I am a geochemistry professor who has worked in Nevada where erionite occurs. This mineral is a known and serious inhalation hazard, which can occur in altered volcanic rocks common to the western United States.
However, such rocks are exposed in mountain blocks and not in the soils of desert valleys. Any erionite eroded and transported to valley soils will likely break down into other minerals.
The drying of valley floors by water development may produce more dust in our air. That alone would be bad for Utah. But it is unlikely to increase the amount of erionite in our air.
Physicians for Social Responsibility has plenty of reasons to oppose the water grab without speculating in areas outside their expertise.