The balance of long-term Japanese government debt may have topped 1,000 trillion yen ($8.2 trillion) for the first time at the end of March, officials said Thursday. The estimate signals that the nation’s fiscal health, already the worst among major developed countries, has been further deteriorating on swelling social security costs as a result the aging population, falling tax revenues and emergency spending in response to the coronavirus pandemic, the officials said. Growing interest payments on the accumulated debt following a recent uptrend in bond yields would be a headache for the gover…