Fashewar Shenhai-Hujja
Kwalta foda zai iya zama mai fashewa lokacin da yayi kyau sosai.
A matsayin abubuwan farko na kwalta, polycyclic aromatic hydrocarbons, lokacin da isasshe niƙa, suna da saurin haifar da ƙura. Sakamakon faffadan fili na kwalta, yana mu'amala da iska a hankali, yana ƙara haɗarin fashewar kura.