MercyOne Air Med is celebrating its 40th anniversary of service to patients across Iowa on Nov. 10 at 1 p.m., with events in Des Moines, Clinton and Mason City. The public can tour the helicopters and meet the people behind MercyOne Air Med’s lifesaving care over the last four decades. The Clinton event will be at the MercyOne Clinton Medical Center Helipad, 1410 N. Fourth Street…