2010 March 31: AZ Nogales: Particle Pollution: high PM levels

2010 March 31: AZ Nogales: Particle Pollution: high PM levels


Three-day weather synopsis:

A very strong winter-like storm will impact AZ today and Thursday then move to the east on Friday. For the Nogales area the strongest winds and highest potential for dense blowing dust is forecast to occur today followed by showers and possible thunderstorms on Thursday. Due to the storm’s proximity, gusty winds will continue on Thursday then decrease Friday and Saturday. No high PM levels are expected after today.

TUESDAY’S Air Quality Index (AQI) Levels: PM-10=24 PM-2.5=31


Day #1: Thu 04/01/2010


Day #2: Fri 04/02/2010


Day #3: Sat 04/03/2010


PM-10 & PM-2.5 (PARTICLES):

Description – The term “particulate matter” (PM) includes both solid particles and liquid droplets found in air. Many manmade and natural sources emit PM directly or emit other pollutants that react in the atmosphere to form PM. Particles less than 10 micrometers in diameter tend to pose the greatest health concern because they can be inhaled into and accumulate in the respiratory system. Particles less than 2.5 micrometers in diameter are referred to as “fine” particles and are responsible for many visibility degradations such as the “Valley Brown Cloud”
(see http://www.phoenixvis.net/). Particles with diameters between 2.5 and 10 micrometers are referred to as “coarse”.
Sources – Fine = All types of combustion (motor vehicles, power plants, wood burning, etc.) and some industrial processes. Coarse = crushing or grinding operations and dust from paved or unpaved roads.
Potential health impacts – PM can increase susceptibility to respiratory infections and can aggravate existing respiratory diseases, such as asthma and chronic bronchitis.
Units of measurement – Micrograms per cubic meter (ug/m3)
Averaging interval – 24 hours (midnight to midnight).
Reduction tips – Reduce or eliminate open burning including fireplace use, stabilize loose soils, slow down on dirt roads, carpool, and use public transit.

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
When the AQIis in this range: …air quality conditions are:
Unhealthy for Sensitive Groups
151 to 200
201 to 300
Very Unhealthy
301 to 500

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 greater than 300. This would trigger a health warnings of emergency conditions. The entire population is more likely to be affected.


Health Services Director:
Kevin J. Irvine Kevin J. Irvine
520) 375-7900



In preparing this material, every effort has been made to ensure that the information provided is correct.
The information is provided as a public service and Santa Cruz County assumes no liability for any inaccuracies that it may contain.

Physical Location:
2150 N Congress Dr.
Nogales, AZ 85621
(520) 375-7800

This entry was posted in A-B States = AL, AK, AZ, AR = Alabama, Alaska, Arizona, Arkansas. Bookmark the permalink.

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