By the way, doctor: Do mold spores cause lung cancer?
Q. An article on lung cancer mentioned "certain other airborne substances" as risk factors. What about mold spores?
A. Your question is a good one. Mold or fungal spores can cause certain lung disorders, including infections (pneumonia), allergic reactions (rhinitis or asthma), and reactions in which the body's immune system attacks lung cells, causing inflammation (pneumonitis). Mold spores also produce toxins (mycotoxins) that can affect the lungs, skin, and nervous system. But we have no definitive evidence linking them to specific diseases — and no evidence that mold spores cause lung cancer.
Exposure to tobacco smoke is the biggest risk factor for lung cancer. Others include a prior lung disease (such as emphysema), a chronic inflammatory condition (such as tuberculosis), or a close family member with lung cancer. Airborne particles apart from cigarette smoke account for a much smaller proportion of lung cancers. Asbestos fibers pose a risk, especially if you smoke. Many homes and commercial buildings still contain asbestos, although it's not harmful unless it's released into the air by deterioration or demolition. Another hazard is radon, a by-product of uranium breakdown; it may be found at high levels inside houses built on soil containing natural uranium deposits.