Mr. Nriagu, meet John Paling, a man of many parts: academic, TV producer, wildlife photographer, statistician, and all-round wit. You don’t perceive this at first glance, however. Your first impression is that of wimpishness. Even his name supports the impression: “Paling,” as in bleaching out before your very eyes.

Wrong! He soon morphs, Clark Kent-like, into a fearless adventurer, one who ventures into swamps to photograph 12-ft-long alligators and into the forest to trace the behavior of woodpeckers defending themselves from pythons.

Paling surfaced earlier this year at the Dallas convention of the International Institute of Ammonia Refrigeration, where he wowed an early morning audience of specialists — hardly the venue for a very funny presentation.

There is nothing inherently humorous about ammonia refrigeration. Quite the opposite. This technology has traditionally been preoccupied by safety codes, OSHA regulations, and EPA risk management programs.

In fact, risk management is one of Paling’s specialties, a subject that he treats in his sprightly book, Up to Your Armpits in Alligators?

People worry about the wrong things. Correction: They worry too much about the wrong things and too little about the right things. Consider the woman who was enjoying a smoke during a cigarette break who asked him if she should buy a water purification system to ensure safe drinking water. “She was focusing a huge amount of energy on a relatively small risk while ignoring a much larger one.”

Paling has created a series of charts showing risks, from the most to the least hazardous. Some charts reflect the risk we all face over a lifetime, like smoking. Other charts mirror risks we confront in a single year, like being mugged in Newark.

An even more striking chart shows the least risky event, shown as the “Bobbitt Zone,” about which no more need be said except that it is a singular, one-time event in the 10 billion-to-1 range.

One wonders how Paling would assess the risk of the killer candles study, or of drinking CFC-12 in moderation, as its inventor was said to have done way back in the 1930s to demonstrate its benign nature.

Note to association executives: Get this guy for your next convention! His film clip of the woodpecker and the serpent is worth the price of admission. Call me for more details.