The UK news sites are reporting that a French truck (lorry) driver may have been the first human casualty of Ulva lactuca, otherwise known as sea lettuce.

Let me explain. For years lactuca has been growing along the coastline of Brittany in France. Researchers suspect that nitrogen-rich runoff from farms and untreated sewage are fueling the explosive growth. The seaweed washes ashore, where it decays and releases hydrogen sulfide, the gas that makes rotten eggs stink.

Normally the mess is smelly. This year, however, it’s turned deadly. A study of one beach by France’s National Institute for Environmental Technology and Hazards (Ineris) revealed hydrogen sulfide concentrations of up to 1,000 parts per million—enough to kill in minutes.

The concentrations were strong enough to kill a horse and incapacitate its rider. Now it’s emerged that hydrogen sulfide may have also killed the 48-year-old truck trucker. The driver had been carrying truckloads of the seaweed off the beach in July, when he fell unconscious and swerved into a wall. Initially medical examiners ruled that a heart attack was the likely cause of death, but now the local prosecutor wants a more thorough investigation.

The driver’s family has so far refused to allow an autopsy.

Credit: K. Peters/Wikipedia