Description
Leaf blowers can be a labor-saving device to remove litter from walkways and public areas, however, there are concerns that their use might result in bystander exposure to particulates during and after their use. Leaf blowers are used daily on San Diego State University (SDSU) campus to control leaf litter and debris. The purpose of this study was to determine if leaf blowing had a significant effect on air quality, how long particulate matter (PM) levels remained elevated, and if there is a protective distance for bystanders.12 days of PM measurements were taken before, during, and after blowing on campus walkways while the path of the leaf blower was tracked using GPS. PM1 (aerodynamic diameter <1 μm), PM2.5 (aerodynamic diameter <2.5 μm), PM4 (aerodynamic diameter <4 μm), PM10 (aerodynamic diameter <10 μm), total suspended particles (PMTotal), and ultrafine particles (UFP) levels were collected during air sampling. PMTotal and UFP showed the largest increases in concentration during blowing: an overall 117% median increase for PMTotal (mass concentration) and an overall 273% median increase for UFP (particle concentration), although overall, no increases were statistically significant. The median PMTotal concentration during blowing was 1.5 times higher than PM10 and almost 2 times higher than PM2.5. When comparing within the same day a significant increase was seen for 75% of days for PM2.5, 83% for PM10, 92% for PMTotal, and 90% UFP; 75% of days showed a significant decrease 15 minutes after blowing had stopped for all particle sizes. A significant negative correlation was found between distance of operator and particle concentration for all particle sizes. A distance of 55 meters appears to be protective for smaller particles (PM1, PM2.5, PM4), and a distance of 75 meters seems to be protective for larger particles (PM10, PMTotal). These results argue that in the cases observed here, keeping bystanders at a greater than 75 meter distance during blowing and for a 15 minute period following blowing. However, these recommendations may not hold for other locations and times of day. More research is needed to determine the impacts of leaf blowers on air quality on SDSU campus.
