Many low-income families tend to live in poor quality public housing. According to a study, public housing was usually found to be infested with cockroaches, mice, and vermin. The study also found mold, lack of air conditioning, and tobacco smoke to be common in public housing. According to this study, 22% of children who lived in public housing were diagnosed with asthma, while 7% of children who lived in single-family homes were diagnosed with asthma.