Environmental Biosensors

A biosensor is any “device for the detection of an analyte that combines a biological component with a physicochemical detector component” [1] consisted of a sensor, a detector, and a signal processor. The use of biosensors is important in the detection of varying chemicals that induce reactions on promoters in gene sequences thus emitting a form of measurable output. The advantages of environmental biosensors over the current methods are the portability, relatively low cost, and environmentally friendly characteristics of microorganisms over bulky equipment. Biosensors have potential to be maintained on-site able to monitor conditions continuously in the soil or marine environments without significant effort being placed into the maintenance as is customary in expensive equipment that must be maintained and used by skilled workers.

For traditional “offsite” laboratory testing, the samples must be sent in proving to be a costly and ineffective method. The new trend towards biosensors aims to “provide fast, reliable, and sensitive measurements with lower cost; many of them aimed at on-site analysis.” [2] Most biosensor systems have focused on the use of bacterial organisms, while the use of eukaryotic organisms is rare. One particular concern is the presence of water-soluble aromatic components of petroleum products in drinking water that often persist in the environment. [2]

According to The Department of Environmental Biochemistry in Barcelona, “Genetic engineering provides an elegant way not only for providing unlimited amounts of biorecognition molecules, but also for the alteration of existing properties and the supplementation with additional functions”, which addresses our problem directly.[2]

Oil Spills

Because of the recent Deepwater Horizon Oil Spill disaster and the resulting implications of oil contamination in the environment, we hope to provide you a thorough informational resource for learning about not only the current oil spill, but also general information regarding oil spills because of its direct connection to the one of the main goals of our project.

Facts:

• The United States uses 700 million gallons of oil a day
• Oil has many uses in human activities: fuel source, lubricate machinery, make plastics, make medicines and pesticides, make asphalt
• Natural seepage of crude oil from geologic formations below the seafloor is estimated to exceed 47,000,000 gallons in North American waters and 180,000,000 gallons globally every year

Oil spills cause the oil to float on the saltwater of the ocean, spreading out rapidly across the surface of the water to create a thin sheen. The methods of clean up for oil spills include booms, floating barriers to oil, skimmers, sorbents, dispersants, in-situ burning, vacuum trucks, and washing.

There are four major sources of pollution: naturally occurring oil seeps, extraction, transportation, consumption. Despite popular thought, the oil spills caused by transportation and disasters only constitute a small portion of the oil that enters marine environments every year. The following charts based on information provided by the Ocean Studies Board and Marine Board of the National Academy of Sciences, show the percentage of oil contamination as per each category of source of pollution.

Similarly, oil spills have differing impacts depending on a variety of factors including location, size, and temperature. However, the size of an oil spill does not necessarily dictate the impact that an oil spill will have on a marine environment; rather, the impact of an oil spill depends on its location.

Deepwater Horizon Oil Spill

The Deepwater Horizon Oil Spill, referred to also as the BP Oil Spill and the Gulf Oil Spill, is a large oil spill in the Gulf of Mexico that is currently the largest oil spill in America’s history with hundreds of millions of gallons of oil spilled. Following a deep oil rig explosion occurring on April 20, 2010 killing 11 workers, the leak has been gushing oil.

Follow the link to watch a short and interesting video relating to the [http://www.youtube.com/watch?v=XLiqvZOP8TY/ Deepwater Horizon Oil Spill mechanics].

The Deepwater Horizon Oil Spill had caused serious backlash and worry over the environment surrounding the impacted oil rig, and the toxic compounds and environmental hazards of oil have been looked into again in order to create an efficient clean up of the oil spill.

The toxic compounds in oil vary, but some of the most worrisome of compounds are the polycyclic aromatic hydrocarbons (PAHs) including napthalenes, benzene, toluene, and xylenes not only to the environment but to humans as well. According to experts, the ecology nearest to the spill and in the upper water column will be greatly affected and “contamination could ultimately end up having cascading effects up the food chain.” According to the article, “when an oil spill occurs, there are no good outcomes.” [3]

The northern Gulf of Mexico hypoxic zone, an “underwater area with little or no oxygen known commonly as the ‘dead zone”’[4] , has been predicted to grow and be negatively affected by the growing crisis with the Gulf Oil spill. There is evidence of underwater oil plumes which could be attributed to BP’s injection of chemical dispersants at the source of the leak. “These reports found that the high pressure of oil released from a deepwater blowout causes droplets and bubbles to form. Natural gas also rushes into the ocean, joins the crude, and helps form a buoyant plume of oil and gas. As this plume rises, it pulls in dense water from the ocean’s depths. Eventually, the denser water in the mixture slows the plume’s ascent.” [5] The more time that oil spends in the water, the more time the components of oil – including the more toxic compounds such as the PAHs and aromatic compounds – have to dissolve into the water and affect the aquatic ecosystem. Also, there are reports over the actual values of biodegradation occurring in the ocean environments. Typically, biodegradation occurring in marine environments is measured through the depletion of oxygen; however, some critics of dispersant use claim that the decreased oxygen use could actually be caused by oil- eating microbes consuming particles of the dispersant rather than the intended petroleum.

Deepwater Horizon Oil Spill Updates

The following information is taken from the [http://www.doi.gov/ Department of the Interior] and the [http://topics.nytimes.com/top/reference/timestopics/subjects/o/oil_spills/gulf_of_mexico_2010/index.html?scp=1-spot&sq=BP%20Oil%20Spill&st=cseupdates/ New York Times] on the updates of the BP Oil Spill. To look for more detailed information regarding the BP Oil Spill visit the [http://www.bp.com/extendedsectiongenericarticle.do?categoryId=40&contentId=7061813/BP Global Site Oil Spill Response].

July 19:

• • Subsea containment efforts continue with the capping stage
  • 408 controlled burns

July 15:

• • 5,000 personnel are currently responding to protect the shoreline and wildlife
  • 32.9 million gallons of an oil-water mix have been recovered
  • 1.84 million gallons of total dispersant have been applied
  • 581 miles of Gulf Coast shoreline are currently oiled

July 14:

• • 31.8 million gallons of an oil-water mix have been recovered
  • 348 controlled burns
  • 572 miles of Gulf Coast shoreline are currently oiled
  • 1.82 million gallons of total dispersant have been applied

July 13:

• • 31.4 million gallons of an oil-water mix have been recovered
  • 330 controlled burns have been conducted
  • 550 miles of Gulf Coast shoreline are currently oiled

July 6:

• • ensure the safety of seafood coming from the Gulf, the Food and Drug Administration (FDA), National Oceanic and Atmospheric Administration (NOAA), and state authorities have agreed upon a shared protocol
  • BP also has begun connecting a floating riser pipe to third vessel, the Helix Producer, which will increase collection capacity to an estimated 53,000 barrels per day
  • 45,700 personnel are currently responding to protect the shoreline and wildlife
  • 484 miles of Gulf Coast shoreline are currently oiled
  • 1.72 million gallons of total dispersant have been applied

July 5:

• • NOAA expanded the closed fishing area in the Gulf of Mexico to include portions of the oil slick
  • Tar balls collected from the Crystal Beach on the Texas coast were from the Deepwater Horizon Oil Spill with approximately 35 gallons of sand/seaweed/tar balls collected
  • 45,000 personnel are currently responding to protect the shoreline and wildlife
  • 31.3 million gallons of an oil-water mix have been recovered
  • 492 miles of Gulf Coast shoreline are currently oiled

July 4:

• • making progress on new oil that washed because of bad weather in Hurricane Alex

July 1:

• • 42,700 personnel are currently responding to protect the shoreline and wildlife
  • 1.61 million gallons of total dispersant have been applied
  • 428 miles of Gulf Coast shoreline are currently oiled

June 30:

• • EPA Releases First Round of Toxicity Testing Data for Eight Oil Dispersants
  • 42,700 personnel are currently responding to protect the shoreline and wildlife
  • 1.61 million gallons of total dispersant have been applied
  • 423 miles of Gulf Coast shoreline are currently oiled

June 29:

• • Vice President Biden Travels to Gulf Coast to Assess Response Efforts
  • Fish and Wildlife Service and Coast Guard, released more than 70 rehabilitated brown pelicans back to the wild from the USCG station in Brunswick, Ga.
  • 38,900 personnel are currently responding to protect the shoreline and wildlife and cleanup vital coastlines
  • 1.6 million gallons of total dispersant have been applied
  • 413 miles of Gulf Coast shoreline are currently oiled

June 28:

• • NOAA-Supported Scientists Predict Increase in Area Containing Depleted Oxygen or the “dead zone”
  • 38,600 personnel are currently responding to protect the shoreline and wildlife
  • 28.2 million gallons of an oil-water mix have been recovered
  • 213 miles of Gulf Coast shoreline are currently oiled

June 25:

• • 37,000 personnel, more than 4,500 vessels engaged
  • 275 controlled burns have been carried out to date, removing about 239,000 barrels of sea surface oil

References

[1] [http://en.wikipedia.org/wiki/Biosensor / Wikipedia, Biosensor.]

[2] [http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.133.6222&rep=rep1&type=pdf/ Rodriguez-Mozaz, S., Marco, M., de Alda, M. L., & Barceló, D:"Biosensors for environmental applications: Future development trends", Pure and Applied Chemistry, 76(4):723-752, 2004.]

[3] [http://www.nature.com/scientificamerican/journal/v303/n1/full/scientificamerican0710-16.html / Scientific American 303, 16-18 doi:10.1038/scientificamerican0710-16; July 2010.]

[4] [http://www.sciencedaily.com/releases/2010/06/100629122948.htm/ National Oceanic and Atmospheric Administration (2010, June 29). NOAA- supported scientists predict 'larger than average' Gulf dead zone. ScienceDaily. Retrieved July 5, 2010, from http://www.sciencedaily.com/releases/2010/06/100629122948.htm]

[5] [http://pubs.acs.org/cen/coverstory/88/8824cover.html/ Johnson, J., & Torrice, M. (2010, June 14). BP's Ever-Growing Oil Spill | Cover Story | Chemical & Engineering News. C & EN: Chemical & Engineering News. Retrieved July 6, 2010, from http://pubs.acs.org/cen/coverstory/88/8824cover.html]

Bullet graphics thanks to [http://www.bellsnwhistles.com/ bellsnwhistles.com].