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Movers And Shakers

Beirut-based atmospheric chemist Najat Saliba discusses the challenges of doing science during political and economic turmoil

The atmospheric chemist is studying the Beirut chemical explosion’s effects on air pollution

by Benjamin Plackett, special to C&EN
June 13, 2021 | A version of this story appeared in Volume 99, Issue 22

Photo of Najat Saliba, an atmospheric chemist at the American University of Beirut, wearing glasses, a scarf, and a black jacket, with hands folded under her chin.
Credit: Courtesy of Najat Saliba

The pandemic made 2020 a tough year for many countries, and Lebanon has endured more than its share of trouble. Political and economic disorder in Lebanon worsened when one of the world’s largest nonnuclear explosions rocked its capital city. Amid a backdrop of a disintegrating banking system and soaring inflation, the massive chemical explosion in the Port of Beirut in August killed over 200 people and injured more than 6,000. Outrage over how the chemicals were negligently stored forced the country’s prime minister—elected only 8 months earlier—to resign, though he remains in position as a caretaker until a new government is formed.


Hometown: Beirut

Favorite city: Paris

Studies: MSc, California State University, Long Beach; PhD, University of Southern California

Professional highlight: Being chosen as the 2019 L’Oréal-UNESCO for Women in Science laureate for Africa and the Arab States. Receiving the award “gave hope to a lot of young girls. It showed that if you do science, you can be recognized worldwide.”

Favorite molecule: “Oxygen, the symbol of clean air.”

Hobby: Gardening

Best professional advice she’s received: “Your research team is your family.”

Worst professional advice she’s received: “Stay away from the media.”

Najat Saliba, an atmospheric chemist at the American University of Beirut, has studied the city’s air quality for years and is now examining the environmental effects of the explosion. She did her PhD work in Southern California and has compared air samples from Los Angeles and Beirut to understand their similarities and differences: both cities are coastal metropolises with a Mediterranean climate and are affected by smoke from forest fires.

Benjamin Plackett talked with Saliba about the challenges of doing her work during a time of upheaval. This interview was edited for length and clarity.

Even before the chemical explosion, your research showed that Lebanon had a pollution problem—is that right?

Yes. In terms of air pollution, when the World Health Organization puts out recommendations, it focuses on limiting particulate matter without going into the details of its chemical composition. The question is whether the content of particulate matter can create an added risk.

This was the idea behind taking particulate matter from Beirut and Los Angeles and trying to dissect these samples—getting into their chemical components and seeing whether their toxicity was the same. We found the amount of polycyclic aromatic hydrocarbons that exist inside the particles collected from Beirut was 7–10 times as high as in Los Angeles (Sci. Total Environ. 2013, DOI: 10.1016/j.scitotenv.2013.09.104). That was very alarming. These chemicals originate from combustion sources such as gasoline engines, diesel generators, and trucks, and some of them are classified as highly carcinogenic.

So a gram of particulate matter from Beirut is worse than a gram of particulate matter from Los Angeles?

In brief, that’s what it says. There’s also a much higher mass of particulate matter in Beirut than Los Angeles.

On top of all this, the explosion in August emitted vast amounts of chemicals into the atmosphere. What effects did the explosion have?

No glass door or window on campus remained in place after the explosion. The university paid over $10 million to repair the damage.

The army wouldn’t let scientists go inside the port to take samples, but my lab took rubble samples close to the port where the blast happened. We were mostly interested in asbestos because we had learned that’s what most of the port was made of. Luckily, we didn’t find any. However, the samples didn’t come from the port itself, so they’re not conclusive.

We were worried that asbestos might trail into the city through the air, so we collected air samples in a couple of places inside the city and sent them to labs in France and Switzerland for analysis. However, due to the pandemic, everything has been put on hold, and the testing hasn’t yet confirmed or denied the presence of asbestos or other toxic substances. Nothing about this explosion has been clear.

Any basic material that I need for the lab, I have to wait. Because of that, I have to plan ahead of time. I don’t have the luxury of trying several things until something works.

How are you managing to do research with all of Lebanon’s problems at the moment?

It’s a compounded disaster with the pandemic and the depreciation. You’re losing money while sitting at home and not even spending it. Depreciation has now reached 85%, and then you have protests and roadblocks, along with a corrupt government that doesn’t want to leave. At the same time, you have a country that is completely divided. Fortunately, my research funding is in US dollars, but the Lebanese banking system is also collapsing. Anytime we want to buy something, it’s a battle.

Every time I want to order something—say, a pH meter—I have to wait 3 months. Any basic material that I need for the lab, I have to wait. Because of that, I have to plan ahead of time. I don’t have the luxury of trying several things until something works.

Working in a comfortable environment, on the other hand, makes your mind flow, dream, and go far. We might come up with the same result in the end, but it comes at the expense of a lot of hard work.

We are trying to survive and continue to do research despite all of these huge challenges.

Your research seems very relevant in these times.

Chemistry, particularly analytical chemistry, is extremely relevant because there’s so much air pollution. And when it comes to safety standards and handling chemicals, everything I teach now is related to the explosion and ammonium nitrate storage. The students are so avid, and they just want to learn what went wrong, which was mostly negligence and ignorance about those safety standards.

Benjamin Plackett is a freelance writer based in London. A version of this story first appeared in ACS Central Science:



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