Once it enters water, much of it moves back into the atmosphere quickly, but some of it enters plants, then small animals, then fish. Fish from various waterways contain TCE in the range of 10 to 100 ppb. Fresh bread contains 7 ppb, various brands of margarine contain 440 to 3600 ppb. These are not national averages, so the foodstuffs in your refrigerator may contain less or more than these values. In sum, we industrial humans have managed to spread TCE everywhere.
Humans ingest TCE by drinking fluids, by breathing, and through their skin.
In 133 American cities, TCE averaged 0.47 ppb in water samples at the tap. If you take a shower in such water, you inhale considerable TCE but you also absorb an equal amount through your skin. All of this explains why Americans have measurable amounts of TCE on their breath. There is no doubt that TCE causes leukemia in animals. But the evidence for leukemia in humans is not so clear.