Unit 4: Do oil dispersants do more harm than good?

Water; it’s essential to all life on Earth. It is the most common liquid on Earth and Canada is known for being the country with the largest surface area of freshwater. But what happens when this water becomes contaminated with an oil spill? Unfortunately, this is a common occurrence in the world, with the largest oil spill in the world being the one in the Gulf of Mexico in 2010. In order to clean up, 1.84 million gallons of oil dispersant was used.

What are oil dispersants?

In section 8.3 of the textbook, we learned that oil (a hydrocarbon) is unable to mix in water due to their unlike polarities; water is polar and oil is nonpolar. When the oil dispersant comes in contact with the contaminated water, the molecules of the oil dispersant bonds with the molecules of the oil. The oil then turns into small droplets, making them easier to dissolve into the water and more biodegradable (able to be decomposed by the organisms in water). Figure 1 shows the bonding process of water molecules and disperant molecules. To put it in perspective, think of dish soap when cleaning a greasy pot. The dish soap is able to pull away the oil from the water. In this case, the dish soap as the oil dispersant. Aircrafts drop the oil dispersants from the air to ensure they are equally distributed throughout the body of water (see figure 2). Although they are unlikely to be harmful to humans, they can negatively impact aquatic organisms (ex. shrimp, oysters, corals) as the chemicals in the oil dispersant damages their skin.

Figure 1: the oil dispersant molecules and water molecules attach to each other. Wind then spreads this throughout the water.

Figure 2: aircraft dropping oil dispersant over the Gulf of Mexico

The cons of oil dispersants

The reason why scientists could be reluctant to using oil dispersants is that it does not eliminate the crude oil from the body of water. Instead, it transfers it to another ecosystem. In tranquil bodies of water, the oil dispersant may not be effective as it sits at the bottom of the water. However during the time of the oil spill in the Gulf of Mexico, the water current was quite aggressive due to hurricane season. Oil dispersants are also quite toxic. COREXIT, an oil dispersant company had to send seven workers to the hospital during the cleanup process due to shortness of breath and nausea.

Going back to the 2010 oil spill in Mexico, the company was not too familiar with the use of oil dispersants, making the clean up process experimental. The dispersant was applied at an incorrect depth, therefore most of the oil was unable to rise to the surface. The oil broke down at a slow rate in cold weather. A study conducted by Georgia Tech found that the oil dispersant made matters worse, as the water became more toxic.

I believe there are many issues involving the use of oil dispersants. There are more pros than cons, which is why I hope experts discover an alternative as soon as possible. It harms aquatic organisms, which is an ethical issue and it harms the workers who conduct the cleanup, which can be a negative legal implication for the company COREXIT. I would suggest improving the protective clothing of the workers to ensure that they are more protective to prevent workers from becoming ill. The worst part of this all is that despite all of this effort, they may not be effective if the water is tranquil; which is not always predictable. It would be preferable to use a substance that has a higher success rate.

My question:

I want to know your opinion. My question to you is: why do you think experts continue to use oil dispersants, despite all of their cons?

Citations:

Main article: Giuseppe M. Di. Nelson Chemistry 11. Toronto, Ont: Nelson Thomson Learning, 2002. Print.

Hellerman, Caleb. “What Are Oil Dispersants?” CNN, Cable News Network, 15 May 2010, www.cnn.com/2010/US/05/15/oil.spill.dispersants/index.html.

“Oil Dispersants.” Wikipedia, 21 Dec. 2018, en.wikipedia.org/wiki/Oil_dispersants.

Peek, Katie. “How Do Oil Dispersants Work?” Popular Science, 28 May 2010, www.popsci.com/science/article/2010-05/how-do-oil-dispersants-work.

“Water.” Natural Resources Canada, Natural Resources Canada, 30 Oct. 2017, www.nrcan.gc.ca/earth-sciences/geography/atlas-canada/selected-thematic-maps/16888.