Odors Associated with Oil Spills
TASA ID: 897
The BP Oil Spill of 2010 has brought attention to the human senses, especially the sense of smell. Humans could easily smell the oil spill from shoreline locations, in an ocean breeze blowing toward the shore, well before the oil was on the beach or even within view of the shore.
Odors have long been associated with oil spills. The volatile and semi-volatile compounds within the oil create a large variety of odors that are easy to recognize. The human nose can smell to levels approaching parts per billion or parts per trillion range. This is the low end of human odor detection, and the highest concentrations that humans can smell are concentrations only ten to fifty times above the detection threshold level. The maximum concentration that a human can smell is often the maximum intensity that humans can detect. As perceived by humans, odors have five basic properties that can be quantified: intensity, degree of offensiveness, character, frequency and duration. Human sensitivity to odor is quite variable among the population and changes with age and other factors. There are many animals, such as dogs and bears, with smell sensitivities that are many times greater than the human nose.
ODORS
Some of the specific odors that are being identified and associated with the BP Oil Spill:
"Rotten Egg" Odor
This odor is commonly associated with hydrogen sulfide (H2S), a compound commonly found in association with crude oil and natural gas. The levels of H2S that have been reported to date may cause irritation, but as stated above, these effects should go away when H2S levels go down, or when a person leaves the area. While H2S is associated with oil and natural gas extraction, it also comes from marshes and sewage treatment plants in anaerobic or reducing environments. According to the US EPA, because H2S has only been seen at individual monitors on an infrequent basis, this indicates the H2S is more likely from a local source near the monitor rather than from the oil spill. The US EPA does not know the exact source of H2S in these areas.
"Gas Station-Like" Odor
The gas station odor indicates volatile organic compounds, or VOCs. The odor is similar to the smell associated with filling up at a gasoline station. The key toxic VOCs in most oils are benzene, toluene, ethylbenzene, and total xylenes. Benzene has been identified as a carcinogen by some regulatory agencies. Exposure to low levels of VOCs may cause temporary irritation of the eyes, nose, throat, and skin. Health organizations such as the CDC note that people with asthma may be more sensitive to the effect of inhaled VOCs. According to the US EPA, the VOC smell may give someone a headache or upset stomach but is not expected to cause long-term health effects. The health effects relate to the specific compound and the concentration of the compound as well as the exposure pathways and sensitivity of certain individuals to these types of compounds. Those individuals sensitive to the smell of VOCs should stay indoors to limit exposure. In addition, it is recommended to close windows and doors to minimize exposure. Also, setting the air conditioner to a recirculation mode can help to limit exposure from outdoor air. The smell may become stronger if the wind or weather changes.
Historical data on oil spills indicate that VOCs are likely to evaporate, disperse and/or react quickly after the oil reaches the surface of the water. The US EPA is measuring very low levels of VOCs.
"Oily" or "Tar-Like" smell
Some chemicals in the weathered crude oil are known as semi-volatile organic compounds (or SVOCs), and they are primarily responsible for the "oily odors." Some of these chemicals are hazardous, depending on the concentration and specific composition.
SUMMARY
In sum, there are odors that will be associated with the BP Oil Spill of 2010, and humans can differentiate odors down to the parts per billion and even parts per trillion range. Over time, the spill-related odors will dissipate and become less noticeable. But beyond the odors, there are likely to be enormous environmental damages associated with the BP Oil Spill of 2010. The damages will include the horrible loss of the rig workers and the destruction of the rig on April 20, 2010. Moving closer to shore, the losses include the loss of a way of life, including business opportunities for those in the tourism industry, drilling industry and fishing industries, as well as countless of other businesses in supporting roles. The environment will experience significant long-term damage, as geochemical composition of sediments, marine and non-marine surface and groundwater will react with and change their chemistry as a result of the impact of the BP Oil Spill. Those changes will impact everything living in the Gulf Coast shoreline and offshore areas, including the fish, corals, marine mammals, reptiles, birds and other wildlife. In the BP Oil Spill case, BP, as a member of the resource extraction industry, is removing the natural riches from the federal and state lands, and these lands, as well as private lands, need to be protected so that the responsible removal of those resources occurs in the most efficient and safe manner possible in order to protect all workers, the general public, wildlife and the environment.
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