Conifer monoterpenes emitted to air by logging operations

Concentration levels in air were determined for monoterpenes emitted from forestry operations in south-west Sweden. Field samples were collected on Tenax cartridges and analyzed in the laboratory by techniques based on gas chromatography. Processing of Scots pine as well as Norway spruce with a harvestor gave rise to about 1000 microgram/m3 of total monoterpenes near the machine. The corresponding levels above fresh branch wood were 100-500 microgram/m3. The background level was around 1 microgram/m3. The major monoterpenes were alpha-pinene and 3-carene from Pinus sylvestris and alpha-pinene and beta-pinene from Picea abies. Compounds constituting 1-10 % each of the total monoterpenes were camphene, 3-carene, limonene, beta-phellandrene and myrcene for spruce and camphene, beta-pinene, limonene, beta-phellandrene, myrcene and terpinolene for pine. Representative percent compositions for the two species are given for 13 monoterpenes. Photo-oxidant formation from the monoterpenes is discussed with respect to potential local contributions to strain and damage of the forests. Possible preventive measures are suggested