Asthma sufferers are among those who have been warned after a "Sarahan dust" cloud hit Ireland this week.
Met Eireann wrote on social media that a "dust laden airmass" is moving over Ireland, which could leave an unusual covering of the dust on cars.
Many people across the country have already noticed the "mysterious" red dust on their cars, with more expected to arrive over the coming days.
A spokesperson for the Environmental Protection Agency (EPA) said: “Saharan Dust events can lead to higher levels of particulate matter (fine dust) in our air."
On Tuesday the EPA warned that "poor air quality" air quality could be expected over Ireland.
The organisation's guidelines for these conditions state: "Adults and children with lung problems, adults with heart problems, should reduce strenuous physical activity, particularly outdoors and particularly if they experience symptoms.
"People with asthma may find that they need to use their reliever inhaler more often. Older people should also reduce physical exertion."
UK Met Office forecaster Mark Wilson explained that the phenomenon is caused by strong winds in African bringing the dust northwards.
He said: "Strong winds over the Sahara whip up dust.
"That goes into the sky and upper part of the atmosphere and heads towards the UK.
"Once we get some rain, that washes it out the sky and onto the ground."
