Statistical modeling of sediment and oyster PAH contamination data collected at a South Carolina estuary (complete and left-censored samples)
✍ Scribed by R. E. Thompson; E. O. Voit; G. I. Scott
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 260 KB
- Volume
- 11
- Category
- Article
- ISSN
- 1180-4009
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✦ Synopsis
This paper presents an analysis of polycyclic aromatic hydrocarbon (PAH) sediment and oyster contamination data collected at Murrells Inlet, South Carolina. Murrells Inlet is a high salinity estuary located in a heavily urbanized area south of Myrtle Beach, South Carolina. In the ®rst part, lognormal and Weibull distributions are determined that best ®t the data, as measured by P±P and Q±Q probability plots. The results indicate that the Weibull gives an adequate ®t for almost all the PAH analytes considered. In fact, the Weibull almost always provides a better ®t to the data than the lognormal distribution. The second part addresses issues associated with non-detection points, as they are regularly encountered in environmental analyses. In statistical terms, the existence of non-detection points corresponds to data that are leftcensored. Several statistical methods for estimating the Weibull parameters from such left-censored data are explored. The overall result is in agreement with recent ®ndings reported by other investigators: methods based on the underlying distribution of the data give more consistent results than those obtained by commonly used substitution methods.