Faye McNeill Combats Air Pollution, From the Molecular to the Global Scale

This story is part of a series celebrating the work of women at the Columbia Climate School, in honor of International Women’s Day on March 8, 2022. Read more about the day and our related blog posts here.

At 16, V. Faye McNeill, now a professor and atmospheric chemist at Columbia University, decided to combine her love for chemistry and math in her studies after high school. She opted for a B.S. in chemical engineering from Caltech, which she earned in 1999.

That foundation set her career trajectory towards delving into the intricacies of chemically reacting systems on multiple scales. “This mindset has been very useful for me as an atmospheric chemist,” she said. Chemical engineering enabled the budding scientist to understand the chemical and physical processes that influence aerosols (particles or droplets suspended in the atmosphere) and the formation of clouds.

In 2000, McNeill was awarded the prestigious NASA Earth System Science Fellowship that funded her Ph.D. research project at MIT. At the time, she and her Nobel Prize-winning Ph.D. advisor, Mario Molina, were analyzing the reactions between gases and ice particles in clouds over the South Pole to determine how the Antarctic ozone hole had formed.

“It was clear that these fast reactions were critical to understanding the ozone hole,” said McNeill. “But it defied our previous understanding of ice surfaces’ chemistry. We were following up and tying up loose ends with that story.”

To date, she continues to remain inspired by the late Molina, who predicted and later proved how chlorofluorocarbons (CFCs) were eating into the Earth’s ozone layer over Antarctica. Molina not only worked towards getting CFCs banned, but also led efforts to improve air quality in Mexico, Asia, and the United States. McNeill is determined to continue his legacy by working towards improving air quality by collaborating with researchers in the Global South.

Refining large-scale air quality models to inform public health policies

Seven years after joining Columbia University as an assistant professor in 2007, McNeill went on to become the first woman to be awarded tenure in the chemical engineering department.

With over two decades of experience in atmospheric chemistry, she continues to spearhead research that delves into how emissions from human activities impact air quality.

Emissions from power plants, oil refineries, agriculture, industrial facilities, and other human activities are a major source of air pollution. But in many cases the emitted pollutants undergo complex chemical and physical transformations in the atmosphere to yield the toxic cocktail of smog that impacts human health, explained McNeill. “We’re finding new mechanisms by which the precursors to pollution can be transformed to create haze during their lifetime in the atmosphere,” she said.

In a lab, scientists can discover dramatic effects, but determining how that could play out in the environment is a different ball game altogether, added McNeill. “The need to bridge the discoveries of the lab, which occur one molecule at a time, with air quality on a regional or global scale makes a modeling approach crucial.”

Over the years, McNeill and her team developed their own numerical model of atmospheric interactions. It has enabled them to continue decoding whether or not the molecular-level discoveries from their lab could potentially have an environmental impact.

“Large-scale models of atmospheric chemistry and climate are computationally heavy because they include a lot of different variables,” she said. “Within an atmospheric particle, tens of thousands of chemical reactions take place simultaneously. It’s not possible to map all of that chemical complexity because then it would take a year to run one day’s simulation.”

She aims to reduce this overwhelming volume of complexities by prioritizing which physical processes need to be included in the large-scale model. This will further improve the accuracy of atmospheric models and allow researchers to make more fine-tuned predictions.

“These models will help in determining which policies will be the most effective in tackling climate change and air quality issues,” said McNeill.

Filling air quality data gaps in the Global South

Being a mother of two children who have asthma motivated McNeill to mobilize her state-of-the-art research at Columbia for on-the-ground action. In 2019, she and a large group of colleagues launched the Clean Air Toolbox for Cities. The initiative is an effort to identify and address the causes of urban air pollution in the Global South, so far with a focus on India, sub-Saharan Africa, and Indonesia. Since a lack of air quality data in these places hard-hit by air pollution is holding back progress towards clean air action, one of the initiative’s main goals is to ramp up air quality data collection in low-income countries with limited resources. McNeill and her colleague, Daniel Westervelt, who co-leads the Clean Air Toolbox, have been using low-cost air sensors to bridge the data gaps.

One of the initiative’s focal points is Kolkata, a city in the Indian state of West Bengal. Over the years, McNeill has formed a close bond with the city. Her husband’s family hails from Kolkata, and hearing him speak daily at home with their children, along with their frequent trips to the city, helped her learn Bengali — the region’s local language. “I have a love for the city and because I had already made connections with a network of local atmospheric scientists, it was easy to get started there,” said McNeill.

For the last three years, McNeill has partnered with and supported local experts who have been working on air pollution-related issues. She, along with other Clean Air Toolbox researchers, is helping a local startup, Ideation Technologies Solutions, analyze the large amounts of data being compiled from an air sensor network they set up across Kolkata. They are also helping to expand air pollution monitoring beyond what’s already being done by local groups such as the West Bengal Pollution Control Board (WBPCB).

“The WBPCB is confronted with the huge challenge and responsibility of cleaning up Kolkata’s air,” said McNeill. “They’re looking for expert help and support. They have been an amazing partner throughout all of this.”

The WBPCB uses government-grade air quality monitors, which can be quite costly. In order to gain more information on neighborhood-level air pollution, low-cost sensors have been key, because McNeill and her partners can deploy more of them and cover more area.

But this project has faced several challenges. In May 2020, when Cyclone Amphan wreaked havoc in West Bengal, the team’s data-collecting got disrupted. The COVID-19 pandemic also made it impossible to travel to Kolkata for two years. Thanks to McNeill’s strong partner network in the city, they were able to continue with the work remotely.

At present, the Clean Air Tool Box has set up additional air sensors in Kolkata on a pilot basis. McNeill and her team are also part of a large USAID-funded project — Clean Air Catalyst — in Indore, a city in Central India. In the future, McNeill and colleagues plan on expanding their air pollution research to other Indian cities.

“Everybody breathes air. So, this form of pollution is decreasing everybody’s life expectancy. As countries like India continue to develop rapidly, air pollution needs to be addressed urgently,” she added. “Rather than doing what the U.S. did, which is pollute first and then backtrack — it would be better to develop sustainably. That way, such public health issues could be avoided in the first place.”

Understanding ventilation to prevent indoor COVID transmission

Despite working in the emotionally taxing field of climate science, the aerosol scientist has been channeling her anxieties about the COVID-19 pandemic and air pollution crises into productivity.

Since the pandemic began, McNeill and her research group collaborated with Columbia Facilities to carry out measurements for characterizing the ventilation of indoor spaces on Columbia University’s Morningside Heights and Medical Center campuses.

They compiled data on how ventilation takes place in a range of different buildings, including those that were built in 1894 and after the 1960s. The aim of the study was to understand what measures needed to be taken to prevent the transmission of the coronavirus indoors, and they identified a few spots on campus where additional air filtration systems should be installed. McNeill later gathered a group of researchers who had performed similar studies at other schools and universities across the U.S. to compare their results and recommend best practices for those wishing to gather ventilation data and use it to support decision making.

“All of us felt better once we started with this,” she said. “While dealing with multiple crises, you can either watch from the sidelines and feel paralyzed, or you can get out there and try to do something to help.”