Health threats from the Gulf oil disaster could last for years, and officials lack knowledge on how long chemicals in the spilled oil and dispersants will remain toxic, health experts told a Senate committee Tuesday. At the same hearing, a Food and Drug Administration official said seafood from the Gulf of Mexico available to consumers in stores and restaurants now is safe... The hearing by the Senate Health, Education, Labor and Pensions Committee looked at steps taken so far to monitor and deal with health issues, and what the longer-term threats and effects may be... Lisa Kaplowitz, a deputy assistant secretary of health and human services...said...there is a lack of long-term assessments on the toxicity of oil in the environment.