was time for the more than 900 families to be moved away from the location. Eventually President Carter provided funds to move all the families to a safer area. Hooker’s parent company was sued and settled for 20 million dollars.
None of the chemicals have been removed from the dumpsite. It has been resealed and the surrounding area was cleaned and declared safe. Hooker’s mother company paid an additional 230 million dollars to finance this cleanup. They are now responsible for the management of the dumpsite. Today, the Love Canal dumpsite is known as one of the major environmental disasters of the century.
Workers in gold mines use cyanide (CN) to purify gold from rocks. This is applied for example in Rumania. At 22:00 hours on January 30, 2000 cyanide (fig. 2) used in a gold mine in Baia Mare overflowed into the major river the Somes and subsequently into the river Tisza. The cause of the spill was a break in the dam that surrounded a settling basin. This resulted in the release of at least 100.000 cubic meters of water with very high cyanide concentrations. The waste water did not only contain cyanide, but also heavy metals such as copper, zinc and lead. Copper concentrations exceeded the heavily polluted threshold 40-160 times, the zinc concentration was twice above this standard and the lead concentration 5-9 times greater.
Cyanide is a very aggressive toxin that can kill people. Consequently, when Rumanian authorities were notified of the spill they immediately raised the alarm. This rapid response prevented any human victims. However, the spill did kill all aquatic plant and animal life for dozens of miles downstream. On February 12 it even impacted the major European river Danube, which receives water from the Tisza. This caused the impact to be noticeable in Hungary and Serbia, as well. Inhabitants of Belgrado witnessed Danube water full of dead fish flowing by. Up to 100 people, most of them children, have been treated in hospital after eating contaminated fish. The Rumanian media entitled this environmental disaster ‘the largest since Chernobyl’.
Bovine Spongiform Encephalopathy (BSE), is a fatal cow disease. The disease is sometimes called ‘mad cow disease’ because it causes cows to act strangely and collapse on the spot (see picture). It is concentrated mainly in the cow's brain, spinal cord and certain organs such as the spleen.
Table 1: year of discovery of first BSE cases by country
Many countries banned the use of meat and bone meal after the outbreak of BSE in Europe. However, in Germany meat and bone meal was still permitted in cow feed until 2000. This caused an aftermath of the epidemic in 2003.
*Note that the BSE epidemic of 1990-2001 was mainly concentrated in the western European Union countries
The incidences of BSE are relatively small in number, but the discovery of the disease had a dramatic effect on European beef consumption, which fell to 27%. In 2001 the European BSE epidemic ceased, having only an aftermath in Germany in 2003 (see above). Even after bringing the BSE epidemic under control people are still being diagnosed with its human variant each year, because of its long incubation period. The full extent of the outbreak may still be unknown.
On April 25, 1998 the dam of the mining residual tank of a pyrite mine in Aznalcollar, Spain suffered a rupture, releasing sludge and contaminated wastewater. The wastewater entered the Guadiamar River, polluting the river with heavy metals such as cadmium, lead, zinc and copper. It affected an area of 4.634 hectares, contaminating 2.703 hectares with sludge and 1.931 with acidic water.
The river pollution caused cultivation lands and forests to be affected. Harvests were no longer fit for consumption, causing financial problems for farmers in the area. Major fish mortality occurred and birds died as a result of consumption of polluted fish. It took one whole month for the river water to recover to its original state.
After the wastewater flow had entered the river a major cleanup operation started, including the installation of walls to prevent further spreading of contaminants and the removal of contaminated sludge. The pH values of the soil were restored by liming and arsenic was removed by adding iron oxyhydroxides, causing a precipitation reaction.
Company technicians stated that the rupture of the residual tank was caused by a deep landslide, which provoked the movement of a certain section of the wall. Authorities also researched the cause of the disaster. Apparently the dam was a weak construction and warnings of possible breakthrough were neglected. The Canadian/ Swedish corporation Boliden was held responsible for the wastewater spill. The company was sentenced to financing the cleanup operation and paying compensation to victims.
At approximately 4:00 a.m. on March 28, 1979 the main feed water pumps in the non-nuclear cooling system of reactor 2 of the Three Mile Island nuclear power plant near Harrisburg, Pennsylvania failed. This caused cooling water to drain away from the reactor resulting in partial melting of the reactor core. Operator errors, a stuck valve, faulty sensors and design errors together resulted in a release of approximately one thousandth as much radiation as during the Chernobyl explosion.
Radiation from the Three Mile Island reactor has contributed to the premature deaths of some elderly people that lived in the region. Dairy farmers reported that many animals have died consequential to the accident and local residents have developed cancers. Some studies suggested that premature deaths and birth defects also resulted from the nuclear melt-down.
- Lomborg, B., The Skeptical Environmentalist - Measuring the Real State of the World. Cambridge University Press 1998, United Kingdom
- McKinney, M.L., Schoch, R.M., Environmental Science: Systems and Solutions, Third Edition Jones and Bartlett Publishers, Sudbury Massachusetts 2003
- Encyclopaedia: http://www.wikipedia.org
- Encyclopaedia: http://www.britannica.com
- Bhopal: http://www.unioncarbide.com/
- Bhopal: http://www.bhopal.com
- Chernobyl: http://www.chernobyl.co.uk/ and the Chernobyl Children's Project International: http://www.chernobyl-international.com/aboutchernobyl/disaster.asp
- London Smog: BBC news, London University
- NOAA Oil spill review, published in 2003 - http://response.restoration.noaa.gov/oilaids/spilldb.pdf
- Amoco Cadiz: http://greennature.com/article219.html
- BSE crisis: BBC, Asian Food Information Center
- Spain wastewater spill: Oceanographic Institute of Paris, Environmental Restoration of the Guadiamar River Basin Affected by the Accident at the mine in Aznalcollar, Spain. Paris, October 2002 -> http://www.le-cedre.fr/uk/publication/jourinfo02/esp.pdf
1. Global epidemics (the Plague, Spanish Flu and AIDS)
It is suggested that the AIDS crisis today is an epidemic that could take similar forms as the fourteenth century plague. AIDS (Acquired Immunodeficiency Syndrome) is caused by the Human Immunodeficiency Virus (HIV). HIV is a retrovirus that infects cells of the human immune system, causing people to become much more susceptive to disease. People infected with AIDS die for example of pneumonia.
Other countries that were hard hit with AIDS are in Asia and South America. In Asia, the nations of Cambodia, India, Myanmar and Thailand have suffered major loses as a result of the AIDS epidemic. In Latin America and the Caribbean area Brazil and Haiti also have major segments of their populations that are infected. As in Botswana, the disease decreases life expectancies and causes population declines.
Despite the many efforts of developed countries, such as the Live 8 concerts for AIDS in Africa in 2005, the epidemic lingers on. Its full effect may not be visible for another generation or more.
Arsenic is a poisonous metalloid that can be found in three forms; yellow, grey and black arsenic. Arsenic compounds are used as pesticides and in various alloys. It is not only toxic to insects and some plants, but also to humans. Its toxicity stems from the similarity of the chemical structure to phosphorus, causing it to partly substitute phosphorus in chemical reactions.
Legal proceedings began in London in 2003 to determine whether the British Geological Survey was negligent in failing to detect arsenic in Bangladeshi water supplies. The organization conducted research on behalf of the Bangladesh government in 1992, but did not test the groundwater for arsenic. The organization pleas 'not guilty' and argues that at the time of its report little was known about the geological origins of arsenic poisoning.
We have very recently experienced a natural environmental disaster that made worldwide news. In December 2004 an oceanic earthquake of 9-9,3 on a Richter scale caused devastation in Asian countries. The earthquake was among the 10 deadliest in history. Scientists reported that it had lasted nearly ten minutes when most major earthquakes last no more than a few seconds. Since 1900 the only earthquakes recorded with a greater magnitude were the 1960 Great Chilean Earthquake (9,5), the 1964 earthquake in Prince William Sound (9,2), and the 1957 earthquake near the Andreanof Islands (9,1). But all these areas were less densely populated than the Asian earthquake area in 2004 and therefore had a much smaller death toll.
This year (2006) a report was released by the Tsunami Evaluation Coalition (TEC) on the efficiency of international aid after the earthquake and tsunami in Asia. TEC is a cooperation between UN-organisations such as Unicef and WHO, consultancies, donors and organisations for humanitarian aid such as Oxfam Novib.
Table 3: categories of the Richter scale
Tropical cyclones are a type of low pressure system which generally forms in the tropics. They are an important part of the atmospheric circulation system, which moves heat from the equatorial region toward higher latitudes. Tropical cyclones can be either tropical storms, typhoons or hurricanes, depending on the winds speed.
The Saffir-Simpson hurricane scale
Hurricanes are ranked according to the Saffir-Simpson hurricane scale, according to wind speeds. The scale was developed in 1969 by civil engineer Herbert Saffir and National Hurricane Center director Bob Simpson. In terms of effects, the rankings are not absolute because any type of hurricane can inflict terrible damage, even when wind speeds are not very high relatively. If hurricanes with low wind speeds result in floods and landslides damages are still considerable.
Table 4: categories of the Saffir-Simpson hurricane scale
There have been hurricanes all over the tropics for many centuries.
Examples of some other hurricanes:
On August 17, 1999 a heavy earthquake of 7,5 on a Richter scale (see 1) hit Izmit, a city in Turkey. It occurred on one of the world's longest and best-studied horizontal motion faults, called the east-west trending North Anatolian fault. This fault causes earthquakes at less than 20 km depth, causing people at the surface to be close to where the energy is released.
The earthquake killed some 17.000 people and left thousands more without a home. On November 12 another tremor of 7,2 on a Richter scale hit the location, killing 450 more and leaving 3000 people injured.
On Saturday, January 31 of 1953 the Dutch weather service gave out a warning of an approaching northwester storm on the North Sea. In the night of January 31 – February 1 the storm reached the Netherlands and started increasing. The storm than included heavy winds of 150 km/h.
In 1998 raging wildfires brought on by unimaginable droughts were sweeping the northern Brazilian state Roraima. The fires took place on its savannahs, grassland and deciduous forests. Hundreds of people were killed in the fires and one of the planets most primitive peoples, the Yanomami Indians, were threatened.
It is thought that the first fires started because of forest clearing for agricultural land. Farmers in Brazil often burned parts of forest to gain fertile farmland. Droughts caused fires to linger, rather than burn out.
Other known wildfires
Wildfires have occurred all over the world, particularly in forest regions.
Mount Pinatubo is an active volcano situated on the isle of Luzon in the Phillipines, on the borders of the Pampagna, Balaan and Zambales provinces.
Other volcanic eruptions
Mount Pinatubo is not the only volcano that erupted in the 20th century. Volcanic eruptions have been recorded long before the 20th century, for example Vesuvius in Italy in 79 AD. This eruption ruined the cities Pompeii and Herculaneum and killed 15.000 people. Even now, volcanic eruptions still occur.
Examples of recorded eruptions in the past centuries:
Click here to read more about environmental effects of volcanic eruptions
The United States have a history of tornadoes, destroying homes and land and killing people on their way. About 80% of all tornadoes occur in the US, mostly on the Great Plains. A tornado consists of a rapidly rotating vortex of air that forms a funnel (see picture). Tornadoes become harmful when the funnel touches earth. Winds of 250-300 km/h cause tornadoes to lift objects weighing hundreds of tons and may even drain entire lakes. Tornadoes typically cause destruction in areas of 1 km wide and 10-20 km long.
When the tornado hit West Frankfort most men were working in the mine. About 800 miners had to await a power-failure before they could reach their homes. The 127 deaths and 450 injuries caused by the tornado were mostly among their women and children.
Table 5: death tolls of the Missouri tornado in various states/ towns
The Missouri tornado is currently the number 1 United States tornado with the highest death toll and the most violent winds. In total it killed 671 people and injured another 2.027. Tornadoes still occur and when Americans are surprised by tornadoes in the future, these may cause even more destruction than the Missouri tornado of 1925.
Like earthquake, the strength of a tornado is measured according to a scale, the so-called Fujita scale. The scale was introduced in 1971 by Theodore Fujita of the University of Chicago and Allan Pearson, head of the Forecast Center in Kansas City, Missouri. It is based on the intensity by the damage it inflicts on human-built structures. The actual F scale of a tornado is determined after it has hit, according to satellite images, eye-witness accounts and visible damage. There are a total of six separate categories.
Table 6: categories of the Fujita tornado scale
Tornadoes have occurred all over the United States for many centuries.
Examples of other past tornadoes:
Estimates have shown that dust storms blow about 11,8 millions metric tons of desert sand from Africa to the Northeast Amazon Basin in Brazil annually. Dust storms occur everywhere around the world. Their natural function is replacement of soils and carrying nutrients from one part of the globe to another. Iron and other nutrients are blown out to sea where they maintain marine ecosystems. Central and South American rain forests also receive vital nutrients from Saharan dust storms.
Causes of dust storms include droughts and poor farming and grazing practises. Oxford University geography professor Andrew Goudie stated in 2001 that cars driving the Sahara are another possible cause of dust storm formation.
China - In 1998 a violent dust storm hit Beijing, China, darkening the skies. This was the worst dust storm in over a decade. Dust was blown from the Gobi Desert near Mongolia into the city. At least 12 people went missing during the storm and power and water supplies were cut. Three Beijing construction workers were killed when strong winds blew iron wire and asphalt off the top of a 2-story building.
Australia - In 2002 Queensland, Australia was hit by a violent desert storm, which shut down regional airports and urged residents to stay indoors. Visibility fell as low as 50 meters in regions with reduced vegetation cover. The dust storm was at least 6 km high at Chaleville, South Queensland and blew more than a million tonnes of dust into the region. Some claimed this was the worst dust storm witnessed in 20 years.
Dust storms are fairly common. Even in Europe the results of a dust storm can sometimes be witnessed as a small dust layer on the tops of cars.
Examples of other dust storms include:
- 1901 dust storm from the Sahara to Europe and the Ural Mountains
- McKinney, M.L., Schoch, R.M., Environmental Science: Systems and Solutions, Third Edition, Jones and Bartlett Publishers, Sudbury Massachusetts 2003
- Encyclopaedia: http://www.wikipedia.org
- Richter scale: http://www.seismo.unr.edu
- Arsenic poisoning: BBC News, Unesco Courier
- Tsunami Asia: http://www.giro800800.nl
- Turkey earthquakes: http://www.earthquakes.bgs.ac.uk/turkey_nov99.htm
- Flood: http://www.bibliotheek.nl
- Volcanic eruptions: various websites
- Wildfires: Daniela Hart, Brazilian Wildfires Threaten Indians, The Washington Post March 1998 and FOA organization, South American Region Fire Assessment, 2003
- Tornadoes: http://www.tornadoproject.com
- Dust storms: BBC News, Herald Sun, MSNBC, New York Times