Intra-seasonal variation of particulate matter and volatile organic compound emissions during electrically driven lawn mowing

Lawn mowing is a widespread urban management practice that can generate significant biogenic emissions, even when electric equipment is used. This study investigates the intra-seasonal variability of particulate matter (PM1, PM2.5, PM10) and volatile organic compounds (VOCs) emissions during electrically driven lawn mowing over a full growing season (March–September) in a sub-urban area of central Italy. Measurements were conducted every four weeks on a 100 m2 turfgrass plot using high-frequency monitoring (0.6 Hz, about 250 data points per session, 80 data points per experiment), allowing detailed characterization of emission dynamics before, during, and after mowing. Results show that mowing itself is the dominant driver of particulate emissions, with very large effects for PM10 and PM2.5 (F = 177 and 123, respectively; p < 0.001). Strong intra-seasonal variability was also observed, with coefficients of variation exceeding 130% for all particulate fractions and approximately 69% for VOCs. Normalization by the mass of grass removed did not attenuate seasonal patterns, indicating that emissions appear to be influenced by seasonal changes in plant physiological status, environmental conditions, and vegetation structure rather than biomass yield alone. Particulate matter emissions exhibited a pronounced mid-season peak, whereas VOC emissions were highest in early spring and declined thereafter. Correlation analysis confirmed a strong coupling among particulate fractions (r = 0.97–0.996) but weak associations between particulate matter and VOCs, highlighting distinct emission mechanisms. These findings demonstrate that particulate matter and VOC emissions from lawn mowing are highly dynamic and season-dependent, with implications for urban air quality and operator exposure, even under low-combustion management practices. © 2026 Turkish National Committee for Air Pollution Research and Control