A surge in COVID-19 infections overseas in places like China has prompted the U.S. Centers for Disease Control and Prevention to consider testing airplane wastewater for the virus.
The agency announced plans to begin inspecting airplane wastewater last month and now it is looking to clear a legal hurdle. Scientists have already found that testing wastewater for traces of the COVID-19 is a viable process and agreed that the method can act as a new defense weapon against the spread of the virus in the U.S.
An upgraded line of defense is needed as requiring international travelers to test negative for the virus before entering the country has been proven to not completely mitigate the spread of the virus. In December 2021, an airplane wastewater analysis of a flight from Ethiopia to France showed that despite passengers testing negative for COVID-19, the omicron variant was still present in waste.
Experts suggested that analyzing airplane wastewater can even help scientists determine how vaccines should be updated.
"If you do have a new variant that's coming and you have a wastewater sample, it's going to be more concentrated coming out of a smaller sewer shed or an airport," Sandra McLellan, professor of freshwater sciences at the University of Wisconsin-Milwaukee, told NBC. "If you just look in the municipal wastewater, you could miss it."

When it comes to a potential legal dispute in assessing airplane wastewater, some countries could consider airplanes their own territory and removing anything from them could be considered theft, according to Kata Farkas, research officer at Bangor University and contributor to a new airplane wastewater study.