A recent report from the University of Houston (UH) has revealed that the air along the Gulf of Mexico coast in Texas may be more polluted than previously thought.
The mass concentration of aerosols found on the coast was between three and 70 times higher than that observed in other clean marine atmospheres, per the study.
Aerosols are microscopic particulate matter that can be either solid or liquid, such as fog or mist. In the case of the study, these aerosols contain highly processed and acidic chemical components.
To gather atmospheric data for the study, Shan Zhao and her team spent weeks in both Corpus Christi and San Antonio in 2021, per a UH news release. Zhao is a research assistant professor of atmospheric chemistry at UH.
The findings of the study were published in the Environmental Science & Technology journal on March 20.
Zhao explained in the press release that the study was inspired by her research showing that the ocean air “was hazier and more polluted” than the air found on land.
Finding this strange, she began to investigate why.
Her focus on Corpus Christi was due to the metropolitan area being understudied by researchers in her field. They tend to focus their studies on Houston-Galveston and Dallas-Fort Worth.
In the end, two main culprits were revealed by the study.
The first is manmade.
According to the study, the aerosols from the Gulf of Mexico contained roughly 57% of sulfate on average. This is a particularly high level of concentration for this substance and indicates it is a significant contributor to the area’s air pollution.
Human-generated shipping emissions produce these sulfate-rich aerosols, which are then pumped into the ocean air. With a strong sea breeze, this polluted air is carried to the coast.
Approximately 78% of the total sulfate in the air is a result of emissions over the Gulf of Mexico.
The Gulf of Mexico is recognized as one of the most heavily trafficked maritime transport regions in the United States, as 11 out of the 15 busiest water ports are situated along its coastline, per the news release.
The second is environmental.
Intense sunlight intensity, high levels of humidity, and hot temperatures were also found to contribute to the air pollution seen in the Gulf of Mexico.
These meteorological conditions provide an ideal environment for chemical reactions that form secondary aerosols, which can be harmful to both the lungs and the heart.
How these two factors work together is as follows.
As a result of the high maritime traffic seen in the gulf, large commercial vessels burn substantial amounts of fuel oil, which can generate sulfur oxides.
The combination of humidity with pollutant chemicals creates an optimal environment for sulfur dioxide to transform into sulfates. Water acts as a catalyst that triggers this chemical reaction, causing the pollution to move quickly.
Zhao observed that coastal air pollution is very acidic, which means it is more harmful to health than non-acidic particles.
Next, she aims to better understand how these air pollutants found in the coastal atmosphere might impact the quality of air seen further away from the coast.
“Almost the entire state of Texas is potentially under oceanic flow throughout the year. How far can this sulfur pollution can come inland and how frequently can this happen?” Zhao wondered.
