With the winter smog becoming a seasonal event in northern China, a growing number of affluent Chinese families are spending a fortune "smog-proofing" their homes.
Madam Wang Jiang and husband Ludovic Bodin have spent around US$11,500 (S$16,400) on air purifiers to remove the harmful particles in the air.
The sum is out of reach for most families in Beijing, where the average monthly salary is US$1,414 - the highest in China, according to China Daily.
The couple have two daughters, a six-year-old and a three-month-old infant.
"It's 'very expensive'," Madam Wang told CNN.
"But think about the health. There is nothing to trade off," she said.
Here is a breakdown of how much her family has spent:
US$4,300 on a fresh air filtering system, which works like a ventilation device, cleaning outside air and pumping it into their home.
US$7,200 on eight air purifiers, one in each room.
US$430 in recurring charges per month to change the purifiers.