Navigation Links
Unraveling the mystery of Saharan dust migration

Satellite pictures of Saharan dust clouds have been in the news all summer, but to Shankar Chellam, they have just raised more questions.

How much impact did the Saharan dust have on Houston's air? Is it more toxic than our home-grown dust?

Chellam, a professor in the department of civil and environmental engineering at the University of Houston's Cullen College of Engineering, is searching for answers to those and other questions.

Clouds of African dust often migrate across the Atlantic Ocean during summer months, affecting Houston's air quality from mid-June through mid-September. Chellam said it's especially prevalent in late August and early September.

The dust, whipped up by sandstorms in northwest Africa and carried by trade winds across the Atlantic Ocean, takes about 10 days to two weeks to reach the United States and, ultimately, Houston.

Chellam said he collaborates on the project with Joseph Prospero, professor emeritus of marine and atmospheric chemistry at the University of Miami.

Chellam became interested after he noticed "the most curious coincidence" as he was collecting data on industrial air pollution outside plants along the Houston Ship Channel in 2008.

He began the project expecting that the plants would emit a constant amount of pollution, as measured from just beyond their property lines. But he discovered that on some days they emitted relatively little, while emissions were much higher on other days.

"What we quickly realized was that the impact of the refineries varied with time," he said. "We naively had gone into our research expecting that if we took three months of data, we would get an average."

A five-day period in July and August 2008 showed a large variation. That coincided with an influx of Saharan dust, Chellam said.

To determine the actual impact of the Saharan dust required scientific detective work. Chellam and his team determined the "fingerprint" of the African dust, allowing them to differentiate it from other types of pollutants in their samples: industrial dust, vehicle pollutants and smoke from wildfires, among other things.

"There are millions of sources of pollution," he said.

His lab works with African dust collected in Barbados, before it has picked up other contaminants along the route to the United States. Still, he said, the metals in the dust are distinct.

That finding allowed him to determine that a spike in pollution levels in the 2008 readings reflected the arrival of Saharan dust. A paper on those findings has been accepted for publication in in the journal Environmental Science and Technology. In addition to Prospero, his co-authors include Ayse Bozlaker, a post-doctoral researcher working with Chellam, and Matthew Fraser of Arizona State University.

Work by other scientists has linked the dust migration with coral reef stresses and other environmental problems, but the impact on human health is less clear.

Chellam, whose research does not extend into health impact, said he would expect it to affect people with asthma and other respiratory problems.

"But clearly more research is needed," he said. "The composition of the dust is not the same" as other industrial and vehicle dust.

"And if the composition is different, the health impact may be different," he said.


Contact: Jeannie Kever
University of Houston

Related biology news :

1. Unraveling genetic networks
2. Unraveling the scientific basis of the infant feeding axiom breast is best
3. Unraveling the threads: Simplest cotton genome offers clues for fiber improvements
4. Lets get moving: Unraveling how locomotion starts
5. Unraveling biological networks
6. Scientists solve a 14,000-year-old ocean mystery
7. CSHL geneticists solve mystery of EEC Syndromes variable severity in children
8. Mystery solved: Why people on dialysis have increased risk of heart attack
9. Final chapter to 60-year-old blood group mystery
10. Los Alamos science sleuth on the trail of a Martian mystery
11. University of Miami geologists to address the mystery of an evolution gap in reef corals
Post Your Comments:
(Date:6/22/2016)... 22, 2016  The American College of Medical Genetics and ... Magazine as one of the fastest-growing trade shows during ... the Bellagio in Las Vegas . ... of growth in each of the following categories: net square ... number of attendees. The 2015 ACMG Annual Meeting was ranked ...
(Date:6/21/2016)... Columbia , June 21, 2016 ... to the new role of principal product architect ... named the director of customer development. Both will ... chief technical officer. The moves reflect NuData,s strategic ... in response to high customer demand and customer ...
(Date:6/15/2016)... June 15, 2016 Transparency ... titled "Gesture Recognition Market by Application Market - Global Industry Analysis ... 2024". According to the report, the  global gesture recognition ... 2015 and is estimated to grow at a ... by 2024.  Increasing application of gesture ...
Breaking Biology News(10 mins):
(Date:6/27/2016)... ... 27, 2016 , ... Cancer experts from Austria, Hungary, Switzerland, ... a new and helpful biomarker for malignant pleural mesothelioma. Surviving Mesothelioma has just ... now. , Biomarkers are components in the blood, tissue or body fluids ...
(Date:6/27/2016)... 2016  Liquid Biotech USA ... a Sponsored Research Agreement with The University of ... from cancer patients.  The funding will be used ... with clinical outcomes in cancer patients undergoing a ... be employed to support the design of a ...
(Date:6/24/2016)... ... June 24, 2016 , ... While the majority of commercial spectrophotometers ... 5000 and the 6000i models are higher end machines that use the more unconventional ... spectrophotometer’s light beam from the bottom of the cuvette holder. , FireflySci has ...
(Date:6/23/2016)... Mass. , June 23, 2016   ... development of novel compounds designed to target cancer ... napabucasin, has been granted Orphan Drug Designation from ... the treatment of gastric cancer, including gastroesophageal junction ... stemness inhibitor designed to inhibit cancer stemness pathways ...
Breaking Biology Technology: