The vent terminal is allowing down drafts to enter thus one would have to install a return bend on this pipe to prevent the air from entering but it will allow sewer fumes to escape
yes. water caught in the drain line may contain food particulate which can decompose and cause gasses to escape back into the house.
ummmmm............. your not supposed to i suggest you get that checked!!
Code there doesn't always require a 'P' trap to hold water and thus block sewer gases from backing into the house.
Either you have a blockage present or your vents on your sewer lines have become blocked or you need to install more vents.
Awful.
Awful.
Over time yes as it does cause some type of brain and liver cancers
Have you noticed an unpleasant odor drifting through your home? You didn’t burn dinner. You just cleaned the house. Still, for some reason, your home smells like the sewer. You can try to cover up the stench with scented candles, but this probably isn’t the best solution. This smell is typically caused by one of three reasons: Sewer trap plugs. Missing or loose sewer trap plugs are the most common cause of indoor sewer smell. Your sewer access pit contains a house trap. This is a U-shaped piece that traps water to serve as a barrier between the city sewer and your home. If the plug on this trap is poorly fitted or gone entirely, public sewer odor can travel into your home. Simply replace the plug, and your air should clear. Dried trap. If the water in the U-trap has dried up, it no longer acts as a barrier to the sewer odor. Run some water into the trap to recreate the barrier. This should eliminate the odor. City sewer. Is the odor coming from outside? A sewer smell outdoors can indicate the city sewer is experiencing major plumbing problems, not your home. However, if the smell persists, it may be due to the drains from your house. Contact a plumber to check your drainage system for proper functioning. When home or property owners are experiencing heavy drain clogs in UK, they call the experts at MR Drains, as they are experts in all aspects of drainage from blocked drains, to CCTV camera surveys, to all aspects of drain repairs.
Lime
TCP
Of course, the codes do require a minimum of height and diameter (normally 4" to prevent hoarfrost) and depending if the roof is used for weather protection I have installed vent piping 7 feet above the roof to prevent sewer fumes from entering the structure and 7 feet is the min required for promenade roofing systems.
It is probably sewer gas or something coming up from the drain.