The ever-increasing use of systemic fertilizers that penetrate plants and cannot be removed by washing is responsible for the chemical residues that have become the main hazard of eating plant-based foods. Lassitude, weakness and appetite loss may be symptoms of the flu, but they also characterize chronic fertilizer poisoning. It is precisely because the symptoms resemble those of many other ailments that it is hard to determine the precise effect of fertilizers on the human body. The people most at risk are the farmers themselves, if they spray the chemicals on their crops without taking the necessary protective measures. The mortality rate of farmers in western Greece is some 40 percent higher than that of Greeks who live in cities, Panayiotis Ginopoulos, professor of oncology at Aghios Andreas Hospital in Patras, told Kathimerini. This is a serious indication of the link between the incidence of cancer and the use of agricultural chemicals in that area. Similar suspicions have been raised about other parts of Greece – such as around Iraklion in Crete – but no systematic research has been done and cancer is attributable to many factors. But in rivers where fertilizers are deposited when the fields are irrigated, fish have actually changed gender because fertilizers mimic estrogen. When using agricultural chemicals, farmers must comply strictly with the waiting period so that there is no residue left on the produce when it goes to market. Even so, growers often harvest fruits and vegetables directly after spraying them, calculating the days before they are sold as part of the required waiting period. This tactic is far from safe for consumers. An apple that has been sprayed must stay on the tree for at least 20 days before all traces of residue disappear. But if the fruit is refrigerated, the spray will stay on the apple for 120 days.