Most people think of their pets as family, loyal dogs, affectionate cats, or cheerful birds that bring comfort and companionship. But a large U.S. study suggests that pet ownership, particularly of cats and birds, might come with unexpected long-term health risks for women.
A 20-Year Look at Pets and Lung Cancer Risk
Researchers followed more than 13,700 U.S. adults for 18 years to see whether owning pets had any link to lung cancer deaths. Their findings, published in Environmental Research, were surprising, and concerning, especially for women.
Women who owned any type of pet were found to have more than double the risk of dying from lung cancer compared to women without pets. The risk was even higher for women who owned cats or birds, while dog ownership showed no increased risk.
Here’s how the numbers looked:
• Any pet: 2.3 times higher risk
• Cat owners: 2.85 times higher risk
• Bird owners: 2.67 times higher risk
• Dog owners: No increased risk
What About Men?
Interestingly, the same pattern did not appear in men. The study found no link between pet ownership and lung cancer mortality among men, regardless of the type of pet.
It’s Not About Smoking
Because smoking is the biggest known cause of lung cancer, the researchers were careful to adjust for it — along with other important factors like secondhand smoke exposure, alcohol use, physical activity, body weight, and allergic conditions.
Even after these adjustments, the link between pet ownership and lung cancer deaths in women remained strong, suggesting that other environmental or biological factors may be at play.
How Pet Particles Might Affect Your Lungs
Scientists don’t yet know exactly why owning certain pets might raise lung cancer risk, but several biological and environmental clues point to indoor air exposure. Modern homes are designed to be energy efficient, tightly sealed with air recirculating through HVAC systems. While this keeps temperatures comfortable, it also means that microscopic particles shed by pets tend to stay trapped indoors.
Cats and birds, in particular, release extremely fine particles from their skin, feathers, saliva, and waste. These particles are small enough to float in the air for hours and reach the deepest parts of the lungs when inhaled. Over many years, they may cause low-level inflammation and oxidative stress, gradual damage that can make lung cells more vulnerable to cancer.
Bird owners may also be exposed to fungal spores or microbes carried in droppings and dust from cages. For cat owners, allergens such as Fel d 1 are among the smallest and most persistent airborne proteins known, easily spreading throughout homes and attaching to dust and fabrics.
Pet dander can also bind to household dust that already contains pollutants like tobacco smoke residue, cleaning chemicals, and outdoor pollutants brought inside. Together, these form a complex mix of biological and chemical irritants that the lungs have to filter daily.
Interestingly, the study found that only women showed this increased risk. Researchers believe that women’s lungs may be more sensitive to environmental carcinogens or inflammatory triggers, possibly due to hormonal and immune differences.
None of this means people should avoid having pets. It does, however, highlight the importance of good indoor air quality, using HEPA air purifiers, ventilating rooms, cleaning regularly, and grooming pets often to reduce airborne particles.
Why This Matters for Women’s Health
Lung cancer remains one of the top causes of cancer death in women, even among non-smokers. The researchers believe that pet exposure may be a previously overlooked environmental risk factor, one that has been largely ignored in public health discussions about indoor air quality.
Because pet ownership is so common, with over 60% of U.S. households owning pets, understanding how long-term exposure affects respiratory health could have major public health implications.
What You Can Do
If you have pets, you don’t need to give them up, but you can take simple steps to reduce exposure to airborne particles and improve home air quality:
• Use HEPA air purifiers in main living areas and bedrooms.
• Vacuum frequently with HEPA filters and clean surfaces where dander collects.
• Groom pets regularly, and keep birds’ cages clean and well-ventilated.
• Avoid smoking indoors, as combined exposures could multiply the risk.
• Increase ventilation by opening windows or using air exchange systems when possible.
A Call for More Research
This study doesn’t prove that pets cause lung cancer, but it opens an important conversation about how everyday indoor exposures may influence long-term health. The authors emphasize that more research is needed to confirm these findings and understand why women seem particularly vulnerable.
From the authors:
“The role of living with pets in lung cancer etiology has been overlooked for decades. Given the high prevalence of pet ownership, it is time to revisit this issue.”
Reference
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