INFLUENCE OF AIR VELOCITY, APPLICATION DOSE, AND TEST AREA SIZE ON THE VOLATILIZATION OF LINDANE

The volatilisation of lindane from soil and French beans was tested in a wind tunnel under defined conditions. Volatilised lindane was deter mined directly by passing a partial air stream through an adsorbent. A pplications of a lindane formulation onto soil and plant surfaces were performed using a moving nozzle. Soil volatilisation experiments were conducted using different air velocities (0.4, 1.1, 1.7 m/s). At high er air velocities the volatilisation rate increased from 12% to 31% wi thin 24 h (initial dose 100%). For plant experiments with different ve locities (0.4, 1.0, 2.0 m/s) the volatilisation rate increased from 52 % to 62% at the highest velocity. Additionally, as higher air velociti es were applied, air concentrations of lindane during the first hour d ecreased from 1.61 mu g/m(3) at 0.4 m/s to 0.61 mu g/m(3) at 2.0 m/s. In soil experiments with different application doses of lindane (33 mg /m(2), 117 mg/m(2)) the volatilisation rate was decreased (23%) at the higher application dose in comparison to the lower dose (39%). The vo latilisation rate was also influenced by the size of the treated area in the wind tunnel. From a larger soil surface (0.84 m(2)) a lower amo unt of lindane (23%) volatilised than from a smaller surface (31% at 0 .28 m(2)).