Natasha Dave

Natasha N. Dave @NatashaNDave is a nephrologist and medical director for Strive Health. Her interests include tele-nephrology, social media and value based care.

“We have modified our environment so radically that we must now modify ourselves to exist in this new environment.” – Norbert Weiner

Air quality and its health effects has garnered public attention and is top of mind to many individuals living in vulnerable regions. With smart phone weather applications now reporting the air quality index (AQI) of your city to cities like Beijing halting outdoor school activities/public transportation/construction when pollution is 10x the World Health Organization (WHO) recommended level; air pollution is the leading environmental health risk and impacts life in the 21st century. Many believe this is a modern era problem due to vehicle emissions/coal-fueled power plants/manufacturing etc., interestingly, the history of poor air quality extends far past the industrial revolution.

The earliest reports of polluted air can be traced back to 400 BC in the book Airs, waters and places where Hippocrates correlates illness to the air quality. Later in Rome, Seneca 63-65 AD studied as well as experience health impacts of smoke inhalation; he even took leave from Rome due to this quoting ‘awful odour of reeking kitchens which, in use, pour forth a ruinous mess of steam and soot’ and felt his health mending once in the country ‘I am my old self again, feeling now no wavering languor in my system, and no sluggishness in my brain.’ Between 947-1279 AD air pollution was noted along the Silk Road in Asia and China due to coal burning. In addition to outdoors, our ancestors assessed indoor air quality and later improved it with the creation of the chimney in the 12th century. To learn more about the history of air pollution check out this review article and detailed timeline from the article below that walks through major air pollution milestones.

Fowler, et al. 2020. A chronology of global air quality. Phil. Trans. R. Soc. A.3782019031420190314 http://doi.org/10.1098/rsta.2019.0314

Currently, the WHO estimates one out of every nine deaths globally is attributed to ambient air pollution-related conditions with health risks amplified in lower/middle income countries, children under five, adults aged 50-75 and patients with preexisting conditions. Long-term exposure can lead to death attributable to air pollution of which 36% is due to lung cancer, 35% is from COPD, 34% is from stroke and 27% is from ischemic heart disease.

Patients with kidney disease are at a higher likelihood of increased morbidity and mortality in comparison to the general population. Interestingly, not much is mentioned on the WHO website on air pollution and its influence on this cohort which leaves one to wonder: Are patients who have kidney disease are at a higher risk of complications compared to patients who live in areas with better air quality? And furthermore, are individuals who live in highly polluted areas are at a higher likelihood of developing kidney disease?

The answers lie in the November 2022 issue of AJKD. Two articles, Duan et al and Xi et al, explore pollution and its impact on patients with kidney disease.

• First up, Xi et al explores the likelihood of cardiovascular morbidity and mortality that is likely to occur in in-center hemodialysis patients. This study follows 314,079 patient, identified from USRDS, initiating hemodialysis between 2011-2016 in the United States. The results show a correlation between long-term ambient PM2.5 exposure and cardiovascular events and cardiovascular disease-specific mortality. Risks for cardiovascular disease were higher with each 1ug/m3 increase in annual average of PM2.5, for older patients, those with COPD and those who were Asian.

• Next, Duan et al investigates the correlation between long-term exposure to air pollution (taking in consideration humidity/temperature) and incident CKD in China. This study follows 74,425 patients in 21 counties of China from 2005-2017. The results showed long-term exposure to high levels of ambient PM2.5 was associated with a higher likelihood of incident CKD (hazards ratio 1.71, 95% CI, 1.58-1.85) and risks were even greater in high-humidity environments.

Both articles illustrate a correlation between poor air quality index and adverse health consequences. As clinicians, seldom do we consider environmental exposures during our routine assessment. With evidence drawing a correlation between quality of air and health, clinicians should consider screening as well as educating patients on the impact of their environment. For example: patients with kidney disease who live in vulnerable regions should keep track of the air quality index of their city and stay indoors or take precautions during particularly polluted days.

As humans continue to modify the planet, it is important for us to take stock of how this impacts our health and the health of those around us. Perhaps making it personal, shedding light how this relates to all, can help ignite the change needed to  prevent pollution and more importantly, improve health outcomes.

– Post prepared by Natasha Dave @NatashaNDave

To view Duan et al (Open Access) and Xi et al (Open Access), please visit AJKD.org.

Title: Association of Long-term Ambient Fine Particulate Matter (PM2.5) and Incident CKD: A Prospective Cohort Study in China
Authors: Jing-wen Duan, Ya-lan Li, Shen-xin Li ,Yi-ping Yang, Fei Li, Yan Li, Jie Wang, Pei-zhi Deng, Jing-jing Wu, Wei Wang, Chang-jiang Meng, Ru-jia Miao, Zhi-heng Chen, Bin Zou, Hong Yuan, Jing-jing Cai,Yao Lu
DOI: 10.1053/j.ajkd.2022.03.009

Title: Association Between Long-term Ambient PM2.5 Exposure and Cardiovascular Outcomes Among US Hemodialysis Patients
Authors: Yuzhi Xi, David B. Richardson, Abhijit V. Kshirsagar, Timothy J. Wade, Jennifer E. Flythe, Eric A. Whitsel, Ana G. Rappold
DOI: 10.1053/j.ajkd.2022.04.008