Protection Agency Classifies
Phoenix Area as Serious for Carbon Monoxide
past July, the Environmental Protection Agency announced that the Phoenix
metropolitan area has not attained the carbon monoxide (CO) national ambient
air quality standard (NAAQS), and thus has been reclassified from "moderate"
Under the Clean Air Act, pollution classifications are established for
levels of carbon monoxide, ozone and particulates when they exceed the
federal government's air-quality standards. When areas exceed health standards,
they are seen as having nonattainment.
The intent of the reclassification is to allow the state of Arizona 18
months from the EPA's action in July to submit a new state implementation
plan (SIP) which will demonstrate how attainment of the CO NAAQS will
Under the Clean Air Act, states in nonattainment areas must develop a
SIP, which contains the regulations it will use to clean up the polluted
areas. For the CO pollution in Maricopa County, attainment should be met
as expeditiously as practical, but no later than December 31, 2000.
Carbon monoxide is a tasteless, odorless and poisonous gas that threatens
a person's health by restricting the body's absorption of oxygen. The
pollutant is generally at risk for exceeding health standards in the Valley
during the months of October through March.
The primary source of carbon monoxide is vehicle exhaust, while other
sources include emissions from large industry, airplanes and fireplaces.
On five occasions during the 1995/96 season (October 1 through March 1),
carbon monoxide exceeded the ambient health levels. While air quality
in the Valley has improved over the years due to stringent air pollution
programs (89 CO violations were recorded in 1987), it has not improved
enough to keep up with the continued growth and increase in traffic in
the Phoenix area.
As a major employer in Maricopa County, the Maricopa Community Colleges
participates in the County's Trip Reduction Program, which is one of the
measures geared towards reducing air pollution. (Other measures include
reformulated gasoline and enhanced vehicle emissions testing.)
During this year's high pollution advisory season, advisories from District
Trip Reduction will be posted via the District's electronic mail system
in the event that carbon monoxide approaches unhealthy levels.
Carbon monoxide levels can be curtailed by driving less, avoiding drive-through
services and not using wood-burning fireplaces during the period in which
the advisory is in effect. Other options include staggered hours to avoid
peak rush hour traffic (before 4:00 p.m.) and telecommuting to eliminate
travel to the worksite.
Options regarding a change in work schedule should have prior supervisor
approval. For assistance with carpooling, call District Trip Reduction
in the Winter 1997 Edition of In Brief