Nitrogen oxides are produced by automobile exhaust, and are found in higher concentrations in living spaces that are close to roads. They can also be produced by heating appliances, fireplaces and stoves. They can irritate the airways and increase susceptibility to respiratory illnesses.

The investigators in this study looked at three plant species and the soil in which they were potted, to see what contributed to removal of nitrogen oxides from the air. As it turned out, the planting media did much of the work, so the authors suggested easy-to-maintain plants.

They looked specifically at Spathiphyllum wallisii ‘Verdi’, also known as Peace Lily; Dracaena fragrans ‘Golden Coast’, aka Dragon Tree; and Zamioculcas zamiifolia, sometimes called a “ZZ Plant.” The last one is described online as “unkillable.”

Those of you who visited the office I shared with Dr. Gonzalez will remember that it had many plants. Friday afternoons would see him with a watering can and a towel to mop up drips, using plant care to wind down. Plants have benefits beyond improving air quality!