Statistical modeling of sediment and oyster PAH contamination data collected at a South Carolina estuary (complete and left-censored samples)

Richard Thompson, E. O. Voit, G. I. Scott

Research output: Contribution to journalArticle

Abstract

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 first part, lognormal and Weibull distributions are determined that best fit the data, as measured by P-P and Q-Q probability plots. The results indicate that the Weibull gives an adequate fit for almost all the PAH analytes considered. In fact, the Weibull almost always provides a better fit 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 left-censored. Several statistical methods for estimating the Weibull parameters from such left-censored data are explored. The overall result is in agreement with recent findings 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.

Original languageEnglish (US)
Pages (from-to)99-119
Number of pages21
JournalEnvironmetrics
Volume11
Issue number1
DOIs
StatePublished - Jan 2000
Externally publishedYes

Fingerprint

Censored Samples
Statistical Modeling
Polycyclic Aromatic Hydrocarbons
Sediment
Estuaries
Hydrocarbons
Contamination
PAH
Sediments
estuary
Weibull
Weibull distribution
Beaches
sediment
Log Normal Distribution
modeling
Statistical methods
Substitution reactions
Probability Plot
Salinity

Keywords

  • Gumbel
  • Left-censoring
  • Lognormal
  • P-P probability plots
  • PAH contamination
  • Q-Q probability plots
  • Weibull

ASJC Scopus subject areas

  • Environmental Science(all)
  • Environmental Chemistry
  • Statistics and Probability

Cite this

Statistical modeling of sediment and oyster PAH contamination data collected at a South Carolina estuary (complete and left-censored samples). / Thompson, Richard; Voit, E. O.; Scott, G. I.

In: Environmetrics, Vol. 11, No. 1, 01.2000, p. 99-119.

Research output: Contribution to journalArticle

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