December 7 marks the seventy-sixth anniversary of the Japanese attack on Pearl Harbor, an act of aggression that propelled the United States into an all-out war that forever altered our society, economy, politics and place in the world.

The damage inflicted by Japanese forces that day was severe: nineteen capital ships destroyed or damaged; 347 military aircraft destroyed or damaged. The casualties were terrible: 2,408 Americans killed and another 1,178 wounded.

Almost half of the casualties at Pearl Harbor occurred on the USS Arizona, a massive battleship that was hit four times by Japanese bombers and eventually sank with 1,177 crewmembers killed. Of those that perished, 1,102 remain today still entombed within the sunken wreckage of the Arizona at the bottom of Pearl Harbor.

Above the sunken battleship, on the surface, stands the USS Arizona Memorial, a solemn white structure built to honor the ultimate sacrifice of those who died there and to mark the final resting place of those who still lie below.

Over the years, millions of people from all over the world have visited the memorial. Each one has had a chance to quietly reflect on the awful events of that day, and to do so with reverence in a beautiful setting made sacred by the presence of the fallen.

The sacred solemnity of the memorial site is heightened by what people have come to call the “tears of the Arizona.” The sunken battleship still holds a few hundred gallons of oil in its fuel tanks. Most, but not all, was burned off during the fiery death of the ship. Slowly, very slowly, the trapped fuel leaks out, a few droplets at a time. They gently float to the surface where they briefly spread out in a small rainbow sheen before dissipating completely. These small droplets, the sad black tears of the Arizona, have moved millions.

But not everyone. Some environmentalists have expressed concern about what they see as a threat to water quality. They have argued that the Arizona Memorial site should be cleaned up, the ship’s fuel tanks drained to stop the current leakage and to eliminate any future threat that might be posed by the oil if it remains on aboard. Really.

Aside from illustrating how insensitive some environmentalists can be to all considera­tions other than their own, proposals to shut off the tears of the Arizona also shed light on a fundamental misconception that has defined and driven environmental risk assessment for decades. According to this mistaken belief, the smallest amount, even a single molecule, of a pollutant is presumed to pose a potentially serious threat to the health of any individual who comes into contact with the molecule just one time.

Serious health threats from a single exposure to a single molecule? Put transparently into plain English, the idea sounds preposterous, which is why it is rarely put into plain English. Instead, the assumption is embedded deeply in the opaque complexities of quantitative environmental risk assessment techniques that employ things like the Linear No-Threshold Model and One-Hit Dose Response Models.

This one-hit by one molecule assumption, and statutes that delegate extensive authority to regulators to pursue broadly defined policy goals, have combined to produce an administrative regime of environmental regulation with no limiting principle. Mission driven regulators set allowable limits for pollutants at lower and lower levels. With increasing frequency, they set limits at levels that cannot be detected with certainty or measured with accuracy.

The Trump administration has undertaken a number of initiatives to improve regulations and regulatory processes. The administration could contribute significantly to the transparency of the processes used to set pollutant limits for environmental regulations if it initiated a thoroughgoing science-based public discussion to revisit, and revise as appropriate, the one-hit by one molecule assumption and the risk assessment models that it supports.

In the meantime, let us hope that the USS Arizona is allowed to continue shedding its sad tears for those who died there this Thursday, seventy-six years ago.

J. Kennerly Davis served as Deputy Attorney General for Virginia from 2013-2014. He is a contributor to the Federalist Society’s Regulatory Transparency Project.