Inhaled fine particulate matter travels beyond the lungs to the brain
KIST identifies how trace amounts of fine particulate matter move through the body
image: Hydrocarbons labeled with ¹⁴C were pyrolyzed to synthesize ¹⁴C-labeled fine particulate matter. The particles were then adjusted to environmentally relevant concentrations and used to expose mice. The amount of fine particulate matter accumulated in each organ was subsequently measured with high precision using accelerator mass spectrometry (AMS). Based on these measurement, the concentrations and total amount in each organ were calculated to determine the distribution within the body.
Credit: Korea Institute of Science and Technology
Checking the fine particulate matter levels along with the weather every morning has become a daily routine. Research continues to show that fine particulate matter affects not only the respiratory system but also the brain and overall health; prolonged exposure can lead not only to reduced lung function but also to inflammatory responses in various organs. For these reasons, these particles are recognized as an environmental issue directly linked to public health.
However, where fine particulate matter moves within the body and how it is distributed after inhalation have not yet been clearly understood. In previous experiments simulating exposure to fine particulate matter, technical limitations made it difficult to quantitatively how much of the particles reached individual organs. As a result, researchers have struggled to accurately determine their actual distribution. Until now, assessments have largely relied on rough estimates focused on the lungs, where these particles are expected to accumulate the most.
A research team led by Drs. Byung-Yong Yu and Gwan-Ho Lee at the Advanced Analysis and Data Center of the Korea Institute of Science and Technology (KIST; President Sang-Rok Oh) announced that it has developed a new analytical platform that can precisely measure the accumulation of fine particulate matter in individual organs, overcoming the limitations of existing analytical technologies. The study is significant because it presents a technology capable of quantitatively measuring even trace amounts of fine particulate matter that reach individual organs after small animals are exposed to environmentally relevant concentrations of these particles.
The research team produced fine particulate matter labeled with radiocarbon (¹⁴C) and conducted exposure experiments using the labeled particles. By combining this approach with accelerator mass spectrometry (AMS), a technique capable of detecting and measuring trace amounts of radioisotopes, the team established an analytical method that can quantify the particles introduced into the body down to the picogram (pg) level. This approach enabled the researchers to precisely quantify the movement pathways of fine particulate matter within the body and its accumulation in specific organs-information that had previously been difficult to determine.
Results from animal exposure experiments using radiocarbon-labeled fine particulate matter showed that the particles were not confined to the lungs, but were distributed to various organs, including the liver, kidneys, and brain. Even after just one hour of exposure at a concentration corresponding to the "very poor" air quality level, approximately 150 μg/m³ of PM10, particles were detected in multiple organs. Repeated exposure for three hours a day over seven days also showed an increasing trend in the amounts of particles distributed to each organ. These findings suggest that fine particulate matter may gradually accumulate in the body depending on the frequency and duration of exposure.
This analytical platform is expected to significantly improve the precision of future fine particulate matter risk assessments and provide a scientific basis for establishing environmental standards and public health policies. In particular, by enabling health impact assessments that go beyond respiratory-focused research to consider systemic effects on the brain, liver, and other organs, the platform is expected to play an important role in developing policies to protect vulnerable populations, including pregnant women, older adults, and patients with respiratory or cardiovascular diseases. Furthermore, the research team plans to expand this analytical platform to evaluate various environmental hazards, including microplastics, and apply it to broader industrial and environmental safety management.
Dr. Gwan-Ho Lee of KIST stated, "This study is the first to quantitatively determine the amount of fine particulate matter taken into the body and its organ-specific accumulation using accelerator mass spectrometry," adding, "It has laid the groundwork for precisely measuring the distribution of the particles within the body even under conditions similar to real-life environments."
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KIST was established in 1966 as the first government-funded research institute in Korea. KIST now strives to solve national and social challenges and secure growth engines through leading and innovative research. For more information, please visit KIST’s website at https://kist.re.kr/eng/index.do
This study was supported by the Ministry of Science and ICT (Minister Kyung-Hoon Bae) and carried out as part of KIST's major institutional research program and the Comprehensive Research Project on Atmospheric Environment. The findings were recently published in the international journal Environmental Science & Technology (Impact Factor 11.3, ranked in the top 4.9% of its JCR category).