The oil spill in the Gulf of Mexico that began on April 20, 2010, when an oil rig exploded in Louisiana, killing 11 workers, is now the worst US environmental disaster. The amount of oil that gushed into the Gulf since then could be as high as 60,000 barrels a day. Various measures to cap and stop the flow had been unsuccessful until July 15, when the oil leak was observed to have stopped after a new containment cap was completely installed on July 12. Also on July 15, a well integrity test was implemented to measure pressure within the oil well and to determine whether the new cap will successfully hold back the flow of oil or prevent a new leak from forming elsewhere. At the time of this interview, the results of the test remain uncertain.
Regardless, the impact to the local ecosystem and to the livelihoods of residents in the affected Gulf states continues to worsen. Detrimental health effects are being observed in the animal and marine life; the body of water of the Gulf itself remains contaminated by an estimated current volume of 90-180 million gallons of oil; oil and tar balls have been washing up on the shores; and volatile organic compounds (VOCs) are still being released into the surrounding ambient air.
The methods used for cleaning up the oil, such as the application of dispersants and burning the oil, are also presenting challenges, introducing new exposures from other chemical pollutants and from particulate matter (PM).
A significant growing concern is how the health of coastal residents and response workers involved with the cleanup efforts could be affected over the short and long term.
At the request of the US Department of Health & Human Services, the Institute of Medicine (IOM) quickly convened a workshop, "Assessing the Human Health Effects of the Gulf of Mexico Oil Spill," on June 22 and 23 in New Orleans, Louisiana. Experts in attendance agreed that existing research that evaluated the adverse health effects for humans from previous oil spills is surprisingly lacking; many of these studies were small, used poor methodology, or focused on short-term health outcomes only.
The US Centers for Disease Control and Prevention (CDC) has published a collection of content updated daily for health professionals, coastal residents, response workers, and the general public that is devoted to this disaster on their Website, CDC: 2010 Gulf of Mexico Oil Spill.Vikas Kapil, DO, MPH, is the Associate Director for Science for the Deepwater Horizon Oil Spill Response at the CDC in Atlanta, Georgia. Dr. Kapil spoke about the potential physical health effects in humans who are exposed to an oil disaster and what clinicians can do in response to such situations.
(My comment: WHAT ABOUT THE CITIZENS OF MEXICO???? Who will offer them help when they become ill and suffer the health problems of this spill? Will anyone care for them? And what about the MARINE LIFE??? All the birds, fish, sea mammals, etc. that live in this area of the Gulf?)
What are the potential hazardous substances related to the oil spill itself as well as its cleanup, and what are their specific effects on human health?
Dr. Kapil: The recent Gulf of Mexico oil spill more likely presents a risk for adverse ecologic impact rather than severe adverse human health effects. However, depending on the exposure, the potential exists for human health effects.
On the basis of data from oil recovered from other wells in this area, we expect that the more hazardous substances found in crude oil, such as benzene and sulfides, will make up less than 1% of this oil spill.
Workers at the site of the spill may be more at risk of being exposed to the VOCs, such as benzene or toluene, that are present in crude oil. This guides the National Institute for Occupational Safety and Health's (NIOSH's) recommendations on personal protective equipment for workers. Oil spill workers may need to wear personal protective equipment on the basis of the particular cleanup duties that they perform. The NIOSH Website has more information about their ongoing efforts to protect the health and safety of response workers.
Many of the VOCs have largely evaporated from the weathered oil that reaches the shore, so they present less of a risk for the general public and for those working onshore.
The crude oil involved in this oil spill is called medium sweet crude. "Sweet" means that the oil contains fewer sulfur compounds and is therefore less toxic than other forms of crude oil. Medium crude generally has fewer VOCs and fewer chemicals known to pose long-term health risks compared with other oil types.
One method being used to reduce the amount of oil before it arrives on the shores of the Gulf of Mexico is to burn it. Burning oil may generate PM. PM includes a mix of very small airborne particles and liquid droplets. PM varies in size; some of the smaller PM can be inhaled and deposited in the lung.
Because intentional burning is being conducted far offshore, it is unlikely to reach inhabited areas of the coast. In situ burning is monitored by the US Coast Guard for safe operational practices. As crews burn spilled oil, they carefully watch the weather, wind, and water conditions and monitor the air. If any problems are encountered, oil burning is stopped immediately. The CDC and the Agency for Toxic Substances and Disease Registry (ATSDR) are monitoring the air sampling results to help guide public health decisions. Up-to-date information about the public health effects of burning oil can be found on the CDC Website.
If PM does make it to the shore, it may pose a greater risk for people with underlying health conditions, such as asthma, chronic obstructive pulmonary disease, or heart disease.
People in the area who smell or see smoke may take certain steps to protect themselves:
- They can choose to leave the area. Those at greatest risk of breathing smoke should evacuate.
- They can limit their exposure to smoke by remaining indoors and using an air conditioner to filter the air. If available, air conditioning units should be set to "recirculation mode." Those without access to an air conditioner may wish to evacuate until the smoke is completely gone.
- They should refrain from physical exertion. Physical activity that places extra demands on the lungs and heart -- exercise or physical chores, indoors or outdoors -- should be kept to a minimum.
Dust masks, bandanas, or other cloths -- even if wet -- will not protect against smoke inhalation.
The oil spill is not expected to affect any municipal water supplies. If people have concerns about the quality of their water, they should contact their local water utility.
The US Environmental Protection Agency (EPA) is monitoring the air quality in the region. Maps and charts at http://gulfcoast.airnowtech.org show current ozone and fine particulate Air Quality Index values that are being measured by air quality monitors located along the Gulf Coast. These maps and charts are updated hourly to show the most recent conditions.
Oil spill response workers may be exposed to many different chemical and physical hazards. The risk for each type of exposure depends on the type and location of the oil spill, the type and stage of response, and the workers' specific tasks.
Chemical exposures may include:
- Benzene, toluene, ethylbenzene, xylenes, and other VOCs;
- Oil mist; or
- Naphthalene and other polycyclic aromatic hydrocarbons.
Physical hazards may include:
- Heat stress due to the high temperatures and humidity;
- Ergonomic hazards that can cause injury to the musculoskeletal system;
- High noise levels;
- Sun exposure and dehydration; and
- Injuries due to slips, trips, and falls on slippery walking and working surfaces.
Other safety hazards may come from the use of tools, equipment, machinery, and vehicle operations near workers.
The dispersants used in the oil spill have been COREXIT® 9500 and 9527 [Nalco Company; Naperville, Ill]. Both will begin to break down once applied to the oil slick. In aquatic environments, each will break down within 16 days. Exposures to dispersants will most likely occur among workers applying the material.
Health effects that could be experienced are dependent on the extent of exposure to the dispersants and may include:
- Defatting and drying of the skin and possibly dermatitis, as a result of prolonged contact with the skin;
- Chemical pneumonitis, if aspirated into the lungs;
- Respiratory irritation as a result of repeated and prolonged inhalation exposure to vapor; and
- Eye irritation as a result of repeated and prolonged exposure.
Repeated or excessive inhalation exposure to dispersants may lead to nausea, vomiting, hemolysis, renal or hepatic injury, metallic taste, central nervous system depression, or anesthetic or narcotic effects. 2-Butoxyethanol, a component of one of the dispersants, has not been classified as to its carcinogenicity. For most people brief contact with a small amount of oil dispersants presents no harm.
Employers should train oil spill response workers about their potential hazards and safe work practices to prevent and control these risks.
What is the CDC doing to monitor or track the potential human health effects in the areas affected?
Dr. Kapil: The CDC and the US Department of Health & Human Services recognize the importance of anticipating, monitoring, and responding to any potential public health hazards that may affect human health. Currently, over 300 CDC and ATSDR staff members are involved in the response, including a number of staff members deployed to Gulf Coast states.
The CDC, along with state and local health departments, is conducting surveillance across the 5 Gulf states for health effects possibly related to the oil spill using national and state-based surveillance systems, including the National Poison Data System (NPDS) and BioSense. These surveillance systems track symptoms related to the eyes; skin; and respiratory, cardiovascular, gastrointestinal, and neurologic systems of exposed persons.
This tracking effort also includes collecting data on persons with worsening of asthma or those with cough, chest pain, eye irritation, nausea, and/or headache. If these surveillance systems identify groups of people with these symptoms, state and local public health officials will be able to follow up as needed to investigate whether an association is present between the symptoms and the oil spill. This follow-up is important because the same symptoms could be related to a different cause.
NIOSH is working to protect workers and volunteers from potential safety and health hazards related to the spill and cleanup efforts. The CDC is sharing its health information with industry, the Occupational Safety & Health Administration (OSHA), the US Coast Guard, and other federal and state agencies. NIOSH is also helping OSHA and the National Institute of Environmental Health Sciences (NIEHS) by providing technical assistance for training response workers.
Furthermore, NIOSH is collaborating with British Petroleum (BP) Safety and OSHA compliance personnel to coordinate the collection and analysis of injury and illness data that BP are reporting to OSHA. NIOSH is also establishing a voluntary roster of workers participating in the response to create a record and a mechanism to contact these workers about spill-related symptoms of illness or injury, if it becomes necessary.
More than 45,000 responders -- BP-trained, volunteer, vessel of opportunity operators, and federal workers -- have been added to the roster. Workers are entered into the roster through a voluntary system at the staging areas to which workers report daily and during worker training, and through an electronic version of the form that is posted on a secure Website; NIOSH has provided the link to multiple federal agencies and BP, and has asked them to refer workers to the Website to complete the roster form electronically.
A CDC team of environmental health experts continues to review environmental data packages in coordination with the EPA. CDC scientists are reviewing these data to determine whether exposure to oil, oil constituents, or dispersants might cause potential short- or long-term health effects. These data include sampling results for air, water, and soil/sediment as well as waste oil samples, which are material actually reaching the beaches or marshes.
Some of the pollutants that have been reported may cause temporary eye, nose, or throat irritation; nausea; or headaches, but scientists believe that levels are not high enough to cause long-term harm.
The EPA and CDC will continue to monitor the air, water, and soil/sediment. If we begin to find levels that may be of health concern, we will update the public. The latest information on air quality and monitoring data along the Gulf Coast is available on the EPA and Data.gov Websites.
The breadth of this type of disaster is unheard of in this country, and its potential toll on human health has yet to be fully determined. Exposure to oil appears to affect multiple systems of the body; however, few human studies or experiences are available that provide actual guidance on what to expect. What might be extrapolated from existing data about the potential acute or short-term physical health effects?
Dr. Kapil: Any potential acute or short-term health effects are generally dependent on amount and duration of exposure. Prolonged skin contact with crude oil and petroleum products can cause skin erythema, edema, and burning. Swallowing crude oil, unless in large quantities -- for example, greater than 8 oz -- is unlikely to result in more than transient nausea, vomiting, gastrointestinal tract disturbances, and diarrhea. Ocular exposure can cause chemical conjunctivitis. Serious ocular injury is uncommon in the absence of other contaminants. Exposure to fresh crude oil may result in inhalation of associated vapors from volatile hydrocarbon components. Symptoms may include headache, dizziness, confusion, nausea, or vomiting.
Heat-related illness, such as heat stroke, heat exhaustion, heat cramps, or fainting, related to cleanup of the oil spill is an important health concern, particularly for responders. In addition, workers, volunteers, and residents of affected communities may experience stress and fatigue and may also be at risk for more serious mental health consequences. It's important that responders and residents of affected communities monitor their health and well-being closely and seek professional medical and/or mental health assistance when indicated.
One of the main concerns is whether this exposure to the oil spill might promote the development of a malignancy in the future. What do you anticipate to be possible malignancies or other chronic health effects?
Dr. Kapil: Questions about long-term human health effects are important and complex. Little research has been conducted to examine the long-term health consequences of oil spills and related human exposures, including cancer outcomes. Much of what we know is from our experience with occupational exposure to crude and refined oil among oil workers, and a few limited studies of previous oil spills that primarily focused on short-term health outcomes. Findings from these previous studies are difficult to extrapolate for the current situation because many differences exist in the nature of the exposures and other related circumstances.
We can also look at the limited toxicity data related to individual components of the oil or dispersants. Evaluation of the impact of exposures is complicated due to a number of factors, including weathering of oil components and the presence of complex mixtures of substances. In other kinds of exposure settings and in some toxicologic studies, some of these substances and degradation products have been associated with a variety of chronic and/or long-term health effects. Therefore, people should be advised to minimize exposures to oil and dispersants in general, with particular attention to vulnerable populations and those with existing comorbidities.
Although some components of oil are known human carcinogens (such as benzene), associated cancer risks are difficult to assess due to a number of factors that affect exposure and influence health outcomes, including:
- Weathering and degradation of oil components;
- Level of adherence to exposure prevention efforts;
- Individual susceptibility;
- Other common exposures to carcinogens;
- The particular circumstances surrounding the exposure; and
- Routes of exposure.
The CDC is working closely with the EPA and other partners to attempt to better assess potential exposures related to the oil spill among workers and the general public in the affected areas of the Gulf states.
To date, environmental assessments for various crude oil constituents in air, sediment, and water have revealed levels above the limit of detection in only 5%-15% of all samples. Environmental samples of oil constituents measured above the limits of detection have been at levels far below those associated with any long-term health effects. In conducting this assessment, the CDC is using the most conservative estimates of exposure possible, for example, 70 years of exposure even though the vast majority of exposures will occur over days, weeks, or months.
On the basis of our current assessment and understanding of exposures, the likelihood of long-term health effects, including cancer, remains low, but scientific gaps exist in our knowledge. The CDC is working closely with many partners and stakeholders, including affected communities, to further evaluate and better understand the longer-term health effects.
At the request of the US Department of Health & Human Services, the IOM held a public workshop in June to draw upon the best scientific expertise available to examine a broad range of health issues resulting from the oil spill, including:
- Reviewing the current knowledge about the effects on human health of exposure to oil, weathered oil products, and dispersants, and identifying gaps in this knowledge;
- Reviewing and assessing ways to monitor the spill's potential negative effects on health in the short and long term; and
- Exploring methods and strategies for gathering data to further our understanding of the risks to human health.
Certain populations appear to be more sensitive to or at greater risk for adverse physical health effects. Pregnant women, infants and children, the elderly, and people with preexisting respiratory conditions or compromised immune systems have been identified as populations of concern. What might be the particular adverse health effects experienced by members of these special populations?
Dr. Kapil: The oil may contain some chemicals that could, under some conditions, cause harm to special populations, such as children, the elderly, and pregnant women or their babies. However, the CDC has reviewed and continues to review sampling data from the EPA and believes that the levels of these chemicals are well below the level that would generally cause harm to persons in these vulnerable groups. The effects that chemicals might have depend on many things: means of contact with the oil; duration and frequency of exposure; and the overall health of the person exposed.
People can be exposed to oil spill-related chemicals by inhalation from the air, by ingestion from water or food, or by skin contact. If possible, everyone should avoid the oil spill-affected areas. The EPA and CDC are working together to continue monitoring the levels of oil in the environment. If levels are more likely to become harmful, the public is informed. The EPA Website has the most current information on monitoring data along the Gulf Coast.
Swimming in water contaminated with oil will be unpleasant and should be avoided. The public needs to be alert to local beach closings and advisories. Visitors to the Gulf of Mexico should stay away from cleanup activities and follow the advice and warnings from state and local health departments.
For now, those in populations of concern should avoid touching any oil, as well as any oil-stained water and sand. They also need to stay clear of areas where cleanup activities are under way. If some of the oil gets on their skin, they should wash it off as soon as possible with soap and water. If they notice a rash or other skin abnormalities even after washing the area of skin that came in contact with the oil, they need to consult a healthcare professional.
The amount and extent of seafood consumption by people could also potentially pose a health concern. As a general precaution, fishing areas affected by the spill are closed to fishing and oyster collection, for both personal and commercial use. Any seafood available in stores comes from waters open for fishing. Seafood that is unsafe will not be allowed in stores.
The US Food and Drug Administration (FDA) and the National Oceanic and Atmospheric Administration National Marine Fisheries Service are monitoring the oil spill and will alert the public if any problem is found with seafood from fishing areas in this area of the country. If harmful levels of chemicals are found in Gulf-area seafood, the CDC will work quickly with other federal agencies, such as the FDA and state agencies, to make sure that the public is notified.
The FDA Website has some general guidelines about eating seafood during pregnancy in case your pregnant patients are interested in more information on this topic.
Contact with dispersants is unlikely for the general public because they are applied subsea or under controlled conditions offshore. The use of dispersants is carefully controlled and monitored because some of the chemicals in the dispersants can cause harm to people under some conditions. Pregnant women and children should avoid contact with dispersants. For most people, brief contact with a small amount of oil spill dispersants will not cause harm.
However, contact of longer duration can cause a rash, dry skin, and/or eye irritation. In the unlikely event of breathing in or swallowing dispersants, other health effects -- such as nausea, vomiting, and throat and lung irritation -- are possible. Individuals concerned about oil spill dispersants should contact their local poison control center. The CDC Website also has more information on oil dispersants.
How can healthcare providers adequately screen patients from various populations exposed to the Gulf of Mexico oil spill or a similar disaster? What other guidance would you recommend that providers offer or communicate to their patients?
Dr. Kapil: Because many environmental-associated diseases either manifest as common medical problems or have nonspecific symptoms, an exposure history is vital for correct diagnosis. By taking a thorough exposure history, clinicians and specialists in toxicology, neurology, emergency medicine, occupational medicine, and other specialties can play an important role in detecting, treating, and preventing disease due to a potential toxic exposure. More detailed information about taking an exposure history is available on the ATSDR Website.
Some people may have dermal reactions to crude oil. Depending on the amount and duration of exposure, skin contact with crude oil may be mildly to moderately irritating; in a sensitive individual, the skin effects may be more pronounced after a smaller or shorter exposure.
Prolonged skin contact with crude oil and petroleum products may cause skin erythema, edema, and burning. The skin effects can worsen by subsequent exposure to sunlight, because trace contaminants in the oil, such as PAHs, may be more damaging when exposed to light. Skin contact with these products can result in defatting of the skin, increasing the possibility of dermatitis and secondary skin infections.
For most people, an occasional brief contact with a small amount of oil, such as that found in a tar ball, will do no harm, but this type of exposure is not recommended. Individuals, however, may have idiosyncratic reactions to various chemicals, including the hydrocarbons found in crude oil and petroleum products. They may have an allergic reaction or develop dermatitis even from brief contact with oil.
In general, dermal contact with oil should be avoided. If contact occurs, washing the area with soap and water is the preferred method for cleaning the skin. Do not use solvents, gasoline, kerosene, diesel fuel, or similar products on the skin. These hydrocarbon-based products, when applied to the skin, may present a greater health hazard than the smeared tar ball itself.
Healthcare providers can obtain assistance with questions about the treatment and management of oil- or dispersant-exposed persons by calling their local poison control center.
If providers are managing the care of persons exposed to crude oil and/or oil dispersants, they can consider some general guidelines depending on the route of exposure.
If a patient presents with skin contamination, no major complications should be observed; the oil can be wiped off whenever convenient in the patient treatment process. Oil- and oxygen-enriched atmospheres are potentially explosive; oil-contaminated clothing removed from patients, and oily cloths or rags used to wipe off patients, represent a potential fire hazard due to the risk for spontaneous combustion.
If a patient presents with wound contamination, current occupational practices for external and superficial wound cleaning are being modified to include use of waterless hand cleaners, white petroleum, mineral oil, corn oil, or antibiotic ointments. These agents must also be removed as completely as possible from within the wound after efforts to remove the crude oil have been completed.
If a patient presents with ocular exposure, which can result in irritation and transient conjunctivitis, no serious injury should result if treatment is instituted rapidly. Immediate treatment should include flushing the eye with copious amounts of water for at least 15 minutes. If the person wears contact lenses, remove them prior to irrigation. Contaminated contact lenses need to be discarded.
If a patient presents with ingestional exposure to a small amount of crude oil, clinical signs of toxicity are generally limited to mild gastrointestinal disturbances. The main danger of swallowing crude oil is that it can cause a chemical pneumonia if ingested oil is vomited and subsequently aspirated into the lungs. To treat patients exposed via ingestion, do not induce vomiting because this may lead to aspiration of the crude oil into the lung. Healthcare providers can consult their local poison control center for consultation.
If a patient presents with inhalational exposure to fresh crude oil vapors, inhalation of associated volatile hydrocarbons can also result. Symptoms, including headache, dizziness, confusion, nausea, or vomiting, may occur from breathing vapors given off by crude oil. Inhalation of weathered crude oil vapors is of less concern because of the diminution of volatile hydrocarbon amounts. Relocate the patient to a clear area and provide supplemental oxygen if needed.
- Oil- and oxygen-enriched atmospheres are potentially explosive; oil-contaminated clothing removed from patients, and oily cloths or rags used to wipe off patients, represent a potential fire hazard due to the risk for spontaneous combustion.
- Dermal contact with oil should be avoided. If contact occurs, however, wash the area with soap and water.
- Immediate treatment of ocular exposure should include flushing the eye with copious amounts of water for at least 15 minutes. If the person wears contact lenses, these should be removed prior to irrigation. Contaminated contact lenses need to be discarded.
- Patients exposed via ingestion should not be induced to vomit because this may lead to aspiration of the crude oil into the lung.
- Oil spill workers may need to wear personal protective equipment on the basis of the particular cleanup duties that they perform. The NIOSH Website has more information about their particular ongoing efforts to protect the health and safety of response workers.
- If any questions remain about the treatment and management of oil- or dispersant-exposed persons, call your local poison control center at 1-800-222-1222.
Dr. Kapil: The response to the Gulf Oil Spill is being managed by a Unified Command made up of many federal agencies as well as BP and Transocean, the 2 private companies involved in the spill. If you or someone you know is interested in volunteering, please call the Deepwater Horizon Response Volunteer Request Line at 1-866-448-5816. Interested individuals can also search the Internet for state-specific volunteer opportunities, including in the Gulf states directly affected by this oil spill:
Are there any final takeaway messages that clinicians and other healthcare professionals can keep in mind as we learn more about the health impact of this and similar disasters?
Dr. Kapil: Local poison control centers are an excellent resource for clinicians with questions about the evaluation, management, and treatment of persons exposed to both crude oil and oil spill dispersants.
The CDC recommends that people in the areas affected follow local and state public health guidelines and warnings related to the use of beaches and coastal water for recreational activities and fishing. The EPA is collecting samples of water along the coast to estimate the effects on fish, wildlife, and human health. The most up-to-date information on water sampling results is available on the EPA Website.
Centers for Disease Control and Prevention. 2010 Gulf of Mexico Oil Spill. Available at: http://emergency.cdc.gov/gulfoilspill2010 Accessed July 21, 2010.
Institute of Medicine. Assessing the Human Health Effects of the Gulf of Mexico Oil Spill: An Institute of Medicine Workshop. June 22-23, 2010.
Available at: http://www.iom.edu/Activities/PublicHealth/OilSpillHealth/2010-JUN-22.aspx Accessed July 21, 2010.