According to the Association of Flight Attendants (which represents almost 60,000 cabin crew at 19 airlines) around 50 countries require pesticide spraying on all or selected flights, apparently to prevent the importation of insects that either carry tropical disease or damage plant/animal health. The cabin may also be pre-treated in a country that does not require pesticide spraying. In response to concerns about transporting insects that could carry the Zika virus, some countries are going to add disinsection (pesticide spraying) rules on either all or selected incoming flights.
Pesticide spray application in the occupied or soon-to-be occupied aircraft cabin and cockpit can be a serious health hazard for crewmembers and passengers says the AFA. Pesticide/solvent exposure can be significant, and some crewmembers must work in the sprayed environment regularly and repeatedly. The sprays contain an active ingredient (typically 2% permethrin or d-phenothrin), solvents, and in some cases, propellants. Reported symptoms include acute respiratory and sinus problems, rash/hives, headache, and anaphylactic shock, as well as chronic immune, respiratory, and neurological problems. Damp mattresses and carpet in the crew bunk rooms have posed particular problems for cabin and cockpit crew.
In 1975, the US Centers for Disease Control stopped requiring routine disinection on incoming flights. The agency cited evidence that the sprays were making some people sick, and there was insufficient evidence that the sprays were effective.
In 2012, two academics released “Quantifying Exposure to Pesticides on Commercial Aircraft,” a detailed report funded by the Federal Aviation Administration (FAA). After examining aircraft cabins and flight crews, the report concluded: “This study documents that flight attendants on commercial aircrafts disinsected with pyrethroid insecticides are exposed to pesticides at levels that result in elevated body burden and internal accumulation comparable to pesticide applicators, exceeding levels in the general U.S. population. It is expected that flying public would be similarly exposed to pesticides on those flights.”
A report by USA Today notes: “The Big Three U.S. major network airlines—American, Delta and United—all claim they do not spray with passengers onboard:
American states it only disinsects on aircraft operating to Port of Spain. A spokesman explains: “Spraying is done during overnight cleans for the aircraft. Maintenance clears the planes for up to two hours until it’s safe to re-enter.”
Delta states that “spraying is performed without passengers or crew members onboard,” either prior to boarding or after deplaning. A source at Delta advises the two primary destinations for disinsection are Australia and Chile, although it occurs “occasionally” in West Africa.
United states the carrier “carefully follows” all entry requirements for the nations it serves, and aircraft disinsection is required in some countries. However, the airline states: “No destination that United serves requires routine spraying while passengers and crew are on board.”
Countries currently require aerosol spraying of in-bound flights while passengers are on board: • Cuba, • Ecuador (Galapagos and Interislands only), Grenada, India, Kiribati, Madagascar, Seychelles, Trinidad and Tobago, Uruguay, and Zimbabwe.
Countries require residual treatments or spraying when passengers are not on board for all in-bound flights: Australia, Barbados, Cook Islands, Fiji, Jamaica, and New Zealand.
Countries that require disinsection of selected flights include Egypt, Italy and the U.K. for flights from Zika infected nations. The Italian government is now requiring that all aircraft arriving from Brazil, France, Polynesia, USA and El Salvador be treated with a disinsection product.
The CDC does not recommend routine use of insecticides inside commercial passenger airplanes to prevent the spread of Zika virus. It is thought that the probability of any mosquito being on a plane is low. There is no evidence to show that using insecticide to kill mosquitoes inside aircraft cabins is effective in preventing introduction and spread of mosquito-borne diseases.