Question

Methane and Hydrogen Sulfide Gases

My daughter lives in Mexico. She has a very strong smell in all 3 of the bathrooms. The sink drains were installed upside-down and there is no seal on the toilets. This smell is making her whole family very sick. How dangerous is this, and how can she determine how bad it actually is? Limited resources in Mexico. I am concerned for their safety. Can you give me some more info. Her husband needs to be convinced on concerns for health. They have 5 little kids in the house.
Thank You

Answer

Before I even start to answer this question, I advice that your daughter call a certified plumber/professional sewer company or contact her local government over there for recommendations of certified companies to help them fix the sewer gas odor you described.

Before they try to open the sewer lid, the worker/plumber/sewer contractor should be aware or made to be aware that sewer manholes or any enclosed space within the sewer system contain invisible life threatening dangers such as Hydrogen sulfide gas, explosive gases and absence of oxygen.

Hydrogen sulfide (H₂S) is a highly poisonous and inflammable gas which occurs naturally in natural gas, volcanic gases, crude petroleum and other natural occurrences. It is also produced by the bacterial breakdown of waste materials usually found in waste treatment plants, sewer systems, swamps. Hydrogen sulfide gas has a foul odor of rotten eggs similar to what you described in your question "very strong smell in all 3 of the bathrooms". For the purpose of this question, I will base my answers on sewer gas (Hydrogen sulfide produced by the break down of waste materials in sewer systems/waste management systems) This is how Hydrogen sulfide is produced in sewer systems/waste management systems: When microorganisms decompose waste materials in the sewer system/waste management system, this is done in the absence of oxygen and the resulting gas is Hydrogen sulfide (sewer gas)...