The new NIEHS Early Stage Investigator Highlights Webinar series continued on May 11, with a performance by Marissa Baker, Ph.D.on the mental health of boaters during the COVID-19 pandemic, and a talk by Michael Petriello, Ph.D.about how chemicals such as perfluoroalkyl and polyfluoroalkyl substances (PFAS) can affect the gut microbiome.
Baker, an assistant professor at the University of Washington, is affiliated with the Interdisciplinary Center for Exposures, Diseases, Genomics and Environment. Petriello, a pharmacology student at Wayne State University, is affiliated with the school Center for Urban Responses to Environmental Stress Factors. Both entities are supported by the NIEHS Environmental Health Sciences Basic Centers Program.
The webinar series is hosted by María José Rosa, Ph.D.Y Douglas Walker, Ph.D.Members of the Mount Sinai Transdisciplinary Center on Early Environmental Exposures.
COVID-19 and the mental health of sailors
Baker characterizes workplace exposures experienced by vulnerable or underrepresented populations. She explores workplace determinants of understudied occupational health outcomes such as mental health, stress, and fatigue.
His talk was titled “Seafarers’ Mental Health and Wellbeing During COVID-19 and Beyond.” She noted that before the pandemic, data on sailors’ mental health was limited.
“It hadn’t really been tested in this population at all,” Baker said. “It was supposed to be good. There was a study that looked at seafarers around the world, so it was really the pandemic that was the trigger that helped them realize that we need to do something about it.”
He noted that more than 75% of US trade involves shipping. As of 2020, approximately 200,000 seamen from the country were on 3,650 registered merchant marine vessels. Boaters can often experience extreme weather conditions, long working hours, no internet access, and few people on board, which can lead to feelings of isolation.
Those issues continued when COVID-19 hit and were compounded by a lack of shore license access, Baker told attendees.
Sailors couldn’t go home, voyages became longer, and work protocols changed. Baker conducted a survey to assess mental health outcomes and barriers to accessing care, seeking to prioritize interventions to improve sailor well-being during and after the pandemic.
It evaluated the probability of five mental health outcomes based on 1,589 responses it received. Baker noted high rates of depression, anxiety, suicidal ideation, perceived stress, and PTSD. Women and younger sailors had higher rates than their male and older counterparts.
Although the sailors had high job satisfaction, the rate of adverse mental health outcomes warrants ongoing intervention and evaluation, according to Baker. She recommends proper training and communication; increase the privacy of surfers to access telemental health; increase social support on board; focus on the needs of younger and underrepresented women and seafarers; and strong reporting policies.
Pollution and the gut microbiome
Petriello studies the links between nutrition, exposures, and metabolic disorders. (Photo courtesy of Michael Petriello)Petriello studies how chemicals like PFAS and polychlorinated biphenyls (PCBs) can change the gut microbiome and potentially influence atherosclerosis. That condition is marked by a buildup of plaque on the walls of the arteries and contributes to cardiovascular disease.
Cardiovascular disease is influenced by interactions between non-modifiable factors, such as genes and family history, and modifiable factors, such as the environment, diet, and lifestyle. To study the progression of atherosclerosis, Petriello analyzed lipid markers, cholesterol, and inflammation in mice predisposed to high cholesterol.
“We can expose the mice to our contaminant of interest and check to see if atherosclerosis is accelerated,” he said.
In their work, mice exposed to PCBs developed lesions and markers of inflammation. They were also more likely to absorb cholesterol-like compounds, which could predispose them to atherosclerosis. Furthermore, PCBs depleted the gut microbiota that metabolizes cholesterol.
“For toxicology, it’s interesting to think that the microbiota metabolizes contaminants, but also that contaminants can directly impact bacterial health,” Petriello said.
He exposed mice to a mixture of PFAS and found that the chemicals increased circulating cholesterol and inflammation in the livers of female mice. In another study, PFAS increased circulating cholesterol levels in some mice and decreased bile acid excretion, a mechanism that can increase cholesterol levels and warrants further study, according to Petriello.
(Susan Cozier is a contract writer for the NIEHS Office of Communications and Public Outreach.)
