Engineers are designing breath-analysis devices that can give an accurate picture of exposure to environmental contaminants.
‘Breathing reflects both what we inhale and what we metabolise,’ said project lead Prof Andrea Dietrich of the Department of Civil and Environmental Engineering at Virginia Tech.‘Toxins and non-toxins diffuse into the blood and then out of the body through breath.’
The study of breath, including using odours of the mouth to determine an illness, is centuries old, and studies of exposure to benzene and other toxins via air have been taking place since the 1970s.
New technologies — including hair-thin sorption devices found in microelectromechanical systems — can detect trace amounts of possible toxins in a person’s breath on the parts per billion or the micro-particle scale, and have improved test performance in terms of identifying biomarkers, and reduced analysis time, sample volume, and consumables such as solvents and reagents.
These improved lab tools come in conjunction with discoveries in gaseous toxins found in significant quantities in our homes, workplaces, and outdoor surroundings, such as emissions from paints, carpeting, plastic-based flooring.
‘The sources of some chemicals are well known and extensively studied in the literature, while others simply appear in the complex chemical soup that surrounds us with no identified, or several potential, sources,’ Dietrich said.
The team asks subjects to breathe into sterile plastic, then it processes the captured exhaled air through small sorption devices about the size of a penny.