Toxicological Review of Barium and Compounds

were measured using a thermal precipitator; the concentration of barium in the dust was not 

measured.  Barite samples were analyzed for quartz, silica, and iron content.  No quartz was 

detected, and the total silica and total iron (as Fe

2

O

3

) concentrations were 0.07%–1.96% and 

0.03%–0.89%, respectively. 

Ten of the eleven workers examined in 1961 were reexamined in 1963 (18 months later). 

Two new cases of pneumoconiosis were diagnosed.  Thus, 9 of 10 workers exposed to barium 

sulfate for 1.5 to 19.5 years (mean of 8.2) had well-marked baritosis.  Three of these workers 

reported a slight or occasional cough and none had dyspnea.  Among the nine workers with 

baritosis, three did not smoke, four smoked 

#

1 pack/day, and two smoked >1 pack/day.  In six of 

the seven workers with previously diagnosed baritosis, no significant changes in the degree of 

pneumoconiosis were observed; an increase in the number of opacities was observed in the 

seventh worker.  Spirometric lung function tests (vital capacity, flow rate, and forced expiratory 

volume) were performed in five workers.  For three of these workers, the results of the lung 

function tests were similar to predicted normal values (89%-119% of predicted values).  Lung 

function was below normal in the other two workers (70%-85% of predicted values).  It is 

questionable whether the impaired lung function was related to barium exposure.  One of the two 

workers was an alcoholic and heavy smoker, and the other had a fibrotic right middle lung lobe 

that probably resulted from a childhood illness. 

In 1964, the barite grinding facility closed.  Follow-up examinations were performed in 

1966, 1969, and 1973 on five of the workers.  Termination from barium exposure resulted in a 

decline in the profusion and density of opacities.  In 1966, there was slight clearing of opacities; 

by 1973, there was a marked decrease in profusion and density.  No significant changes in lung 

function were observed during this 10-year period. 

NIOSH (1982) conducted a health survey of past and present workers at the Sherwin-

Williams Company’s Coffeyville, KS, facility.  Work performed at the facility included grinding, 

blending, and mixing mineral ores.  At the time of the study, four processes were in operation: 

“ozide process,” which involved blending several grades of zinc oxide; “ozark process,” which 

involved bagging very pure zinc oxide powder; “bayrite process,” which involved grinding and 

mixing several grades of barium-containing ores; and “sher-tone process,” which involved 

mixing inert clays with animal tallow.  A medical evaluation was performed on 61 current 

workers (91% participation) and 35 laid-off or retired workers (27% participation).  Information 

on demographics, frequency of various symptoms occurring during the past 2 months, chemical 

exposure, occupational history, smoking history, and history of renal disease, allergies, and 

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hypertension was obtained from directed questionnaires.  In addition, spot urine and blood 

samples and blood pressure measurements were taken.  Exposures to barium, lead, cadmium, and 

zinc were estimated from 27 personal samples collected over a 2-day period.  In the seven 

personal breathing zone samples collected from the bayrite area, the levels of soluble barium 

ranged from 87.3 to 1920 

:

g/m

3

 (mean of 1068.5 

:

g/m

3

), lead levels ranged from not detected to 

15 

:

g/m

3

 (mean of 12.2 

:

g/m

3

, excluding the two no-detect samples), zinc levels ranged from 

22.4 to 132 

:

g/m

3

 (mean of 72 

:

g/m

3

), and all seven samples had no detectable levels of 

cadmium.  Soluble barium was also detected in breathing zone samples in the ozark area (10.6-

1397 

:

g/m

3

, mean of 196.1 

:

g/m

3

), ozide area (11.6-99.5 

:

g/m

3

, mean of 46.8 

:

g/m

3

), and sher­

tone area (114.3-167.5 

:

g/m

3

, mean of 70.45 

:

g/m

3

). 

Two approaches were used to analyze the results of the health survey.  In the first 

approach, the workers were divided into five groups based on current job assignments.  Of the 61 

current workers, 14 worked in the bayrite area.  No statistically significant increases in the 

incidence of subjective symptoms (e.g., headache, cough, nausea) or differences in mean blood 

lead levels, number of workers with blood lead levels of greater than 39 

:

g/dL, mean free 

erythrocyte protoporphyrin (FEP) levels, mean hematocrit levels, mean serum creatinine levels, 

number of workers with serum creatinine levels of greater than 1.5 mg/dL, number of workers 

with BUN levels of greater than 20 mg/dL, blood pressure, or mean urine cadmium levels were 

observed among the different groups of workers.  In the second approach, the workers were 

divided into seven groups based on past job assignments.  One group consisted of 12 workers 

working in barium process areas (bayrite process and other processes no longer in operation at 

the facility that involved exposure to barium ores and barium carbonate) for at least 5 years; 

barium exposure levels were not reported for this group of workers.  The results of the health 

survey for the barium-exposed workers were compared with results for 25 workers who stated 

that they had never worked in barium process areas.  No statistically significant differences in 

mean age, number of years employed, number of current or past smokers, prevalence of 

subjective symptoms, mean FEP levels, mean hematocrit levels, mean urine cadmium levels, 

mean 

$

2-microglobulin levels, or the prevalence of workers with elevated serum creatinine, 

BUN, or urine protein levels were observed between the two groups.  The number of workers 

with elevated blood pressure (defined as systolic pressure 

$

140 mm Hg or diastolic pressure 

$

90 mm Hg, or taking medication for hypertension) was significantly higher (p=0.029) in the 

barium-exposed group (7/12, 58%) than in the comparison group (5/25, 20%).  The number of 

workers in the barium group with blood lead levels of >39 

:

g/dL was lower than in the 

comparison group (0% vs. 28%); however, the difference was not statistically significant 

(p=0.072).  Additionally, there was no significant difference between mean blood lead levels in 

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