Air pollution reduces sperm count through brain inflammation, study suggests

Air pollution reduces sperm count by causing inflammation in the brain, findings of a new study conducted on mice suggests.

New research from the University of Maryland School of Medicine (UMSOM) has shown that a specific kind of neuron associated with the sleep cycle and obesity was responsible for the reduced sperm count due to air pollution.

There is a direct line between these neurons, found in the part of the brain that typically governs sex drive, hunger and thirst, and the reproductive organs, which in turn triggers the inflammation response that results in a low sperm count, researchers found.

Lead study author Zhekang Ying, PhD, Assistant Professor of Medicine at UMSOM, said: “Our findings showed that the damage due to air pollution—at least to the sperm count—could be remedied by removing a single inflammation marker in the brains of mice, suggesting that we may be able to develop therapies that could prevent or reverse the damaging effects of air pollution on fertility.

“Looking back, it makes perfect sense that the neurons in the hypothalamus are the culprits perpetuating this inflammation response that results in low sperm count, as we know that the hypothalamus is a major pathway link between the brain and the reproductive system.”

It is estimated that around 92 per cent of the world’s population live in areas where the level of fine particles in the air exceed the minimum safety standards defined by the World Health Organisation (WHO).

These pollutants arise from a number of sources, including car exhausts, factories, wildfires, and wood-burning stoves.

Charles Hong, MD, PhD, the Melvin Sharoky, MD Professor in Medicine and Director of Cardiology Research at UMSOM, said: “These findings have wider implications than just fertility, as there are many conditions, such as high blood pressure, diabetes, and heart disease that can result from brain inflammation due to air pollution.”

Those that face conditions such as a diminishing sperm count as a result of frequent exposure to fine particles tend to be poor or people of colour, said Executive Vice President for Medical Affairs, E. Albert Reece.

It is “important” to continue with studies into the impact of pollution on health in tackling “health disparities”, he added.

He said: “ Environmental pollution is a problem of equity in that some persons who are poor or of colour tend to face more severe health-related conditions due to greater exposure.

“It is important to explore the mechanisms by which pollution affects the body, so we can devise ways to prevent or treat these conditions to eliminate these health disparities.”