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.
Bleeding or spotting later in pregnancy may be caused by: 1  Labor. 2  Having sex. 3  An internal exam by your health care provider.  Problems with the cervix, like an infection or cervical insufficiency. This is when a womanâs cervix opens too early.