Summer Vacation: Airplane Health Risks

General Airplane Health

Almost two billion people travel aboard commercial airlines every year, making it essential that health care providers are aware of the potential health risks linked to air travel. Environmental and physiological changes during routine commercial flights may lead to mild hypoxia, an oxygen deficiency, which can intensify chronic medical conditions or trigger medical events while in flight. Medical kits, defibrillators, and tele-medical ground support are always available to assist flight crew and volunteering physicians in the case of emergency. The most common air travel illnesses are related to changes in air pressure, humidity and oxygen concentration, relative immobility during flights, and close proximity to other passengers who may have communicable diseases. Ventilation systems may also spread highly contagious pathogens onboard. Passengers with pre-existing medical conditions may be at higher risk than healthy passengers.


Tuberculosis (TB) is a disease caused by the bacterium Mycobacterium tuberculosis. TB bacteria can attack any part of the body, often affecting the lungs, kidney, spine, and brain, though not everyone infected becomes sick. If not treated properly, TB may be fatal, and almost a century ago it was the leading cause of death in the United States. People with weak immune systems are at a greater risk of contracting active TB, in which the bacteria begin to multiply and destroy bodily tissue. Latent TB occurs when the TB germ has entered the body, but no sign or symptoms have occurred. People who have latent TB infection do not feel sick or show symptoms, and cannot spread TB to others, but may develop full-blown TB. Most patients with latent TB will take anti-tuberculosis medication to prevent active TB from developing.

Transmission: TB bacteria are released from person to person. They spread through the air when an infected person coughs, sneezes, or breathes. TB bacteria are usually lodged in the lungs and throat, which makes transmission easy. The risk of contracting TB on commercial flights is relatively low, but longer flights pose a greater risk of infection. Most reports show that passengers who contracted the disease in-flight were in close proximity, usually sitting within 1-4 rows of an infected passenger.

Symptoms: Symptoms of TB may vary, depending on the location of bacteria in the body, but may include an extremely bad cough, chest pain, coughing that produces blood or mucus, fatigue, loss of appetite, chills, fever, and night sweats. Those with latent TB typically do not show symptoms or feel any sign of sickness.

Prevention: Healthcare professionals suggest immediate medical consultation in the presence of these symptoms if TB is suspected. A full physical exam and annual Mantoux testing, a skin test to check for TB, is necessary to determine if the patient has active or latent TB. In general, tuberculosis is preventable, particularly in people with strong immune systems. To prevent TB transmission during air travel, air quality and ventilation must be maintained. Planes recycle air through a series of filters 20- 30 times per hour. Newer aircrafts recycle air through high-efficiency particulate air (HEPA) filters, similar to those used in hospital respiratory isolation rooms. These filters capture bacteria and large viruses to prevent transmission. Individuals with active TB are advised to be quarantined because TB is highly contagious. Before the government issued the public health “Do Not Board Plan” (DNB) in June 2007, which gives airport authorities the right to deny susceptible passengers from boarding, CDC Quarantine Station officers worked directly with airlines and health departments to prevent persons known or suspected of having communicable diseases that posed serious threats to fellow passengers from traveling on commercial flights. CDC data from 2007 to 2008 indicated that the CDC received requests for the quarantine of 42 passengers on the DNB list, all of whom were suspected of having or were confirmed with TB. BCG, or Bacille Calmette-Guérin, is a vaccine for tuberculosis (TB) disease. BCG is used in many countries, like Japan, with a high prevalence of TB to prevent childhood tuberculosis meningitis. However, BCG is not generally recommended for use in the United States because of the low risk of infection with tuberculosis. There is also the potential risk of side effects to the vaccination, such as a high fever, chills, flu-like symptoms, nausea, increased sensitivity to light, headache, difficulty urinating, and diarrhea or constipation. The BCG vaccine should be considered only for selected persons who meet specific criteria and in consultation with a TB expert.

Treatment: Patients who have active TB are usually treated with four antibiotics, including isoniazid (Nydrazid® or INH), rifampin (Rifadin®), ethambutol (Myambutol®), and pyrazinamide. This regimen may change if susceptibility tests later show some of these drugs to be ineffective. Depending on the severity of the disease and whether there is drug resistance, one or two of the four drugs may be stopped after a few months. If a positive TB test is encountered, but not active disease, a doctor may recommend preventive drug therapy to destroy dormant bacteria that might become active in the future. The individual will likely receive a daily dose of isoniazid. For treatment to be effective, the individual usually takes isoniazid for 6-9 months. Long-term use can cause side effects, including the life-threatening liver disease hepatitis. A doctor will monitor the individual’s liver function closely while taking isoniazid. It is best to avoid using acetaminophen (Tylenol®) and avoid or limit alcohol while taking isoniazid, due to an increase in liver problems.


Influenza is a highly contagious virus, especially for people in enclosed, poorly ventilated spaces. Commonly referred to as the flu, influenza is a contagious infection of the respiratory system caused by viruses, including influenza types A, B, and C. Avian (bird) flu is a type of A virus. Type A viruses most commonly affect adults and are the most severe, while type B viruses typically affect children and may also be severe. Type C may cause very mild illness, usually in children, but it does not have the potential for severe public health impact associated with types A and B.

Transmission: Influenza is transmitted through the air in tiny droplets when infected people cough, sneeze, or talk. Others are then exposed to the virus through inhalation, or by contact with objects, such as door handles, railings, telephones, and other contaminated surfaces. Infection may occur when the virus is then transferred to the eyes, nose, or mouth. An influenza pandemic (an epidemic that is geographically widespread; occurring throughout a region or even throughout the world ) occurs when a new strain of influenza A virus emerges for which there is little or no immunity in the human population. The new virus then begins to cause serious illness and spreads easily from person-to-person worldwide. The ventilation filters in aircrafts are able to catch the droplets that carry the virus and prevent onboard spread. Transmission of influenza on airplanes is usually associated with passengers sitting 2-3 rows from the infected person.

Symptoms: Mild cases of flu have symptoms that are very similar to the common cold, including sneezing, nasal drainage, stuffy nose, sore throat, and low fever. Symptoms usually appear suddenly, and in more severe cases, include fever of 101 degrees Fahrenheit (°F) or above, cough, muscle aches, pains, headache, sore throat, chills, sweating, loss of appetite, fatigue and malaise. Fever and body aches may last 3-5 days, and cough and lack of energy may last for two weeks or more. Most adults recover within 1-2 weeks, but the elderly and those with compromised immune systems, such as HIV/AIDS or cancer patients, may feel weak and be debilitated for several weeks after the infection has gone.

Prevention: Crew and personnel on ships and aircrafts are trained to identify and monitor any suspicious symptoms that travelers may have. During an influenza pandemic, local and state health authorities will heighten surveillance at airports. In these cases, airlines distribute travel health-alerts on commercial flights, and have the authority to quarantine infected passengers and crew. The CDC works closely with the World Health Organization (WHO) to monitor all reported outbreaks of influenza, and the U.S. Department of Health and Human Services will notify local airports and healthcare providers. If the level of transmission is high, flights may be canceled.

Treatment: Healthcare professionals recommend bed rest, liquids, and proper nutrition for rapid recovery and to prevent dehydration (fluid loss). Medical treatment may not be necessary unless symptoms persist for more than a few weeks or are severe. Over-the-counter (OTC) medications may reduce the duration and discomfort of symptoms, including body aches and pains, congestion, runny nose, and cough. These products are available in formulas that treat symptoms separately, and in combination. Antibiotics are not effective against the flu. Antibiotics are medicines that kill bacteria and are, therefore, only useful for treating bacterial infections. The flu is a viral infection, not bacterial.

Severe Acute Respiratory Syndrome (SARS)

Severe acute respiratory syndrome (SARS) is a contagious respiratory infection that may be fatal. The risk of transmission while onboard an aircraft is very low, but cases have been reported. The World Health Organization (WHO) lists that the most recent reported cases of SARS were found in Canada, Singapore, China, and Vietnam. The WHO also recommends that travelers educate themselves about the virus and take in-flight precautions, such as those mentioned below.

Transmission: SARS is highly contagious and spreads from person to person through airborne mucus droplets. Mucus droplets may enter the air when an infected person coughs, sneezes, laughs, or talks. If another individual inhales these mucus droplets or particles, he or she may become infected. SARS may also be spread when a person touches contaminated objects, such as airplane magazines, overhead compartments, railings, and buttons, and then touches one’s face.

Symptoms: Experts believe that patients are only contagious when symptoms are present and that the risk of spreading SARS is highest the second week after symptoms develop. The U.S. Centers for Disease Control and Prevention (CDC) recommends that individuals with SARS avoid public areas for at least 10 days after symptoms are gone. Between 2-10 days after exposure to the SARS virus, patients typically develop a temperature of 100.4oF or higher. Symptoms typically include soreness, chills, muscle soreness, headache, and general feeling of discomfort.

Prevention: Individuals should try to learn about SARS before planning trips to areas known to have had SARS outbreaks, such as China, Taiwan, Singapore, and Canada. The CDC and WHO keep updated information about these locations on their websites. In addition, patients should talk with their health care providers before traveling to such areas. To reduce the chance of contact with a pathogen that is spread through aircraft vents over passenger seats, consider turning the vent off. Passengers should also wash their hands as often as possible, avoid touching the face, and consider using antibacterial wipes or gels. If a person with possible SARS flies on an airplane while ill, the CDC will work with the state and local health authorities to monitor all travelers for 10 days for possible SARS symptoms.

Treatment: Eating a well-balanced diet and striving for eight hours of sleep a night may boost the immune system, which helps the body fight infections. Patients who are diagnosed with SARS are usually prescribed antiviral drugs.

Deep Vein Thrombosis and Blood Vessel Disorders

Deep vein thrombosis (DVT) is an under-diagnosed, preventable condition that occurs when a blood clot forms in a large vein. These clots develop in the leg, thigh, arm, and pelvis. DVT can happen to any person and may be fatal. DVT is preventable and treatable if diagnosed early and correctly.

Transmission: DVT is not a transmittable or communicable disease. It is a condition that can happen to almost any person. DVT occurs when a blood clot forms in a large vein, usually in the leg, and may travel into the lung, causing a pulmonary embolism. Pulmonary embolism is a blockage of the pulmonary artery, usually occurring when a blood clot becomes dislodged from its site and travels to the arterial blood supply of one of the lungs. Factors that increase the risk of developing DVT include fracture, severe muscle injury, surgery, confinement, limited movement, family history, obesity, smoking, and increased estrogen. Passengers onboard aircrafts are at a greater risk for getting DVT because of sitting too long in one position or having limited movement.

Symptoms: The most common symptoms for DVT are swelling, pain and/or tenderness in the legs, and redness of the skin. Symptoms of a pulmonary embolism include shortness of breath, rapid breathing, chest pain, cough, and possibly sudden death in more severe cases.

Prevention: The Centers for Disease Control and Prevention (CDC) recommends that passengers should get up and walk around the cabin when sitting for long periods. The CDC also provides leg exercises to perform while sitting, such as raising and lowering the heels of the foot while keeping the toes on the floor, and tightening and releasing the leg muscles. Wearing loose-fitting clothes can also help prevent DVT. The CDC also suggests drinking plenty of water and avoiding alcohol and caffeine.

Treatment: Medication is used to prevent and treat DVT. The most common medicines are blood thinners. Compression stockings are sometimes recommended to prevent DVT and relieve pain and swelling. In more severe cases, the clot may need to be removed surgically. Emergency care in a hospital is necessary to treat a pulmonary embolism. There are medications, such as thrombolytics that can dissolve the clot, and anticoagulants to prevent more clots from forming.

Panic attacks/anxiety

Panic attacks associated with flying are extremely common. It may happen to anyone at anytime and without warning. Anxiety is a psychological and physiological disorder that creates unpleasant feelings associated with fear or worry. The body reacts as if it is dealing with a possible threat. They are treatable and not fatal.

Symptoms: The most common symptoms associated with anxiety or panic attacks are heart palpitations, shortness of breath, sweating, chest pain, dizziness, fatigue, headaches, or nausea. Blood pressure and heart rate are increased. A person experiencing a panic attack might feel as if they are about to die or pass out. Panic attacks are sometimes confused with heart attacks.

Prevention: There are many different preventative measures that one can do to prevent panic attacks. Passengers that are prone to having anxiety or panic attacks should avoid stimulants, such as caffeine, diet pills, and smoking. Learning how to control one’s breathing will help relieve symptoms of panic attacks. Meditation will also help with muscle relaxation. Passengers should try to keep their mind occupied by reading a book or using in-flight entertainment. Lastly, learning about panic will help relieve distress. Gaining knowledge about anxiety and panic disorder will help distinguish them from other illnesses or health problems.

Treatment: Antidepressants and benzodiazepines are used to treat panic attacks. Antidepressants take time to build up in the body, so it is important to take them continuously for several weeks before traveling. Benzodiazepines are anti-anxiety drugs that act quickly, such as Xanax®. They provide rapid relief of symptoms, but they may have side effects, such as sleepiness. Benzodiazepines are highly addictive, so they should be used with caution.

Environmental effects

The main environmental concerns associated with airplanes are climate change, ozone reduction, regional pollution from emissions of nitrogen oxides, and local pollution of noise and decreased air quality caused by aircrafts. During flight, aircraft engines emit carbon dioxide, nitrogen oxides, sulfur, water vapor, and hydrocarbons. These emissions alter the chemical composition of the atmosphere. Many of the emissions from aircraft change the absorption of solar radiation and the absorption and emission of thermal radiation, which may affect climate. Aircraft emissions of greenhouse gases, such as carbon dioxide, act to warm the surface of the earth globally. Liquid hydrogen as a fuel may clearly remove the carbon dioxide effect at the point of emission.

Wildlife effects

Airplanes have to work to keep wildlife away from planes in order to prevent disasters. According to the Federal Aviation Administration (FAA), there were 5,622 bird strikes that were recorded in the United States in 2008. A bird strike happens when there is a collision between an airborne animal and an airplane. The most recent and well-known bird strike happened in January of 2009, when a US Airways plane crashed into the Hudson River with 155 passengers. The pilot reported a double bird strike, which caused the plane to lose its engine power and crash into the river. Luckily, all passengers survived.

Airport personnel run patrols on the outfield and runway to look for wildlife or foreign objects in order to help prevent possible bird strikes. The FAA declares that airports must conduct wildlife hazard assessments and prepare a Wildlife Hazard Management Plan. This plan provides measures to alleviate or eliminate wildlife hazards, identifies persons with authority for implementing the plan, provides priorities for needed habitat modification, and provides wildlife control measures. To prevent wildlife hazards, the FAA suggests that airports control vegetation, fill up water sources, and use wildlife harassment tools, such as air guns, dogs, and traps.