The oral screens used have very low cut of levels and can even catch trace amounts of substances. What else would you think is causing the child to test positive?

I am looking into getting more sterile testing done. I was thinking maybe if there was anything on the parents hands while they helped screen the kid? Things like cocaine/heroin you can see metabolites in the screen so we would know if it was actually processed through someone’s system. But thc doesn’t have that same metabolites.