Influence of air velocity, application dose and test area size on the volatilisation of lindane

The volatilisation of lindane from soil and French beans was tested in a wide tunnel under defined conditions. Volatilised lindane was determined directly by passing a partial air stream through an adsorbent. Applications of a lindane formulation onto soil and plant surfaces were performed using a moving nozzle. Soil volatilisation experiments were conducted using differnt air velocities (0.4, 1.1, 1.7 m/s). At higher air velocities the volatilisation rate increased from 12% to 31% within 24 h (initial dose 100%). For plant experiments with different velocities (0.4, 1.0, 2.0 m/s) the volatilisation rate increased from 52% to 62% at the highest velocity. Additionally, as higher air velocities were applied, air concentrations of lindane during the first hour decreased from 1.61 micron gramm/cbm at 0.4 m/s to 0.61 micron gramm/cbm at 2.0 m/s. In soil experiments with different application doses of lindane (33 mg/sqm, 117 mg/sqm) the volatilisation rate was decreased (23%) at the higher a pplication does in comparison to the lower dose (39%). The volatilisation rate was also influenced by the size of the treated area in the wind tunnel. From a larger soil surface (0.84 sqm) a lower amount of lindane (23%) volatilised than from a smaller surface (31% at 0.28 sqm).