Grantee Research Project Results
Real-Time Analysis of Aerosol-Phase Plastic Additives in a Coastal Marine Environment in California
EPA Grant Number: R840424Title: Real-Time Analysis of Aerosol-Phase Plastic Additives in a Coastal Marine Environment in California
Investigators: Slade, Jonathan H
Institution: University of California San Diego
EPA Project Officer: Chung, Serena
Project Period: May 1, 2022 through April 30, 2025
Project Amount: $399,464
RFA: Measurement and Monitoring Methods for Air Toxics and Contaminants of Emerging Concern in the Atmosphere (2021) RFA Text | Recipients Lists
Research Category: Early Career Awards , Air Quality and Air Toxics
Objective:
Almost 10% of the annual production of plastics, including personal care products, accumulate in the world’s oceans, where their toxic chemical additives can leach into the surrounding water and become enriched at the sea surface or partition to the air. Preliminary work by our group identified several toxic plastic additives collected onto aerosol filter samples in coastal San Diego, CA, which scaled in abundance with their levels in seawater and proximity to wastewater outflow. This work suggests sea spray aerosol may be an important route of airborne transport of plastic additives requiring further study. Their concentrations in aerosols may depend on season, time of day, wave height, and biological activity in the ocean, but have not been studied. This proposal aims to build on and significantly improve online detection and quantification of several understudied toxic plastic additives of emerging concern in aerosol in a coastal marine environment, including UV filters, antimicrobials, and plasticizers. Specific objectives include:
- Continuous online measurement and quantification of plastic additives in the aerosol phase with extractive electrospray ionization (EESI-TOF) high-resolution mass spectrometry during summer and winter at a coastal site to evaluate seasonal and diel profiles.
- Quantify the targeted plastic additives in collected seawater and twice-daily high-volume aerosol filter samples employing Orbitrap LC-ESI-MS2.
- Apply molecular networking and statistical analysis of the compositional data along with wave height, wind speed, biological activity, rainfall, and river discharge rates to assess drivers and conditions under which plastic additives become airborne.
Approach:
EESI-TOF will be employed for online analysis of aerosol phase components complemented by offline analysis of aerosol filter extracts using Orbitrap LC-ESI-MS2. The plan of work involves calibration of an EESI-TOF incorporating isotopic internal standards for sensitive and reliable quantification online, and field observations in summer and winter over the project duration at the Scripps Pier in La Jolla, CA. Compositional analysis of seawater samples will be conducted offline using Orbitrap LC-ESI-MS2. Statistical relationships will be studied via the Global Natural Products Social (GNPS) molecular network and principle coordinate analysis.
Expected Results:
Plastic pollution has become the greatest threat to the environment next to global warming. We anticipate that concentrations of some plastic additives from personal care products will be more prevalent in summer due to greater beach recreational activity. Concentrations of all plastic additives are likely to vary with wastewater outflow rates, decrease during daytime from photochemical oxidation, and decrease due to biotic degradation with increased biological activity in the water. This work will generate new knowledge to help inform environmental regulation and risk assessment analyses of plastic additives.
Publications and Presentations:
Publications have been submitted on this project: View all 4 publications for this projectJournal Articles:
Journal Articles have been submitted on this project: View all 1 journal articles for this projectSupplemental Keywords:
plastics, additives, aerosol, marine, mass spectrometryProgress and Final Reports:
The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.