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Observations of damage to vegetation, acute reductions in surface water pH, and kills of small fish prompted the Biomedical
Operations and Research Office at the John F. Kennedy Space Center to initiate intensive environmental evaluations of possible
acute and long-term chronic impacts that may be produced by repeated launches of the space shuttle. An important step in this
evaluation was the identification of deposition patterns and the quantification of ecosystem loading rates of exhaust constituents
from the solid rocket motors (SRMs) in the area of the launch pad. These constituents are primarily aluminum oxide (Al2O3) and hydrochloric acid (HCl). During three launches of the space transportation system (STS-11, 13, and 14) up to 100 bulk
deposition collectors, 83 mm in diameter containing 100 ml of deionized water, were deployed in a grid pattern covering 12.6
ha north of launch pad 39-A. Estimates of HCl and particulate deposition levels were made based on laboratory measurements
of items entrained in the collectors. Captured particulates consisted of a variety of items including Al2O3, sand grains, sea shell fragments, paint chips, and other debris ablated from the launch pad surface by the initial thrust
of the SRMs. Estimated ranges of HCl and particulate deposition in the study area were 0–127 g/m2 and 0–246 g/m2, respectively. Deposition patterns were highly influenced by wind speed and direction. These measurements indicate that,
under certain meteorological conditions, up to 7.1 × 103 kg of particulates and 3.4 × 103 kg of HCl can be deposited to the near-field environment beyond the launch pad perimeter fence. 相似文献
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Hanlon EA Fan XH Gu B Migliaccio KW Li YC Dreschel TW 《Journal of environmental quality》2010,39(5):1724-1733
Restoration of the Florida Everglades is important for the health of the natural system, including both the "River of Grass" and its downstream estuaries. Water quality improvement is one indicator of successful restoration in this complex ecosystem. Using the period of record of 1977 through 2005, we evaluated data from seven inflow sites to the Everglades National Park (ENP) for temporal trends of various forms of phosphorus (P) and nitrogen (N) and analyzed them using principal component analysis and factor analysis without flow adjustments. Locally estimated scatter plot smoothing (LOESS) trend lines identified two inflection points (three time periods) of changing trend in total P (TP) concentration at the seven sites. Results indicated that overall water quality in ENP inflow improved from 1977 to 2005, with significant downward trends in TP concentration. The overall trend ofTP is probably mediated by hydrology, which is evident by a negative relationship between flow and annual average TP concentration at the majority of stations within the available data, although additional changes in vegetation due to hydroperiod may have some effects. Total N (TN), total Kjeldahl N, and total organic N concentrations also generally decreased at inflow sites. Water quality standards for TP, TN, and NH4+ -N were exceeded at selected sites during the study period. Principle component analysis and factor analysis detected a grouping of sampling sites related to the water delivery system that could be used as indicators to better manage monitoring resources. Study results suggest that water quality data analyses could provide additional insight into the success of a restoration management plan and on how monitoring may be modified for more efficient use ofresources. 相似文献
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