[Date Prev][Date Next][Date Index]

E-M:/ EPA proposal to update air pollutant system

Enviro-Mich message from "MICHAEL W. MURRAY" <MURRAY@nwf.org>

EPA has announced a plan to revise its Pollutant Standards Index
system (for the criteria air pollutants), involving, in part, an
additional category just above the health standard, and uniform color
system for charts/maps used by state and local agencies. 45-day
comment period to being shortly.  
   Mike Murray




In an action which will help local tv and radio weather casters better
inform citizens about upcoming good or bad 
air quality days, EPA today announced a proposal to revise the
Agency's Pollutant Standards Index (PSI), also known 
as the Air Quality Index, to enhance the public's  right-to-know about
daily air pollution levels in their local 
communities.  The PSI provides EPA with a uniform system of measuring
pollution levels for the major air pollutants 
regulated under the Clean Air Act.  State and local officials use the
PSI as a public information tool to advise 
the public about the general health effects associated with different
pollution levels, and to describe what 
precautionary steps may be appropriate if levels rise into the
unhealthy range.  States monitor the daily levels of 
five pollutants for which EPA has established national ambient air
quality standards:  ground-level ozone (smog), 
particulate matter, sulfur dioxide, carbon monoxide and  nitrogen
dioxide.  The proposal would also provide 
information for a new national Internet website that includes more
timely air quality data, along with forecasts of 
summertime smog levels in many states (website:  www.epa.gov/airnow). 
Under the Clean Air Act, EPA was required to 
establish a nationally uniform air quality index for the reporting of
air quality, and in 1976 the Agency 
established the PSI to help state and local government agencies
provide citizens with accurate, timely and easily 
understandable information on protecting their health.  These five
pollutants all have separate numerical health-
protection standards, so to avoid confusion, state and local agencies
use the index to convert their monitored 
levels to one number on a uniform scale ranging from 0 (good) to 500
(hazardous) and report this number to the 
public.  Today's proposal would add an additional air quality category
just above the level of the health standard 
100.  Currently, PSI values from 101 - 200 are characterized as
"unhealthful"; the change would establish a new 
category from 101 - 150 characterized as "unhealthy for sensitive
groups" (such as asthmatics) and a category of 
151 - 200 as "unhealthy".  To the extent that state and local agencies
use color maps or charts to communicate PSI 
values to the public, this proposal would require uniform colors
associated with each PSI category.  For instance, 
the "unhealthy" category would be represented by the color red. 
Today's proposal will appear soon in the Federal 
Register with a 45-day public comment period, but can be read
immediately on the Internet under "Recent Actions" at 
website:  http://www.epa.gov/ttn/oarpg.  For further technical
information, phone Susan Stone at 919-541-1146 (e-
mail:  stone.susan@epa.gov) or Terence Fitz-Simons at 919-541-0889
(e-mail:  fitz-simons.terence@epa.gov) of EPA's 
Office of Air Quality Planning and Standards.

R-163                                                            ###

ENVIRO-MICH:  Internet List and Forum for Michigan Environmental
and Conservation Issues and Michigan-based Citizen Action.   Archives at

Postings to:  enviro-mich@great-lakes.net      For info, send email to
majordomo@great-lakes.net  with a one-line message body of  "info enviro-mich"