Gulf Oil Spill Health Hazards

Dr. Michael Harbut, Karmanos Cancer Institute

Dr. Kathleen Burns, Sciencecorps

June 10, 2010   Version 2.0

Many people will be exposed to airborne and waterborne chemicals as a result of the BP Gulf of Mexico spill.  It is important to understand the potential toxic effects and take appropriate steps to reduce exposure and harm.   

This page contains information, primarily from federal sources, on health effects that can result from exposure to crude oil.  A tandem webpage that discusses potential heatlh effects of dispersants can be accessed at:

These webpages should not be relied upon for diagnosis or medical treatment and do not provide specific medical guidance, which must be obtained from an individual’s personal medical care provider. 


 Crude Oil Health Hazards

Crude oil contains hundreds of chemicals, many of them well established as being toxic to people.  Many of the crude oil chemicals are comprised hydrogen and carbon (e.g., simple straight chain paraffins, aromatic ring structures, naphthenes), and some also contain sulfur, nitrogen, heavy metals, and oxygen compounds. 

A list of common chemicals in crude oil is listed in Table D-1 of   the U.S. Centers for Disease Control “Toxicological Profile for Petroleum Hydrocarbons” at:  (CDC, 1999).

Crude oil composition varies slightly by its source, but its toxic properties are fairly consistent. Chemicals such as benzene and polycyclic aromatic hydrocarbons (PAHs) are very toxic components of crude oil and of high concern.  These and many other chemicals in crude oil are volatile, moving from the oil into the air.  Once airborne, they can blow over the ocean for miles, reaching communities far from the spill.  They may be noticed as petroleum odors. Consequently, both those working on the spill and people who are far from it can be exposed to crude oil chemicals in air.

To provide brief summaries of crude oil health hazards for the public, we prepared the following handouts that can be downloaded and printed.

With respect to public policy, an emphasis on protection and prevention of disease is an appropriate public health strategy when faced with the potential for widespread contamination and public exposure to toxic chemicals.  


Exposure can occur through skin contact, inhalation of contaminated air or soil, and ingestion of contaminated water or food. These can occur simultaneously.  Exposure pathways may result in localized toxicity (e.g., irritation of the skin following contact), but most health effects are systemic because ingredients can move throughout the body.  Exposure varies based on the duration and concentrations in contaminated media. Differences may result from location, work and personal activities, age, diet, use of protective equipment, and other factors. 

Concurrent exposure to other toxic chemicals at work and home must be considered when evaluating the potential toxic effects of crude oil chemicals.

Reassurances that crude oil reaching the shore is all “weathered” are contradicted in many locations where shoreline oil is not weathered.  When possible, obtain accurate local information from an objective source with the means to evaluate the oil’s composition. Unweathered crude oil contains the volatile organic chemicals (VOCs), including benzene, that are listed in the CDC document linked under “sources” below (see Table D-1).   Claims that weathered crude oil is safe are incorrect, although it is less toxic than unweathered crude oil with respect to the presence of VOCs.

Some chemicals in crude oil are volatile, moving into air easily, and these can often be detectable by smell.  Not all airborne chemicals have a detectable odor, so the absence of oil odors does not mean that there are no crude oil chemicals in the air.  Some information on the locations and amounts of chemicals is at:  Unfortunately, the information is very limited and not readily accessible, as discussed on our tandem webpage at: under the heading: “Failure of the Federal Government to Fully Disclose Test Results”. 

Reducing exposure will invariably reduce harm. OSHA guidance on protective strategies for oil spill response workers is available at:  A protective approach requires minimizing the amount of exposure to crude oil chemicals.


Basic Physiological Effects

Crude oil is a complex mixture of chemicals that have varying abilities to be absorbed into the body through the skin, lungs, and during digestion of food and water. Most components of crude oil enter the bloodstream rapidly when they are inhaled or swallowed. Crude oil contains chemicals that readily penetrate cell walls, damage cell structures, including DNA, and alter the function of the cells and the organs where they are located. Crude oil is toxic, and ingredients can damage every system in the body:

respiratory                                                  nervous system, including the brain

liver                                                             reproductive/urogenital system

kidneys                                                       endocrine system

circulatory system                                       gastrointestinal system

immune system                                           sensory systems

musculoskeletal system                              hematopoietic system (blood forming)

skin and integumentary system                  disruption of normal metabolism

Damaging or altering these systems causes a wide range of diseases and conditions. In addition, interference with normal growth and development through endocrine disruption and direct damage to fetal tissue is caused by many crude oil ingredients (CDC, 1999). DNA damage can cause cancer and multi-generational birth defects.



Acute Exposure Hazards – brief exposure at relatively high levels[1]

Crude oil contains many chemicals that can irritate the skin and mucous membranes on contact.  Irritant effects can range from slight reddening to burning, swelling (edema), pain, and permanent skin damage.   Commonly reported effects of acute exposure to crude oil through inhalation or ingestion include difficulty breathing, headaches, dizziness, nausea, confusion, and other central nervous system effects. These are more likely to be noticed than potentially more serious effects that don’t have obvious signs and symptoms: lung, liver and kidney damage, infertility, immune system suppression, disruption of hormone levels, blood disorders, mutations, and cancer. 

Chronic Exposure Hazards – long-term exposure at relatively low levels

This type of exposure should be avoided, if at all possible, because the potential for serious health damage is substantial.  Chronic health effects are typically evaluated for specific crude oil components (see CDC, 1999), and vary from cancer to permanent neurological damage.  They cover a range of diseases affecting all the organ systems listed above.

Susceptible Subgroups

Children are vulnerable to toxic chemicals in crude oil that disrupt normal growth and development.  Their brains are highly susceptible to many neurotoxic ingredients. Endocrine disruptors in crude oil can cause abnormal growth, infertility, and other health conditions. Children’s exposures may be higher than adults and can include contaminated soil or sand. Newborns are especially vulnerable due to incompletely formed immune and detoxification systems.

Many people with medical conditions are more susceptible to crude oil toxicity because chemical ingredients can damage organ systems that are already impaired. Specific susceptibilities depend on the medical condition (e.g., inhalation poses risks for those with asthma and other respiratory conditions).

People taking medications that reduce their detoxification ability, and those taking acetaminophen, aspirin, haloperidol, who have nutritional deficiencies or who concurrently drink alcohol may be more susceptible. Some inherited enzyme deficiencies also increase susceptibility (listed in CDC, 1999).

People exposed to other toxic chemicals at work or home may be at higher risk.

Pregnancy places increased stress on many organ systems, including the liver, kidneys, and cardiovascular system. Chemicals in crude oil that are toxic to these same systems can pose serious health risks. Pregnancy also requires a careful balance of hormones to maintain a health pregnancy and healthy baby. Endocrine disruptors in crude oil can jeopardize the hormone balance.

The developing fetus is susceptible to the toxic effects of many chemicals in crude oil. Many cause mutations, endocrine disruption, skeletal deformities, and other types of birth defects.

Personal and Public Protection

It is critical that people who work with or around crude oil wear appropriate personal protective equipment such as gloves, masks, respirators, and water repellant clothing, to minimize exposure.  The necessary equipment will depend on the kind of exposure that can occur (dermal, inhalation, ingestion). See OSHA guidance at the OSHA, 2010 link below. 

Susceptible members of the public require notice when exposure may occur (e.g., when contaminated air masses move inland) so they can take protective actions.


CDC, 1999:

OSHA, 2010:

NLM: – very limited information on human health

The National Toxicology Program (NIEHS-NIH) provides information on carcinogenic crude oil ingredients (e.g., benzene) & limited information on reproductive hazards

California’s EPA provides a list of chemicals know to cause cancer and/or reproductive harm:

Children’s Health – International pediatric consensus statement regarding children’s susceptibility to toxic chemicals:  This contains a link to 120 scientific papers presented at the Conference on Children’s Susceptibility to Environmental Hazards.

Federal focus on children’s environmental health including policies designed to protect children: 

The medical literature can be consulted via the National Library of Medicine to obtain the most current information: 


Michael R. Harbut, MD, MPH, FCCP
Professor, Internal Medicine, Wayne State University
Chief, Center for Occupational & Environmental Medicine

Director,  Environmental Cancer Initiative
Karmanos Cancer Institute
118 N. Washington,

Royal Oak, Michigan 48067-1751


Kathleen Burns, Ph.D.



Lexington, Massachusetts

[1] The exposure of susceptible individuals, such as newborns and people with specific health problems, may result in acute exposure health effects at levels that would not result in observable harm in healthy adults.

Special thanks to Richard Charter

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