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.
Additional causes of bleeding in early pregnancy include: 1  Cervical changes. During pregnancy, extra blood flows to the cervix. 2  Infection. Any infection of the cervix, vagina, or a sexually transmitted infection (such as chlamydia, gonorrhea, or herpes) can cause bleeding in the first trimester.