Morning walk in winter may harm health, experts warn

KATHMANDU: If you have a habit of taking early morning walks, you may need to reconsider your routine. Experts warn that stepping out for a walk at dawn during winter could be more harmful to health than beneficial.

Compared to summer, winter air tends to be more polluted. Before sunrise, cold air remains trapped close to the ground, increasing pollution levels. Experts recommend walking only after the sun rises when the air quality improves. Pollutants such as dust, smoke, and carbon particles remain suspended close to the surface in colder temperatures.

Environmental expert Bhushan Tuladhar explains that winter mornings see higher pollution levels than summer. “It is best to go outside after sunrise because warmer air begins to rise, reducing pollution near the ground,” he said. “During the night, the ground cools rapidly, preventing cold air from dispersing, which keeps pollution concentrated at the surface.”

Kathmandu, due to its valley geography, traps pollution even more, worsening air quality during winter. Increased burning of firewood, coal, and liquefied petroleum gas (LPG) for heating and cooking adds to the problem. In rural areas, traditional firewood use remains common, further accelerating pollution.

“According to the 2021 national census, 51% of Nepalese households still rely on firewood, and 3% use cow dung for cooking,” Tuladhar noted. “This results in severe indoor air pollution, primarily affecting women and children.” A recent study revealed that air pollution causes approximately 48,500 deaths in Nepal annually.

Vehicles also contribute significantly to pollution in winter. Experts say fuel combustion efficiency decreases in colder temperatures, increasing emissions of carbon monoxide and nitrogen oxides. Additionally, rural areas see increased burning of straw and waste, including plastic, worsening air pollution. Industries such as brick kilns, coal-based power plants, and cement factories continue operating in winter, further intensifying pollution.

Climate expert Manjit Dhakal emphasizes that vehicle emissions are a major contributor to pollution. “Reducing emissions would also help mitigate climate change by cutting down carbon output,” he stated.

Higher Risk for Heart Patients

Heart specialist Dr. Ranjit Sharma warns that pollution levels before sunrise are particularly dangerous for heart patients. “Pollution is harmful at any time of the day, but early morning exposure can be even riskier,” he said. “People with heart conditions should take extra precautions before stepping outside.”

Individuals with heart disease, high blood pressure, diabetes, high cholesterol, chronic illnesses, or respiratory issues like asthma should avoid outdoor exercise in the early morning. Dr. Sharma explained that winter increases hormone levels in the body, thickening blood and constricting blood vessels. This can reduce oxygen supply to the heart, increasing the risk of heart attacks and strokes.

“In cold weather, the heart has to work harder, which can lead to clot formation and severe complications,” he warned. “It’s best to wear warm clothing, use masks, and go outside only after sunrise whenever possible.”

Public health expert Dr. Samir Adhikari also cautions that increasing air pollution can lead to respiratory issues, colds, coughs, asthma flare-ups, lung cancer, high blood pressure, strokes, and heart attacks. He urges people to take necessary precautions to protect their health during winter.