Block · one region of the page, as the scanner read it. It may hold a whole story, part of one, several, or an advertisement; stitching blocks into articles is the next step. Text is supplied OCR.
Page 5 · column 2 of 6 · from the scan, no model involved
Meadows has shown a summertime increase of four percent per year from 1982 to 1992. “We’re getting more of the pollution in the summer that contributes to poor visibility,” reported Gubler. “The annual averages may stay the same or may even be decreasing, but the summertime levels of pollution-when we get the most visitors—have increased.” said Gubler.
Studies have shown that a change in the amount of air pollution does not necessarily produce the same change in the human preception of visibility. So although we’ve gotten four percent more particles per summer since 1982, visitors may not be able to notice the gradual decrease in visibility. “But we can say the pollution, and therefore the visibility, is not getting better,” said Julie Thomas, park air program manager. As for nationwide visibility conditions in 1970, it was bad then, too, bad enough for Congress to pass the Clean Air Act.
Summertime visibility ranges the last three years in Shenandoah have steadily risen from 24 percent poor days in 1991, to 31 percent in 1992, to 36 percent in 1993. These ranges were determined by human observation and cross-checked with the transmissometer data. “These numbers agree with our transmissometer data, and tell us that the
<i
89.3%