Utahns are understandably worried about the prospect that a big bomb test at the Nevada Test Site would spew old radioactive dirt into the atmosphere.

But there is also a possibility that the Defense Threat Reduction Agency could be right that the test would pose no threat.

The agency wants to set off a 700-ton ammonium nitrate/fuel-oil bomb to evaluate its effectiveness against an underground bunker. That's 280 times bigger than the bomb Timothy McVeigh used against the Alfred P. Murrah Federal Building in Oklahoma City.

This test, dubbed Divine Strake, would be conducted on ground where the federal government has detonated almost 1,000 nuclear bombs.

The agency claims that the test is safe, that it will not cause radioactive material to be thrown into the air and come down on unsuspecting Utahns. And perhaps it is right.

It's time to prove up. The claim is subject to objective analysis, and it's time such an analyisis was undertaken by an independent entity. Perhaps the material in the soil has, in fact, decayed to the point where it is no longer a threat, as the government says. Perhaps the spot at which Divine Strake would be exploded is not terribly contaminated from past tests. Such things can be measured. They just shouldn't be measured solely by the government.

Utahns are rightfully skeptical of government assurances. Throughout the 1950s, officials assured residents that nuclear tests -- which were actually visible from Southern Utah -- were perfectly safe, that the blasts and the fallout from them posed no threat to people on the ground. With such assurances, watching bomb blasts became a family activity in Utah's Dixie, and some residents even made a game of using Geiger counters to find the hottest fallout spot.

Unknown to them, they were in serious danger, a fact that only became apparent when Utahns -- dubbed downwinders -- started coming down with sicknesses and cancers that were clearly linked to radiation exposure. Among the casualties was former Gov. Scott Matheson.

It took decades to get the government to grudgingly admit responsibility for the blasts and offer some compensation for those who were sickened or who lost loved ones to the fallout. The government admitted as recently as 2000 that the Nevada Test Site is contaminated with 4 tons of plutonium after decades of bomb blasts, more than it had previously said was there. Airborne material is especially deadly since it can be inhaled. This is not reassuring.

But there is a way the government can assure Utah that the Divine Strake test would be safe: Let an independent team examine all the data and tell us their findings. This should be done by people who have no connection with the DOE, either through past employment or current contracts. Utah deserves a truly unbiased result.

An independent review that concludes the test is safe would vindicate the government's assertions. And it would have real credibility, something the government lacks.

Until an independent review is undertaken, the test should not proceed. Gov. Huntsman and Utah's congressional delegation in Washington should insist on an independent review.

This story appeared in The Daily Herald on page A5.