AMBIENT OZONE (O-3) IN 3 CLASS-I WILDERNESS AREAS IN THE NORTHEASTERNUSA - MEASUREMENTS WITH OGAWA PASSIVE SAMPLERS

Ambient ozone (O-3) was measured in two Class I wilderness areas, one within the White Mountain National Forest in north central New Hampshi re (NH) and one within the Green Mountain National Forest in southwest ern Vermont (VT), for six weeks between 5 July and Id August 1994, usi ng Ogawa passive nitrite-coated filter samplers and a one week exposur e period each time. Results for 7-day mean ambient O-3 concentrations from the passive samplers were compared to results from a co-located c ontinuous ultraviolet photometric O-3 analyzer both in NH and VT. Alth ough the size of the data set was small, agreement through simple line ar regression between mean 7-day O-3 concentrations determined by the continuous monitors, and those obtained from the passive samplers was generally very good (adjusted R(2) = 0.759; p = 0.0003). Overall, excl uding the one outlier value, any observed differences in the results o btained by the two methods when comparing co-located passive samplers to the continuous monitor within a given study location, appeared to b e solely due to experimental error.