18
Jan
Research Shows Pesticide Accumulation at High Altitudes
(Beyond Pesticides, January 18, 2007) A new study conducted in Costa Rica’s mountain forests indicates that surprisingly high concentrations of pesticides are accumulating far above the low altitudes at which they are used. Previously thought to be safe from pesticides applied to distant agricultural areas, some remote mountain forests of Costa Rica were found to have pesticide levels almost ten times greater than those in low-lying areas closer to farms and plantations. The study, led by University of Toronto, Scarborough professor Frank Wania, Ph.D., measured air and soil pesticide levels at 23 sites across Costa Rica in order to produce a model to predict potential accumulation of chemicals at high altitudes. The insecticide endosulfan and the fungicide chlorothalonil were found in the largest concentrations, with up to 1 part per billion (ppb) of chlorothalonil and 3 ppb endosulfan in soil. The high concentrations can be explained by a process in which polluted air above the farms and plantations is pushed up into the mountains, where it then cools and becomes polluted rainwater or fog. The hydrophilic nature of modern pesticides makes the occurrence of this phenomenon much more likely; as Crispin Halsall, Ph.D., of Lancaster University (U.K.) explains, “Most currently […]
