A recent investigation involving mice has revealed alarming effects of prolonged exposure to low levels of air pollution from traffic.
This research suggests that such environmental factors may contribute significantly to liver health issues, particularly increasing the risk of metabolic-associated fatty liver disease, also known as hepatic steatosis.
This condition is characterized by an abnormal buildup of fat in liver cells and stands as the most common liver disease worldwide.
If untreated, fatty liver disease can lead to serious complications such as inflammation, cirrhosis, and an increased risk of liver cancer and failure.
Impact of Air Pollution on Liver Health
Professor Hui Chen, the lead researcher from the University of Technology Sydney (UTS), pointed out that while many associate air pollution mainly with respiratory illnesses, it can also have far-reaching impacts on liver health.
The liver is vital for various metabolic functions, including detoxifying harmful substances, managing blood sugar levels, and producing critical proteins and vitamins.
A decline in liver function often results in feelings of fatigue and general unease.
The study specifically examined how fine particulate matter, known as PM2.5, from polluted air enters the bloodstream through the lungs.
Once in circulation, these fine particles can lead to the accumulation of toxins, including heavy metals like arsenic, lead, nickel, and zinc, within the liver—its role being that of a filtration organ.
Research Findings and Implications
Co-author Professor Jacob George, a renowned liver expert and Director of the Storr Liver Centre at The Westmead Institute for Medical Research, noted that about one-third of adults in Australia are affected by fatty liver disease.
This condition tends to be more prevalent in those who are overweight or living with diabetes.
The findings reinforce the importance of considering environmental factors, particularly traffic-related air pollution, alongside lifestyle influences such as poor diet and lack of exercise, in the onset of fatty liver disease.
The study, titled “Prolonged exposure to low-dose traffic-derived PM2.5 causes fatty liver disorder in mice,” was published in the Journal of Environmental Sciences.
In this research, the team exposed mice to a daily dosage of PM2.5 equivalent to 10 micrograms—a reflection of typical air pollution levels encountered in Sydney, especially near busy thoroughfares.
Researchers monitored various markers of liver inflammation and scarring over periods of four, eight, and twelve weeks.
Within four weeks, only slight changes were observed.
However, by the eight-week point, the mice exhibited significant disruptions in liver metabolism.
By the conclusion of the twelve-week observation, researchers noted a notable increase in immune cell activity, liver inflammation, and the formation of scar tissue.
Recommendations for Reducing Exposure
Additionally, the study uncovered enhanced fat processing in the liver, along with elevated levels of potentially harmful lipids like triglycerides and ceramides, while the liver’s ability to store sugar for energy purposes diminished.
Detailed analyses identified changes in 64 specific proteins linked to fatty liver disease, immune system dysfunction, and even the progression of cancer.
While previous research established links between high pollution levels and liver conditions, this recent study underscores that even lower pollution concentrations can provoke harmful effects, indicating that there may be no truly safe threshold for exposure to traffic-related air pollution.
To cope with these pollutants, Professor Chen offers practical advice.
She suggests avoiding travel during peak traffic hours, choosing less congested routes for walking or biking, and wearing masks when necessary.
Additionally, keeping car windows rolled up and utilizing air recirculation features in vehicles during heavy traffic can significantly reduce exposure to harmful air contaminants.
Source: ScienceDaily