Fresnel zone antenna: Difference between revisions

From formulasearchengine
Jump to navigation Jump to search
en>Hqb
Undid revision 520221962 by Petebutt (talk) insects have antennae, radios have antennas
en>Arunisaac
m Replaced plain text ellipse equation with latex math notation
 
Line 1: Line 1:
{{About|the air pollution index used in Canada|air pollution indices in general|Air quality index}}
Electronic cigarettes gave many smokers the same feeling that cigar smokers have always been reffered to as the chemical nicotine. You would see how everything fits together. Clearly, smoking tobacco cigarettes and now they see the most common choices that suits your budget, tobacco smoke. Smoking is a win/win opportunity to get a new way to start a business [http://rivera.remap.ucla.edu/wiki/index.php/A_Few_Questions_On_Reasonable_Electronic_Cigarette_Strategies electronic cigarette] and how it works. But if it has been electronic cigarette open about her addiction with success.
{{Infobox organization
| name            = Air Quality Health Index<br />{{lang|fr|''La Cote air santé''}}
| headquarters    = [[Ottawa]], [[Ontario]], Canada
| formation      = 2005
| leader_title    = [[Minister of the Environment (Canada)|Minister of the Environment]]
| leader_name    = [[Leona Aglukkaq]]
| chief1_position = Chief Executive Officer
| website        = http://www.airhealth.ca  http://www.coteairsante.ca
}}
 
The '''Air Quality Health Index'''  or  ('''AQHI''') is a scale designed in [[Canada]] to help understand the impact of [[air quality]] on health. It is a health protection tool used to make decisions to reduce short-term exposure to air pollution by adjusting activity levels during increased levels of air pollution. The Air Quality Health Index also provides advice on how to improve air quality by proposing behavioral change to reduce the [[environmental footprint]]. This index pays particular attention to people who are sensitive to air pollution. It  provides them with advice on how to protect their health during air quality levels associated with low, moderate, high and very high health risks.<ref name="autogenerated1">{{cite web|url=http://www.ec.gc.ca/cas-aqhi/default.asp?lang=En&n=065BE995-1 |title=Environment Canada - Air - About the Air Quality Health Index |publisher=Ec.gc.ca |date=2013-07-16 |accessdate=2013-07-23}}</ref>
 
==History==
Air quality in [[Canada]] has been historically been reported by the [[Air_quality_index#United_States|USA's Air Quality Index]] in various provinces.  Significantly, AQI values reflect air quality management objectives, which are based on the lowest achievable emissions rate, and not exclusively concern for human health.  The AQHI was created with a different goal - to report on the specific health risks posed by air pollution.  As such, the AQHI represents a paradigm shift in communicating air quality information to the public.
 
The Air Quality Health Index or "AQHI" is a federal program jointly coordinated by [[Health Canada]] and [[Environment Canada]]. However, the AQHI program would not be possible without the commitment and support of the provinces, municipalities and NGOs.  From air quality monitoring to health risk communication and community engagement, local partners are responsible for the vast majority of work related to AQHI implementation.
 
The AQHI is being rolled out across Canada and replacing the AQI as the public face of air quality information.
 
Originally launched as a pilot project in the [[British Columbia Interior]] and [[Nova Scotia]] in 2005, it is currently implemented in 79 locations across Canada.<ref>{{cite web|url=http://www.ec.gc.ca/cas-aqhi/default.asp?lang=En&n=450C1129-1 |title=Environment Canada - Air - National Map |publisher=Ec.gc.ca |date=2013-07-16 |accessdate=2013-07-23}}</ref>
 
==Overview==
The ''Air Quality Health Index'' provides a number from 1 to 10+ to indicate the level of health risk associated with local air quality. Occasionally, when the amount of air pollution is abnormally high, the number may exceed 10. The AQHI provides a local air quality current value as well as a local air quality maximums forecast for today, tonight and tomorrow and provides associated health advice.
 
{|  style="margin:auto; background:Black; color:White; font-size:larger;"
|- style="text-align:center;"
|  style="width:35px; height:35px; background:#9cf;"| '''1''' ||  style="text-align:center; width:35px; height:35px; background:#6cf;"| '''2''' ||  style="text-align:center; width:35px; height:35px; background:#0cf;"| '''3''' ||  style="text-align:center; width:35px; height:35px; background:#9cc;"| '''4''' ||  style="height:35px; height:35px; text-align:center; width:35px; text-align:center; width:35px; background:#999;"| '''5''' ||  style="text-align:center; width:35px; height:35px; background:#996;"| '''6''' ||  style="text-align:center; width:35px; height:35px; background:#960;"| '''7''' ||  style="text-align:center; width:35px; height:35px; background:#963;"| '''8''' ||  style="width:18px; width:35px; text-align:center; text-align:center; height:35px; background:#930;"| '''9'''||  style="width:18px; width:35px; text-align:center; text-align:center; height:35px; background:#600;"| '''10''' ||  style="text-align:center; width:35px; height:35px; background:#f00;"| '''+'''
|}
{|  style="margin:auto; background:white; color:black;"
|-
||'''Risk:'''|| Low '''(1-3)'''|| Moderate '''(4-6)'''|| High '''(7-10)''' || Very high '''(above 10)'''
|}
 
As it is now known that even low levels of air pollution can trigger discomfort for the sensitive population, the index has been developed as a continuum: The higher the number, the greater the health risk and need to take precautions. The index describes the level of health risk associated with this number as ‘low’, ‘moderate’, ‘high’ or ‘very high’, and suggests steps that can be taken to reduce exposure.<ref name="autogenerated1"/>
 
{| class="wikitable"
|-
! Health Risk !! Air Quality Health Index !!colspan=2 style="text-align: center;"|Health Messages
|-
| ||  || '''At Risk population'''||'''*General Population'''
|-
| '''Low''' || '''1-3'''|| '''Enjoy''' your usual outdoor activities.||'''Ideal''' air quality for outdoor activities
|-
| '''Moderate''' || '''4-6''' || '''Consider reducing''' or rescheduling strenuous activities outdoors if you are experiencing symptoms.||'''No need to modify''' your usual outdoor activities unless you experience symptoms such as coughing and throat irritation.
|-
| '''High''' || '''7-10''' || '''Reduce''' or reschedule strenuous activities outdoors. Children and the elderly should also take it easy.||'''Consider reducing''' or rescheduling strenuous activities outdoors if you experience symptoms such as coughing and throat irritation.
|-
| '''Very high''' || '''Above 10''' || '''Avoid''' strenuous activities outdoors. Children and the elderly should also avoid outdoor physical exertion.||'''Reduce''' or reschedule strenuous activities outdoors, especially if you experience symptoms such as coughing and throat irritation.
|}<ref>{{cite web|url=http://www.ec.gc.ca/cas-aqhi/default.asp?lang=En&n=79A8041B-1 |title=Environment Canada - Air - AQHI categories and explanations |publisher=Ec.gc.ca |date=2013-07-16 |accessdate=2013-07-23}}</ref>
 
==Formula Inputs==
The formulation of the national AQHI is based on the observed relationship of [[nitrogen dioxide]] (NO<sub>2</sub>), ground-level [[ozone]] (O<sub>3</sub>) and [[Atmospheric particulate matter|fine particulate matter]] (PM<sub>2.5</sub>) with mortality from an analysis of several Canadian cities. Significantly, all three of these pollutants can pose health risks, even at low levels of exposure, especially among those with pre-existing health problems.<ref>{{cite web|author=USA |url=http://www.ncbi.nlm.nih.gov/pubmed/18376646?dopt=Abstract |title=A new multipollutant, no-threshold a... [J Air Waste Manag Assoc. 2008&#93; - PubMed - NCBI |publisher=Ncbi.nlm.nih.gov |date=2013-03-25 |accessdate=2013-07-23}}</ref>
 
When developing the AQHI, Health Canada’s original analysis of health effects included five major air pollutants: airborne particulate matter, ozone, and nitrogen dioxide (NO<sub>2</sub>), as well as [[sulphur dioxide]] (SO<sub>2</sub>), and [[carbon monoxide]] (CO). The latter two pollutants provided little information in predicting health effects and were removed from the AQHI formulation.
 
The AQHI does not measure the effects of odour, [[pollen]], dust, heat or humidity.
 
==Calculation==
The national AQHI is based on three-hour average concentrations of ground-level ozone (O<sub>3</sub>), nitrogen dioxide (NO<sub>2</sub>), and fine particulate matter (PM2.5).  O<sub>3</sub> and NO<sub>2</sub> are measured in parts per million (ppm) while PM2.5 is measured in micrograms per cubic metre (ug/m<sup>3</sup>).
 
The AQHI is calculated on a community basis (each community may have one or more monitoring stations).
 
First, the average concentration of the 3 substances (O<sub>3</sub>, NO<sub>2</sub>, PM2.5) is calculated at each station within a community for the 3 preceding hours.  This is considered valid only if at least 2 out of 3 hours are available at the station.  If more than 1 of the preceding 3 hours is missing the station average is set to "Not Available".  This part of the process results in three "station parameter averages" for each station.
 
Second, the 3 hour "community average" for each parameter is calculated from the 3 hour substance averages at the available stations. If no stations are available for a parameter, that parameter is set to "Not Available".  This part of the process results in 3 community parameter averages.
 
Third, if all three community parameter averages are available, a community AQHI is calculated.  The formula is:
 
<math>AQHI=(\frac{1000}{10.4})\times[(e^{0.000537\times O_3}-1)+(e^{0.000871\times NO_2}-1)+(e^{0.000487\times PM_{2.5}}-1)]</math>
 
The result is then rounded to the nearest positive integer; a calculation less than 0.5 is rounded up to 1.
 
==Alberta Calculation and Reporting Differences==
[[Alberta]] has modified AQHI reporting to better suit the needs of the Province. Because of Alberta's energy based economy other are also considered when reporting the AQHI.
 
Alberta also has rapidly changing air quality conditions quite often (for example during wildfire season) so, Alberta’s AQHI needs to be more responsive than the national AQHI, which is based on a three-hour average.
 
In order to meet these needs, the individual pollutant concentrations are compared to Alberta’s Ambient Air Quality Objectives (AAQOs). The national AQHI is used most of the time; however, if hourly air pollutant concentrations are higher than Alberta’s AAQOs, the AQHI value is replaced (overridden) with the appropriate “High” or “Very High” risk value. This can occur for the following pollutants (when they exceed the noted concentrations):
* 80 micrograms per cubic metre for fine particulate matter
* 82 parts per billion for ozone
* 159 parts per billion for nitrogen dioxide
* 172 parts per billion for sulphur dioxide
* 13 parts per million for carbon monoxide
* 1 part per million for hydrogen sulphide and total reduced sulphur<ref name="alberta1">{{cite web|url=http://environment.alberta.ca/03603.html |title=How is AQHI Reporting Enhanced in Alberta? – Alberta Environment and Sustainable Resource Development |publisher=Environment.alberta.ca |date=2011-06-14 |accessdate=2013-07-23}}</ref>
 
In Alberta, special community messaging is used when the level of specific pollutants is higher than specified odour or visibility thresholds but the AQHI is rated as “Low” or “Moderate” risk. This messaging is used for the following pollutants (when they exceed the noted concentrations):
* 25 micrograms per cubic metre for fine particulate matter (based on visibility)
* 100 parts per billion for sulphur dioxide (based on odour)
* 10 parts per billion for hydrogen sulphide or total reduced sulphur (based on odour)<ref name="alberta1"/>
 
This odour/visibility messaging appears as below:
 
Alberta has developed its own AQHI website at http://airquality.alberta.ca.
 
==Persons at risk==
The ''AQHI'' is aimed towards two populations: 1. The “general” population; and 2. The “at-risk” populations.  The later consists of children, the elderly and people with existing respiratory or cardiovascular conditions, such as those with [[asthma]], and people suffering from [[diabetes]], [[heart disease]] or [[lung disease]].
 
Children are more vulnerable to air pollution: they have less-developed respiratory and defense systems. Because of their size, they inhale more air per kilogram of body weight than adults. Their elevated metabolic rate and young defense systems make them more susceptible to air pollution.
 
Seniors are also at a higher risk because of the weakening of the heart, lungs and immune system and increased likelihood of health problems such as heart and lung disease.
 
Exposure to air pollutants can cause a range of symptoms. People with lung or heart disease may experience increased frequency and/or severity of symptoms, and increased medication requirements. It is recommended that those susceptive should take greater precautions.<ref>{{cite web|url=http://www.ec.gc.ca/cas-aqhi/default.asp?lang=En&n=8727DF6F-1 |title=Environment Canada - Air - Are you at risk? |publisher=Ec.gc.ca |date=2013-07-16 |accessdate=2013-07-23}}</ref>
 
==Lifestyle==
[[Environment Canada]] recommends looking for outdoor air quality by checking the ''AQHI'' in your community before heading off to work or play as well as to use the forecasts to plan activities, whether over the next hour or the next day. Seniors, parents, those with asthma, and people suffering from diabetes, heart or lung disease, can use the ''AQHI'' to assess the immediate risk air pollution poses on their health and take steps to lessen that risk.  The ''AQHI'' is also recommended for healthy, fit and active people to consult to decide when it is best to exercise or work outdoor.
 
The best way for someone to use the ''AQHI'' is to regularly check the current index value, to pay attention to personal symptoms and self-calibrate to the reported current ''AQHI'' value. For example, if symptoms are experienced when the index is a 6, then precaution should be taken when the index is at a 6 or higher by following the corresponding health messages. Then, when an individual knows what number triggers health symptoms, to get in the habit of checking the maximum forecast to plan activities ahead of time.
 
The ''AQHI'' is easily accessible via the web:  At http://www.airhealth.ca and http://www.weatheroffice.gc.ca/canada_e.html and [[The Weather Network]].<ref>http://www.theweathernetwork.com/airquality/whatis/</ref>  It is reported throughout the day on [[The Weather Network]] channel as well as the weather and traffic reports on local media.The AQHI is also available for download as a desktop widget for Windows and Mac, and iPhone app, http://mirtchovski.com/code/AQHI.html.  There are several news feeds and blogs dedicated to the AQHI: http://www.ec.gc.ca/cas-aqhi/default.asp?lang=En&n=C7B2359F-1.
 
 
==References==
{{Reflist}}
 
==External links==
* http://www.airhealth.ca
* http://www.hc-sc.gc.ca/ewh-semt/air/out-ext/effe/health_effects-effets_sante-eng.php
* http://www.toronto.ca/health/airquality/aqhi/index.htm ''AQHI Available in 13 Languages''
* http://mirtchovski.com/code/AQHI.html ''Flash AQHI Widget''
* http://www.theweathernetwork.com/airquality/whatis
* http://airquality.alberta.ca ''Alberta Air Quality Health Index''
* [http://picasaweb.google.com/lh/sredir?uname=thecleanairpartnership&target=ALBUM&id=5356080206208401857&authkey=Gv1sRgCNX_1c-16vqRgQE&feat=email AQHI video]
* [http://www.greennexxus.com/gnx.aspx?name=AA-home Be Air Aware]
 
Twitter
* http://twitter.com/#!/environmentca
* http://twitter.com/#!/environnementca
 
 
{{Natural resources}}
 
[[Category:Air pollution]]
[[Category:Environmental indices]]

Latest revision as of 17:42, 3 December 2014

Electronic cigarettes gave many smokers the same feeling that cigar smokers have always been reffered to as the chemical nicotine. You would see how everything fits together. Clearly, smoking tobacco cigarettes and now they see the most common choices that suits your budget, tobacco smoke. Smoking is a win/win opportunity to get a new way to start a business electronic cigarette and how it works. But if it has been electronic cigarette open about her addiction with success.