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Predicting benzene vapor concentrations with a near field/far field model.
J Occup Environ Hyg. 2008 Sep; 5(9):599-608.JO

Abstract

Published data on benzene vapor concentrations in work simulation settings were used to examine the predictive ability of a near field/far field vapor dispersion model with an exponentially decreasing vapor emission rate. A given simulation involved two 15-min periods of applying a known volume of benzene-containing liquid to equipment on a worktable in a room with a measured air exchange rate. Replicate personal breathing zone (15-min time-weighted average, TWA) and room area (1-hr TWA) air samples were collected. In our modeling, the benzene vapor concentration in the near field zone (at the worktable) represented the personal breathing zone exposure level, and the benzene vapor concentration in the far field zone represented the room area concentration. Across 10 simulation combinations of two factors (the mass of benzene applied and the room air exchange rate), the mean of the personal breathing zone exposure levels ranged from 0.2 to 9.9 mg m(-3), and the mean of the room area concentrations ranged from 0.05 to 5.05 mg m(-3). Our model provided reasonably accurate estimates of the measured benzene vapor concentrations. Linear regression of the mean measured personal breathing zone exposure versus the predicted near field concentration yielded slope = 0.93 and r(2) = 0.94; the null hypothesis that the true slope equals one was not rejected (p-value = 0.39). Linear regression of the mean measured room area concentration versus the predicted far field concentration yielded slope = 0.90 and r(2) = 0.94; the null hypothesis that the true slope equals one was not rejected (p-value = 0.20). Other statistical tests showed no significant differences between measured and predicted values. In addition, most predicted concentrations fell within an approximate range of one-half to twofold the respective measured concentrations.

Authors+Show Affiliations

School of Public Health, University of California, Berkeley, California 94720-7360, USA. mnicas@berkeley.eduNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

18615292

Citation

Nicas, Mark, and John Neuhaus. "Predicting Benzene Vapor Concentrations With a Near Field/far Field Model." Journal of Occupational and Environmental Hygiene, vol. 5, no. 9, 2008, pp. 599-608.
Nicas M, Neuhaus J. Predicting benzene vapor concentrations with a near field/far field model. J Occup Environ Hyg. 2008;5(9):599-608.
Nicas, M., & Neuhaus, J. (2008). Predicting benzene vapor concentrations with a near field/far field model. Journal of Occupational and Environmental Hygiene, 5(9), 599-608. https://doi.org/10.1080/15459620802282375
Nicas M, Neuhaus J. Predicting Benzene Vapor Concentrations With a Near Field/far Field Model. J Occup Environ Hyg. 2008;5(9):599-608. PubMed PMID: 18615292.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Predicting benzene vapor concentrations with a near field/far field model. AU - Nicas,Mark, AU - Neuhaus,John, PY - 2008/7/11/pubmed PY - 2008/8/20/medline PY - 2008/7/11/entrez SP - 599 EP - 608 JF - Journal of occupational and environmental hygiene JO - J Occup Environ Hyg VL - 5 IS - 9 N2 - Published data on benzene vapor concentrations in work simulation settings were used to examine the predictive ability of a near field/far field vapor dispersion model with an exponentially decreasing vapor emission rate. A given simulation involved two 15-min periods of applying a known volume of benzene-containing liquid to equipment on a worktable in a room with a measured air exchange rate. Replicate personal breathing zone (15-min time-weighted average, TWA) and room area (1-hr TWA) air samples were collected. In our modeling, the benzene vapor concentration in the near field zone (at the worktable) represented the personal breathing zone exposure level, and the benzene vapor concentration in the far field zone represented the room area concentration. Across 10 simulation combinations of two factors (the mass of benzene applied and the room air exchange rate), the mean of the personal breathing zone exposure levels ranged from 0.2 to 9.9 mg m(-3), and the mean of the room area concentrations ranged from 0.05 to 5.05 mg m(-3). Our model provided reasonably accurate estimates of the measured benzene vapor concentrations. Linear regression of the mean measured personal breathing zone exposure versus the predicted near field concentration yielded slope = 0.93 and r(2) = 0.94; the null hypothesis that the true slope equals one was not rejected (p-value = 0.39). Linear regression of the mean measured room area concentration versus the predicted far field concentration yielded slope = 0.90 and r(2) = 0.94; the null hypothesis that the true slope equals one was not rejected (p-value = 0.20). Other statistical tests showed no significant differences between measured and predicted values. In addition, most predicted concentrations fell within an approximate range of one-half to twofold the respective measured concentrations. SN - 1545-9632 UR - https://www.unboundmedicine.com/medline/citation/18615292/Predicting_benzene_vapor_concentrations_with_a_near_field/far_field_model_ L2 - https://www.tandfonline.com/doi/full/10.1080/15459620802282375 DB - PRIME DP - Unbound Medicine ER -