A320
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
General Physical Injury / Incapacitation
Aircraft
Upon boarding the aircraft to do preflight duties we immediately encountered a rancid heavy pungent odor permeating the entire aircraft. It smelled of rotten eggs; wet socks or dirty laundry smell. Even with heavy deodorizers the smell continued. We began to feel very nauseated. We reported it to the Captain who said it was fine and we were taking it as is.We then taxied out onto the runway and mid demo the engine roared to make a turn. Then the air from the bleed air in the aft galley vent blew air onto my face while reading the demo. I lost my breath; became dizzy; started coughing and wheezing and had difficulty breathing. I felt disoriented with a severe migraine; nausea and tremor on the left side of my body. My heart began racing and I felt very ill. I tried to finish the demo as quickly as possible. We made an Emergency call to Captain stating that myself and several passengers in the aft cabin were feeling very ill from the noxious fumes. He decided that a gate return was in order. I felt as though I was losing consciousness so with the assistance of [another] Flight Attendant I obtained a POB and took oxygen which helped the racing sensation in my heart and the dizzy disorientation.Maintenance did not replace or address the Wet Seals where the toxins were coming from. Instead they simply ran the engines for 20 minutes and changed the filters. After this I was told that there was no Flight Attendant available and if I went home sick then the flight would cancel. So I felt pressured to continue the trip. I arrived very sick from the chemical exposure. I will work my flight home and then will go to a [facility] for chemical exposure testing upon arrival [at home].We need a Cabin Air Quality program at the airline and a mandated mandatory Wet Seal change out program for our aircraft bleed air systems in order to prevent future Fume Events and Aerotoxic Syndrome exposures to our Cabin Crews and Passengers.
Flight Attendant reported becoming ill from noxious fumes (that smelled of rotten eggs or dirty socks) in the cabin.