Characterization of airborne BTEX exposures during use of lawnmowers and trimmers.

Few studies have evaluated airborne exposures to benzene, toluene, ethylbenzene, and xylenes (BTEX) during operation of two-stroke and four-stroke small engines, such as those in lawn maintenance equipment. Full-shift, 8-hour personal samples were collected during a simulation study to characterize yard maintenance activities including mowing, trimming, and fueling. Short-term, 15-minute personal samples were collected to separately evaluate mowing and trimming exposures. Mean 8-hour time weighted average (TWA) BTEX concentrations were 2.3, 5.8, 0.91, and 4.6 ppb, respectively (n = 2). Mean 15-minute TWA BTEX concentrations were 1.6, 1.8, 0.22, and 1.3 ppb, respectively, during mowing and 1.2, 3.6, 0.68, and 3.3 ppb, respectively, during trimming (n = 3 per task). Measured BTEX concentrations during fueling were 20-110, 61-310, 8-41, and 40-203 ppb, respectively (n = 2, duration 2-3 minutes). These exposure concentrations were well below applicable US occupational exposure limits.