Please, please -- Gulf Coast beach goers -- endanger your own health if you must, but don't injure or kill your kids prematurely. They have their whole lives ahead of them. The following WKRP (Channel 5, Mobile -- Pensacola) news video should be required viewing for anyone planning a beach visit!
See HERE for further discussion re toxicity levels (parts per million) discussed in this video. (Unexplainably, the last water sample exploded before chemical analysis could be completed. High concentration of methane offered as a possibility.)