Environmental depleted uranium is far-fetched because there isn't very much of it, it is not retained or accumulated in the body, it tends not to move through the environment, and compared to many other elements widely found in the environment it has a lower health risk, both radiologically and chemically.

For example, thorium in the environment is a much greater health risk and far more common as well. One of the problems with studies of environmental non-depleted (read: worse) uranium exposure is that results tend to be dominated by effects of environmental thorium such that any effects from uranium are below the noise floor.

Depleted uranium is a pretty harmless environmental contaminant as heavy metals go. In the US we routinely dump thousands of tons of uranium around population centers in the form of coal ash. There are small but measurable health risks to living around coal ash, but those risks are attributed almost entirely to other components of coal ash (like the aforementioned thorium).

Environmental contamination by industrial organic chemicals is vastly more probable than uranium as a cause.