35 swimmers hospitalized after chemical exposure at San Jose pool

File photo of generic hospital emergency room. Close up of sign for emergency department in hospital File photo of generic hospital emergency room. Close up of sign for emergency department in hospital Photo: ERproductions Ltd / Getty Image Photo: ERproductions Ltd / Getty Image Image 1 of / 1 Caption Close 35 swimmers hospitalized after chemical exposure at San Jose pool 1 / 1 Back to Gallery

Thirty-five patients are getting treated for chemical exposure after a San Jose pool attendant poured the wrong type of chemicals in pool tanks at the Shadow Brook Swim Club around noon Thursday, officials said.

A pool attendant responsible for maintaining the chlorine and muriatic fluid tank levels mistakenly poured the wrong chemicals into one of the tanks, causing a cloud of yellow gas to seep into the pool deck where people were swimming, said Capt. Mitch Matlow, a spokesman for the San Jose Fire Department.

“The pool chemical person had to hold his nose to leave the room,” he said.

Responding firefighters were notified of a possible hazardous materials incident and found people vomiting and experiencing shortness of breath. Some swimmers experienced dizziness, Matlow said, while others experienced no symptoms at all.

Thirty-five affected swimmers were transported to nine different hospitals after getting stripped of their clothes and rinsed with water, Matlow said.

If they had gone untreated, he noted, people could have potentially drowned from fluid buildup in their lungs.

Hazmat officials are still measuring the chemical levels in the water and the air surrounding the pool Thursday afternoon.

As of 3:15 p.m., officials measured 15 ppm of chlorine in the pool tank room, which still qualifies as being toxic for humans.

“One part per million in a 15-minute work period is the maximum exposure,” Matlow said.

It is unclear how long it will take for officials to get chlorine levels back to safe levels.

More than 30 fire personnel responded to the scene, including 32 from the San Jose Fire Department and two from the Santa Clara Fire Department.

Lauren Hernandez is a San Francisco Chronicle staff writer. Email: lauren.hernandez@sfchronicle.com