Regional ground-level ozone trends in the context of meteorological influences across Canada and the eastern United States from 1997 to 2006

Coal has two main energy applications, with about 90% used for electricity generation and 10% used for commercial and residential heating. In terms of electricity generation in the United States, coal is responsible for about 28%, a significant decrease from 53% twenty years earlier when it was the leading energy for producing electricity. There are two primary commercial methods for generating electricity from coal including pulverized coal combustion and fluidized bed coal combustion. To safely burn coal, sulfur, nitrogen, and heavy metals are removed at the electric plant. The sequestering of sulfur and nitrogen are important steps for limiting acid rain and ground level ozone. To generate electricity, the United States has about 360 coal plants with about 790 generators, of which greater than 90% use pulverized coal technology. Most coal is transported by rail.

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Unraveling the sources of ground level ozone in the Intermountain Western United States using Pb isotopes

The Science of The Total Environment ◽

10.1016/j.scitotenv.2015.04.054 ◽

2015 ◽

Vol 530-531 ◽

pp. 519-525 ◽

Cited By ~ 7

Author(s):

John N. Christensen ◽

Peter Weiss-Penzias ◽

Rebekka Fine ◽

Charles E. McDade ◽

Krystyna Trzepla ◽

...

Keyword(s):

United States ◽

Ground Level ◽

Pb Isotopes ◽

Western United States ◽

Ground Level Ozone

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Ontario Medical Association Position Paper on Health Effects of Ground-Level Ozone, Acid Aerosols and Particulate Matter

Canadian Respiratory Journal ◽

10.1155/1998/285495 ◽

1998 ◽

Vol 5 (5) ◽

pp. 367-384 ◽

Cited By ~ 1

Author(s):

BT Boadway ◽

J MacPhail ◽

C Jacobson

Keyword(s):

United States ◽

Air Pollution ◽

Nitrogen Oxides ◽

Health Effects ◽

Sulphur Dioxide ◽

Air Pollutants ◽

Ground Level ◽

The United States ◽

Ground Level Ozone ◽

Emission Limits

This review of the evidence of the health effects of air pollutants focuses on research conducted in Ontario. Seven key Ontario studies are cited. These findings are highly significant for people living in the Great Lakes basin (and particularly the Windsor-Quebec corridor), where high levels of certain air pollutants (eg, ground-level ozone and ultra-fine particles) occur more frequently than in other parts of Canada. The issue is a serious one, requiring an integrated and comprehensive approach by many stakeholders, including the active involvement of organized medicine. It is important that the health effects of these air pollutants are understood. Governments must act to reduce emission levels through statue and regulation bolstered by noncompliance penalties.The findings of research have included the following: in a Toronto study, a 2% to 4% excess of respiratory deaths were attributable to pollutant levels; children living in rural Ontario communities with the highest levels of airborne acids were significantly more likely to report at least one episode of bronchitis, as well as to show decreases in lung function; and have been linked to increases in pollutants, emergency room visits and hospitalizations in Ontario.Every Ontarian is affected by air pollutants, although he or she may be unaware of the asymptomatic effects such as lung and bronchial inflammation. This health problem is preventable; while physicians know of the adverse health impacts of air pollution and they are concerned, individually they now focus on the treatment of symptoms. The major recommendations of the report are as follows:* Enactment of more stringent sulphur and nitrogen oxide emission limits, including a provincewide sulphur dioxide reduction of 75% from current cap levels, and the maximum allowable nitrogen oxides emission limits of 6000 tonnes annually from Ontario Hydro.* New transportation sector emission limits that should include California-level standards for light and heavy duty vehicles, reductions from off-road engines, an expanded vehicle inspection and maintenance program, and tougher standards for sulphur-in-fuel content.* Petitioning the United States Environmental Protection Agency administrator under Section 115 of the United States Clear Air Act to require reductions in the American emission of sulphur dioxide and nitrogen oxides, which damage the health of Canadian residents and their environment.* Physician advice to patients about the risks of smog exposure, physician support for more health effects research on air pollution, and physician promotion of the development of air pollution-related health education materials.The recommendations discussed in this paper will, if acted upon, lead to a significant reduction in the overall burden of illness from air pollutants, especially in children and the elderly. These recommendations have been selected from a review of recommendations made by various authorities, and are those that the OMA feels a particular responsibility to support.

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Precursor reductions and ground-level ozone in the Continental United States

Journal of the Air & Waste Management Association ◽

10.1080/10962247.2015.1079564 ◽

2015 ◽

Vol 65 (10) ◽

pp. 1261-1282 ◽

Cited By ~ 15

Author(s):

George M. Hidy ◽

Charles L. Blanchard

Keyword(s):

United States ◽

Ground Level ◽

Ground Level Ozone

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Baseline levels and trends of ground level ozone in Canada and the United States

Atmospheric Chemistry and Physics ◽

10.5194/acp-10-8629-2010 ◽

2010 ◽

Vol 10 (18) ◽

pp. 8629-8647 ◽

Cited By ~ 45

Author(s):

E. Chan ◽

R. J. Vet

Keyword(s):

United States ◽

Ground Level ◽

Western Canada ◽

Eastern Canada ◽

Ground Level Ozone ◽

Mixing Ratios ◽

Western Us ◽

The Us ◽

Baseline Levels ◽

Ozone Precursor

Abstract. A statistical method was developed to extract baseline levels of ground level ozone in Canada and the US, and to quantify the temporal changes of baseline ozone levels on annual, seasonal, diurnal and decadal scales for the period 1997 to 2006 based on ground-level observations from 97 non-urban monitoring sites. Baseline ozone is defined here as ozone measured at a given site in the absence of strong local influences. The quantification of baseline levels involved using a Principal Component Analyses (PCA) to derive groups of commonly-varying sites in contiguous regions by season, followed by using backward air parcel trajectories to systematically select ozone mixing ratios associated with the baseline condition in each of the PCA-derived regions. Decadal trends were estimated by season for each of the regions using a generalized linear mixed model (GLMM). Baseline ozone mixing ratios determined by this method were found to vary geographically and seasonally. For the 1997–2006 period, baseline mixing ratios were calculated for annual and seasonal periods in seven regions of North America based on multi-site multi-year averages of the baseline data sets. The annual average (±1 standard deviation) baseline mixing ratios for the regions are as follows: Continental Eastern Canada=30±9 ppb, Continental Eastern US=30±10 ppb, Coastal Eastern Canada=27±9 ppb, Coastal Western Canada=19±10 ppb; Coastal Western US=39±10 ppb, Continental Western Canada=28±10 ppb and Continental Western US=46±7 ppb. Trends in the baseline mixing ratios were also found to vary by season and by geographical region. On a decadal scale, increasing baseline ozone trends (temperature-adjusted) were observed in all seasons along the Pacific coasts of Canada and the US, although the trends in California were not statistically significant. In the coastal zone of Pacific Canada, positive trends were found with a rate of increase of 0.28±0.26, 0.72±0.55, and 0.93±0.41 ppb/a in spring (MAM), summer (JJA) and winter (DJF), respectively. In the Atlantic coastal region, the trends were also positive in 3 of the 4 seasons (but only significantly so in MAM). In the high ozone precursor emission areas of the Eastern United States, decadal trends in baseline ozone are, in general, negative in the spring, summer and fall and appear to be controlled by the strong within-region changes induced by decreasing ozone precursor emissions.

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Climate-driven ground-level ozone extreme in the fall over the Southeast United States

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1602563113 ◽

2016 ◽

Vol 113 (36) ◽

pp. 10025-10030 ◽

Cited By ~ 39

Author(s):

Yuzhong Zhang ◽

Yuhang Wang

Keyword(s):

United States ◽

Climate Models ◽

Weather Condition ◽

Ground Level ◽

Field Studies ◽

The United States ◽

Fire Emissions ◽

Ground Level Ozone ◽

Ozone Concentrations ◽

Ozone Precursor

Ground-level ozone is adverse to human and vegetation health. High ground-level ozone concentrations usually occur over the United States in the summer, often referred to as the ozone season. However, observed monthly mean ozone concentrations in the southeastern United States were higher in October than July in 2010. The October ozone average in 2010 reached that of July in the past three decades (1980–2010). Our analysis shows that this extreme October ozone in 2010 over the Southeast is due in part to a dry and warm weather condition, which enhances photochemical production, air stagnation, and fire emissions. Observational evidence and modeling analysis also indicate that another significant contributor is enhanced emissions of biogenic isoprene, a major ozone precursor, from water-stressed plants under a dry and warm condition. The latter finding is corroborated by recent laboratory and field studies. This climate-induced biogenic control also explains the puzzling fact that the two extremes of high October ozone both occurred in the 2000s when anthropogenic emissions were lower than the 1980s and 1990s, in contrast to the observed decreasing trend of July ozone in the region. The occurrences of a drying and warming fall, projected by climate models, will likely lead to more active photochemistry, enhanced biogenic isoprene and fire emissions, an extension of the ozone season from summer to fall, and an increase of secondary organic aerosols in the Southeast, posing challenges to regional air quality management.

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Changing Patterns in U.S. Air Quality

Eos ◽

10.1029/2015eo024509 ◽

2015 ◽

Vol 96 ◽

Author(s):

Colin Schultz

Keyword(s):

United States ◽

Air Quality ◽

Nitrogen Oxide ◽

Ground Level ◽

Nitrogen Oxide Emissions ◽

Ground Level Ozone ◽

Northeast United States ◽

Changing Patterns

Over the northeast United States, ground-level ozone will peak in the winter rather than the summer thanks to continued reductions of regional nitrogen oxide emissions from smokestacks and tailpipes.

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