Exposure of Operators to Air Pollutants from Lawn and Garden Equipment
Automobile traffic is a major source of urban air pollution, but off-road engines such as lawnmowers, line trimmers and chainsaws are also important. In South-East Queensland, lawn-mowing contributed approximately 1700 tonnes (0.7%) of volatile organic compounds (VOCs) and 5200 tonnes (1.3%) of CO to yearly air emissions in the 1990s.
This project investigated the potential personal exposure to selected VOCs such as benzene, toluene, ethyl benzene and xylenes of over 25 operators during gardening activities in the Brisbane residential area when using lawn-mowers and line trimmers. Commercial ultra passive sampler badges with Tenax as the sorbent (SKC # 590-100) were worn on the operator's collar near the breathing zone during gardening operations. Blank/background samples were collected on the same day as samples, either upwind whilst mowing, or by exposure before mowing. The sorbent was transferred to an automated thermal desorption tube and analysed by automated thermal desorption and gas chromatography-mass spectrometry analysis. After analysis, the levels of VOCs adsorbed were calculated using published diffusion rates.
Preliminary results indicate that an aged petrol 2-stroke push mower exposed the operator to benzene concentrations up to 600µg/m3, and toluene and xylenes up to 1500µg/m3. High levels of benzene, toluene and xylene are also found when using line trimmers while 4-stroke mowers produced lower amounts of VOCs. These results demonstrate potentially hazardous exposure of VOCs through extended use of garden equipment powered by 2-stroke petrol engines. While the risk to weekend gardeners may be acceptable, the risk to professional garden workers may require closer attention.