The throat swabs used for nucleic acid testing are toxic. Will excessive testing cause cancer?

Nucleic acid testing is an important means of rapid screening and detection of COVID-19 infection, and its importance in epidemic prevention and control is evident. Recently, there have been claims on the Internet that the throat swabs used in nucleic acid testing are carcinogenic. Is this true?

First of all, you should know that the "stick" for nucleic acid testing is actually called a throat swab. The cotton-like substance on it is actually not cotton wool, but polyester or nylon fiber. Although it is chemically synthesized, it is not as harmful as you think. For example, nylon fiber is the same as the bristles on our toothbrushes. Someone has raised this question: if it does not cause cancer once or twice, who can guarantee that it will be fine if you do it every day? It is impossible to do it more than the number of times you brush your teeth. If brushing your teeth does not cause cancer, why are you afraid of throat swabs?

Some people think that there will be chemical reagents on the throat swab, which will get into the mouth when applied. From the principle of nucleic acid sampling, this statement is not true. The throat swab is dipped into the secretions on the pharyngeal mucosa through mechanical friction, and then the throat swab head is directly immersed in the reagent for extraction. The throat swab itself does not contain any reagent components except fiber.

Some people are also worried that the throat swabs will be sterilized with industrial disinfectant - ethylene oxide during the processing, which is carcinogenic to a certain extent. In fact, throat swabs are medical devices, and there are strict standards for processing and production. No matter what form of disinfection is used, there are requirements. If ethylene oxide is used for sterilization, the residual ethylene oxide should not exceed 10ug/g when leaving the factory, which will not cause damage to the body.

So, why do some people experience oral discomfort after nucleic acid sampling in reality? In fact, the answer is very simple. It is mainly caused by the pharyngeal swab scraping the pharynx and oral mucosa. For example, some people have a sensitive pharynx. When scraping the posterior pharyngeal wall, they feel uncomfortable, irritated, and have a foreign body sensation, which will cause itching or vomiting. Some people have a greater tolerance. These individual differences are relatively large. Of course, this is also related to the technique and strength of the sampler.

Therefore, nucleic acid testing with throat swabs will not cause any harm to your health. Even if the samples are collected repeatedly due to the epidemic, there will be no risk of cancer. There is no need to worry too much.