A wave of anti-science bills has been introduced in statehouses across America this year, pushed by people with special interests who have close ties to Health Secretary Robert F. Kennedy Jr. An Associated Press investigation found more than 420 bills attacking longstanding public health protections such as vaccines, milk safety and fluoride in most states. Meanwhile, vaccination rates continue to fall, allowing the infectious diseases measles and whooping cough to make comebacks as Kennedy has sought to broadly remake federal policies on public health matters including fluoride and vaccines.