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Global dimming: Air pollution clogging skies worldwide
 By Doyle Rice, USA TODAY
photo By Frederic J. Brown, AFP/Getty
The sun rises over polluted skies in Beijing in 2008. Skies in South Asia have grown progressively dimmer over the past three decades due to air pollution
Air pollution has caused skies above most of the world's land areas to dim slightly over the past 30 years, says a study out today in the journal Science.
Scientists found that most of the blame for the dimming can be traced to aerosols — suspended airborne pollution — that are released from the burning of fossil fuels, especially coal and other fuels that release sulfur dioxide. Aerosols in the atmosphere block sunlight from reaching the Earth's surface.
The dimming has been nearly worldwide:
The authors write that while visibility worsened only slightly in North America, it "decreased substantially over south and east Asia, South America, Australia, and Africa, resulting in net global dimming over land."
Europe, however, has actually experienced brightening skies, the authors say, where visibility has increased since the mid-1980s. This is due to declines in pollution over that continent, likely due to controls on using sulfur in coal, according to study co-author Robert Dickinson of the University of Texas.
When averaged globally, the dimming has been rather subtle, akin to a 100-watt bulb dimming only to a 99-watt bulb. But it has been more noticeable in the most polluted locations.
The research was conducted by Dickinson and Kaicun Wang and Shunlin Liang of the University of Maryland. Wang and his team used a database from the National Climatic Data Center in Asheville, N.C., to collect visibility measurements from 3,250 meteorological stations worldwide from 1973 to 2007.
While decreases in atmospheric visibility have been reported in the past, the new study compiles satellite and land-based data for a longer period than had been available.
Some are unsure of their findings: Ellsworth Dutton, a scientist at NOAA's Earth System Research Laboratory in Boulder, Colo., wrote in an e-mail that the locations of the weather stations, which in many cases are near population centers, do not represent the entire land area distribution of the planet.
"Also, their methodology does not account for any changes in aerosols above the lowest 10 or so meters of the atmosphere, which can be strongly affected by rain and wind," writes Ellsworth.
While the effects of increased greenhouse gases (such as carbon dioxide) on global warming are clear, the effects of increased aerosols are not, the scientists report. Studies of the long-term effects of aerosols on climate change have been largely uncertain up to now, due to limited aerosol measurements over land, Wang and his team say.
However, with this study, Wang says researchers now can compare temperature, rainfall and cloud cover data from the past 35 years with the aerosol measurements in the new database. Wang says "this is the first time we have gotten global long-term aerosol information over land to go with information already available on aerosol measurements over the world's oceans."
Contributing: Associated Press
Los Angeles had the second highest ozone level among 96 metropolitan areas studied over an 18-year period by a California researcher.
USA TODAY file photo
Ozone pollution amplifies risk of fatal respiratory illnesses
By Liz Szabo, USA TODAY
For the first time, a large study shows the deadly effects of chronic exposure to ozone, one of the most widespread pollutants in the world and a key component of smog, according to a study in today's New England Journal of Medicine.
Doctors have long known that ground-level ozone — which is formed when sunlight interacts with pollution from tailpipes and coal-burning power plants — can make asthma worse. This study, which followed nearly 450,000 Americans in 96 metropolitan areas for two decades, also shows that ozone increases deaths from respiratory diseases.
OZONE LEVELS:
This ground-level ozone has very different effects than the ozone layer high above the Earth, which helps filter out harmful ultraviolet radiation, says lead author Michael Jerrett, an associate professor of environmental health sciences at the University of California-Berkeley.
Although Jerrett found there was no safe level of ground-level ozone, some cities fare worse than others. People in Riverside, Calif., the highest ozone city, were 32% more likely to die in a given year of respiratory diseases compared with people in San Francisco, the city with lowest average annual ozone concentrations.
Ozone pollution likely translates into thousands of additional deaths every year across the USA, Jerrett says. About 240,000 Americans a year die of respiratory illnesses.
Controlling ozone — one of the main greenhouse gases involved in global warming — may both save lives and also fight global climate change, Jerrett says.
The study shows yet another way that air pollution can harm public health, says Janice Nolen, assistant vice president of national policy and advocacy for the American Lung Association.
"It doesn't have to be a peak ozone day to be a problem," says Nolen, who wasn't involved with the new study. "If you're breathing it day in and day out over a longer period of time, the risk of premature death increases."
The study also suggests the Environmental Protection Agency may need to reconsider its safety standard for ozone, Nolen says. Instead of just looking at the effect of being exposed to peak ozone levels, the agency may need to look at long-term exposure to lower levels of the gas.
Last year, the EPA changed its air quality standards for ground-level ozone from an average of 84 parts per billion to 75 parts per billion over an eight-hour period, although the agency's scientific advisers had urged an even tougher standard of 60 to 70 parts per billion.
One in three Americans lives in a city that's in violation of the EPA's current ozone standard, Jerrett says.
President Obama's new EPA chief, Lisa Jackson, told USA TODAY last month that the agency should reconsider the ozone standard. "We need to go back to the basics here: science and the law," she said.
Contributing: Traci Watson
Ozone levels
An 18-year study finds that long-term exposure to ozone raises the risk of dying from respiratory problems.
Of 96 metro areas studied, those with the highest levels (in parts per billion):
RANK CITY STATE Ozone levels, in parts per billion
1
|
San Francisco
|
CA
|
33
|
 |
2
|
Salinas-Seaside-Monterrey
|
CA
|
41
|
 |
3
|
Portland
|
OR-WA
|
41
|
 |
4
|
Seattle-Everett
|
WA
|
41
|
 |
5
|
Fort Lauderdale-Hollywood
|
FL
|
42
|
 |
6
|
Corpus Christi
|
TX
|
42
|
 |
7
|
Tacoma
|
WA
|
43
|
 |
8
|
Vallejo-Fairfield-Napa
|
CA
|
45
|
 |
9
|
Minneapolis-St.Paul
|
MN-WI
|
48
|
 |
10
|
Portsmouth-Dover-Rochester
|
NH-NE
|
50
|
 |
11
|
Chicago
|
IL
|
51
|
 |
12
|
Utica-Rome
|
NY
|
51
|
 |
13
|
Flint
|
MI
|
51
|
 |
14
|
Madison
|
WI
|
51
|
 |
15
|
Lansing-East Lansing
|
MI
|
51
|
 |
16
|
Orlando
|
-
|
52
|
 |
17
|
New Orleans
|
LA
|
52
|
 |
18
|
Kansas City
|
MO
|
52
|
 |
19
|
San Jose
|
CA
|
52
|
 |
20
|
Wichita
|
KS
|
52
|
 |
21
|
San Antonio
|
TX
|
52
|
 |
22
|
Colorado Springs
|
CO
|
52
|
 |
23
|
Detroit
|
MI
|
52
|
 |
24
|
Charleston-North Charleston
|
SC
|
53
|
 |
25
|
Portland
|
ME
|
53
|
 |
26
|
Tampa-St Petersburg-Clearwater
|
FL
|
54
|
 |
27
|
Worcester
|
MA
|
54
|
 |
28
|
Rochester
|
NY
|
54
|
 |
29
|
Jacksonville
|
FL
|
54
|
 |
30
|
Syracuse
|
NY
|
54
|
 |
31
|
Milwaukee-Waukesha
|
WI
|
55
|
 |
32
|
Gary-Hammond-East Chicago
|
IN
|
56
|
 |
33
|
Springfield-Chicopee-Holyoke,MA
|
-
|
56
|
 |
34
|
Nassau-Suffolk
|
NY
|
56
|
 |
35
|
Providence
|
RI
|
56
|
 |
36
|
Jackson
|
MS
|
56
|
 |
37
|
Nashville-Davidson
|
TN
|
56
|
 |
38
|
New York
|
NY-NJ
|
56
|
 |
39
|
Columbus
|
OH
|
57
|
 |
40
|
South Bend
|
IN
|
57
|
 |
41
|
Greeley
|
CO
|
57
|
 |
42
|
Toledo
|
OH-MI
|
57
|
 |
43
|
Cleveland
|
OH
|
57
|
 |
44
|
Racine
|
WI
|
57
|
 |
45
|
Oklahoma City
|
OK
|
57
|
 |
46
|
Steubenville-Weirton
|
OH-WV
|
57
|
 |
47
|
El Paso
|
TX
|
57
|
 |
48
|
Charleston
|
WV
|
57
|
 |
49
|
Kenosha
|
WI
|
58
|
 |
50
|
Pittsburgh
|
PA
|
58
|
 |
51
|
Youngstown-Warren
|
OH
|
58
|
 |
52
|
Johnstown
|
PA
|
58
|
 |
53
|
Tucson
|
AZ
|
59
|
 |
54
|
Little Rock-North Little Rock
|
AR
|
59
|
 |
55
|
Harrisburg
|
PA
|
59
|
 |
56
|
Lexington-Fayette
|
KY
|
59
|
 |
57
|
St. Louis
|
MO-IL
|
59
|
 |
58
|
Shreveport
|
LA
|
59
|
 |
59
|
New Haven-West Haven
|
CT
|
59
|
 |
60
|
Evansville
|
IN-KY
|
60
|
 |
61
|
Newark
|
NJ
|
60
|
 |
62
|
York
|
PA
|
60
|
 |
63
|
Huntington-Ashland
|
WV-KY-OH
|
60
|
 |
64
|
Reading
|
PA
|
60
|
 |
65
|
Denver
|
CO
|
60
|
 |
66
|
Indianapolis
|
IN
|
61
|
 |
67
|
Roanoke
|
VA
|
61
|
 |
68
|
Dayton
|
OH
|
61
|
 |
69
|
Lancaster
|
PA
|
61
|
 |
70
|
Jersey City
|
NJ
|
62
|
 |
71
|
Washington
|
DC-MD-VA
|
62
|
 |
72
|
Dallas
|
TX
|
62
|
 |
73
|
Hamilton-Middletown
|
OH
|
62
|
 |
74
|
Las Vegas
|
NV
|
62
|
 |
75
|
Columbia
|
SC
|
63
|
 |
76
|
Cinncinnati
|
OH-KY-IN
|
63
|
 |
77
|
Norfolk-Virginia Beach-Portsmouth
|
VA-NC
|
63
|
 |
78
|
Greensboro-Winston Salem-High Point
|
NC
|
63
|
 |
79
|
Memphis
|
TN-AR-MS
|
63
|
 |
80
|
Knoxville
|
TN
|
64
|
 |
81
|
Wilmington
|
DE-NJ-MD
|
64
|
 |
82
|
Philadelphia
|
PA-NJ
|
64
|
 |
83
|
Phoenix
|
AZ
|
64
|
 |
84
|
Greenville-Spartanburg
|
SC
|
64
|
 |
85
|
Houston
|
TX
|
65
|
 |
86
|
Raleigh-Durham-Chapel Hill
|
NC
|
65
|
 |
87
|
Richmond
|
VA
|
65
|
 |
88
|
Sacramento
|
CA
|
65
|
 |
89
|
Chatanooga
|
TN-GA
|
65
|
 |
90
|
San Diego
|
CA
|
66
|
 |
91
|
Trenton
|
NJ
|
66
|
 |
92
|
Charlotte-Gastonia
|
NC
|
66
|
 |
93
|
San Buenoventura (Ventura)
|
CA
|
75
|
 |
94
|
Fresno
|
CA
|
76
|
 |
95
|
Los Angeles-Long Beach
|
CA
|
91
|
 |
96
|
Riverside-San Bernardino-Ontario
|
CA
|
104
|
 |
Source: Michael Jerrett,University of California-Berkeley
Canada Launches Air Quality Health Index
Culled from Netscape.com
Article Date: 10 Jul 2007
Canada's new government and the state government of Ontario yesterday announced they were establishing the world's first National Air Quality Health Index (AQHI) with the launch of an 18-month pilot programme in Toronto. The programme will receive an investment of 30 million dollars and will serve as a model for rolling out to the rest of the country.
The AQHI gives a number between 1 and 10 (and occasionally may show as 10+) that rates air quality according to risk to health.
According to the World Health Organization (WHO), 800,000 people die worldwide (1.4 per cent of all deaths) because of urban outdoor air pollution. In Canada, 5,900 deaths a year are linked to urban air pollution in 8 Canadian cities, and scientists suspect that poor air quality is also linked to thousands of Canadians being admitted to hospital every year.
The AQHI pilot was announced in Toronto by John Baird, Minister of the Environment and Tony Clement, Minister of Health together with representatives of Toronto Public Health.
Speaking on CTV Newsnet yesterday, Health Minister Clement said that the AQHI is:
"Basically a tool that people can use to ensure that they know the health impacts on a particular day of the amount of pollutants in the air."
Environment Minister Baird said in a prepared statement that:
"We promised Canadians we would clean up the air we breathe and improve our health."
"Our investment in this personal health protection tool will provide Canadians with current and forecasted local air quality information that they can use to take actions to reduce risks posed by air pollution," he added.
Speaking at a news conference yesterday, Toronto's Medical Officer of Health, Dr David McKeown said that:
"Air quality affects different people in different ways. Healthy individuals may not notice poor air quality when it happens, where as those with particularly severe breathing and heart problems can be very sensitive to bad air."
Canada's AQHI is the world's first index to show the health risks associated with the mix of pollutants present in air and to give health advice to reduce the risk.
"Air pollution has been linked to illness and death and particularly impacts our children, our elderly and people with heart and lung disease," said Minister Clement.
The federal funding of 30 million dollars will be spread over the next four years to roll out the AQHI to medium and large communities across the country. Municipal and provincial partnerships will be key to the program's success say the government.
The Toronto pilot project is based on successful pilots in Nova Scotia and British Columbia. Over the coming years, Environment Canada will improve its air quality forecasting capacity across the country.
The AQHI is one of a series of measure the new government of Canada has pledged to introduce to fight air pollution. In April it launched Turning the Corner: An Action Plan to Reduce Greenhouse Gases and Air Pollution under which industry will be required to halve air pollution by 2015.
Depending on how long you are exposed to air pollution, and how healthy you are, your genetic background and the quality of the air, air pollution can make it harder to breathe, irritates your eyes nose and throat, and worsens conditions like bronchitis, emphysema and asthma. It can also cause heart attacks, hear failure and other heart problems because the blood vessels can become constricted, heart rhythms change and blood clots can form.
The AQHI describes the level of health risk by showing a number and an associated health risk range: 1 to 3 is "Low health risk", 4 to 6 is "Moderate health risk", 7 to 10 is "High health risk" and 10+ is "Very high health risk".
The Index will also suggest steps that people can take to reduce their exposure. As well as giving the current air quality information the AQHI will give a daily forecast.
The AQHI is a measure of the health risks from pollutants; it does not give a measure of the health effects of odour, dust, heat or humidity.
It is a measure of the combined risk posed by a number of common air pollutants which are known to be harmful. These include Ozone (O3) at ground level, particulate matter (PM2.5/PM10) and nitrogen dioxide (NO2).
The plan is that as the AQHI is rolled out across the country, Canadians will be able to check their local index, for instance on a website, and take air pollution into account when they plan their day and decide how much to work or exercise outdoors.
Critics of the government say that it's all well and good measuring the air quality, but where is the action to reduce air pollution?
Speaking to CTV yesterday, Franz Hartmann of the Toronto Environmental Alliance said:
"They have a tool to gauge the problem, but nothing, no new announcement today about how to actually clean the air."
Written by: Catharine Paddock
Writer: Medical News Today
Copyright: Medical News Today
Not to be reproduced without permission of Medical News Today
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