The Virgin Islands is seeing a lot of dust making its way across the Atlantic Ocean from the Sahara Desert in Africa but whether it’s a trend remains to be seen, dust expert Ginger Garrison said.
“It’s too soon to say whether it’s a trend or normal variation,” she said.
As for the current situation, meteorologist Ernesto Morales at the National Weather Service in San Juan said that Monday had dust in the northern dry part of a tropical wave making its way through the area. However, there was also in increase in humidity that added to the haziness.
Morales said to expect more dust on Wednesday.
According to Morales, June is typically a dusty month but it starts to lessen in July as hurricane season heats up.
Garrison said there has been an increase in the amount of dust starting in the late 1970s until end of the 1990s. The dust began to increase following a decade-long drought in the Sahara Desert.
The Florida-based Garrison, who retired in May from a career as a research marine scientist with the U.S. Geological Survey, began studying the dust in 1997 while living on St. John.
The dust that blows from Africa is reddish brown. It’s most visible as flakes on windowsills and countertops. It also coats screens. Garrison said that the dust that blows this way when the Montserrat volcano goes off is gray.
In any case, inhaling the dust isn’t healthy, particularly for people with heart and respiratory conditions.
On dusty days, Garrison suggested that people with respiratory and heart conditions not exercise outdoors.
Health Department medical director Dr. Marc Jerome said in early June during a dust event that the people most affected by the dust already have respiratory disease.
He urged those with breathing issues to stay inside, turn on the air conditioner if they have one and close the windows on the side of the building where the breeze blows in to keep the dust out.
Garrison applauded the local government for sending out advisories about dust events. Those come from the Planning and Natural Resources Department, and spokesman Jamal Nielsen said the department does so because it impacts air quality.
“It has serious health implications,” Nielsen said.
Dust conditions are very bad in Mali, where Garrison based some of her studies. She said that 74 to 98 percent of the days have conditions that exceed World Health Organization and European Union guidelines.
However, she said that much of the dust that arrives in the Eastern Caribbean from Africa is made up of fine particles that can be easily inhaled.
“The part that you can inhale is the bad stuff,”
Additionally she said the dust undergoes chemical changes as it makes its way across the Atlantic. She said these chemical changes can make the dust more toxic and active in the body.
Why this happens is unknown but a study is now under way to help determine the answer. Garrison said funding is needed to find out what is the effect of mixtures of chemicals, fine particles and metals like iron and lead in the particles.
Testing is expensive. According to Garrison, one sample costs $1,000 for basic tests. Add in the test for metals and the bill goes up by $100. Microbe testing costs another $600.
That dust at times contains chemicals that are known to be potentially toxic and cancer causing. However, she said it’s not a simple matter for African farmers to stop using them because DDT and dieldrin kill the locusts that eat the African crops.
“They eat all the crops and people die,” she said.
Pesticides are also used to kill the organisms that cause malaria, river blindness and yellow fever.
Additionally Garrison said the dust can contain viruses, bacteria and fungi.
How much dust develops in Africa depends on several factors. Garrison said it depends on the sea temperatures on either side of the African continent, the amount of wind and rain that happens in the region and what is on the ground.
There is a silver lining to the dust issue. As it blows across the Atlantic Ocean, the dryness inhibits hurricane development. And Garrison said the iron from the dust that falls into the Atlantic stimulate plankton blooms, which in turn stimulates fisheries.