Environmental Engineering Reference
In-Depth Information
The amount of oil released by the
Deepwater Horizon
spill is one of the largest oil spills in history. The devast-
ation of wildlife and ecosystems, combined with the economic losses to people such as fishermen and the tour-
ism industry, is dramatically higher than that of most spills due to the proximity to the coastline and barrier is-
lands, and to the biologically productive nature of the Gulf of Mexico.
Waterborne Diseases and Pathogens
Health effects from pathogens and waterborne diseases are more immediately devastating than those from any
other form of water pollution. These waterborne diseases include cholera, typhoid, hepatitis A,
E. coli,
dysen-
tery, SARS, giardiasis, and many others. An increasing number of people worldwide have access to safe and
clean drinking water, but an unreasonably high number of people still do not, mainly in developing countries.
Nutrients
Nutrient overload from fertilizers and sewage runoff can create eutrophication, hypoxia, and dead zones in
both marine and freshwater ecosystems, affecting wildlife, ecosystems, and humans.
Eutrophication
occurs
when excess nitrogen or phosphorous enters an aquatic system, leading to an excessive growth of phytoplank-
ton, algae, and other plants. As organisms die off and decompose, the bacteria consuming them use large
amounts of oxygen, which ultimately can deprive an ecosystem of oxygen. A
hypoxic
environment, lacking
oxygen, can form, and much of the ecosystem life cannot survive or will leave the area. An extreme hypoxic
environment can become devoid of any life and become a
dead zone.
Trash
Trash that ends up in oceans can end up in organisms, as some fish and marine organisms consume small
pieces in the assumption that it is food. Some items, such as plastics, do not break down in the organisms' di-
gestive tracts and if it cannot be passed, will remain inside the organism for its lifespan. This can shorten an or-
ganism's life span through a slow release of synthetic chemicals or through the lodging of the trash inside their
bodies. Organisms also can become tangled in fishing gear and other debris, trapping them and ultimately lead-
ing to starvation and death.
Noise
Noise pollution can cause immediate irreversible hearing loss in the event of an extremely loud instantaneous
burst, or it can gradually impact hearing through long-term repeated exposure. Other effects include increased
stress levels, hypertension, aggression, sleep deprivation, short-term hearing loss, and tinnitus. Organisms in
ecosystems are also impacted by noise pollution and may lead to a decline in biodiversity in some areas.
Light
Anthropogenic light can affect organisms by causing distractions or by altering their natural cycles. Light can
alter feeding cycles, prompt unnatural periods of attraction that lead to disruptions in reproductive cycles, dis-
orient migratory birds, and interfere with intraspecies communication. Thus, bright lights are a form of habitat
destruction, altering behaviors, with effects that can be passed throughout an ecosystem.
Also, using more light requires more electricity, which uses more energy and leads to increased emissions.
Genetic
Since genetic pollution is still relatively new, we are still discovering its long-term effects, both good and bad.
Known adverse effects of genetically modifying crops and organisms include the following:
