IN THE OZONE

Ozone, a colorless gas that turns noxious when combined with sunshine, is a major constituent of Southern California’s infamous smog. The product of auto exhausts, refineries, power plants and factories, ozone is closely monitored by the South Coast Air Quality Management District, which maintains 37 air monitoring stations in Orange, Los Angeles, Riverside and San Bernardino counties.

A Stage 1 alert is called when ozone concentration reaches 0.20 parts of the gas per million parts of air,

considered to be unhealthful for everyone, particularly those with a respiratory ailment or heart condition. A Stage 2 alert is called when ozone levels reach 0.35 parts per million. Air in a Stage 2 alert is considered hazardous for everyone, and even healthy people are advised to reduce strenuous exercise and outdoor activity.

The table below charts annual first- and second-stage ozone episodes since 1976 for the five Orange County air monitoring locations and selected other stations.

Location 1976 1977 1978 1979 1980 1981 Anaheim * 4/0 * 0/0 13/0 5/0 6/0 5/0 La Habra 15/0 8/0 24/1 21/1 14/0 15/0 El Toro 3/0 2/0 10/0 6/0 3/0 5/0 Los Alamitos 2/0 * 0/0 5/0 2/0 3/0 0/0 Costa Mesa 0/0 * 0/0 3/0 1/0 0/0 1/0 Los Angeles 11/0 3/0 16/0 14/0 10/0 8/0 Azusa 47/1 64/0 76/5 71/10 74/7 65/2 Riverside 46/2 66/1 62/2 55/0 67/4 34/0 San Bernardino 51/0 70/1 72/1 62/0 72/2 58/1 Palm Springs * 3/0 5/0 3/0 * 3/0 4/0 0/0 Crestline 11/0 63/0 73/0 80/3 54/0 49/1 TOTAL ** 100/7 121/11 117/23 120/17 101/15 100/5

Location 1982 1983 1984 1985 1986 1987 Anaheim 7/0 10/0 5/0 11/0 1/0 3/0 La Habra 12/0 15/0 15/0 13/0 8/0 6/0 El Toro 3/0 10/0 3/0 7/0 1/0 1/0 Los Alamitos 2/0 2/0 0/0 0/0 0/0 0/0 Costa Mesa 0/0 2/0 1/0 1/0 0/0 0/0 Los Angeles 7/1 12/0 8/0 9/0 8/0 2/0 Azusa 40/1 63/3 55/0 48/1 45/0 26/0 Riverside 26/0 42/1 29/0 35/1 19/0 20/0 San Bernardino 38/0 49/0 36/0 30/0 41/0 27/0 Palm Springs 0/0 0/0 1/0 2/0 0/0 0/0 Crestline 29/0 48/0 49/0 41/0 34/0 22/0 TOTAL ** 63/2 84/3 97/0 83/7 79/1 66/0

* Less than 12 full months of data.

** Number of days in which first/second stage episodes occurred for all of South Coast Air Basin.

Source: South Coast Air Quality Management District.

BREAKING STANDARDS

The Federal Clean Air Act sets its ozone level standard at .12 parts per million; the state sets a more stringent standard of .10 parts per million. The table below charts how many days ozone levels exceeded the federal and state standards in 1987, for the five Orange County air monitoring locations and selected other stations.

OZONE Location Federal State Anaheim 25 48 La Habra 41 77 El Toro 16 36 Los Alamitos 4 15 Costa Mesa 2 23 Los Angeles 36 91 Azusa 111 163 San Bernardino 117 166 Palm Springs 33 74 Crestline 119 156

Source: South Coast Air Quality Management District.