[Update: In June 2016, a report by the Canadian Transportation Agency (CTA) concluded that "there is little or no evidence that there is a risk of anaphylaxis due to inhalation of or dermal contact with peanut, nut or sesame seed allergens while on board aircraft." The report also made recommendations for effective risk mitigation, which includes a row of buffer zone in which the allergic passenger is seated. For the full report, visit the Canadian Transportation Agency website.]
As we approach March Break at elementary and secondary schools, many families will be taking flight to leave behind the cold Canadian weather for sunnier destinations. With recent media coverage around mid-flight allergic reactions and calls for nut-free zones aboard airplanes, we asked the American Peanut Council’s Health Consultant, Dr. Andrew Craig to help set the record straight.
With a food allergy to peanut or tree nuts, is it likely for an allergic reaction to occur from one person opening a bag of nuts on a plane, four rows ahead? According to Dr. Matthew Greenhawt, paediatric allergist at the University of Michigan, “it is highly unlikely for a passenger to inhale nut protein from someone consuming nuts a few rows in front of him/her. There is no evidence that has been able to show that such dust circulates.” Five studies in the past 10 years had investigated this question and found favourable conclusions which should reassure any airline passenger with a nut allergy. Briefly they are:
- • Close exposure (12 inches) to inhaling peanut butter aroma produced no reactions in severely peanut-allergic people. Smelling peanuts may make concerned passengers uncomfortable, but there are no active proteins involved in breathing in the aroma of re-heated or pre-roasted nuts;
- • Peanut particles (dust) could not be detected in the air from stomping on peanuts on the floor or from opening an airline-style bag;
- • Peanut dust and peanut butter residues are both easily cleaned from hands and surfaces using soap and warm water or hand cleansers;
- • Inhaling (thereby ingesting) a dose of an airborne allergen is very unlikely on an airplane because there is little "recirculation" and commercial jets are required to frequently refresh the cabin air and subject it to HEPA filtration.
So the widespread and often repeated belief about dangerous particles becoming airborne from opened nut packets is a myth. Instead, Dr. Greenhawt cautioned that the problem could be from nut allergens in peanut or tree nut dust and residues that may accumulate on surfaces such as tray tables, seats, carpets and surrounding areas. A nut allergic person – such a small child – could potentially touch a surface that hadn’t been wiped down first, and theoretically ingest some level of allergen. Pointing to many reports of in-flight reactions, with anaphylaxis occurring in up to 1/3 of all reactions, Dr. Stukas said the evidence was that these were “not believed to be due to airborne food allergen, but from contact with seats, pillows, seat trays, etc. The universal theme with almost all cases of reported anaphylaxis is lack of use of epinephrine, either due to no availability or improper recognition/treatment.”
The best course of action is awareness and preparedness. Those concerned about flying with food allergies may want to take the following precautions:
- • Before booking your flight, find out more about the airline's allergy policy, which is often available online. You might also be able to find out which snacks are regularly served aboard, reducing your risk of exposure.
- • Bring wipes to clean the seat, arm rests and tray tables which may have been contaminated with homemade snacks from other passengers.
- • Avoid use of the airline-supplied pillows and blankets.
- • Carry epinephrine auto-injectors, and any associated medications, with you at all times.
Source: American Peanut Council