What is the Local Environmental Impact of Fracking?

Investigating the traffic-related environmental impacts of hydraulic-fracturing (fracking) operations (13 page pdf, Paul S. Goodman, Fabio Galatioto, Neil Thorpe, Anil K. Namdeo, Richard J. Davies, Roger N. Bird, Environment International, Feb. 1, 2016)

Today we review an aspect of fracking, not often investigated: the impact of local fracking wells which is a combination of the air pollution emissions from the fracking itself and the removal of waste water by tanker trucks which adds vehicle emissions and noise. There is a requirement for 9,000 to 29,000 cubic metres per well, or 54,000 to 174,000 cubic metres for a six-well pad. Total CO2 emissions associated with extraction of shale gas from a well were small (0.2–2.9%) compared to the combustion of the gas from the well. Modelling of NOx emissions showed increases reaching 30% over non-fracking periods and noise levels doubling.

fracking traffic

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How Does Global Climate Warming Look Locally?

Regional estimates of the transient climate response to cumulative CO2 emissions (Abstract, Martin Leduc, H. Damon Matthews & Ramón de Elía, Nature Climate Change, Jan.4, 016)
Also discussed here: Impact of human activity on local climate mapped (Science Daily, Jan. 20, 2016)

Today we review research that examines the projected climate warming using 12 model runs from cumulative carbon emissions from preindustrial levels to four times those emissions on different regions of the world. Not unexpectedly, temperatures increase the most in polar regions (more than 5 deg C per trillion tons of emissions) than in low latitude areas and more over land (1.3 deg C) than over oceans (less than 1 deg C). The influence of ice albedo and ocean circulation caused warming that was linear than in land areas far from ice. This approach offers much in the assessment of future climate impacts on a regional or locals scale.

local climate chnage

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Modelling the Dynamics of Traffic Congestion and Urban Air Pollution Hot Spots

MIT Study devises new algorithm to predict traffic patterns (Becca DeGregorio, The Daily Free Press, Nov. 13, 2014)

Also discussed here: Understanding Road Usage Patterns in Urban Areas (6 page pdf, Pu Wang, Timothy Hunter, Alexandre M. Bayen, Katja Schechtner & Marta C. Gonzalez, Scientific Reports, Nature, Dec. 20, 2012)

And here: Phone data helps pinpoint source of traffic congestion (On Balance, Dept. Civil and Environmental Engineering, Massachusetts Institute of Technology, Jan. 2013)

And here:

(48 sec You-Tube, Marta Gonzalez, Dec. 8, 2013)

And here: Gridlock Traced to Just a Few Key Commuters (Rocket News, Dec. 21, 2012)

Today we review research from MIT aimed at diagnosing the dynamics of traffic congestion using mobile phone records and population and origin-destination statistics to identify key congested road segments that lead to major congestion across major cities such as San Francisco and Boston. These congested areas rapidly lead to high levels of pollution that affect the entire urban area which puts both drivers and others such as cyclists who use the roads at risk to their health. Better design of the road network and method to reduce traffic peaks such as congestion pricing are offered as solutions.

traffic congestion

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Sharpening the Spatial Resolution of Exposure to Particulate Matter

Spatio-temporal modeling of particulate air pollution in the conterminous United States using geographic and meteorological predictors (34 page pdf, Jeff D Yanosky, Christopher J Paciorek, Francine Laden, Jaime E Hart, Robin C Puett, Duanping Liao and Helen H Suh, Environmental Health, Aug. 5, 2014)

Today we review a paper describing how a statistical model can be used to provide the necessary spatial detail on the exposure to particulate matter. Knowing this is especially important near major roads in urban areas where there is a high volume of diesel powered vehicles which emit PM2.5 and where the distance from the emission sources to where people live or work is critical. The authors show examples of the mapping for cities such as New York as well as across the USA.

high resolution PM in NYC

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Atmospheric Energy Imbalances and Climate Change

Energy and Climate – Dr Kevin E Trenberth(Royal Meteorological Society, Feb, 2013)

Also discussed here:
(NCAR, Apr. 14, 2010)

And here:
Surface Energy Budget of Central Canada(194 pages, William Pugsley. Publication in Meteorology #96, Arctic Meteorology Research Group. Dept of Meteorology, McGill University, Montreal, PQ, Sep. 1970)
Today we review a topic close to my heart and the subject of my MSc thesis 40 years ago- the flows of energy and radiation in the atmosphere and with the earth’s and ocean surface. Dr Trenberth suggests that the balance that existed between outgoing and incoming radiation has changed recently with an unexplained or missing amount of energy that may be stored or accumulating in the deep ocean. He calls for better global atmospheric-oceanic modeling to account for this and to better anticipate the net impact that carbon fuel use has on atmospheric warming and climate change – which, as we have seen from previous posts, mainly affect people and their health in cities.

To see Key Quotes and Links to key reports about this post, click HERE

How Does Waste Heat from MegaCities Affect the Global Atmospheric Circulation?

Energy consumption and the unexplained winter warming over northern Asia and North America(5 Page pdf, Guang J. Zhang, Ming Cai and Aixue Hu, Nature Climate Change, Jan 27, 2013)

Also discussed here: Cities change temperatures for thousands of miles(UCAR ATMOS News, Jan. 27, 2013)

And here: City heat affects temperatures 1,000 miles away(The Times of India, Jan. 28, 2013)

Today we review global climate modeling research that examined the contribution of the waste heat produced by buildings and vehicle emissions in very large cities. Although this heat is small compared to the warming from greenhouse gasses in the atmosphere for the entire world, the model simulations reveal large changes in the regional circulation near these cities which may intensify local weather events such as droughts or extreme storms.


To see Key Quotes and Links to key reports about this post, click HERE

Top 10 Posts for 2012 on Pollution Free Cities-WordPress Edition

At year end, bloggers sometimes look back at their posts to see which ones were the most popular- and I did just that with the list of links clipped below, in case you want to revisit any of them. There continues to be interest in pollution free cities such as Masdar City in the United Arab Emirates and advances being made to reduce or eliminate energy consumption, traffic congestion, pollution (including noise) in cities, along with an ongoing interest in the health impacts of all this. Perhaps surprising is that only one post in the last year was as popular as the older posts- the one on GEO Medicine and accumulated exposure to air pollution over a lifetime.

Masdar City – zero carbon, zero waste

Health Effects of Noise

Low and Zero Energy Buildings (ZEB)

Global Health Impact of Air, Land and Water Pollution

Managing Urban Noise

Traffic-Related Air Pollution Literature Review

The Cleanest (and Dirtiest) Cities in the World

Health Effects of Air Pollution from Motor Vehicles

Impact of Traffic Air Pollution on Health in Toronto

GEO Medicine and Lifetime Exposure to Poor Air Quality

Health and Urban Poverty

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Mapping Urban Greenhouse Gases down to the Street Level

Quantification of Fossil Fuel CO2 Emissions on the Building/Street Scale for a Large U.S. City(Abstract, Kevin R. Gurney, Igor Razlivanov, Yang Song, Yuyu Zhou, Bedrich Benes, and Michel Abdul-Massih, Environ. Sci. Technol., Aug. 15, 2012)

Also discussed here: Greenhouse Gas Emissions Mapped to Building, Street Level for U.S. Cities(ScienceDaily, Oct. 9, 2012)

Today we review research aimed at mapping greenhouse gases in cities down to the scale of streets using a variety of surface data which in turn permits agencies to monitor and identify sources of emission across the urban landscape. This “ground” data is to be used in conjunction with a satellite to ne lanced in 2013 that will permit the implementation of effective greenhouse gas legislation at ultimately the global level.

To see Key Quotes and Links to key reports about this post, click HERE

What is the Future of Air Pollution Globally?

Effects of business-as-usual anthropogenic emissions on air quality(23 page pdf, A. Pozzer, P. Zimmermann, U.M. Doering, J. van Aardenne, H. Tost, F. Dentener, G. Janssens-Maenhout and J. Lelieveld, Journal of Atmospheric Chemistry and Physics, Aug. 1, 2012)

Also discussed here: Air Pollution Worsening Worldwide: Cut Emissions Further, Experts Urge(ScienceDaily, Jul. 31, 2012)

Today we review a paper that looks at the state of air quality globally for the next 40 years, using an index that represents the five major pollutants and a global circulation model to produce scenarios into the future if we continue with “business as usual” policies. These scenarios show that countries and large cities with the worst widespread pollution (in Indo-Asia, the Middle East and North Africa) will not surprisingly deteriorate. The rest of the world’s state of pollution will worsen on average to what we see today in East Asia with the negative health results and enhanced anthropogenic climate change that this implies. Clearly improved atmospheric environmental policy is called for in almost all countries.

To see Key Quotes and Links to key reports abut this post, click HERE

Collecting and Distributing Air Quality Data in Europe in Near Real-Time

Map of the Member States of the European Union

Map of the Member States of the European Union (Photo credit: Wikipedia)

Reporting and exchanging air quality information using e-Reporting (62 page pdf,  European Environment Agency,  EEA Technical report No 5/2012)

Also discussed here: EIONET – the Ambient Air Quality Portal

And here: EIONET- Reporting Obligations Database (ROD)

Today we review a report concerned with the more timely reporting, processing and distribution of air quality data in Europe via an E-Reporting system to come online on January 1, 2014. It makes a number of recommendations concerning data formats, standardized procedures and making the data more easily absorbed into air quality models. What is most interesting to this observer who comes from a country with the same challenges involved in different (provincial) jurisdictions where similar agreements and coordination is needed to ensure timely delivery of air quality information and warnings.

To see Key Quotes and Links to key reports about this post, click HERE


Pollution “Radar” and the London Olympics

Sensors to create 3D map of Olympic pollution levels  (Mark Prigg, London Evening Standards, Apr. 30, 2012)

Also discussed here: UK develops technology to study traffic impact during London Olympics (Road Traffic Technology, May 1, 2012)

And  here: CityScan – The Pollution Radar

And here: 3-D Map of Air Pollution in London (London Air, King’s College London)

The site of each Olympics, it seems, is in or near a large city with high pollution levels.This year is no different with London following Beijing. By no coincidence, national authorities take steps to monitor and  improve the air quality not only for the competing athletes but also for the millions of visitors to the event. Today we review progress on the development of a compact optical device, a “pollution radar”, which can produce time sequenced 3D maps of  NO2 for the entire city with a resolution of 50m and 5 minutes from three monitoring sites.

To see Key Quotes and Links to key reports about this post, click HERE

The Better Air Quality at Beijing Olympics- government controls or lucky weather conditions?


Beijing 2008 

Emission controls versus meteorological conditions in determining aerosol concentrations in Beijing during the 2008 Olympic Games (15 page pdf, Y. Gao, X. Liu, C. Zhao, and M. Zhang, Atmos. Chem. Phys.,  Dec. 28, 2011)


Also discussed here: Weather Deserves Medal for Clean Air During 2008 Olympics (Science Daily, Dec. 28, 2011)


And here: Impact of Changes in Transportation and Commuting Behaviors During the 1996 Summer Olympic Games in Atlanta on Air Quality and Childhood Asthma (9 page pdf,  Michael S. Friedman, Kenneth E. Powell, Lori Hutwagner, LeRoy M. Graham,W. Gerald Teague, Journal American Medical Association,  Feb. 21, 2001)


Credit for the surprisingly good air quality at the 2008 Beijing Olympics has been given to the Chinese government for various steps taken to reduce pollution sources, especially vehicle emissions, during and before the games- as they had been, with equally good health results, at the Atlanta, USA Games in 1996. A more detailed analysis of the added effect of meteorology, summarized in the article under review, shows that favourable winds and well-timed rainfall had at least as much to do with the  results. The lesson to be learned from this, especially for those cities with unhealthy air, with or without Olympic fever, is that major reductions in pollution and improvements in health are possible with enough government will to engage public support.


To see Key Quotes and Links to key reports about this post, click HERE

The State of Air Pollution in Europe

The European Environment – State and Outlook 2010 – Air Pollution (46 page pdf, European Environment Agency, 2010)

The report reviewed today is an overview of the progress (or lack of progress) being made or forecast in Europe to meet EU objectives. Clearly, the main challenge has to do with particulate matter and nitrogen dioxide and managing the main sources: hydro plants and transportation. One striking observation is that as electric vehicles are introduced to reduce urban emissions, rural areas may suffer as the sites of expanded electric generating utilities.

To see Key Quotes and Links to reports about this post, click  HERE

The Application of Air Quality Models in Europe

The application of models under the European Union’s Air Quality Directive: A technical reference guide  (76 page pdf, European Environment Agency, Sep. 2011)

Today’s focus is on the application of air quality models in Europe, noting the limitations and benefits of models in combination with ground-based or space-based monitors. There are several very useful tables showing the policy standards for a range of air pollutants for various applications and scales.

To see Key Quotes and Links to key reports about this post, click HERE

Particulate Hot-Spot Analyses

Transportation Conformity Guidance for Quantitative Hot-spot Analyses in PM2.5 and PM10 Nonattainment and Maintenance Areas (143 page pdf, Transportation and Regional Programs Division, Office of Transportation and Air Quality, U.S. Environmental Protection Agency, Dec. 2010)

Today’s focus is on a guide to analyse PM hotspots in order to assess non-compliance with federal air quality standards for emissions from roads and highways in the USA.

To see Key Quotes and Links to key reports about this post, click HERE

Climate Change, Air Pollution and Health in 21st Century

Climate Change Set to Increase Ozone-Related Deaths Over Next 60 Years, Scientists Warn (Science Daily, Sep. 27, 2011)

Today’s review post has a broad focus on the impact of climate change on health and, in particular, ozone-related deaths  in some European countries which may increase by 14% in the next 50 years.

To see Key Quotes and Links to key reports about this post, click  HERE

EPA Statement on Health Impacts from Roadside NO2 Emissions

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US Environmental Protection Agency- Six Common Pollutants, Nitrogen Dioxide, Health
The EPA’s summary of health impacts from exposure to nitrogen oxides (which also produce ozone with health impacts) is worth noting, especially the scale of the problem- affecting 16% of the entire  U.S. population who live within 300 ft of  transportation emissions from traffic- and the fact that these concentrations are underestimated by conventional air quality network monitors.

To see Key Quotes and Links to key reports about this post, click HERE

Reaching Climate Stabilization by Reducing Non-CO2 emissions

Non-CO2 greenhouse gases and climate change (Abstract, S. A. Montzka, E. J. Dlugokencky & J. H. Butler, Nature 476, 43–50, Aug.4, 2011)

Stabilizing climate change  requires reducing emissions from carbon fuels alone by almost 100%.  It is clear that even if the world found a way of doing this that it would not be achieved in a century or more- far too long to avoid the impacts from a changing atmosphere. The article reviewed today examines the non carbon gas emissions which have much shorter lifetimes in the atmosphere , contribute significantly to climate change and therefore represent an opportunity to reach stabilization more quickly than through  CO2 emission reductions alone.

To see Key Quotes and Links  to key reports about this post, click HERE

Monitoring Local Pollution Across Canada

Creating National Air Pollution Models for Population Exposure Assessment in Canada (7 Page pdf, Perry Hystad, Eleanor Setton, Alejandro Cervantes, Karla Poplawski, Steeve Deschenes, Michael Brauer, Aaron van Donkelaar, Lok Lamsal, Randall Martin, Michael Jerrett, and Paul Demers, Environmental Health Perspectives, volume 119, number 8, August 2011)

Today’s focus is on a study of how well the national air pollution network, supplemented by satellite data and regional land use regression modeling, can estimate local variability in 7 Canadian cities. Modelling improved the  prediction of variability of NO2 from 18% using standard interpolation to 43% with supplemental data and techniques.

NO2 model (0-105 ug/m3)                                                               0                    1,000 km (1 km resolution)

To see Key Quotes and Links to key reports about this post, click HERE

Can Simulation Modelling Steer Us toward Sustainability?

Cover of "The Limits to growth: A report ...

Cover via Amazon

Virtual Sustainability (16 page pdf, Sims Bainbridge, W. Sustainability 2010, 2, 3195-3210, Sep. 30,2010)

Models simulating  the ways that people interact with the natural world and themselves have long been used to create scenarios that allow environmental and economic policies to be tested. The World 2 model was developed Jay W. Forrester in 1970, using system dynamics techniques to examine global energy and consumption trends, and led to the “Limits to Growth” book from the Club of Rome. The article reviewed today takes that concept further by examining social interactions in an online multi-player environment to test such propositions as telecommuting.

To see Key Quotes and Links to key reports about this post, click HERE

Improving Knowledge and Communication for Decision Making on Air Pollution and Health in Europe


Today’s review article is a summary of the work of the Aphekom project in Europe over the last 3 years. It points to findings which show that living near busy roads (defined as those with typically more than 10,000 vehicles per day) present a significant health risk in terms of reduced life expectancy and health costs.

To see Key Quotes and Links to key reports about this post, click  HERE

Does the Charging of Hybrid Cars Produce Significant Pollution?

Air quality impacts of plug-in hybrid electric vehicles in Texas: evaluating three battery charging scenarios (12 page pdf, Tammy M Thompson, Carey W King, David T Allen and Michael E Webber, Environmental Research Letters, Volume 6, Number 2, Apr. 19, 2011)


Today’s focus is on the impact of the charging of hybrid cars on air quality because of emissions from the sources of electricity (at night) which would replace the emissions from the mobile sources mainly daytime. The modelling experiment took place in one of the states with higher levels of pollution. The conclusion appears to be that the shift does not have a significant impact on the environment.

To see Key Quotes and Links to key reports about this post, go to the new Internet platform for Pollution Free Cities by clicking HERE

Modelling Exposure to Health Risks from Air Pollution

Combining Regional- and Local-Scale Air Quality Models with Exposure Models for Use in Environmental Health Studies (12 page pdf, Vlad Isakov, Jawad S. Touma, and Janet Burke, Danelle T. Lobdell, Ted Palma, Arlene Rosenbaum, Haluk Ozkaynak, Journal of the Air & Waste Management Association, Vol. 59:461– 472, Apr. 2009)


Today’s focus is on ways of measuring the exposure of humans to air pollution and the models being used to assess the health risks, including the EPA’s Community-Focused Exposure and Risk Screening Tool (C-FERST), the Hazardous Air Pollutant Exposure Model [HAPEM] and the Stochastic Human Exposure and Dose Simulation [SHEDS] model. The noted links point to reports that describe how each functions. One conclusion is that the complex patterns and gradients in air pollution across a city requires more than one or two representative measurement points if one needs to adequately define the health risk to urban communities.

To see Key Quotes and Links to reports about this post, go to the new internet platform for Pollution Free Cities by clicking HERE

The Nitrogen Cycle

Reducing One’s ‘Nitrogen Footprint’: New Web-Based Tool Helps People Make Sustainable Living Choices (Science Daily, Feb. 22, 2011)


The natural equilibrium established between food creation and consumption is moderated by various forms of nitrogen in the land, air and water. Nitrogen also makes up the main emission from transportation and along with Particulate Matter is a major impact on health. By studying the nitrogen cycle as the review article today does, society can achieve this equilibrium in a sustainable way. The newly developed “N-Print” calculator provides a way for individuals to estimate their “Nitrogen Footprint” and find ways to reduce it, if need be.

To read more about this post and see Key Quotes and relevant reports on Pollution Free Cities new internet platform, click HERE

Short-Lived Pollutants and Climate Change

Tackling short-lived pollutants offers big benefits (Options, International Institute for Applied Systems Analysis/IIASA, Nov. 2010)

Also discussed here: Climate Change Strategy to Curtail Short-lived Pollutants (Pollution Free Cities, Dec. 15, 2010)

And here: The Impact of Short-Lived Pollutants on Arctic Climate (25 page pdf, Arctic Monitoring and Assessment Programme, Norway, Jan. 19, 2009)

And here: Sources and Mitigation Opportunities to Reduce Emissions of Short-term Arctic Climate Forcers (16 page pdf, Arctic Monitoring and Assessment Programme, Norway, Nov. 18, 2008)

Today’s review article from the International Institute for Applied Systems Analysis, one of the world’s leading think tanks in futures and modelling research on energy, resource consumption and environment issues for 40 years. The article evaluates the benefits of mitigating the impacts of climate change by reducing emissions of short –lived non CO2 greenhouse gases, such as black carbon particles and nitrous oxide. As these pollutants also have significant health impacts and arise mainly in urban areas from the transportation sector, reductions would not only delay the climate change in the short run, but also have direct health benefits.

Key Quotes:

“Tackling these short-lived climate forcers[black carbon (soot), tropospheric ozone, and methane]..could lead to quickly won benefits ranging from slowing the Arctic ice thaw to improved air quality leading to better health, particularly in developing countries.. reside for much less time in the atmosphere than CO2 yet exert significant warming effects at the regional scale”

“CO2 emissions stay in the atmosphere for over a hundred years..there will be a substantial time lag between measures the world takes today to cut CO2 and their impact on global warming”

“baseline emissions of non-CO2 GHGs will decline by 14 percent between 2005 and 2030”

“non-CO2 GHG emissions ..by 2030 can be reduced by up to 41 percent below the 2005 level through full application of currently available technical mitigation measures..one of the few options to prevent irreversible damage to sensitive ecosystems and changes in rainfall patterns in the near term”

“Although black carbon lasts only up to a few weeks in the atmosphere, its warming potential is about 700 times greater than CO2 during the 100 years following emission. Methane, with its warming effects around 25 times greater than CO2, has an atmospheric lifetime of only 10–12 years”

“If these 15 measures were aggressively implemented by 2030, they could reduce global methane emissions by up to 45 per cent, black carbon emissions by some 70 per cent, and carbon monoxide emissions by 55 per cent below our baseline projections”

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3D Forecasts of Air Quality – PREV’AIR

PREV’AIR -An Operational Forecasting and Mapping System for Air Quality in Europe (11 page pdf, Bulletin of American Meteorological Society, Jan. 2009)

Also discussed here: PREV’AIR

Key Quotes:

“[French] local authorities in charge of air pollution can now inform the public and take emergency decisions related to air pollution control not only on the basis of measurements, but also by accounting for numerical forecasts”

“three main functions of the PREV’AIR system:

  1. The “forecasting” function delivers forecasted atmospheric concentrations of ozone, particulate matter (PM10 and PM2.5), and nitrogen oxides, simulated throughout Europe at low resolution (0.5° × 0.5°) and over France with a higher resolution (0.15° × 0.1°).
  2. The “analysis” process uses available near-realtime observations to build the “analyzed” maps that are considered as the most realistic description of pollution patterns.
  3. The “performance evaluation” function of the system uses observation data that are routinely acquired for continuous evaluation of the model forecasts, with descriptive indicators given online. Every day, statistical skill scores (bias, errors, percentage of errors lower than a certain level, and correlation) are calculated and updated on the PREV’AIR Web site”

“In case of a pollution episode, when concentrations exceed the regulatory thresholds, PREV’AIR forecasts are broadcast on television channels to enhance public information.“

“system provides real-time information about air pollutant concentrations throughout Europe, with a focus on France, which is particularly relevant to health prevention in acute pollution episodes.“

“Air quality forecasting and mapping is an efficient tool for authorities in charge of air quality management. Anticipating pollution events with concentrations exceeding regulatory levels allows them to inform the general public and to decide emergency control measures.”

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Atmospheric Chemistry Processes in Smog Formation

Predicting Smoggiest Days: Experiments Improve Accuracy of Ozone Predictions in Air-Quality Models (Science Daily, Oct. 28, 2010)

Also discussed here: Rate of Gas Phase Association of Hydroxyl Radical and Nitrogen Dioxide (Abstract, Science, Vol. 330. no. 6004, pp. 646 – 649, Oct. 29, 2010)

Key Quotes:

“The reaction of OH and NO2 to form gaseous nitric acid (HONO2) is among the most influential in atmospheric chemistry….We demonstrate the impact of the revised value on photochemical model predictions of ozone concentrations in the Los Angeles airshed.”

“The key reaction in question in this research is between nitrogen dioxide and the hydroxyl radical.. Until about the last decade, scientists thought these two compounds only combined to form nitric acid, a fairly stable molecule with a long atmospheric life that slows ozone formation”

“researchers found the loss of hydroxyl radical and nitrogen dioxide is slower than previously thought-although the reactions are fast, fewer of the radicals are ending up as nitric acid than had been supposed, and more of them are ending up as peroxynitrous acid.”

“a small but significant impact on the predictions of computer models used to assess air quality, regulate emissions and estimate the health impact of air pollution,”

“the laboratory results suggest that, on the most polluted days and in the most polluted parts of L.A., current models are underestimating ozone levels by 5 to 10 percent”

“a 10 part-per-billion increase in ozone concentration may lead to a four percent increase in deaths from respiratory causes-any increase in expected ozone levels will be important to people who regulate emissions and evaluate health risks”

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Modelling Air Quality in an Urban Canyon

Estimation of CO concentrations for an urban street canyon in Ireland (8 page pdf, Air Quality, Atmosphere & Health, Mar. 5, 2010)

Today’s review article looks at the performance of two canyon air quality models – STREET and OSPOM – when compared with stationary monitor located near a busy roadway in Dublin. In addition an assessment is made using emission factors (HEF for hourly and CEF for Composite) to judge the models as to the emissions from the source

Key Quotes:

“The WHO has estimated that 1.4 billion urban residents in developing countries breathe air in which pollutant concentrations exceed WHO air quality guidelines (WHO 1992). Urban air pollution episodes are associated with sudden incidences of high concentrations of pollutants, which are generally governed by local meteorology, emissions and dispersion conditions (Mayer 1999). The major source groups responsible for urban air pollution are primarily motor traffic and industries”

“In most European cities, traffic is the most important source of air pollution, with the highest ambient concentrations often found on streets in urban centres. Vehicular pollution dispersion models are therefore essential computational tools for predicting the impacts of emissions from road traffic”

“two urban street canyon models, namely STREET and Operational Street Pollution Model (OSPM), were investigated at Pearse Street, an important traffic route in the centre of Dublin city

“Hourly background concentrations were obtained from an urban air quality monitoring station.. approximately 100 m from the nearest trafficked street. All this recorded parameters were used in computing the modelled CO concentrations. These were then compared with measured CO concentrations”

“An emission factor is the relationship between the amount of pollution produced and the amount of raw material processed or burned. For road traffic, it is the relationship between the amount of pollution produced and the number of vehicle kilometres travelled (grams per kilometre). By using the emission factor of a pollutant and specific data regarding quantities of materials used by a given source, it is possible to compute emissions for the source”

“This paper tries to highlight the STREET model as a suitable screening model for the prediction of CO concentrations in an urban street canyon. When compared with monitored data, concentrations calculated using STREET and OSPM both successfully predict observed variations in air quality”

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Neuro-fuzzy Urban Air Quality Modelling

Haze over Kuala Lumpur.
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Adaptive neuro-fuzzy modeling for prediction of ambient CO concentration at urban intersections and roadways (10 page pdf, Air Quality, Atmosphere & Health, May 19, 2010)

Modelling of urban air pollution has developed from purely statistical to deterministic but today’s article focuses on neuro-fuzzy techniques which bridges the use of “expert” modelling techniques from artifical intelligence research to estimate extremes as well as average concentrations- in this case, for carbon monoxide at the street/intersection level.

Key Quotes:

“There has been a substantial growth in road traffic over the years and that has resulted in increase in air pollution. In many cities across Europe, USA, Japan, China, and Singapore, vehicular exhaust emissions (VEEs) are now considered as one of the most important sources of urban air pollution”

“screening, assessment, and prediction of ambient air pollutant due to VEE in such urban corridors has become an essential requirement as a part of an efficient local/episodic urban air quality management plan”

“environmental damage is caused both by extreme as well as by the average concentrations of pollutants. Hence, the models should predict not only ‘extreme’ ranges but also the ‘middle’ ranges of pollutant concentrations, i.e., the entire range.”

“Two types of forecast models have been developed. The first model uses a fuzzy expert system and forecasts the possibility of high O3 concentration. The second model uses a neural network system to forecast daily maximum concentration of O3 on the following day”

“The fuzzy models are capable of analyzing linguistic information and efficiently carry out programming/processing with improved knowledge representation and uncertainty reasoning. In addition, the neuro-fuzzy modeling technique can interpret and analyze any kind of information (numeric, linguistic, and logical) and possesses self-learning, self-organizing, and self-tuning capabilities, thus improving the quality of forecasts. The present study was under taken to develop models for CO based on neuro-fuzzy approach for different seasons”


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Life-Cycle Assessment of Nanotechnology and Health

Jay Wright Forrester
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Sustainable Nanotechnology: Through Green Methods and Life-Cycle Thinking (16 page pdf, Sustainability 2010, 2(10), 3323-3338, Oct. 25, 2010)

Before futurist Jay W. Forrester at MIT, developed the “World” model for the Club of Rome in 1970, he focussed on the same Systems Dynamic approach by applying it to an urban setting.  Many years later, we are still learning that a cradle-to-grave approach is needed to build pollution-free sustainable cities, especially with the advent of electronic devices such as TVs and cell phones, whose lifetimes are measured in weeks or months. The result of this and even greater miniaturization is an ever growing mountain of highly toxic materials which form part of either urban waste centres or shipments to even bigger mountains in China, India and other countries, as discussed in this post E-Waste

The article reviewed today assesses the life cycle of nanotechnology with some interesting observations such as the need to identify health impacts as soon as possible in development of these devices.

Key Quotes
“Sustainability and futures studies are linked to each other; the time scales involved may be different from the individual viewpoints of stakeholders, depending on whether they are futurists environmentalists. Futures thinking calls for planning in the time scale of hundreds of years whereas the environmental research community may think in terms of a few decades at the most”

“the need to conduct ―life cycle-based assessments as early in the new product development process as possible, for a better understanding of the potential environmental and human health consequences of nanomaterials over the entire life cycle of a nano-enabled product”

“The wide-ranging applications of nanotechnology have an equally widespread potential to adversely affect human health and the environment, through various exposure routes of nanoparticles, including occupational exposure”

“nano-based products that seem environmentally preferable over other alternatives in the Use stage may not actually turn out to be so when the whole life cycle is considered”

“the effects on human health and the environment are characterized based on environmental loadings… calculated using formulas based upon quantities of pollutants discharged to air, water, and land.”

Risk Assessment goes from quantities of pollutants discharged to analyzing their effects under ambient conditions, through various exposure pathways”

“current Life-Cycle Assessment methodology, developed for use with conventional bulk materials, needs to be reconsidered and modified, if necessary, to make it suitable for evaluating nanomaterials”

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Exposure of Population to Air Pollution Near Major Roads in Europe

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Development of a methodology to assess population exposed to high levels of noise and air pollution close to major transport infrastructure (131 page pdf, European Commission-Entec UK Ltd, April 2006)

This key report from the European Commission examined various methods for estimating population exposure to air and noise pollution near roads, airports and railways.

Key Quotes:

“Assess the relevant information available in EU Member States on transport infrastructures and activities as well as evaluations of population at risk, due to population living close to transport infrastructure.. Major transport infrastructures have been defined as roads with more than 3 million vehicles per year..” < 3 M veh/yr is equivalent to 8,219 veh/day or 342 veh/hour>

“ stages to be completed to assess population exposure:

  • Define what is a “major” transport infrastructure
  • Locate “major” transport infrastructures within spatial area of interest based on definition
  • Define criteria for high levels of air and noise pollution from transport infrastructures
  • Identify areas of high levels of air and noise pollution in the vicinity of major transport infrastructures
  • Identify population exposed within area of high levels of air and noise pollution”

“the results show that in the EU25 Member States approximately 29% of the population live within 500 metres of a major road”

“For exposure to high levels of noise and air pollution the results suggest that .. population exposed to >1% of the NO2 limit value ..7.2% due to emissions from roads”

“By assuming that all population living within 10-20 metres of a major road (and possibly railway) is exposed to high levels of noise and air pollution should give a more accurate estimate of the overall exposure of the population, particularly with respect to urban areas where overall exposure is currently underestimated by using a European high level approach.”

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Modelling Urban Air Pollution Hot Spots

Modelling Urban Traffic Air Pollution Dispersion (The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Vol. XXXVII. Part B8. Beijing 2008)

The article being reviewed today addresses the need for local authorities to know the distribution of urban air pollution both in the horizontal, as reported in Ottawa Air Quality Information System and in the vertical. The result is a system which authorities can use to identify the extent of hot spots and potential health threats along roadways, as well as vertically in buildings along the road.

Key Quotes:

“The prime aim of this research is to support decision making, e.g., air quality impact analysis, human health assessment, through spatially modelling traffic-induced air pollution dispersion in urban areas at street level. “

“composed of basically three parts: an urban base data model, a dispersion model with a spatial database and a 3D GIS environment for visualisation. “

“local authorities are facing the challenge of being responsible for effective counter measures if limit values of air pollution are exceeded.. need ‘high-resolution’ information on air pollution levels that give not only the pollution levels for few measurement stations within a city (macro-level) but also pollution levels for the individual streets (micro-level). “

“Providing information about traffic air pollution and finding out its distribution is therefore a crucial starting point for planning effective measures to improve air quality…The location of hot spots of high pollution levels that exceed a certain threshold has besides a horizontal also a vertical dimension; the latter is usually neglected. ”

“a warning line that represents where pollution limit value is exceeded can be used to calculate the number of floors affected as well as allow an estimation of the number of influenced inhabitants. “

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Air Pollution, Sleeping Problems and Heart Disease

Age-standardised disability-adjusted life year...
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Associations of PM10 with Sleep and Sleep-disordered Breathing in Adults from Seven U.S. Urban Areas (1 page pdf Abstract, American Journal of Respiratory and Critical Care Medicine, May 27, 2010)
Also discussed here:
New Link Between Pollution, Temperature and Sleep-Disordered Breathing (Science Daily, June 14, 2010)
The link between air pollution and respiratory disease has been well established, as has the link with heart disease. The article under review today explores a particular aspect of heart disease related to air pollution’s impact on sleep quality.

Key Quotes:
“Researchers from Brigham and Women’s Hospital and the Harvard School of Public Health have established the first link between air pollution and sleep-disordered breathing (SDB), a known cause of cardiovascular diseases.. the link between air pollution levels, temperature increases and sleep-disordered breathing”

“SDB affects up to 17 percent of U.S. adults, many of whom are not aware that they have a problem. Air pollution is also an endemic issue in many of the nation’s urban areas

“Increases in apnea or hypopnea…were associated with increases in short-term temperature over all seasons, and with increases in particle pollution levels in the summer months.”

“…Poor sleep [associated with poor health outcomes] may disproportionately afflict poor urban populations. Our findings suggest that one mechanism for poor sleep and sleep health disparities may relate to environmental pollution levels.”

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Mapping Health Impacts of Urban Vehicle Emissions

Ottawa Air Quality Information System (1 page pdf,  Poster, 44th Annual Congress Canadian Meteorological and Oceanographic Society, Ottawa, June 2010)

The paper reviewed today is the result of development of satellite mapping of air pollutants carried out by A-MAPS Environmental as reported at the 2009 Annual Meeting of the American Meteorological Society Mapping Small Scale Air Pollution Distribution using Satellite Observations an a Large Canadian City and extensions to the mapping to incorporate health impacts of traffic by Risk Sciences International based on the Air Quality Benefit Assessment Tool, using concentration response functions developed by Health Canada in 2006, as described in AQBAT – Estimating Health Impacts for Changes in Canada’s Air Quality

This work was supported by funding from GeoConnections Program of Natural Resources Canada and the European Space Agency

or see  Ottawa Air Quality Information System-slideshow (10 page pdf)

Key Quotes

“This air quality information system is capable of displaying concentrations of NO2, NO, O3, PM2.5 and CO on an hourly basis for the 5,600 km2 area of the National Capital Region.”

“a graphical user interface was developed, enabling analyses of the data in terms of standard statistical and custom designed functions such as averaging, max, min, standard deviation, percentiles and critical pollutant level exceedances.“

“The Traffic Health Impact module is a user friendly software application capable of providing pollution consequences on population health (morbidity, mortality, hospitalisation, health cost“

“Highway 417 is closed for three days and traffic is diverted northeast (white arrows). The total health costs of this traffic diversion is then estimated using the health end points module, listing the impacts in terms of premature deaths, illnesses and costs in dollars.“

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Global Mortality Impact of Air Pollution

An Estimate of the Global Burden of Anthropogenic Ozone and Fine Particulate Matter on Premature Human Mortality using Atmospheric Modeling ( 36 page pdf, Environ Health Perspect, 09 April 2010)

A key reference and estimate of the overall impact of particulate matter and ozone on worldwide deaths.

Key Quotes

“estimate the global burden of mortality due to O3 and PM2.5 from anthropogenic emissions using global atmospheric chemical transport model simulations of preindustrial and present day (2000) concentrations to derive exposure estimates.”

“Using simulated concentrations rather than previous methods based on measurements allows the inclusion of rural areas where measurements are often unavailable and avoids making assumptions for background air pollution.”

“While O3 and PM2.5 concentrations have increased most in industrialized areas, observations show that background concentrations have also increased in remote regions“

“PM2.5 mortality estimates are about 50% higher than previous measurement-based estimates based on common assumptions”

“Estimated PM2.5 mortalities are five times O3 mortalities, suggesting PM2.5 is the dominant contributor to the global health burden of outdoor air pollution.“

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Secondary Organic Aerosols

OnAir: Research Underdogs Fill Atmospheric Blind Spot (EPA Greenversation, Apr. 6, 2010)

Also discussed here: Carnegie Mellon Researchers Urge Regulators To Rethink Strategies for Controlling Soot Emissions (Carnegie Mellon News, Mar 1, 2007)

And here: The Missing Source of Secondary Organic Aerosols (SOAs) (Science Quick Picks, Mar. 7, 2007)

Key Quotes:

“What we actually observe in the atmosphere is a factor of 3 – 100 times more than the SOA traditional models predict,”

“new chemical processes that occur after soot and gaseous pollutants are emitted from cars and trucks, changing the chemical and physical properties of the soot particles and creating new particulate matter.”

” this chemical processing leads to more particulate matter in the air, meaning that regulators are likely underestimating how sources such as cars and trucks contribute to pollution,”

“A second important finding is that the properties of this new particulate matter are different than we previously thought and potentially more toxic”

“We’re seeing that urban pollution doesn’t stay contained in the cities, but impacts rural and other downwind areas, creating even more complicated issues for regulators,”

“For the longest time, particulate matter has been the least understood component of the climate system.”

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Air Pollution – Health Effects Methodology

Air pollution
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Case-Crossover Analysis of Air Pollution Health Effects: a Systematic Review of Methodology and Application (47 page pdf, Environ Health Perspect, 31 March 2010)

Key Quotes:

“systematic review of case-crossover (CCO) designs used to study the relationship between air pollution and morbidity and mortality, from the standpoint of methodology and of application..first systematic review to cover the application of case-crossover designs to the study of the health effects of air pollution.“

“The dependent variables most frequently analyzed were those relating to hospital morbidity, while the pollutants most studied were those linked to particulate matter.“

“The papers published by Lee et al. (1999) and Neas et al. (1999) were the first studies to report the relationship between air pollution and mortality, using a CCO design. These studies performed a re-analysis of the effects of air pollution and mortality in the cities of Philadelphia and Seoul, respectively, obtaining a relationship that proved statistically significant.“

“The use of CCO designs has undergone considerable growth, with the most widely used designs being those that yield better results in simulation studies, namely, symmetric bidirectional and time-stratified CCO”

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Monitoring Population Exposure to Particulate Matter from Satellite

Global Estimates of Ambient Fine Particulate Matter Concentrations from Satellite-based Aerosol Optical Depth: Development and Application (33 page pdf, Environmental Health Perspectives, 16 March 2010)

Key Quotes:

“Global ground-level PM2.5 concentrations were mapped using total column aerosol optical depth (AOD) from the MODIS and MISR satellite instruments and coincident aerosol vertical profiles from the GEOS-Chem global chemical transport model.”

“Global aerosol observations from satellite could substantially improve estimates of population exposure to PM2.5….a long-term PM2.5 exposure decrease of 10 μg/m3 increases life expectancy by 0.61 ± 0.30 years for the United States.“

“Eastern and central Asia have the highest levels of PM2.5 concentrations with 38-50% of the regional population exceeding the WHO Air Quality Interim Target-1..of 35 μg/m3.. Globally 80% of the population lives in regions that exceed the Air Quality Guideline”

“Our estimates suggest the global population-weighted geometric mean PM2.5 concentration is 20 μg/m3 and that 80% of the global population resides in locations where ambient concentrations exceed the WHO Air Quality Guideline of 10 μg/m3.“

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Can Highway Barriers Contain Pollution from Traffic?

Tracer studies to characterize the effects of roadside noise barriers on near-road pollutant dispersion under varying atmospheric stability conditions (Atmospheric Environment, Volume 44, Issue 2, January 2010, Pages 204-214)

Discussed here: Highway Barriers Stifle Sound, Sight, and Soot (Science Daily, Jan. 5, 2010)

Also discussed here Highway Barriers Stifle Pollution (the earthy report, Jan. 8,2010)

Key Quotes:

“to systematically and comprehensively investigate the role of atmospheric stability in real world conditions on the movement of pollutants near highway barriers”

“the barriers ..reduce high concentrations of pollutants from those vehicles by lifting and channeling them away from the adjoining areas, often a residential area,”

“Researchers were able to conduct tracer studies in unstable, neutral and stable atmospheric conditions in tightly controlled circumstances, to quantify the effects of roadside barriers on pollutant dispersion”

“We also found that the barriers tended to trap pollutants in the area of the roadway itself, especially at night in low wind speed conditions.. The amount of pollutants was much higher on roadway areas flanked by barriers than in areas without them.”

“The study did not assess the impact on drivers who are exposed to higher levels of pollutants while driving through these barriers”

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Satellite-based Estimates of Aerosol Optical Depth and Particulate Matter

What Can Affect AOD–PM2.5 Association? ( 2 page pdf, Environ Health Perspect,  Mar.1, 2010)

Also discussed here:

Limitations of Remotely Sensed Aerosol as a Spatial Proxy for Fine Particulate Matter (6 page pdf, Environ Health Perspect, June 2009)

Key Quotes:

“The columnar measurement of AODS consists of aerosols generated by anthropogenic (human) sources …is influenced by moving large air masses and observes a strong spatial and temporal structure.”

“The concentration of PM2.5, however, can vary significantly within short distances. Therefore, there is a significant mismatch in the magnitude and extent of spatial and temporal variability of AODSn and AODS”

“Recent literature suggests that 1-km and 5-km AODS observe a significantly better association with PM2.5 monitored on the ground than the 10-km AODS”

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Traffic Air Pollution, Asthma and Standards

Road-traffic pollution and asthma – using modelled exposure assessment for routine public health surveillance (International Journal of Health Geographics 2004, 3:24)

This article describes well the monitoring and modelling of roadside air pollution in the UK and how this links to public health policy at the municipal level.

Key Quotes:

“Air Quality Strategy for England, Scotland, Wales and Northern Ireland published in January 2000.. sets standards and objectives for ten pollutants that have an adverse effect on human health, vegetation or ecosystems and target dates for achieving them.. now include benzene, 1,3 butadiene, carbon monoxide, lead, NO2, PM10, SO2, ozone (O3), NOx and polycyclic aromatic hydrocarbons. The predominant source of most of these pollutants is road traffic, but industrial and domestic sources are also contributors.”

“Government has issued guidance to local authorities on how to conduct Reviews and Assessments required under the system of Local Air Quality Management (LAQM).. Part IV of the Environment Act 1995 requires a local authority to designate an Air Quality Management Area (AQMA) covering any part of its administrative area where air quality objectives are not likely to be achieved.. For each AQMA the local authority has a duty to draw up an Air Quality Action Plan (AQAP) setting out the measures the authority intends to introduce to deliver improvements in local air quality”

“As of June 2004, there were 120 designated AQMAs in the UK, with 80 AQAPs produced outlining how air quality would be tackled in these areas.”

“A routine surveillance system recording spatial variation in pollutant levels would allow improved understanding of the link between road-traffic pollution and asthma, ..The results of such assessment would allow local policy decisions concerning the routing of traffic around residential areas or schools and plans to reduce congestion to be made with knowledge of the implications of the decision on the health of the local population. It would also allow systematic monitoring of the health impacts when the policy decisions and plans have been implemented.”

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Modelling Energy Use in Cities

Urban Form, Behavior Energy Modeling in China: Sim City for Real? (Green Flow, Feb. 16, 2010)

The application of urban simulation modelling to the development of new cities in China and an assessment of energy, water and emissions over varying conditions of time of year permits urban planners to find solutions that reduce pollution, while optimizing the resources needed to run the cities.

Key Quotes:

“One of the great challenges in urban planning and green building has been material life cycle energy use”

“myriad consequences on life-cycle energy use that arise from commuting and transit choices, food and product consumption, and building heating or cooling.”

“has integrated building life-cycle assessment (LCA) and urban form agent-based modeling tools to capture embodied, operational and behavioral aspects of urban form energy use and emissions”

“Simulations ran through the four seasons, showing cumulative energy use based on household and individual appliance and transportation use, showing cars or buses shuttling between supermarkets, offices, schools and the Lu Jing Superblock”

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Forecasting Air Pollution with Artificial Neural Networks

3-Day-Ahead Forecasting of Regional Pollution Index for the Pollutants NO2, CO, SO2, and O3 Using Artificial Neural Networks in Athens, Greece (15 page pdf, Water Air Soil Pollut, 29 Aug 2009)

Key Quotes:

The goal of this study is the construction of models, using ANNs, which give the possibility of forecasting the maximum daily value of an ambient air pollution index for NO2, CO, SO2, and O3, for seven different measuring sites of Greater Athens Area (GAA) and for the next three consecutive days, as well as the daily number of consecutive hours with the pollutants above a threshold concentration.

ANNs are a branch of artificial intelligence developed in the 1950s aiming at imitating the biological brain architecture. They are parallel-distributed systems made of many interconnected nonlinear processing elements (PEs), called neurons

we created two different ANNs. The first one (ANN#1) was trained in order to forecast the daily maximum value of the ERPI (for the pollutants CO, NO2, SO2, and O3) for seven different measuring sites in GAA, at the same time, 3 days ahead. The second one (ANN#2) was trained in order to forecast the number of the hours, during the day, with at least one of the pollutants concentrations (CO, NO2, SO2, and O3) above a threshold according to directives of European Union,

The models ability to predict reliably 3 days ahead, the excesses or non-excesses days (days with the limit value of ERPI50), for the year 2005, according to the values of the success index ranges between 84.6% (Liossia 3-day-ahead prediction) and 92.2% (Patission 1-day-ahead prediction).

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New York City Community Air Survey

New York City Community Air Survey: Results Winter 2008-2009 (38 page pdf)

– the first community air survey in the USA (or as far as I know Canada) has just been published for the time of year when urban air quality usually is poorest and when the major sources (vehicle emissions and heating emissions) are greatest with key meteorological factors (inversions due to surface cooling and light winds) also contributing

Key Quotes:

“the New York City Community Air Survey (NYCCAS)… involves measurements of street-level concentrations of combustion-related air pollutants shown to impact public health. Measurements are collected, at 150 locations throughout the city, in each season of the year”

“NYCCAS data quantify, for the first time, the extent to which some areas of the city may have higher average pollution levels than other areas.”

“Despite improvements, NYC PM2.5 and ozone levels continue to exceed clean air

Nitrogen dioxide (NO2): Across all wintertime sampling sessions and sites, NO2 averaged about 32 ppb, but varied greatly across NYCCAS sites throughout the city (from less than 10 to almost 80 ppb.”

“NO2 concentrations were higher for monitoring sites located along bus routes. Monitors on bus routes had NO2 concentrations that were 4.8 ppb higher, on average, relative to non-bus route sites, after adjusting for effects of time, buildings, and general traffic.”

“The map in Figure SO2-4 depicts model-predicted wintertime average SO2
concentrations across New York City. Concentrations are estimated to be higher in more built up parts of the city where there are more residual oil-burning units, including much of Manhattan and parts of the Bronx, Queens and Brooklyn, compared to less-densely built up areas. Unlike the other pollutants, SO2 is not strongly associated with roadway traffic patterns. ”

“NYCCAS data indicate that concentrations within the city vary substantially from place to place. This geographic variation in exposure, as well as geographic variation in population susceptibility to air pollution — which varies with age, health conditions, health care access, and other factors — likely contributes to population differences in the prevalence and severity of air pollution–related illness.”

Other comments on this report at Posh Upper East Side has some of city’s most polluted air: survey (NYC Daily News)

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El Nino, Snowfall and Air Quality

It is often observed that the air quality for a month or season is better when there is above average precipitation which removes the pollutants from the lower atmosphere.  The converse would be true as well with low precipitation associated with poorer air quality.  The problem is that quantitative precipitation forecasts are difficult to get right for more than a few days in advance.  For month or season ahead projections, the best that can be done is an estimate of the anomaly – and even this is only of marginal accuracy.   On the positive side, during El Nino years, changes produced in the atmospheric circulation by prolonged sea surface temnperature anomalies also persist and these have quantitative impacts on regional temperature and precipitation over North America – and typically winter temperatures are above normal.  This year, a relatively strong El Nino is in progress and its impact on the coming winter weather can be estimated, however crudely.

The most recent measurements of sea surface temperatures for the last week of November  from NOAA is shown here (notice the band of above normal temperatures at the equator stretching form the dateline to Peru):

Reference:  El Niño/La Niña Home (Climate Prediction Center, NOAA)

A recent article  Trends in Twentieth-Century U.S. Extreme Snowfall Seasons (Journal of Climate, Dec, 2009), looks at the relationship between El Nino and extreme winter snowfall across the USA over the last century.

Key Quotes:

“In almost all regions of the United States, temperature during November–March is more highly correlated than precipitation to the occurrence of extreme snowfall years”

El Niño events are strongly associated with an increase in low-extreme snowfall years over the United States as a whole, and in the northwest, northeast, and central regions. ”

Going out on a limb,  one might expect to see warmer conditions than normal across North America this coming winter, along with extremely low snowfall in locations where the temperature anomalies are greatest- and as a result, poorer air quality can be expected in the same locations.

Let’s check back next spring and see how it turned out.

Meanwhile here is the latest outlook from Environment Canada:

Forecast predicts less snow in Canada this year (CTV news and video)

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Lightning NOx Production in Thunderstorms

“Of all the sources of tropospheric NOx the one with the greatest uncertainty is that due to lightning”, a quote noted almost a decade ago in this paper: A cloud-scale model study of lightning-generated NOx in an individual thunderstorm during STERAO-A (16 page pdf).

New research this year, based on satellite (OMI) and actual measured data, reduced this uncertainty somewhat and points to reasons why NOx measurements are lower than expected in areas with thunderstorms and lightning, as well as being a positive feedback for climate change – impacts that are being incorporated into air quality models because they may affect local compliance to air quality standards.

Lightning\’s \’NOx-Ious\’ Impact On Pollution, Climate (Science Daily)

Key Quotes:

“In 1827, the German chemist Justin von Liebig first observed that lightning produced NOx — scientific shorthand for a gaseous mixture of nitrogen and oxygen that includes nitric oxide (NO) and nitrogen dioxide (NO2)”

“When the researchers multiplied the number of lightning strokes worldwide by 7 kilograms, they found that the total amount of NOx produced by lightning per year is 8.6 terragrams, or 8.6 million metric tons”

“since most lightning is intracloud, this suggests a great deal more NOx is produced and remains higher in the atmosphere. Compounding this effect, the research also shows that strong updrafts within thunderstorms help transfer lower level NOx to higher altitudes in the atmosphere.”

“lightning could produce a feedback cycle that accelerates global warming. “If a warming globe creates more thunderstorms,” Pickering noted, “that could lead to more NOx production, which leads to more ozone, more radiative forcing, and more warming,” ”

“”Lightning is one of the smaller factors for surface ozone levels, but in some cases a surge of ozone formed from lightning NOx could be enough to put a community out of compliance with EPA air quality standards during certain times of the year,”

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The benefits of reducing 1 ton of air pollution

The influence of location, source, and emission type in estimates of the human health benefits of reducing a ton of air pollution (8 page pdf)

Key Quotes

“The benefit per ton ($/ton) of reducing PM2.5 varies by the location of the emission reduction, the type of source emitting the precursor, and the specific precursor controlled. This paper examines how each of these factors influences the magnitude of the $/ton estimate.”

“This heterogeneity is a product of source location, meteorology, mix of pollutants emitted, and atmospheric conditions, including baseline atmospheric concentrations of pollutants.”

“Three inter-related sources of heterogeneity affect the magnitude of PM2.5 $/ton estimates.

The first relates to the chemical processes that govern the formation of PM2.5 in the atmosphere….

The second source of heterogeneity relates to the characteristics of the emitting source…

The third factor that may influence the heterogeneity in PM2.5-related $/ton estimates is the size of the population exposed to PM2.5 and the susceptibility of that population to adverse health outcomes.”

“It should be noted that, while NOx reductions may occasionally generate PM2.5 disbenefits in certain urban areas, because NOx is also an O3 precursor, additional NOx reductions—even in areas where PM2.5 disbenefits are possible—may produce a downwind O3 benefit.”

“The PM2.5 $/ton estimates in this paper reflect three principal sources of heterogeneity:

Variability across precursors. The $/ton for certain pollutants, such as directly emitted PM2.5, is much higher than others…

Variability across sources. Certain sources may emit a common precursor, but may produce very different $/ ton estimates…

Variability across location. The $/ton for a given pollutant showed some degree of variation based on the urban area in which the pollutant was emitted.”

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The Greenhouse Effect (1896)

On the Influence of Carbonic Acid in the Air upon the Temperature of the Ground (22 page pdf)

“Arrhenius’s paper is the first to quantify the contribution of carbon dioxide to the greenhouse effect and to speculate about whether variations in the atmospheric concentration of carbon dioxide have contributed to long-term variations in climate”

Arrhenius estimated that if the combustion of fossil fuels were to result in a doubling of atmospheric CO2 levels, global temperatures could rise 5 deg. C,  just a little more than recent estimates over 100 years after his research was published.

Svante Arrhenius was the first Swede to win the  Nobel prize in chemistry in 1903.

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Canyons Up the Pollution Ante

Canyons Up the Pollution Ante (EHP online)

Key Quotes:

“The combination of high population density and high traffic volume in urban areas such as New York City means that the health impact of traffic pollution can potentially be much larger than similar sources in less populated areas,”

“Street canyons can exacerbate the health impact of traffic pollutants, hence the need to understand their dispersion dynamics.”

Additional reference:

Factors influencing the spatial extent of mobile source air pollution impacts: a meta-analysis ( 11 page pdf)


“concerns the concept of “hot spots”, or more broadly, the “spatial extent” of impacts from traffic-related air pollutants.”

“pollutant characteristics and background concentrations best explained variability in previously published spatial extent estimates, with a modifying influence of local meteorology, once some extreme values based on health risk estimates were removed from the analysis.”

“provided that a health risk threshold is not imposed, the spatial extent of impact for mobile sources reviewed in this study is on the order of 100–400 m for elemental carbon or particulate matter mass concentration (excluding background concentration), 200–500 m for nitrogen dioxide and 100–300 m for ultrafine particle counts.”

“our findings emphasize that policymakers should be able to develop reasonable estimates of the “zone of influence” of mobile sources”

ny canyon

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Air Pollution Worse On One Side Of The Street

Air Pollution Worse On One Side Of The Street (Science Daily)


Key Quotes:

“air pollution levels change dramatically within small geographical areas dependent on wind patterns, the location of traffic queues and the position and shapes of the surrounding buildings”

“pollution hotspots tend to accumulate on the leeward side of the street, (the sheltered side) in relation to the wind’s direction at roof-top level”

“the leeward side of the street had consistently higher concentrations of carbon monoxide than the windward side. The same trends would be expected for other traffic related pollutants such as ultrafine particles and nitrogen dioxide.”

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