The state-run poison center in Athens has received more than 800,000 calls for assistance since opening 30 years ago, dealing with some unusual as well as worrying cases, government officials said yesterday. Cases of poisoning are mostly accidental (74 percent). Suicide attempts account for 15 percent of calls, but officials said that number is rising. Some of the strange cries for help to the poison center include an elderly man who swallowed a watch battery instead of the painkiller he was reaching for and three adults who consumed French fries they had cooked in motor oil. Authorities blamed careless parents for most cases involving children, who are at the highest risk of being poisoned when they are between the ages of 2 and 4. The center receives an average of 40,000 calls per year.