Environmental Engineering Reference
In-Depth Information
for all living organisms found in Biosphere 2. It included more than 4,000 organisms making up a savanna,
tropical rain forest, desert, freshwater and saltwater wetlands, an ocean with a coral reef, and lakes and
streams.
Unfortunately, the extensive planning failed to correctly predict the complicated interactions, and carbon diox-
ide levels quickly rose to toxic levels, as oxygen was consumed quickly by bacteria in the soil. Nitrogen oxide
also rose to toxic levels. Both the carbon cycling and nitrogen cycling were failing. Due to unpredicted levels
of cloudiness in Arizona, photosynthesis levels dropped. Also, excess nutrients ended up in the water supply as
nutrients were leached from the soil. Species extinctions also occurred rapidly and in large numbers. Insects
were killed off by local ants that entered the facility from the outside ecosystem; most pollinators eventually
died off and 19 small animal species went extinct, as did some bird species. Other species became pests, prolif-
erating in the environment. These included cockroaches and vines. Although there were many roadblocks and
difficulty in growing crops, the inhabitants were still able to produce 80 percent of their food supply.
The human occupants were able to survive in the closed environment for the entire two-year plan for the pro-
ject, despite the setbacks, and without the desired complete closure to outside influences. A leading-edge ex-
periment, Biosphere 2 served as a basis for many unique studies and research. The experiment also demon-
strates the massive complexity and non-replicable structures of Earth's natural ecosystems.
Events
Bhopal Chemical Disaster
Union Carbide Chemical Co., Bhopal, India, created what is often referred to as the Bhopal disaster or Bhopal
gas tragedy. The Bhopal disaster is history's worst chemical industrial catastrophe. A leak of methyl isocyanate
(MIC) gas and other chemicals developed on the night of December 2, 1984, exposing several thousand people
to the toxic fumes and chemicals. The official immediate death toll related to the release of the gases was 2,259
and the confirmed death toll was 3,787. Other agencies estimated the death toll at 15,000. In 2006, the govern-
ment confirmed that the leak, in fact, caused 558,125 fatalities.
Chernobyl Nuclear Disaster
The Chernobyl disaster is the worst nuclear reactor disaster in history. Although the city of Chernobyl was part
of the Union of Soviet Socialist Republics (USSR) until 1991 when the USSR dissolved and Chernobyl be-
came part of the Ukraine. The disaster occurred on April 26, 1986, when reactor number four suffered a power
output surge during an unauthorized system test. When an attempt was made to perform an emergency system
shutdown, a more extreme power output spike occurred, which ruptured the reactor vessel and caused a series
of explosions. The graphite moderator was exposed to the air and ignited. The resulting fire sent a plume of ra-
dioactive fallout into the atmosphere, covering an extensive area. Over 350,000 people were eventually evacu-
ated from the worst contaminated areas. Twenty-eight emergency responders died in 1986 from Acute Radi-
ation Syndrome and 19 more died later as a result of exposure. It is estimated that 4,000 deaths will ultimately
be attributed to the accident due to increased cancers.
Cuyahoga River Fire
The Cuyahoga River is located in northeast Ohio and is most famous for being "the river that caught fire." In
fact, there have been 13 reported fires on the river—one of the country's most polluted—the first being in
1868. The largest fire occurred in 1952, causing over $1 million in damages. On June 22, 1969, the river
