Prolonged Exposure to Low-Dose Traffic Pollution Linked to Fatty Liver Disease: Study

Sydney: Long-term exposure to even low levels of traffic-derived particulate matter (PM2.5) has been found to trigger fatty liver disease, challenging previous assumptions about its causes and posing new risks to public health.

A study published in the Journal of Environmental Sciences has revealed that chronic exposure to air pollution could be a silent driver of liver disorders, even in the absence of traditional risk factors like poor diet and obesity.

The research, conducted by scientists from the University of Technology Sydney, The University of Sydney, and Westmead Institute for Medical Research, exposed BALB/c mice to traffic-derived PM2.5 at 10 μg/mouse/day for up to 12 weeks, measuring the effects on liver health.

The results were alarming. Researchers observed significant inflammation in the liver, evidenced by macrophage infiltration and increased pro-inflammatory cytokine production at both 8 and 12 weeks of exposure.

Additionally, by the 12-week mark, the mice showed significant collagen deposition, signalling the onset of fibrosis. Furthermore, lipid accumulation was observed, with levels of triglycerides, ceramides, and diacylglycerols increasing, while glycogen content decreased, disrupting liver metabolism.

A proteomics analysis revealed 64 significantly altered proteins, linking PM2.5 exposure to liver conditions commonly associated with alcohol-related liver disease, metabolic disorders, and cancer-related changes.

Lead researcher Dr. Hui Chen from the University of Technology Sydney emphasized the dangers of even low levels of air pollution, stating: “There is no safe threshold for air pollution. Our study shows that even at low doses, PM2.5 exposure can cause serious metabolic disruptions in the liver, leading to fatty liver disease.”

Co-author Dr. Jacob George, a hepatology expert from the Westmead Institute for Medical Research, added: “Traditionally, fatty liver disease is linked to obesity and diet. This study shifts the paradigm by showing that air pollution alone is a significant risk factor.”

Environmental health specialist Dr. Brian G. Oliver stressed the public health implications, saying: “Air pollution is not just a respiratory concern—it affects multiple organs, including the liver. People living near highways and industrial zones may be at higher risk.”

The study uncovered how fine particulate matter infiltrates the bloodstream, leading to oxidative stress and chronic inflammation. This triggers an immune response that alters liver metabolism, promoting fat accumulation and fibrosis.

Given these findings, researchers advocate for stricter air quality regulations and increased public awareness. “Reducing vehicular emissions and improving urban air quality should be top priorities,” said Dr. Chen.

The team plans further investigations to explore preventive strategies and potential medical interventions to counteract pollution-induced liver damage.

With air pollution being an unavoidable reality in urban environments, experts urge individuals to take proactive steps such as using air purifiers, reducing outdoor exposure in high-traffic areas, and supporting clean energy policies.

The study reinforces that no level of air pollution is truly safe, and long-term exposure, even at seemingly harmless doses, can have far-reaching health consequences.