Air quality should remain good despite spike |

Air quality should remain good despite spike

Air quality got one point away from an unhealthy for sensitive groups advisory Wednesday, but will probably drop back down to moderate today according to an air district official.

Joe Fish at the Northern Sierra Air Quality Management District said this morning’s cooler temperatures will probably keep the air quality index numbers in the moderate range today between 51 and 100. That means only people with unusual sensitivities to smog should consider reducing lengthy exertion today.

Fish said the Grass Valley area hit 100 on the air index Wednesday, just one point less than the 101 to 150 unhealthy for sensitive groups level. That level is often attained here in summer when temperatures start climbing toward 100 and ozone levels rise.

The unhealthy for sensitive groups bracket includes anyone who has had heart or lung disease, young children, the elderly, pregnant women, athletes and asthmatics. Above that is the unhealthy level at 151 to 200, where all people are told to limit outdoor activity. The worst is very unhealthy, which is 201 to 300 and says only the healthy should go outdoors and not for long.

The air quality in western Nevada County is also affected largely by pollution from the Bay Area and Sacramento being moved into the foothills by prevailing winds. According to Fish, southern winds pushed that pollution to the south earlier this week, but a Delta breeze Wednesday abruptly headed it east into the Sierra.

Federal EPA officials have ordered Sacramento and Bay Area to have a plan to clean up air quality and meet new ozone standards by 2007. EPA did not lump Nevada County with Sacramento attainment standards but indicated the county will have to create new, but less stringent standards for business and transportation.

For more information about air quality, visit

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