Can you hear me OK? cataflam suspension dosis adultos This PCB gradient was established by the General Electric (GE) electronic manufacturing plants at Fort Edward and Hudson Falls in New York State when they dumped as much as 1.3 million pounds of PCBs into the Hudson River between 1947 and 1977. As the PCBs washed downstream from the contamination source, a concentration gradient formed along the length of the river. Even today, the Hudson River drainage basin still contains high PCB levels.