Cooking with Coal or Wood is Associated with Increased Risk of Ocular Surface Diseases

Article: Cooking with coal or wood associated with increased risk of major eye diseases
Source: University of Oxford (U.K.), via Technology Networks
Published: July 30, 2021

A population-based cohort study involving nearly half a million people in China found a clear correlation between cooking with solid fuels, such as coal or wood, and an increased risk of eye diseases. The data was collected from the China Kadoorie Biobank, whose study participants completed questionnaires about their cooking habits, then were tracked for hospital admissions of major eye diseases over a ten-year follow-up period. The data showed 4,877 cases of conjunctiva disorders, 13,408 cases of cataracts, 1,583 disorders of the sclera, cornea, iris and ciliary body (DSCIC), and 1,534 cases of glaucoma among the study participants. After accounting for factors such as age, sex, location of residence, and level of education, the results showed that long-term use of solid fuels for cooking was associated with 32% higher risk of conjunctivitis, 17% higher risk of cataracts, and 35% higher risk of DSCIC compared with those who cooked using clean fuels such as electricity or gas. Despite a few cases of glaucoma in the sample, there was no association between solid fuels use and increased risk of glaucoma. There was no difference of risk between using coal or wood for the other eye diseases, and no difference between cooking with or without cookstove ventilation (including chimneys). Furthermore, people who switched from solid fuels to clean fuels exhibited lower elevated risk. The lead author of the study explains, "The increased risks may be caused by exposure to high levels of fine particulate matter (PM2.5) and carbon monoxide, which can damage the eye surface and cause inflammation." They suggest that there was no association with increased risk for glaucoma because it is a disease that affects internal eye structures rather than the eye surface. With regard to practical applications, the senior author of the study comments, "Switching to clean fuels appeared to mitigate the risks, underscoring the global health importance of promoting universal access to clean fuels." Additionally, the study highlights that eye problems can result from a variety of factors, including environmental factors as seen in this study, and raises awareness about reducing avoidable causes and increasing access to health services.

My rating of this study: ⭐⭐⭐⭐

Chan KH, Yan M, Bennett DA, et al. "Long-term solid fuel use and risks of major eye diseases in China: A population-based cohort study of 486,532 adults." PLOS MEDICINE.  29 July 2021. https://doi.org/10.1371/journal.pmed.1003716