According to Purdue University researchers, even a person breathing or wearing deodorant can adversely affect the air quality of the space they are occupying. To find out how much, the researchers are conducting a massive study of an office space rigged with thousands of sensors.
The scientists hope to identify all types of indoor air contaminants and recommend ways to control them through how a building is designed and operated.
“If we want to provide better air quality for office workers to improve their productivity, it is important to first understand what’s in the air and what factors influence the emissions and removal of pollutants,” said Brandon Boor, an assistant professor of civil engineering at Purdue.
The initial findings, which will be presented at a conference later this month, show that people and ventilation systems greatly impact the chemistry of indoor air, possibly more than anything else in an office space. “The chemistry of indoor air is dynamic. It changes throughout the day based on outdoor conditions, how the ventilation system operates and occupancy patterns in the office,” Boor said.
The building, called the Living Labs at Purdue’s Ray W. Herrick Laboratories, uses an extensive sensor array to precisely monitor four open-plan office spaces and to track the flow of indoor and outdoor air through the ventilation system. The team embedded temperature sensors in each desk chair to track occupancy. Through the building, Boor’s team has begun to identify previously unknown behaviors of chemicals called volatile organic compounds, such as how they are transformed in ventilation systems and removed by filters.
Boor teamed up with researchers at RJ Lee Group to deploy a highly sensitive “nose”—an instrument that scientists call a proton transfer reaction time-of-flight mass spectrometer. The instrument, typically used to measure outdoor air quality, helped “sniff” out compounds in human breath, such as isoprene, in real time. The researchers found that isoprene and many other volatile compounds linger in the office, even after people have left the room. The emissions increase as the number of people in the room increase.
“Our preliminary results suggest that people are the dominant source of volatile organic compounds in a modern office environment,” Boor said. “We found levels of many compounds to be 10 to 20 times higher indoors than outdoors. If an office space is not properly ventilated, these volatile compounds may adversely affect worker health and productivity.”
The team also revealed a pollutant entering from outside, ozone, disappears inside as it interacts with other indoor compounds and the vast surfaces of a furnished office. Ozone and compounds released from peeling an orange, called monoterpenes, mix to form new, super-tiny particles as small as one-billionth of a meter. The newly formed particles could be toxic, because they are small enough to get into the deepest regions of a person’s lungs.
If that news is not bad enough, the scientists also believe that chemicals emitted from self-care products such as deodorant, makeup, and hair spray may elevate levels outdoors as they are vented outside by the ventilation system.