Air Quality Index

 

The AQI is an index for reporting air quality. It tells you how clean or polluted your air is, and what associated health effects might be a concern for you. The AQI focuses on health affects you may experience within a few hours or days after breathing polluted air. EPA calculates the AQI for five major air pollutants regulated by the Clean Air Act: ground-level ozone, particle pollution (also known as particulate matter), carbon monoxide, sulfur dioxide, and nitrogen dioxide. For each of these pollutants, EPA has established national air quality standards to protect public health .Ground-level ozone and airborne particles are the two pollutants that pose the greatest threat to human health in this country.

 

 

Air Quality Index

	Fort Defiance PM2.5	Shiprock PM10	Crownpoint PM10	Tuba City PM10	Nazlini PM 2.5	Nazlini PM 2.5
January 2011	30	19	12	17	4	6
February 2011	25	17	12	21	11	10
March 2011	31	22	18	21	10	11
April 2011	27	20	19	22	22	21
May 2011	22	27	20	45	12	13
June 2011	33	34	32	52	10	12
July 2011	22	21	19	32	7	7
August 2011	18	14	13	28	0	0
September 2011	55	20	14	20	0	0
October 2011	59	20	16	18	0	0
November 2011	40	16	15	18	TBA	TBA
December 2011	TBA	TBA	TBA	TBA	TBA	TBA

 

Air Quality Index for Gaseous Analyer from Shiprock site (PPB):

 

	Ozone	NO2	SO2
January 2011	17	11	1
February 2011	21	7	3
March 2011	26	10	1
April 2011	36	8	1
May 2011	38	6	1
June 2011	0	0	0
July 2011	40	7	1
August 2011	37	7	1
September 2011	24	5	0
October 2011	17	7	1
November 2011	16	7	3
December 2011	TBA	TBA	TBA

 

For a list of the 2009 Achieved monthly Air Quality Index, please click here. For a list of the 2010 Achieved monthly Air Quality Index, please click here.

How Does the AQI Work?

Think of the AQI as a yardstick that runs from 0 to 500, the higher the AQI value, the greater the level of air pollution and the greater the health concern, for example, an AQI value of 50 represents good air quality with little potential to affect public health, while an AQI value over 300 represents hazardous air quality.

An AQI value of 100 generally corresponds to the national air quality standard for the pollutant, which is the level EPA, has set to protect public health. AQI values below 100 are generally thought of as satisfactory. When AQI values are above 100, air quality is considered to be unhealthy-at first for certain sensitive groups of people, then for everyone as AQI values get higher.

Understanding the AQI

The purpose of the AQI is to help you understand what local air quality means to your health. To make it easier to understand, the AQI is divided into six categories:

Air Quality Index (AQI) Values)	Levels of Health Concern	Colors	Meaning
When the AQI is in this range:	...air quality conditions are:	..as symbolized by this color:	This what some situations could fall under.
0-50	Good	Green	Air quality is considered satisfactory, and air pollution poses little or no risk
51-100	Moderate	Yellow	Air quality is acceptable; however, for some pollutants there may be a moderate health concern for a very small number of people who are unusually sensitive to air pollution.
101-150	Unhealthy for Sensitive Groups	Orange	Members of sensitive groups may experience health effects. The general public is not likely to be affected.
151 to 200	Unhealthy	Red	Everyone may begin to experience health effects; members of sensitive groups may experience more serious health effects.
201 to 300	Very Unhealthy	Purple	Health alert: everyone may experience more serious health effects
301 to 500	Hazardous	Maroon	Health warnings of emergency conditions. The entire population is more likely to be affected.

Each category corresponds to a different level of health concern. The six levels of health concern and what they mean are:

• "Good" AQI is 0 - 50. Air quality is considered satisfactory, and air pollution poses little or no risk.
• "Moderate" AQI is 51 - 100. Air quality is acceptable; however, for some pollutants there may be a moderate health concern for a very small number of people. For example, people who are unusually sensitive to ozone may experience respiratory symptoms.
• "Unhealthy for Sensitive Groups" AQI is 101 - 150. Although general public is not likely to be affected at this AQI range, people with lung disease, older adults and children are at a greater risk from exposure to ozone, whereas persons with heart and lung disease, older adults and children are at greater risk from the presence of particles in the air.
  
• "Unhealthy" AQI is 151 - 200. Everyone may begin to experience some adverse health effects, and members of the sensitive groups may experience more serious effects.
• "Very Unhealthy" AQI is 201 - 300. This would trigger a health alert signifying that everyone may experience more serious health effects.
• "Hazardous" AQI that is greater than 300, this would trigger a health warning of emergency conditions. The entire population is more likely to be affected.

Data before AQI or Concentration Values

	Fort Defiance PM2.5	Shiprock PM10	Crownpoint PM10	Tuba City PM10	Nazlini PM 2.5	Nazlini PM 2.5
January 2011	9.10	19.60	13.42	17.88	1.21	1.88
February 2011	7.71	18.25	13.40	22.63	3.25	3.08
March 2011	9.54	23.91	18.74	23.36	3.17	3.46
April 2011	8.18	21.88	20.61	24.00	1.63	2.08
May 2011	6.90	28.56	22.07	49.45	TBA	TBA
June 2011	9.96	27.36	35.90	48.48	TBA	TBA
July 2011	6.88	22.76	20.48	35.34	2.08	2.06
August 2011	5.55	14.78	13.78	29.37	0	0
September 2011	17.02	21.62	14.66	21.67	0	0
October 2011	18.94	21.73	16.52	19.01	0	0
November 2011	12.40	17.17	15.64	18.54
December 2011	TBA	TBA	TBA	TBA	TBA	TBA

Shiprock 2011 Gaseous Analyzer Monthly (Hour Averages)

Months	Ozone	NO2	SO2
January	35.78	12.39	0.54
February	25.10	7.21	1.76
March	31.26	10.55	1.17
April	42.50	8.16	1.12
May	44.86	5.50	1.33
June	0	0	0
July	46.58	6.70	0.64
August	43.55	6.75	0.89
September	29.91	5.27	1.15
October	19.91	6.89	1.35
November	19.20	7.36	1.98
December	TBA	TBA	TBA

 

Designed and Maintained by NNEPA
Updated November 30, 2011 3:22 PM