Breathing Easier (Sort Of)

It may not look like it this week, but the San Fernando Valley’s air is gradually getting cleaner. Smog remains a major problem, but the number of first-stage smog alerts and days when the federal air quality standard for ozone is violated have decreased in the Los Angeles basin, which includes Los Angeles, Orange, Riverside and San Bernardino counties.

The Valley has made notable progress the last decade, officials say, though not as dramatic as that in the San Gabriel Valley, which traditionally has the area’s worst air pollution, partly because wind blows west to east.

The South Coast Air Quality Management District attributes the improvement, in part, to stricter controls on autos and industry. Although not as significant as such controls imposed upon autos and industry, tougher standards on consumer goods and pollution-reducing measures by drivers also help reduce smog.

Air Quality Standards

* Federal standard: Violations occur when ozone levels exceed 0.12 parts per million of air, a level not as tough as the state standard of 0.09. Susceptible people, such as those with heart or lung disease, should minimize outdoor activity.

* Stage 1 alerts: Called by AQMD when ozone reaches 0.20 p.p.m. All persons should avoid vigorous outdoor exercise. Susceptible people, especially those with heart or lung disease, should stay indoors.

* Stage 2 alerts: Occurs when ozone reaches 0.35 p.p.m., an unhealthful level. Everyone is advised to avoid outdoor activity. Stage 2 alerts are not common. The last time one was called in the Valley was 1980, in the basin 1988.

Violations of Clean-Air Standards

Over the last decade, air quality has improved throughout the Valley region, as indicated by the decrease in number of days that pollutants have exceeded the federal clean-air standard. The drop has been recorded at AQMD monitoring stations in Reseda, Burbank, Santa Clarita and Lancaster. Another way of monitoring air quality is to record the number of Stage 1 alerts, which also have declined. Figures on the map are three-year averages for days over the federal standard.

SANTA CLARITA

80-82: 104

85-87: 82

90-92: 66

LANCASTER

80-82: 56

85-87: 45

90-92: 13

BURBANK

80-82: 84

85-87: 85

90-92: 47

RESEDA

80-82: 87

85-87: 69

90-92: 40 The Smog Equation

Two pollutants emitted by car exhausts--hydrocarbons and nitrogen oxides--combine and interact with sunlight to form ozone, a colorless gas that is one of the main components of smog. In Los Angeles, the problem is compounded by thermal inversion, which occurs when cool, wet ocean air laden with pollutants gets trapped close to the ground below warm dry air. When the warm air eventually rises, it lets the cool air escape over the mountains. While this ground-level ozone is harmful, the ozone layer that exists in the upper stratosphere protects against the sun’s harmful ultraviolet radiation.

Cold wet air laden with pollutants trapped close to ground Warm dry air eventually rises, allowing cool air to escape over mountains. How To Reduce Smog

On the road...

* Get with the Smog Check program. The state’s emissions-testing program is a major weapon in fighting air pollution by measuring pollutants coming out of a car’s tailpipe.

* Keep your car’s engine well-tuned. Dirty carburetors, clogged air filters and worn points and plugs cause increased emission of particulate matter and nitrogen oxides.

* Don’t let your car idle. Idling produces large amounts of carbon monoxide and other pollutants.

* Use radial tires. Radials produce less air-damaging particulate matter per mile traveled than bias-ply tires do.

* Avoid “topping off” at the pump. This releases gasoline vapors into the air.

...and at home

* Plant trees. They add oxygen to the atmosphere and break down pollutants. They also shade buildings, reducing air conditioner use and conserving fuel.

* Avoid lighter fluid when lighting barbecue. Lighter fluid sold in Los Angeles has to meet anti-pollution standards but still can add hydrocarbons to the air. Non-polluting alternatives are electric starters and “chimneys” that use newspaper tinder to start the coals.

* Use a rake instead of leaf blower. Use an electric or push mower instead of gas. Cuts down on fine dust particles that blowers cause, as well as toxic fumes.

- Call (800) 242-4022 for air quality updates in Los Angeles County; report vehicles that emit invisible smoke exhaust for more than 10 seconds by calling (800) CUT-SMOG.

Sources: South Coast Air Quality Management District, Encyclopedia Americana Researched and written by JULIE SHEER / Los Angeles Times