Marine Chemistry & Geochemistry karin lemkau POLLUTANTS 34 I half a dozen times. times. adozen half done it I’ve well. routine the Iknow airport. to the then And Francisco. to San trip return the to catch time in just ferry the to it back make and perimeter island’s the around briskly I walk on it. oil with anything collect I’ll 1960s. late the in closed factory of aceramic remnants dishes— ceramic of broken hundreds with covered is shoreline the to rocks, addition in where, States United the in parks dog largest one of the and marina alocal Ivisit day following The rocks. seeking. been I’ve what Ifind where beach, to asmall slope atreacherous down ther far amile Itrek I’m not what But that’s after. vegetation. green brilliant and grasses dry with filled slopes steep and Ocean Pacific of the views breathtaking by rewarded Iam where a half-mile uphill hike and Bridge Gate Golden the over north car my rental Idrive arrives, my flight after Soon museums. and restaurants don’t do San Francisco like most people. most like Francisco don’t San do On the third day, my search takes me by ferry to Angel Island. Island. to Angel ferry me by takes day, my search third the On more to peruse walkway coastal to apopular Idrive Next on them. oil with Rocks Rocks.
O c Does of out sight mean into air the or into fish? SPILLS OIL IN CHEMICALS TOXIC TRACKING I skip the cable cars, Lombard Street, Alcatraz, and the fine fine the and Alcatraz, Street, Lombard cars, cable the I skip e anus M aga zi n e Vol. 49, No. 1, Winter 2011 |www.whoi.edu/oceanus 1, No. Winter 49, Vol. - Cosco Busan Cosco M/V The Where didthatoilgo? of thousandsgallonsheavyfueloilintoSanFranciscoBay. San Francisco-OaklandBayBridge.Agashinitshullspilledtens In November2007,thecontainershipM/VCoscoBusanstruck the purple gloves do. gloves purple the attention, their doesn’t get cranny and nook every in searching and at rocks staring my intense If questions. to stop ask afew looks; me quizzical offer Passersby samples. for oil shoreline the scour whether this decline resulted from the spill or from natural causes. natural or from spill the from resulted decline this whether certainty with say No one can fishery. commercial bay’s only the of closure first the in resulted that populations herring local in decline adevastating caused have may and birds 2,000 more than shores. itsrugged along of oil ring bathtub adirty bay, leaving intothe oil fuel of heavy of gallons of thousands tens released spill Busan Cosco M/V the ship, acontainer by 2007 November in spilled was At each stop, I pull out purple gloves and foil envelopes and and envelopes foil and gloves out purple stop, Ipull each At The spill affected more than 100 miles of coastline. It killed It killed of coastline. miles 100 morethan affected spill The Bay Francisco of San shores for on the I’m oil looking The after it struck the San Francisco-Oakland Bay Bridge. The The Bridge. Bay Francisco-Oakland San the it struck , after oil spill
Courtesy of the U.S. Coast Guard One way to explore this question is to look closely at the oil from the residuum by “cutting,” or adding one of the lighter itself to understand its potential toxicity over time. Once released fuels (such as diesel) to thin the residuum and make it easier to into the environment, the various compounds within an oil can use. Since every residuum is different and the type and amount evaporate, or be dissolved into surrounding waters, eaten by mi- of cutting oil varies, there is no standard heavy fuel oil. Individual croorganisms, or broken down by sunlight. How these so-called components in this complex mixture of oil behave differently in “weathering” processes affect different compounds depends on the marine environment and determine the environmental impacts the individual compounds’ physical characteristics, including their the oil will have. size and chemical structure. Heavy fuel oils are used to power the container ships that carry That’s where I come in. That’s why my suitcase is always filled most of the goods traded in our global economy. The continued with oily samples when I leave San Francisco. Back at the Woods use of these fuels is currently under debate. Because of the high Hole Oceanographic Institution, I am using novel techniques to sulfur content of the residuum, burning heavy fuel oils results in study the diverse chemical compounds that comprise spilled oil, more harmful emissions than alternatives such as diesel fuel. In with the goal of more fully understanding what happens to them fact, one study estimated that decreased air quality from burning after a spill. heavy fuel oils is responsible for approximately 60,000 deaths worldwide each year, primarily in coastal Asia. All oils are not created equal In the past decade countries have begun instituting emission Oil is an intimidating mixture of thousands of compounds, control areas (ECAs). These areas have strict emission regulations and every oil is different. All petroleum-based fuels, including the and severely limit, among other things, the sulfur content in fuels. gasoline we pump into our cars, begin with crude oil that is pulled These ECAs aim to reduce or ban the use of heavy fuel oils, par- from the ground and processed at a refinery, where it is heated and ticularly in coastal areas, in favor of more expensive biofuels or separated into the different products we use. As crude oil is heated, diesel-range products with lower sulfur contents. However, even lighter compounds evaporate and are collected and sold as gaso- with the expansion of ECAs, the use of heavy fuel oils is on the line, jet fuel, kerosene, diesel fuel, and lubricating oil (motor oil). rise as international trade increases. Accidents are inevitable. At the end of this distillation process, there remains a thick Few heavy fuel oil spills have been well-studied, and under- residue of heavier compounds that were not evaporated off during standing how these types of oil weather is critical for targeted oil the refining process, called the residuum. Heavy fuel oil is made spill response and cleanup efforts, as well as for informing discus- sions on their continued use. The M/V Cosco Busan spill involved a heavy fuel oil, a fact that made it worth my while to pack my purple gloves and head west. Whither the naphthalenes? Among the potentially harmful compounds in heavy fuel oil are naphthalenes. You may already know of naphthalenes from the
MIT/WHOI graduate student Karin Lemkau collected samples of oil from the Cosco Busan spill that remained on rocks in several locations (red dots) and brought them back to WHOI. She has been analyzing them to learn what happens to various chemical com- pounds in the oil after it is released to the environment.
0 5 10
N kilometers Richmond Bridge Point Isabel
San Francisco Bay Shorebird Park Berkeley Pirates Cove Sausalito Angel Island Bay Bridge
Golden Gate Oakland Bridge San Francisco Track of the M/V Cosco Busan
Pacific Ocean Jack Cook, WHO I Camilo Ponton
Woods hole oceanographic institution 35 POLLUTANTS
A MOLECULAR MARATHON
The gas chromatograph finishing sooner than those carrying instrument consists of a Comprehensive 2-D gas chromatograph more. Similarly, lighter compounds in syringe injector, a column, of Cosco Busan oil an oil sample travel through the column and a detector. The column at a faster rate than heavier ones. The consists of a long glass marathon is equivalent to the most tube as thin as the lead common form of gas chromatography: in a mechanical pencil. “1-D gas chromatography.” The tube’s interior has a But just as 15 people carrying the chemical coating. A mixture of same weight can run a marathon in the compounds is injected into one same time, 15 compounds with similar end of the column. weights can travel through a column at the As compounds travel through the same speed, and 1-D chromatography can’t column, each compound interacts differently with separate them. the chemical coating, depending on its unique So we send the compounds through a process properties, and proceeds through the coating at called comprehensive 2-D chromatography—a second its own pace. column that separates them by a second dimension, Gas chromatography is like a molecular marathon, their polarities. Think of it this way: The runners with in which the compounds in an oil are the individual the same weights runners. When the gun goes off, all the runners begin who finish the running. For simplicity, let us assume all runners run marathon at the at the same speed. But some runners are carrying a same time, then backpack with extra weight, and you’d expect them run a 100-meter POLARITY to run more slowly depending on how much weight dash, to distin- they are toting. If this were the case, the runners guish them by would gradually separate over the 26.2 miles of how much of a MOLECULAR WEIGHT the marathon, with runners carrying less weight kick they have left.
START FINISH
SEPARATING BY MOLECULAR WEIGHT
RATHO MA N SEPARATING BY POLARITY
METER DA 0- SH 10
COOLING STATION
Amy Caracappa-Qubeck, WHOI
36 Oceanus Magazine Vol. 49, No. 1, Winter 2011 | www.whoi.edu/oceanus the ocean rather than the atmosphere— Busan spill. We looked at compounds the harmful effects on marine life could within the oil that we know behave in be greater. (To complicate matters further, particular ways in the environment and environmental factors play a role: A spill in learned about the impacts that micro- a warmer environment, for example, typi- organisms and sunlight had on our oil cally results in more evaporation than one samples. But we were not able to clearly occurring in a polar setting.) distinguish between the impacts that The likelihood that a compound will evaporation and dissolution had on the move out of the oil and into air or water is oil. Eager for a clearer picture, we decided closely tied to the compound’s weight and to go a step further. polarity. But among smaller compounds, I am now adding a second dimension those with higher polarities are more likely to gas chromatography analyses, using a to be transferred into water. second column to separate compounds Polarity is a property determined by based not just on their weight but also on how electrons within the atoms of a com- their polarity. So now I can calculate the pound are arranged. In polar compounds, percentage of each individual oil com- electrons are not uniformly distributed pound that is likely to dissolve into the across the compound’s structure. That water or evaporate into the atmosphere. Karin Lemkau, M I T/WHO Joint Program gives certain parts of the compound more I am still analyzing samples from San One of Lemkau’s sampling locations was positive or negative charges, making them Francisco Bay and calculating sizes and littered with pieces of broken ceramic more likely to dissolve in water. polarities for each chemical compound dishes from a ceramic factory closed in the within Cosco Busan oil. When I’m finished, late 1960s—some coated with oil from the 2-D gas chromatography we should be able to predict where each of Cosco Busan. To provide a more accurate accounting the compounds within the oil went—into of how much of various compounds was the atmosphere or the water. Then, we will mothballs in your closet. Naphthalenes in transferred into the atmosphere or into have one more piece of the puzzle to help heavy fuel oils come from the cutting oils the surrounding waters after the Cosco us understand what’s happening to the San used to make them. Busan spill, I am using a technique called Francisco Bay herring populations and one From analyzing my oily rock samples, gas chromatography. This method sepa- more tool we can use to study future spills. I know that naphthalene concentrations rates compounds in a mixture by taking Maybe then I can return to San Fran- within the beached Cosco Busan oil de- advantage of individual compounds’ unique cisco and see the city like a normal person. creased dramatically during the initial properties, such as their weight and days after the spill and are still decreasing polarity (see previous page). This research was funded by the Rich- slowly in later samples. That might seem In 2010, we published a study in the ard and Rhoda Goldman Fund, the Coastal like a good thing. But where did these journal Marine Pollution Bulletin in which Ocean Institute at WHOI, the Ocean Ventures compounds go? we used gas chromatography to look at the Fund, and the Seaver Institute. Smaller low-molecular-weight weathering of the oil after the M/V Cosco compounds, such as naphthalenes, are particularly susceptible to the processes of evaporation and water washing. Evapo- karin lemkau ration moves compounds from the oil into Karin Lemkau grew up in the landlocked village of the atmosphere; water washing occurs as Yellow Springs, Ohio. She discovered her love of the waves wash over oil exposed on rocks and ocean as a child, spending months at sea traveling compounds are dissolved into surrounding around the world on a floating university. After an waters, exposing marine plants and inspirational encounter in college working with sea animals to their potential toxicity. turtles, she sought to combine the ocean world with Because evaporation and water washing her interest in organic chemistry. In 2004 she graduated both act on low-molecular-weight com- with a bachelor’s degree in chemistry from Wesleyan pounds, distinguishing their effects is not University and was a Summer Student Fellow at WHOI. easy, and traditional oil spill studies rarely She worked as staff chemist and volunteer (with sea attempt to do so. However, disentangling turtles) at Mote Marine Laboratory in Sarasota, Fla., these two processes is key to determining before joining the MIT/WHOI Joint Program in 2006, working with her Ph.D. advisor how (or whether) a spilled oil will affect Chris Reddy. She has completed two marathons (Cincinnati and Philadelphia) and is marine life. If more naphthalenes than looking forward to her next one. When not scouring shorelines in search of oil, she previously suspected end up in water rather enjoys running, doing projects around the house, and doting on her puppy. Her men- than air, for example—or if certain kinds of tor for this article was Peter Lord, environmental reporter for the Providence Journal. naphthalenes that are more toxic move into
Woods hole oceanographic institution 37