Related Experiment Video
Updated: Jul 29, 2025

Measuring Carbon Content in Airway Macrophages Exposed to Carbon-Containing Particulate Matters
Published on: July 12, 2024
Airborne Pollution: A Potential Risk Factor for Multiple Sclerosis in Colder Climates
Nicola Chalmers1, Sophie St-Hilaire2
1American International School Hong Kong, Kowloon Tong, Hong Kong, SAR PR China.
Multiple Sclerosis (MS), a neurodegenerative disease of unknown etiology, which affects approximately 450 of every 100 000 women in the USA. Using an ecological observational study design and publicly available data from the Center for Disease Control and Prevention in the USA, we assessed trends in county-level, age-adjusted female MS mortality rates between 1999 and 2006 to determine if they were correlated with environmental factors, including the county's PM2.5. In counties with colder winters, there was a significant positive association between the average PM2.5 index and the MS mortality rate, after controlling for the county's UV index and median household income. This relationship was not apparent in counties with warmer winters. We also found that colder counties had higher MS mortality rates, even after controlling for the UV and PM2.5 indices. The findings from this study provide county-level evidence for a temperature-dependent association between PM2.5 pollution and MS mortality rates, which should be further investigated.
Multiple Sclerosis (MS), a neurodegenerative disease of unknown etiology, which affects approximately 450 of every 100 000 women in the USA. Using an ecological observational study design and publicly available data from the Center for Disease Control and Prevention in the USA, we assessed trends in county-level, age-adjusted female MS mortality rates between 1999 and 2006 to determine if they were correlated with environmental factors, including the county's PM2.5. In counties with colder winters, there was a significant positive association between the average PM2.5 index and the MS mortality rate, after controlling for the county's UV index and median household income. This relationship was not apparent in counties with warmer winters. We also found that colder counties had higher MS mortality rates, even after controlling for the UV and PM2.5 indices. The findings from this study provide county-level evidence for a temperature-dependent association between PM2.5 pollution and MS mortality rates, which should be further investigated.
Related Concept Videos
Transmission-based Precautions II: Airborne and Protective Environment
Airborne precautions:
Use airborne precautions when treating patients known or suspected to have diseases that spread through the air—for example, tuberculosis or measles. These organisms are present in smaller droplets expelled by an infected person and...
Asthma-I: Introduction
Chronic Obstructive Pulmonary Disease-II: Pathophysiology
Chronic Inflammation
Decreased Body Temperature
Asthma: Pathogenesis and Management
Asthma is classified as allergic and non-allergic. Allergens such as dust mites, pollen, and pet dander trigger allergic asthma, while factors like cold air, intense emotions, or exercise can induce non-allergic asthma.
COPD: Pathogenesis and Clinical Features
The primary cause for the onset of COPD is cigarette smoking and exposure to air pollution. These hazardous factors initiate a chain reaction within the lungs, resulting in chronic inflammation, damage to the airways, and a...

