Why was he sacked? Pretty obviously to shut him up or discredit him Also, importantly to discourage others in a similar situation from being bold enough to speak out.
But what does this story telll us about the USA where 'free speech' is one of those inalienable rights enshrined in the Constitution? And what does it say about the environmental gencies who are supposed to watch out for hazardous pollution? They are curiously - or typically - silent on any problems to do with the nuclear or fracking industries.
i remember a little book by a New York journalist, Juan Gonzalez, called "fallout" - about the health issues after 9/11 - itemizing so many heavy metals, PCBs, dioxins, etc and the effects these had on the health of so many firemen and First Responders, from many states, and giving chaper and verse about the cover-up by the City authorities and the EPA etc..
Earlier I acquired a thick volume on "Nuclear Lessons" which revealed a sorry catalogue of major and minor mishaps and near-disasters at nuclear power plants. Again the authorities - especially those supposed to watch over this industry like a hawk. - were to say the least very relaxed about any 'risk' to the public.. It took the mega-disaster of Chernobyl to put a halt to the crazy gung-ho attitude of the industry and the politicians.
Maybe one day tar sands, fracking, and the GM industry too will be seen fort they are - crimes against humanity and the world on which we all depend. But hey - what's that compared to the profits to be made?!!! As the old saying goes '"Money Talks."....