Choosing a Restaurant: More Crowds and Stronger Aromas May Signal Poor Air Quality

When picking a restaurant, many people prioritize popularity and enticing aromas. However, experts warn that a crowded dining environment with strong food smells often means poor ventilation, exposing customers to excessive carbon dioxide and volatile organic compounds (VOCs). Prolonged exposure can lead to liver, kidney, and brain nerve damage, and even cancer. Experts advise choosing seats that aren’t in poorly ventilated areas, even if it’s just to avoid feeling cold. When dining in private rooms, make sure they have both an air supply vent and a return vent for proper airflow.

VOCs: A Hidden Danger to Nerves and Cancer Risk

A study jointly conducted by Taiwan's Formosa Plastics Group and the Taiwan Society of Indoor Environmental Quality found that a two-hour stay in a restaurant bar exposes customers to VOC levels 1.27 times higher than Taiwan’s indoor air quality standards. Hookah bars (waterpipe bars) had PM2.5 levels 3.1 times higher than the standard.

The study’s principal investigator, Dr. Lin Yu-Wen, Vice Dean of the School of Medicine at Fu Jen Catholic University, explained that VOCs include alkanes, aldehydes, ketones, and aromatic compounds. Prolonged exposure can damage the liver, kidneys, brain, and nervous system, and may even cause cancer. Carbon dioxide levels, meanwhile, reflect ventilation efficiency—high CO2 means pollutants accumulate more easily.

Surprisingly, Bars May Have Worse Air Quality than BBQ Restaurants

Lin noted a surprising finding: while BBQ restaurants were expected to have the worst air quality, only their carbon dioxide levels exceeded standards. In contrast, restaurant bars exceeded VOC limits by 1.27 times and CO2 by 2 times, while PM2.5 levels stayed within limits. Hookah bars had VOC levels 1.58 times higher and PM2.5 levels 3.1 times higher than standards, though CO2 levels were not exceeded.

"Crowded and Smells Good" May Actually Mean "Poor Air Quality"

Dr. Chang Chen-Ping, co-investigator and Associate Professor of Occupational Safety and Health at Chang Gung University, noted that restaurants known for their appealing food aromas and crowds often have poor air quality: the strong food smells indicate poor air circulation, and crowded spaces cause CO2 levels to rise, degrading air quality.

To reduce exposure to VOCs and high CO2, Chang recommends the “3 actions, 1 principle” approach:

• Three actions: Open windows, install ventilation systems, and add green plants.

• One principle: “Look and sniff”—choose restaurants with visible air quality meters or air vents. Avoid dining areas where cooking smoke or food smells linger heavily.

The Best Seat: Where You Can’t Smell the Food

Chang suggests that some restaurants use green plants to absorb CO2 or VOCs, but many bars and nightclubs, aiming for a certain ambiance, use dim lighting and artificial plants, which don’t purify the air. When entering a restaurant, if you notice no windows or doors are open, look for an air conditioning room or system—this suggests better air circulation.

For a healthier dining experience, opt for restaurants that feel airy when you walk in, where you can’t smell strong food aromas, and where the seating isn’t packed. Ideally, no more than two-thirds of the tables should be occupied; when a restaurant is at full capacity, air circulation tends to be poor. Also, avoid seats in spots where air conditioning doesn’t reach—those areas typically have the worst air quality. If dining in a private room, check for two vents: a round air supply vent and a rectangular return vent. Without a return vent, air can’t circulate properly.

Chang also offered tips for home grilling: whenever possible, place the grill under the range hood. If grilling in the living room (because many people don’t like grilling in the kitchen), set up a fan to blow smoke toward the kitchen, and turn on the kitchen exhaust fan to vent harmful gases outside.