Although the air in our homes or workplaces may seem OK, it might contain harmful compounds emitted by materials such as particleboard and carpeting. New research suggests that we may soon be able to tell if that is the case, using tiny glowing worms.

For the study, scientists at Finland's University of Turku started out with two transgenic strains of the millimeter-long Caenorhabditis elegans nematode.

What makes these roundworms special is the fact that when they smell or taste toxic biological or synthetic compounds, they respond by producing green fluorescent protein (GFP) within 24 hours.

The higher the levels of those compounds, the more protein the worms produce, and thus the more they fluoresce – the intensity of the fluorescence can be objectively measured via either microscopy or spectrometry.

These same types of environmentally sensitive nematodes had previously been used to monitor concentrations of heavy metal pollution in the outdoor environment. This latest study reportedly marked the first time that they had been tested on indoor airborne contaminants.

It was found that the worms reliably fluoresced when exposed to harmful substances such as black mold collected from moisture-damaged buildings, harsh chemicals used in cleaning products, and volatile organic compounds produced by chemicals in degraded plastic carpets. Along with producing more GFP, the worms also became less active – some of them even dying – when such airborne substances were present.

"The nematodes cannot tell us what kind of toxic compounds there are in the air, but they can provide an unbiased opinion on health risks associated with indoor air and on the need for more thorough technical investigations," said the lead scientist, Päivi Koskinen.

A paper on the research – which also involved scientists from Finland's Aalto University and University of Helsinki – was recently published in the journal Pathogens.