Crops on the Big Island of Hawaii are shriveling as sulfur dioxide from Kilauea envelops them in "vog," or volcanic smog. Adults are wheezing and schoolchildren are being kept inside during recess. High gas levels led Hawaii Volcanoes National Park to close several days this month while forcing the evacuation of thousands of visitors. Kilauea on the Big Island has been erupting continuously since 1983. However, conditions in mid-March changed forming a new vent at the summit. The new vent gave Kilauea two large sulfur dioxide outlets instead of one. Sulfur dioxide, a pollutant that is also generated by burning coal and oil, can lead to asthma and other respiratory illnesses and aggravate lung and heart disease. When combined with dust and sunlight, it makes vog. Vog produces acid rain when mixed with atmospheric moisture. Some crops are doing fine. Coffee and macadamia nuts have been largely unaffected. Koa and ohia trees are healthy, but eucalyptus leaves are turning brown, as are Asiatic lilies.