Mixing chemicals with waste in sewage holding tanks or septic. systems may produce toxic fumes, corrode pipelines and tanks, and. pollute soil and ground water when discharged. When chemicals, such as formaldehyde, are added to septic systems, they can cause. bacteria in the system to die.
The cervix is the opening to the womb. Itâs located between the vagina and the uterus and plays a crucial role in pregnancy and labor. During pregnancy, it remains closed and the opening is blocked with a mucus plug.
Placenta previa. This condition occurs when the placenta partially or totally covers the cervix â the outlet for the uterus. Placenta previa is more common early in pregnancy and might resolve as the uterus grows. Placenta previa can cause severe vaginal bleeding before or during delivery.