Has the mystery of the pervasive yellow dust in County Roscommon now been solved?

The mystery of a yellow powdery dust that has scattered on a lake, houses and cars in West and North Roscommon may be solved, according to a local councillor.

The prevalence of the odourless substance has generated a lot of public intrigue, and in some cases concern, since the Herald published a story online this morning about the dust gathering on Gorthaganny Lake in West Roscommon.

MEP Luke Flanagan, who regularly visits the popular lake amenity with his family, took to X (Twitter) earlier this morning to  express his “devastation” at what he initially thought had been paint poured into the water.

Speaking to the Roscommon Herald later, he then shared accounts from other people of a similar airborne substance gathering on property and vehicles. "It's baffling, it appears to have fallen from the sky," said Mr Flanagan.

Despite those initial concerns, it now appears that what happened was a natural occurrence. Since our story this morning, there have been plenty more accounts on our social media channels that the same dust has found its way on houses and cars in many parts of West and North Roscommon.

Local Fianna Fáil councillor Paschal Fitzmaurice said he was speaking to one local woman who claimed that she saw a “yellowy cloud” in the sky yesterday. He said that after she did some research, she discovered the yellow dust was very similar to "pine pollen".

“There are lot of pine forests in West Roscommon. Conditions were probably just right with the warm weather yesterday - it was pretty calm and it wasn’t really that windy. On a day with a high wind, it could have dispersed over a much larger area. I presume the conditions were right when the pollen was released.

“When it landed on the lake, with the wind blowing, it gathered into a corner. You would assume initially it was some kind of sand but it floated. It didn’t sink.

“I’ve never seen it before myself. I noticed some of it on my car in Castlerea, and other people were saying there was more of it on their cars in the Lisacul and Loughglynn areas," he said.

Cllr Fitzmaurice took a sample of the water from Gorthaganny Lake and has given it to the Roscommon County Council laboratory for analysis.

Cursory online research of pine pollen reveals that it “might look similar to algae, but pollen is yellow-green and dust-like and floats mainly on the surface. Over time the pollen will become water logged and sink from sight.”