Differences between Weekday and Weekend Air Pollutant Levels in Atlanta; Baltimore; Chicago; Dallas–Fort Worth; Denver; Houston; New York; Phoenix; Washington, DC; and Surrounding Areas

Abstract We evaluated day-of-week differences in mean concentrations of ozone (O3) precursors (nitric oxide [NO], nitrogen oxides [NOx], carbon moNOxide [CO], and volatile organic compounds [VOCs]) at monitoring sites in 23 states comprising seven geographic focus areas over the period 1998– 2003. Data for VOC measurements were available for six metropolitan areas in five regions. We used Wednesdays to represent weekdays and Sundays to represent weekends; we also analyzed Saturdays. At many sites, NO, NOx, and CO mean concentrations decreased at all individual hours from 6:00 a.m. to 3:00 p.m. on Sundays compared with corresponding Wednesday means. Statistically significant (p < 0.01) weekend decreases in ambient concentrations were observed for 92% of NOx sites, 89% of CO sites, and 23% of VOC sites. Nine-hour (6:00 a.m. to 3:00 p.m.) mean concentrations of NO, NOx, CO, and VOCs declined by 65, 49, 28, and 19%, respectively, from Wednesdays to Sundays (median site responses). Despite the large reductions in ambient NOx and moderate reductions in ambient CO and VOC concentrations on weekends, ozone and particulate matter (PM) nitrate did not exhibit large changes from week-days to weekends. The median differences between Wednesday and Sunday mean ozone concentrations at all monitoring sites ranged from 3% higher on Sundays for peak 8-hr concentrations determined from all monitoring days to 3.8% lower on Sundays for peak 1-hr concentrations on extreme-ozone days. Eighty-three percent of the sites did not show statistically significant differences between Wednesday and weekend mean concentrations of peak ozone. Statistically significant weekend ozone decreases occurred at 6% of the sites and significant increases occurred at 11% of the sites. Average PM nitrate concentrations were 2.6% lower on Sundays than on Wednesdays. Statistically significant Sunday PM nitrate decreases occurred at one site and significant increases occurred at seven sites.

[1]  C. Blanchard,et al.  Understanding the Effectiveness of Precursor Reductions in Lowering 8-Hr Ozone Concentrations—Part II. The Eastern United States , 2004, Journal of the Air & Waste Management Association.

[2]  P. S. Porter,et al.  Modeling Analyses of the Effects of Changes in Nitrogen Oxides Emissions from the Electric Power Sector on Ozone Levels in the Eastern United States , 2008, Journal of the Air & Waste Management Association.

[3]  R. Draxler.  An Overview of the HYSPLIT_4 Modelling System for Trajectories, Dispersion, and Deposition , 1998 .

[4]  Douglas R Lawson,et al.  Evolution of the Magnitude and Spatial Extent of the Weekend Ozone Effect in California’s South Coast Air Basin, 1981–2000 , 2003, Journal of the Air & Waste Management Association.

[5]  D. Chock,et al.  Weekday-Weekend Pollutant Studies of the Los Angeles Basin , 1976 .

[6]  Linsey C. Marr,et al.  Spectral analysis of weekday–weekend differences in ambient ozone, nitrogen oxide, and non-methane hydrocarbon time series in California , 2002 .

[7]  C. Blanchard,et al.  Understanding the Effectiveness of Precursor Reductions in Lowering 8-Hr Ozone Concentrations , 2003, Journal of the Air & Waste Management Association.

[8]  R. Draxler,et al.  Meteorological Factors of Ozone Predictability at Houston, Texas , 2000, Journal of the Air & Waste Management Association.

[9]  P. Stolpman,et al.  Environmental Protection Agency , 2020, The Grants Register 2022.

[10]  C. Blanchard,et al.  Weekday/Weekend Differences in Ambient Air Pollutant Concentrations in Atlanta and the Southeastern United States , 2006, Journal of the Air & Waste Management Association.

[11]  The 2003 North American electrical blackout: An accidental experiment in atmospheric chemistry , 2004 .

[12]  Thomas E. Graedel,et al.  Photochemistry of the "Sunday Effect" , 1977 .

[13]  A. Goldstein,et al.  The weekend effect within and downwind of Sacramento: Part 2. Observational evidence for chemical and dynamical contributions , 2006 .

[14]  Debra Jezouit,et al.  The Clean Air Interstate Rule , 2005 .

[15]  F. Lebron.  A comparison of weekend-weekday ozone and hydrocarbon concentrations in the Baltimore-Washington metropolitan area , 1975 .

[16]  J. Heuss,et al.  Weekday/Weekend Ozone Differences: What Can We Learn from Them? , 2003, Journal of the Air & Waste Management Association.

[17]  Douglas R. Lawson,et al.  Comparison of Emission Inventory and Ambient Concentration Ratios of CO, NMOG, and NOx in California's South Coast Air Basin , 1992 .

[18]  J. Seinfeld,et al.  Atmospheric Chemistry and Physics: From Air Pollution to Climate Change , 1997 .

[19]  C. Seigneur,et al.  Day-of-Week Behavior of Atmospheric Ozone in Three U.S. Cities , 2003, Journal of the Air & Waste Management Association.

[20]  K. Wilson,et al.  Photochemical air pollution: Weekend-weekday differences , 1977 .

[21]  G. Hidy,et al.  The Southeastern Aerosol Research and Characterization Study: Part 1—Overview , 2003, Journal of the Air & Waste Management Association.

[22]  S. Brönnimann,et al.  Weekend-weekday differences of near-surface ozone concentrations in Switzerland for different meteorological conditions , 1997 .

[23]  S. Shutters,et al.  Weekly periodicity of environmental variables in Phoenix, Arizona , 2006 .

[24]  R. Harley,et al.  On-road measurement of fine particle and nitrogen oxide emissions from light- and heavy-duty motor vehicles , 1999 .

[25]  D. Parrish.  Critical evaluation of US on-road vehicle emission inventories , 2006 .

[26]  Reply to comment by D. A. Hansen et al. on “The 2003 North American electrical blackout: An accidental experiment in atmospheric chemistry” , 2005 .

[27]  T E Graedel,et al.  Sunday and Workday Variations in Photochemical Air Pollutants in New Jersey and New York , 1974, Science.

[28]  J. Chow.  Introduction to Special Topic: Weekend and Weekday Differences in Ozone Levels , 2003, Journal of the Air & Waste Management Association.

[29]  Linsey C Marr,et al.  Modeling the effect of weekday-weekend differences in motor vehicle emissions on photochemical air pollution in central California. , 2002, Environmental science & technology.

[30]  N. Motallebi,et al.  Day-of-Week Patterns of Particulate Matter and Its Chemical Components at Selected Sites in California , 2003, Journal of the Air & Waste Management Association.

[31]  A. Goldstein,et al.  The weekend effect within and downwind of Sacramento – Part 1: Observations of ozone, nitrogen oxides, and VOC reactivity , 2007 .

[32]  Barbara Zielinska,et al.  Diurnal and Weekday Variations in the Source Contributions of Ozone Precursors in California’s South Coast Air Basin , 2003, Journal of the Air & Waste Management Association.

[33]  R. Draxler.  NOAA Technical Memorandum ERL ARL-224 DESCRIPTION OF THE HYSPLIT_4 MODELING SYSTEM , 1999 .

[34]  Naresh Kumar,et al.  Improved Light Extinction Reconstruction in Interagency Monitoring of Protected Visual Environments , 2005, Journal of the Air & Waste Management Association.

[35]  R. Draxler,et al.  Modeling assessment of point source NOx emission reductions on ozone air quality in the eastern United States , 2008 .

[36]  E. Atlas,et al.  Observations of Ozone Formation in Power Plant Plumes and Implications for Ozone Control Strategies , 2001, Science.

[37]  Y. Qin,et al.  Weekend/weekday differences of ozone, NOx, Co, VOCs, PM10 and the light scatter during ozone season in southern California , 2004 .

[38]  R. Harley,et al.  Weekly cycles in fine particulate nitrate , 2008 .

[39]  A. M. Dunker,et al.  Modeling Weekday/Weekend Ozone Differences in the Los Angeles Region for 1997 , 2003, Journal of the Air & Waste Management Association.

[40]  P. S. Porter,et al.  Observation-Based Assessment of the Impact of Nitrogen Oxides Emissions Reductions on Ozone Air Quality over the Eastern United States , 2007 .

[41]  Douglas R. Lawson,et al.  Weekday vs. weekend ambient ozone concentrations : discussion and hypotheses with focus on Northern California , 1995 .

[42]  P. T. Roberts,et al.  Weekday versus Weekend Activity Patterns for Ozone Precursor Emissions in California’s South Coast Air Basin , 2003, Journal of the Air & Waste Management Association.

[43]  C. Blanchard,et al.  Differences between Weekday and Weekend Air Pollutant Levels in Southern California , 2003, Journal of the Air & Waste Management Association.

[44]  Linsey C Marr,et al.  Changes in motor vehicle emissions on diurnal to decadal time scales and effects on atmospheric composition. , 2005, Environmental science & technology.

[45]  Roland R. Draxler,et al.  Evaluation of an ensemble dispersion calculation , 2003 .

[46]  F. Vukovich.  The Spatial Variation of the Weekday/Weekend Differences in the Baltimore Area , 2000, Journal of the Air & Waste Management Association.