by SAMANTHA WALLA, Asst. Production Editor
Alicia Mullaley, Ph.D., professor of chemistry at Manhattan College, spent her summer break measuring pollutants that most people are unaware of, but that affect their health on a daily basis.
The Long Island Sound Tropospheric Ozone Study, or LISTOS, is a study put out by New York state that aims to quantify the ozone concentration in the New York City metropolitan area, as well as downwind areas in Connecticut, Rhode Island and Massachusetts. The main objective of the study is to not only quantify the different levels of pollutants, but to get better at monitoring them. Data of this kind contributes to the awareness of high ozone days, which can be beneficial to those with respiratory conditions.
Although Mullaley is an atmospheric chemist by training, the study also ties into her interest in public health.
“I love the idea of ‘citizen science,’ so all majors participate in collecting data. It’s the age of technology with our smartphones; can we somehow use that to help track urban air pollution or collect data?” said Mullaley. “It is consistent with my technical background, but it is also a passion project for me because I care about human health and the local effects it can have on this community. So if we find something that’s alarming I’d like to make sure that we can bring that knowledge to the local people and make that available to them.”
In explaining her research, Mullaley made the distinction between stratospheric ozone, which many people may be familiar with, and tropospheric ozone.
Stratospheric ozone is beneficial and found in the atmosphere, and protects humans from cell mutations. Tropospheric ozone is produced at ground level and is harmful. If conditions are right, precursors to ozone travel up through the atmosphere and react to form the pollutant.
New York City, which is a hot spot for urban air pollution, also has the highly concentrated population that can be affected by ozone.
These pollutants have negative cardiovascular and respiratory effects, especially for young and elderly people, as well as those with pre-existing conditions such as asthma. Air pollution has also been linked to deaths in nations like China, India and Pakistan, where pollution is not regulated by organizations like the Environmental Protection Agency, or EPA.
The EPA measures six pollutants, one of which is ozone. The healthy standard set by the EPA is currently 70 parts per billion (PPB) per volume. Being exposed to over this concentration for longer than eight hours is deemed unhealthy. Despite this standard, Mullaley observed consistent days with measurements over that threshold with some as high as 135 PPB per volume.
Mullaley’s data collection took place in the height of ozone season, which is the middle of June to the end of July. This time period is critical for collecting ozone levels, as ozone is produced in the presence of sunlight.
The study collected data over 40 hours of flight time on two flights a day that took place between the hours of 12 p.m. and 4 p.m.
These flights, which Mullaley was often present for, took place on a four-seater Cozy MK IV, which is technically classified as an experimental aircraft. Mullaley attended these data collections to assure that her equipment was functioning and recording properly.
Mullaley is interested in bringing these tests to MC by setting up the same instruments on top of Hayden to measure ozone concentrations on campus.
Additionally, she hopes to measure indoor pollutants and compare the varying levels. Mullaley plans on recruiting students to help with these measurements.
“What’s going on with the LISTOS campaign is great: to have a better characterization and understanding of how ozone forms, where it comes from and what it could possibly contribute to the local chemistry of the area,” said Mullaley. “But on a personal level, I’m curious as to what’s really going on in the direct neighborhood and I want to be able to bring that to people and possibly have a positive effect on health. So say [someone is] asthmatic and they know an ozone event is coming up. If they stay indoors and away from the pollution, can that help them potentially? I really like the idea of tying that to public health.”
Mullaley’s interest in measuring pollution is not limited to her LISTOS research, as she also enlisted Manhattan College students to help in studying ice cores this past summer.
Ice cores, which are 10 inch diameter cylindrical pieces of ice that forms as snow falls every year. As the snow becomes compressed, air bubbles form that represent the composition of the atmosphere from a certain period of time.
These ice cores provide a record of methane and other gases dating back about 800,000 years. This past summer, Mullaley’s students worked on a core that went back 8,000 years, but she also has samples that date back 20,000 years.
Mullaley is particularly interested in the interactions between carbon monoxide, CO, methane and what is called the hydroxyl radical, OH. CO is a precursor to ozone, which is a created pollutant.
“The atmosphere is really good at cleansing itself and it does this by reacting harmful chemicals with OH,” said Mullaley. “But hydroxyl likes carbon monoxide, so if there’s CO in the atmosphere, which is also a pollutant, it will eat away the OH. If CO takes the OH away, then there’s no OH to react with methane.”
She continued.
“I’m curious to see how the concentration has varied over time and in particular how the different sources of CO have varied. Because carbon monoxide mainly comes from biomass burning — think of forest fires — but it also comes from oxidation. Isoprene is a gas that’s emitted from trees. That isoprene will react in the atmosphere and can produce CO as a product. Methane can become oxidized by OH to produce CO.”
Additionally, Mullaley uses isotopes to discern the sources of pollutants. She uses human fingerprints to explain how isotopes work.
“The different sources of CO have their own isotopic signatures. It’s like a little bit of detective work; each source has its own unique fingerprint,” explained Mullaley. “We can exploit those fingerprints to figure out how much came from biomass burning versus the oxidation of methane and/or non methane hydrocarbons.”
The results from measuring these signatures can help determine the sources of CO and how they change over time.
“Just think about it, once we have a larger population then you can imagine the source from biomass burning might increase if there are more forest fires, if we are doing prescribed burning for example, or burning forests for agricultural reasons,” said Mullaley.
The labor intensive process of studying ice cores lends itself to summer research, meaning that the school year is better for analyzing data.
Peter Parlato analyzed the ice cores over the summer with Mullaley.
“My favorite aspect of [the study] was the hands-on work I got to do. The analytical procedure was complex, but it made it even more exciting when I got to finally see and interpret the data,” Parlato said.
Sophia Misiakiewicz, an environmental science major, liked both the hands-on work and the preliminary research of the project.
“Although doing the actual experiments were great, I really enjoyed doing the background research: learning about other similar studies, and different environmental phenomenon that would contribute the carbon monoxide concentrations in the atmosphere,” said Misiakiewicz. “I also loved learning the atmospheric chemistry; how the molecules interact with each other to form the product we’re studying. It was really incredible to see how so many different things were connected, from accumulation rates in Antarctica, to identifying the contribution of biomass burning to the CO concentrations.”
Mullaley’s research contributed not only to the field of public health, but to the students she recruited for the project.
“There’s a lot of time and energy that goes into acquiring any kind of data, and not everyone realizes it when they go into their textbook and read the graphs and numbers,” said Misiakiewicz. “Working with Dr. Mullaley opened up my perspective to the scientific field, and what it actually means to be a scientist.”