Monitoring indoor exposure to combustion-derived particles using plants

Indoor plants can be used to monitor atmospheric particulates. Here, we report the label-free detection of combustion-derived particles (CDPs) on plants as a monitoring tool for indoor pollution. First, we measured the indoor CDP deposition on Atlantic ivy leaves (Hedera hibernica) using two-photon femtosecond microscopy. Subsequently, to prove its effectiveness for using it as a monitoring tool, ivy plants were placed near five different indoor sources. CDP particle area and number were used as output metrics. CDP values ranged between a median particle area of 0.45 × 10² to 1.35 × 10⁴ μm², and a median particle number of 0.10 × 10² to 1.42 × 10³ particles for the indoor sources: control (greenhouse) < milling machine < indoor smokers < wood stove < gas stove < laser printer. Our findings demonstrate that Atlantic ivy, combined with label-free detection, can be effectively used in indoor atmospheric monitoring studies.