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J D Neefus

Publications and source records attributed to J D Neefus.

5 recordsLinked to original sources
PubMed1977

Cotton dust sampling, III-estimation of statistical errors with vertical elutriators.

Cotton dust levels measured by vertical elutriators have been studied in terms of the variance components associated with statistical errors due to sampling equipment, location, time and repeated sampling. A thumb-rule is proposed for estimating sampling errors of three-hour vertical elutriator samples as a function of average dust level. Relative efficiency of three-hour samples is shown to be superior to that of six-hour samples at moderate dust levels (0.4-0.6 mg/m3) but inferior at low dust levels (0.1-0.2 mg/m3. Errors due to location and equipment are found insignificant from this particular study.

Air Pollutants↗
PubMed1977

Cotton dust sampling, II--vertical elutriation.

Cotton dust sampling by vertical elutriation has existed since 1970. Early medical correlations using this method of sampling used median values instead of mean values because of unexpected high and low values. The methodology necessary to obtain consistent results is difficult to achieve and worthy of review.

Air Pollutants↗
PubMed1975

Cotton dust sampling: I. Short termed sampling.

A short term sampler for cotton dust is introduced which, when used in conjunction with a correctly designed vertical elutriator, gives equivalent results to the Lumsden-Lynch vertical elutriator. The short termed sampler not only offers results which can be applied to the ACGIH TLV but offers an effective means of environmental surveillance in a byssinosis prevention program with the additional advantages of immediate read-out short termed sampling and truer employee exposure.

Byssinosis↗