Long-Term Changes of Source Apportioned Particle Number Concentrations in a Metropolitan Area of the Northeastern United States

Stefania Squizzato,Mark Utell,David Rich,David Chalupa,Mauro Masiol,Philip Hopke,Fereshteh Emami

doi:10.3390/atmos10010027

Abstract

The northeastern United States has experienced significant emissions reductions in the last two decades leading to a decrease in PM2.5, major gaseous pollutants (SO2, CO, NOx) and ultrafine particles (UFPs) concentrations. Emissions controls were implemented for coal-fired power plants, and new heavy-duty diesel trucks were equipped with particle traps and NOx control systems, and ultralow sulfur content is mandatory for both road and non-road diesel as well as residual oil for space heating. At the same time, economic changes also influenced the trends in air pollutants. Investigating the influence of these changes on ultrafine particle sources is fundamental to determine the success of the mitigation strategies and to plan future actions. Particle size distributions have been measured in Rochester, NY since January 2002. The particle sources were investigated with positive matrix factorization (PMF) of the size distributions (11–470 nm) and measured criteria pollutants during five periods (2002–2003, 2004–2007, 2008–2010, 2011–2013, and 2014–2016) and three seasons (winter, summer, and transition). Monthly, weekly, and hourly source contributions patterns were evaluated.

Highlights

In the United States, criteria air pollutants, including particulate matter, are measured at fixed air quality monitoring stations in the National Ambient Air Quality Standards (NAAQS) compliance monitoring network managed by state, local, or tribal agencies [1]
Emission controls were implemented on coal-fired power plants, and new heavy-duty diesel trucks were equipped with particle traps and NOx control systems
During the same period as these policy implementations were taking effect, economic changes influenced the trends in air pollutants [24,25,28]

Summary

Introduction

In the United States, criteria air pollutants, including particulate matter, are measured at fixed air quality monitoring stations in the National Ambient Air Quality Standards (NAAQS) compliance monitoring network managed by state, local, or tribal agencies [1]. Despite the number of stations measuring air quality, limited data are still available for some air pollutants, including submicron particles (SMPs,

Methods

Results

Conclusion