are on the list of conditions eligible for compensation and treatment. Military personnel who were involved in storage, mixture and transportation (including aircraft mechanics), and actual use of the chemicals were probably among those who received the heaviest exposures. Military members who served on Okinawa also claim to have been exposed to the chemical, but there is no verifiable evidence to corroborate these claims. Some studies have suggested that veterans exposed to Agent Orange may be more at risk of developing prostate cancer and potentially more than twice as likely to develop higher-grade, more lethal prostate cancers. However, a critical analysis of these studies and 35 others consistently found that there was no significant increase in prostate cancer incidence or mortality in those exposed to Agent Orange or 2,3,7,8-tetracholorodibenzo-p-dioxin. U.S. Veterans of Laos and Cambodia During the Vietnam War, the United States fought the North Vietnamese, and their allies, in Laos and Cambodia, including heavy bombing campaigns. They also sprayed large quantities of Agent Orange in each of those countries. According to one estimate, the U.S. dropped 475,500 gallons of Agent Orange in Laos and 40,900 in Cambodia. Because Laos and Cambodia were both officially neutral during the Vietnam War, the U.S. attempted to keep secret its military operations in those countries, from the American population and has largely avoided compensating American veterans and CIA personnel stationed in Cambodia and Laos who suffered permanent injuries as a result of exposure to Agent Orange there. One noteworthy exception, according to the U.S. Department of Labor, is a claim filed with the CIA by an employee of "a self-insured contractor to the CIA that was no longer in business." The CIA advised the Department of Labor that it "had no objections" to paying the claim and Labor accepted the claim for payment: Ecological impact About 17.8%——of the total forested area of Vietnam was sprayed during the war, which disrupted the ecological equilibrium. The persistent nature of dioxins, erosion caused by loss of tree cover, and loss of seedling forest stock meant that reforestation was difficult (or impossible) in many areas. Many defoliated forest areas were quickly invaded by aggressive pioneer species (such as bamboo and cogon grass), making forest regeneration difficult and unlikely. Animal species diversity was also impacted; in one study a Harvard biologist found 24 species of birds and 5 species of mammals in a sprayed forest, while in two