A monostatic lidar and a monostatic acoustic sounder were used to observe a common atmospheric volume during several summer days in St. Louis, Missouri. The signal displays were analyzed to show the relative merits of the techniques for observing boundary layer processes important to urban weather modification and air pollution. The observed summer days could typically be divided into three periods: The first was the early forenoon, when aerosols had accumulated under a radiation inversion; here the lidar and the acoustic sounder performed about equally well in defining the depth of the mixed layer. The second was a strong convection period in which thermal plumes rose far above the early forenoon mixing depth; the lidar depicted the full vertical extent of these plumes by using surface-generated aerosols as tracers, but the sounder detected only the lower regions, where thermal turbulence was strong. The third was the period of re-formation of the inversion, which the sounder detected immediutely but which the lidar detected only after a spatial discontinuity of aerosol content had developed. The sounder had a similar advantage in detecting subsidence inversions aloft. Wave structures observed by both sensors were usually well correlated. The response of both systems to convective clouds also was examined.
Two areas, containing a total of over 160,000 people, were examined for mortality rates; one area was directly under incoming flights, near Los Angeles International Airport (LAX). The other was removed from the LAX flight patterns so that jet noise was not dominant. The two areas were chosen so that they were as nearly alike as possible in age, racial distribution, income and in other relevant factors with the sole major difference of jet noise in one of them. It was found that there was a substantial increase in mortality rates in the area under the jets where there was large noise radiation. In particular, by a most conservative statistical treatment there was in the jet noise area: a 15% increase in deaths due to strokes (cerebro-vascular disease) which accounted for 39 deaths in the two-year period of the study--presumably attributable to the excessive jet noise. Further, in the noise-radiated area there was a 100% increase in deaths due to cirrhosis of the liver (primarily attributed to alcoholism)--amounting to 24 extra deaths in the two years, due to jet noise. One of the disturbing side results of this study was that in these relatively poor regions it appears that there should be about 50% more deaths than were reported and recorded by Los Angeles County. These losses were perhaps due to a concentration of bad, given addresses in the areas in question; this serious loss casts grave doubt on previous studies of eath rates for minority peoples (e.g. blacks), suggesting that the rates may be considerably higher than those previously reported.
The test area is in the 90 dBA contour, for 1970–1980, and contains about 100 000 people, under the landing patterns at Los Angeles International Airport. A control area has approximately the same number of people, contiguous to the test area with racial distribution and income the same within a few percent. We can control age distribution by mortality in an age group and compare stress-related nonstress-related deaths. Deaths from respiratory disease, cancer, and mental disorders showed no significant increase in the high noise area. Cardiovascular deaths are increased by 18% in the high noise area for the 75 + age group (97% confidence level); violent deaths by 61% same age group (96% level); suicides alone by over 100% in the 45–54 age group (99% level). This gives 193 extra deaths.
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