Night markets are a vital part of Taiwan’s tourism appeal and local culture. However, the cooking smoke emitted by outdoor stalls often raises concerns about man-made air pollution and could pose long-term health risks to residents living nearby. A recent study by a research team from National Sun Yat-sen University (NSYSU) and collaborating universities has, for the first time, confirmed that air pollutants generated during night market operations not only infiltrate the indoor environments of nearby homes but also negatively impact children’s lung function.

Night markets are a vibrant and distinctive part of Taiwanese tourism, a must-visit for foreign visitors and an integral part of daily life for locals. Yet while the aroma of fried chicken, stinky tofu, grilled skewers, and oyster omelets fills the air, residents near night markets often suffer from the persistent smell of cooking fumes and may be exposed to high levels of harmful fine particulate matter (PM2.5).

This study, a cross-institutional collaboration led by Professor Lin Yuan-Tsung of NSYSU’s Institute of Environmental Engineering and Professor Chen Pei-Shih, jointly appointed by NSYSU and the Department of Public Health at Kaohsiung Medical University, highlights the potential health risks for children living near night markets.

Lin Yuan-Tsung pointed out that while night markets are a unique cultural venue in Taiwan and many Asian countries, there has been a lack of concrete research proving whether the particulate and gaseous pollutants emitted by night market activities pose health risks to nearby residents.

PM2.5 Levels Spike on Night Market Days

The research team from NSYSU and Kaohsiung Medical University surveyed 58 households near night markets in the Kaohsiung area. Using questionnaires, real-time air quality monitors, and lung function tests for children, they found that indoor concentrations of fine particulates (PM1 and PM2.5) were significantly higher on nights when the markets were open compared to nights when they were closed. This demonstrates the direct impact of cooking and burning activities at night markets on local air quality.

Further analysis revealed that homes located within 595 meters of a night market—classified as the "near group"—had consistently higher concentrations of indoor carbon dioxide, carbon monoxide, sulfur dioxide, total volatile organic compounds (TVOCs), and PM10 compared to homes located beyond 595 meters—the "far group."

More critically, even after excluding potential confounding factors such as incense burning, smoking, and home cooking, children in the "near group" still showed significantly lower lung function metrics, including forced vital capacity (FVC) and forced expiratory volume in one second (FEV1), compared to children in the "far group." This suggests that air pollutants released from night market activities have indeed infiltrated indoor environments and may negatively affect children's respiratory development.

The research team warns that long-term exposure to high concentrations of fine particulate matter and gaseous pollutants could increase children's risk of developing respiratory diseases and impair lung development.

The Health Impact of PM2.5: A Serious Concern

Inhaling high levels of PM2.5 over a short period can have severe health effects. PM2.5 particles are small enough to bypass the nasal cavity and trachea, reaching deep into the alveoli and even entering the bloodstream. This can cause significant damage to the respiratory and cardiovascular systems, exacerbating conditions such as asthma, bronchitis, and pneumonia, and increasing the risk of chronic obstructive pulmonary disease (COPD). Acute exposure to high concentrations may also trigger heart disease, arrhythmia, and hypertension, and in some cases, lead to sudden cardiac arrest or stroke.

Night Market Fumes Release Carcinogens, Raising Cancer and Cardiovascular Risks

Past studies by Academia Sinica have also investigated night market air pollution. Their monitoring data showed PM2.5 concentrations at night markets and restaurants ranged from 70 to 200 micrograms per cubic meter, sometimes reaching 500 micrograms—5 to 10 times higher than typical urban outdoor levels. According to Dr. Lung Shih-Chun from Academia Sinica’s Research Center for Environmental Changes, night markets, especially during grilling and frying, emit not only PM2.5 but also carcinogenic compounds that may increase the risk of lung cancer and cardiovascular diseases.

A Call for Policy Action

From a policy perspective, future urban planning and night market zoning should consider air quality and community health impacts. Careful evaluation of the distance between night markets and residential areas is essential. Measures to regulate stall emissions, install air purification equipment, adopt lower-pollution cooking methods, and raise awareness among nearby residents about air pollution risks and protective strategies should all be implemented to safeguard public health.