Ben and Jessa Seewald might think that their new home is just cosy, but a pulmonary specialist told them not to be too complacent about cleanliness and repairs since the house is filled with mould, and warned them that it could lead to some serious health issues.

The season premiere of 19 Kids and Counting opened with Ben and Jessa moving into the old home of the Duggars' paternal grandmother while Jill Duggar and her husband Derick Dillard were given a much bigger house.

But the couple took it in their stride and dismissed speculation of jealousy. Jessa said that she's not jealous of her sister's big house and even joked that a smaller house would be easier to clean.

"The reason why Jill got the big house was because it's really close to Derick's work and so it's kind of the opposite of town. We don't mind though, really," she told E! Online. "That's a lot of work to keep up with. They have three floors. It's got to be a lot of work."

But despite Jessa's positivity, pulmonary specialist Dr. Avi Ishaaya told Radar Online that Ben and Jessa need to address the mould issue soon, since "exposure to high amounts of mould is not healthy for anyone."

"Allergic reaction to mould are the most common health effects and may be immediate or develop after a brief period of time with symptoms that can include sneezing, runny nose, headaches, throat irritation, coughing, wheezing, tearing and redness of the eyes, skin irritation and rash, fever, difficulty breathing and even asthma attacks," he said.

This would be really bad for the couple, who are eager to start a huge family of their own. "We hope to adopt a lot of kids," Jessa earlier told PEOPLE. "If God blesses us with biological kids of our own, it's not going to quench our desire to adopt."