CHACHOENGSAO: Police in Bang Pakong district are investigating why a family of three were found unconscious in their car on the Bangkok-Chon Buri elevated expressway after a stopover to buy drinks.
Pol Capt Suriya Phumiwat said on Monday he would ask the Land Transport Department's engineers to check if engine fumes had leaked into the cab of the Nissan sedan.
Samples of the beverages the family bought would be sent Regional Medical Science Centre 6 in Chon Buri province for testing for possible toxins.
Expressway police on Sunday found the driver, his girlfriend and his daughter unconscious, saliva-drooling from their mouths, in the car, which had stopped on the expressway in Bang Pakong district.
Pol Capt Suriya said Thanainan Chueathirapong, 31, his 7-year-old daughter and Jitrarat Namchampee, 26, were taken to Queen Sirikit Hospital in the Sattahip naval base for high-pressure oxygen therapy, and were recovering.
Mr Thanainan later told police that Ms Jitrarat and his daughter had bought cups of coffee and a green tea at the refreshment stop. They resumed their trip and shortly afterward he noticed an oily smell inside the car and started feeling dizzy.
He managed to pull over onto the shoulder of the expressway and stop before he fainted. He denied they may have tried to commit suicide.