One of the hotter social media feuds in recent weeks saw The Science Babe, an analytical chemist, refuting the assertions of The Food Babe, who vows to help followers rid their lives of toxins. Amidst the claims and counter-claims about GMOs, on one point The Science Babe was dead wrong: claiming that The Food Babe “doesn’t research” and was incorrect about airline passengers being sprayed with pesticides before flights.

In fact, such “disinsection” occurs every day in countries all around the world. And, yes, even U.S. airlines engage in certain forms of the practice, though usually spraying is not done when passengers are onboard. As for the debate over the potential dangers of spraying vs. the potential dangers of airborne diseases? It’s an issue many affected passengers clearly need to know more about—prior to booking.

To spray or not to spray

It can be disconcerting to suddenly be sprayed with pesticides while locked in a pressurized tube. I’ve experienced this myself in several countries, most recently four years ago in India. Conversely, we’ve seen time and again how quickly air travel can allow insect vectors to transmit such deadly diseases as malaria and yellow fever. There is a need for greater information about both types of dangers.

The methods used to disinsect can vary by destination and airline. The World Health Organization (WHO) and the United Nations-chartered International Civil Aviation Organization (ICAO) have established two primary methods: 1) spraying aerosol insecticides in the cabin while passengers are onboard, and 2) treating the airplane’s interior surfaces with a residual insecticide when passengers are not onboard. A third method—often used in Panama and American Samoa—is to spray the cabin when passengers are not on board.

If you’ll be flying internationally and you’d like to know more about airline policies on pesticides, the U.S. Department of Transportation (DOT) provides a detailed overview of what to expect at “Aircraft Disinsection Requirements.” This page, which was recently updated, states the following countries currently require aerosol spraying of in-bound flights while passengers are onboard:

• Cuba
• Ecuador (Galapagos and Interislands only)
• Grenada
• India
• Kiribati
• Madagascar
• Seychelles
• Trinidad and Tobago
• Uruguay

Furthermore, the following countries require residual treatments or spraying when passengers are not onboard for all in-bound flights:

• Australia
• Barbados
• Cook Islands
• Fiji
• Jamaica
• New Zealand

In addition, there are other nations—including several popular destinations for tourists—that require disinsection on selected flights from certain locations. You should learn more if you’re flying into these countries from potentially infected areas:

• Czech Republic
• France
• Indonesia
• Mauritius
• South Africa
• Switzerland
• United Kingdom

Are there risks?

If you’re concerned about disinsection, individual governments and airlines are key sources for further information. And you may want to consider the primer for air travelers provided by WHO. In 1995, WHO issued a report stating aircraft disinsection performed properly should be encouraged: “Although some individuals may experience transient discomfort following aircraft disinsection by aerosol application, there is no objection to any of the recommended methods of aircraft disinsection from a toxicological perspective.”

However, asthma sufferers are among those who should be aware of such “transient discomfort.” In 2010 the International Society of Travel Medicine published a detailed report on this topic.

WHO’s optimism did little to allay many fears. In fact, such concerns are not new, and date back decades; for years now environmentalists, medical professionals, academics and media outlets have questioned using pesticides inside cramped and sealed aircraft cabins. And travel blogs are filled with strongly worded opinions on the potential dangers. In addition, the Centers for Disease Control and Prevention details concerns for aircrew members as part of its workplace safety initiative. Such concerns also can affect frequent fliers facing higher exposure to pesticides.

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.”

Similar warnings have long been voiced by the Association of Flight Attendants-CWA (AFA), which represents almost 60,000 cabin crew at 19 airlines, and offers detailed reading on this topic. A spokeswoman for AFA says the union still has health concern about disinsection, noting: “AFA worked tirelessly to get the FAA Reauthorization bill two years ago to include a requirement for airlines to let passengers know that they’ll be sprayed with pesticides when they buy a ticket to certain countries. This legislation was passed, but the DOT hasn’t yet turned the legislation into a regulation.”

AFA also recommends alternatives to spraying, and supports the use of non-chemical means of disinsection, such as “air blowers at the passenger boarding door and specialized net curtains over the cabin service doors.” The spokeswoman says, “These options were initiated by AFA in 2003 and promoted by the DOT and [U.S. Department of Agriculture], but the momentum has slowed in recent years,” due to a lack of funding. Ultimately, AFA suggests alternatives to spraying will not come from the airlines, but must be regulated by the DOT.

Check with your carrier

While policies on disinsection are established by government agencies, individual airlines implement the methodologies. Some major international carriers—such as Air Canada, British Airways, Qatar Airways and Virgin Atlantic—provide details on their specific policies or links to the DOT’s overview. But you should contact your carrier if you have unanswered questions.

I reached out to the Big Three U.S. major network airlines—American, Delta and United—and asked about their specific policies. 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.” Passengers with any questions are advised to contact Ryan Correa at ryan.correa@aa.com.

• 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.”

Proponents of current aircraft disinsection policies note that failing to address airborne disease is unthinkable, while those worried about harmful side effects recommend alternative methodologies. What seems clear is far too many airline passengers are unaware of such issues until they are faced with mandatory spraying, so the need for greater education is apparent. Even The Science Babe and The Food Babe could probably agree on that.

MORE: Read previous columns

Bill McGee, a contributing editor to Consumer Reports and the former editor of Consumer Reports Travel Letter, is an FAA-licensed aircraft dispatcher who worked in airline operations and management for several years. Tell him what you think of his latest column by sending him an e-mail at travel@usatoday.com. Include your name, hometown and daytime phone number, and he may use your feedback in a future column.