Radiographic and spirometric findings in diatomaceous earth workers

Philip I Harber, James Dahlgren, William Bunn, James Lockey, Gerald Chase

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

Diatomaceous earth is a noncrystalline form of silica; in processing, calcining leads to formation of cristobalite, a form of crystalline silica. Four hundred ninety-two currently employed diatomaceous earth workers in a large mine and processing facility had chest radiographs performed and interpreted by the International Labour Office (ILO) system. Two hundred sixty-seven subjects underwent spirometry testing. Exposure indices for total dust (largely diatomaceous earth) and cristobalite were reconstructed for each individual based upon personnel records. Analysis demonstrated the following prevalences of radiographic findings: 5 % had ILO scores ≤ 1/0, and 25 % had scores of 0/1 or higher. Regression analyses showed that there was a relationship between both total cristobalite exposure and total dust (largely diatomaceous earth) exposure and the ILO score. Radiographic patterns are not typical of those of classic silicosis. Linear regression analyses for forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and FEV1/FVC ratio did not demonstrate a relationship between cumulative exposure and lung function. Such analyses were performed using all subjects and stratified by smoking status. There were differences in spirometric data according to radiographic ILO category, but the results were inconsistent and did not permit determining if physiologic changes are associated with radiographic change or if this is due to confounding. Overall, the study suggests that diatomaceous earth pneumoconiosis (radiographically defined) is an entity distinct from silicosis. Recent exposure levels may produce radiographic abnormalities but do not lead to demonstrable physiologic effect. The prevalence of the disorder has diminished markedly in response to modern dust control measures. Ongoing medical surveillance is recommended in workers with potential exposure to significant quantity of material.

Original languageEnglish (US)
Pages (from-to)22-28
Number of pages7
JournalJournal of occupational and environmental medicine / American College of Occupational and Environmental Medicine
Volume40
Issue number1
DOIs
StatePublished - Jan 1998
Externally publishedYes

Fingerprint

Diatomaceous Earth
Silicon Dioxide
Silicosis
Vital Capacity
Forced Expiratory Volume
Regression Analysis
Pneumoconiosis
Spirometry
Linear Models
Thorax
Smoking
Lung

ASJC Scopus subject areas

  • Public Health, Environmental and Occupational Health
  • Health, Toxicology and Mutagenesis

Cite this

Radiographic and spirometric findings in diatomaceous earth workers. / Harber, Philip I; Dahlgren, James; Bunn, William; Lockey, James; Chase, Gerald.

In: Journal of occupational and environmental medicine / American College of Occupational and Environmental Medicine, Vol. 40, No. 1, 01.1998, p. 22-28.

Research output: Contribution to journalArticle

@article{0f2801597ba64475b11a24305cb4c022,
title = "Radiographic and spirometric findings in diatomaceous earth workers",
abstract = "Diatomaceous earth is a noncrystalline form of silica; in processing, calcining leads to formation of cristobalite, a form of crystalline silica. Four hundred ninety-two currently employed diatomaceous earth workers in a large mine and processing facility had chest radiographs performed and interpreted by the International Labour Office (ILO) system. Two hundred sixty-seven subjects underwent spirometry testing. Exposure indices for total dust (largely diatomaceous earth) and cristobalite were reconstructed for each individual based upon personnel records. Analysis demonstrated the following prevalences of radiographic findings: 5 {\%} had ILO scores ≤ 1/0, and 25 {\%} had scores of 0/1 or higher. Regression analyses showed that there was a relationship between both total cristobalite exposure and total dust (largely diatomaceous earth) exposure and the ILO score. Radiographic patterns are not typical of those of classic silicosis. Linear regression analyses for forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and FEV1/FVC ratio did not demonstrate a relationship between cumulative exposure and lung function. Such analyses were performed using all subjects and stratified by smoking status. There were differences in spirometric data according to radiographic ILO category, but the results were inconsistent and did not permit determining if physiologic changes are associated with radiographic change or if this is due to confounding. Overall, the study suggests that diatomaceous earth pneumoconiosis (radiographically defined) is an entity distinct from silicosis. Recent exposure levels may produce radiographic abnormalities but do not lead to demonstrable physiologic effect. The prevalence of the disorder has diminished markedly in response to modern dust control measures. Ongoing medical surveillance is recommended in workers with potential exposure to significant quantity of material.",
author = "Harber, {Philip I} and James Dahlgren and William Bunn and James Lockey and Gerald Chase",
year = "1998",
month = "1",
doi = "10.1097/00043764-199801000-00007",
language = "English (US)",
volume = "40",
pages = "22--28",
journal = "Journal of Occupational and Environmental Medicine",
issn = "1076-2752",
publisher = "Lippincott Williams and Wilkins",
number = "1",

}

TY - JOUR

T1 - Radiographic and spirometric findings in diatomaceous earth workers

AU - Harber, Philip I

AU - Dahlgren, James

AU - Bunn, William

AU - Lockey, James

AU - Chase, Gerald

PY - 1998/1

Y1 - 1998/1

N2 - Diatomaceous earth is a noncrystalline form of silica; in processing, calcining leads to formation of cristobalite, a form of crystalline silica. Four hundred ninety-two currently employed diatomaceous earth workers in a large mine and processing facility had chest radiographs performed and interpreted by the International Labour Office (ILO) system. Two hundred sixty-seven subjects underwent spirometry testing. Exposure indices for total dust (largely diatomaceous earth) and cristobalite were reconstructed for each individual based upon personnel records. Analysis demonstrated the following prevalences of radiographic findings: 5 % had ILO scores ≤ 1/0, and 25 % had scores of 0/1 or higher. Regression analyses showed that there was a relationship between both total cristobalite exposure and total dust (largely diatomaceous earth) exposure and the ILO score. Radiographic patterns are not typical of those of classic silicosis. Linear regression analyses for forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and FEV1/FVC ratio did not demonstrate a relationship between cumulative exposure and lung function. Such analyses were performed using all subjects and stratified by smoking status. There were differences in spirometric data according to radiographic ILO category, but the results were inconsistent and did not permit determining if physiologic changes are associated with radiographic change or if this is due to confounding. Overall, the study suggests that diatomaceous earth pneumoconiosis (radiographically defined) is an entity distinct from silicosis. Recent exposure levels may produce radiographic abnormalities but do not lead to demonstrable physiologic effect. The prevalence of the disorder has diminished markedly in response to modern dust control measures. Ongoing medical surveillance is recommended in workers with potential exposure to significant quantity of material.

AB - Diatomaceous earth is a noncrystalline form of silica; in processing, calcining leads to formation of cristobalite, a form of crystalline silica. Four hundred ninety-two currently employed diatomaceous earth workers in a large mine and processing facility had chest radiographs performed and interpreted by the International Labour Office (ILO) system. Two hundred sixty-seven subjects underwent spirometry testing. Exposure indices for total dust (largely diatomaceous earth) and cristobalite were reconstructed for each individual based upon personnel records. Analysis demonstrated the following prevalences of radiographic findings: 5 % had ILO scores ≤ 1/0, and 25 % had scores of 0/1 or higher. Regression analyses showed that there was a relationship between both total cristobalite exposure and total dust (largely diatomaceous earth) exposure and the ILO score. Radiographic patterns are not typical of those of classic silicosis. Linear regression analyses for forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and FEV1/FVC ratio did not demonstrate a relationship between cumulative exposure and lung function. Such analyses were performed using all subjects and stratified by smoking status. There were differences in spirometric data according to radiographic ILO category, but the results were inconsistent and did not permit determining if physiologic changes are associated with radiographic change or if this is due to confounding. Overall, the study suggests that diatomaceous earth pneumoconiosis (radiographically defined) is an entity distinct from silicosis. Recent exposure levels may produce radiographic abnormalities but do not lead to demonstrable physiologic effect. The prevalence of the disorder has diminished markedly in response to modern dust control measures. Ongoing medical surveillance is recommended in workers with potential exposure to significant quantity of material.

UR - http://www.scopus.com/inward/record.url?scp=0031891626&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0031891626&partnerID=8YFLogxK

U2 - 10.1097/00043764-199801000-00007

DO - 10.1097/00043764-199801000-00007

M3 - Article

VL - 40

SP - 22

EP - 28

JO - Journal of Occupational and Environmental Medicine

JF - Journal of Occupational and Environmental Medicine

SN - 1076-2752

IS - 1

ER -