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Dennis R Helsel

Explore the profile of Dennis R Helsel including associated specialties, affiliations and a list of published articles. Areas
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Articles 10
Citations 207
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Recent Articles
1.
Banta-Green C, Brewer A, Ort C, Helsel D, Williams J, Field J
Sci Total Environ . 2016 Jun; 568:856-863. PMID: 27338844
Aim: Analysis of wastewater samples can be used to assess population drug use, but reporting and statistical issues have limited the utility of the approach for epidemiology due to analytical...
2.
Johnsen A, Thorling L, Helsel D, Larsen F
Sci Total Environ . 2016 May; 557-558:914-5. PMID: 27133937
No abstract available.
3.
Sheppard P, Helsel D, Speakman R, Ridenour G, Witten M
Chem Biol Interact . 2012 Jan; 196(3):96-101. PMID: 22227064
Previously reported dendrochemical data showed temporal variability in concentration of tungsten (W) and cobalt (Co) in tree rings of Fallon, Nevada, US. Criticism of this work questioned the use of...
4.
Helsel D
Integr Environ Assess Manag . 2010 Sep; 6(3):361-6. PMID: 20821699
Low-level contaminants often are present below the detection or reporting limits of a laboratory, resulting in values reported as a nondetect or less-than. How can these values be summed along...
5.
Ayotte J, Argue D, McGarry F, Degnan J, Hayes L, Flanagan S, et al.
Environ Sci Technol . 2008 Mar; 42(3):677-84. PMID: 18323087
Methyl tert-butyl ether (MTBE) concentrations > or = 0.2 /microg/L were found in samples of untreated water in 18% of public-supply wells (n = 284) and 9.1% of private domestic...
6.
Stetson S, Wanty R, Helsel D, Kalkhoff S, Macalady D
Anal Chim Acta . 2007 Aug; 567(1):108-13. PMID: 17723386
Perchlorate ion (ClO4-) is an environmental contaminant of growing concern due to its potential human health effects, impact on aquatic and land animals, and widespread occurrence throughout the United States....
7.
Helsel D, Frans L
Environ Sci Technol . 2006 Jul; 40(13):4066-73. PMID: 16856718
Trends in environmental variables are often investigated within a study region at more than one site. At each site, a trend analysis determines whether a trend has occurred. Yet often...
8.
Helsel D
Chemosphere . 2006 Jun; 65(11):2434-9. PMID: 16737727
The most commonly used method in environmental chemistry to deal with values below detection limits is to substitute a fraction of the detection limit for each nondetect. Two decades of...
9.
Helsel D
Environ Sci Technol . 2005 Nov; 39(20):419A-423A. PMID: 16295833
No abstract available.
10.
Ulrich E, Helsel D, Foreman W
Chemosphere . 2003 Sep; 53(5):531-8. PMID: 12948537
Complications arise when ratios are used to present environmental data because ratios are an unbounded, multiplicative scale that can lead to asymmetrical (skewed) data distributions. Enantiomeric ratios (ERs), historically used...