Synthetic wollastonite

Health surveillance data

Administrative data

Endpoint:

health surveillance data

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study in accordance with generally accepted scientific standards and described in sufficient detail.

Data source

Reference

Reference Type:

publication

Title:

Respiratory effects and serum type III procollagen in potato sorters exposed to diatomaceous earth

Author:

Jorna TH, Borm PJ, Koiter KD, Slangen JJ, Henderson PT, Wouters EF

Year:

1994

Bibliographic source:

Int Arch Occup Environ Health. 66(4):217-22

Materials and methods

Study type:

medical monitoring

Endpoint addressed:

repeated dose toxicity: inhalation

Test guideline

Qualifier:

no guideline required

Principles of method if other than guideline:

The occurrence of pneumoconiosis and airflow limitations in 172 male workers from 5 potato sorting plants exposed to inorganic dust from former sea terraces high in diatomaceous earth was determined. The presence of fibrosis was evaluated by chest radiograph and serum levels of type 111 procollagen (P-111-P) were measured as an estimate of fibrogenetic activity. Lung function was assessed by flow volume curves and impedance measurements. A validated questionnaire was used to record respiratory symptoms

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Diatomaceous earth

IUPAC Name:

Diatomaceous earth

Details on test material:

- Name of test material (as cited in study report): diatomaceous earth

Method

Type of population:

occupational

Ethical approval:

other: written informed consent of participants was obtained prior to measurements.

Details on study design:

HYPOTHESIS TESTED
The main purpose of this cross-sectional study was to determine whether respiratory hazards are present due to the exposure mix, high in diatomaceous dust in potato sorting.

SETTING AND STUDY POPULATION
Male Caucasian workers (11 = 174) from 5 potato sorting plants of the same agricultural cooperative in the Netherlands were studied (Table 1), and 172 complete data sets were obtained. The study was conducted in the month of October, just after the potato harvest at peak activity of these plants.
Salesmen (n = 29) who experienced short-term exposure during the taxation of the crop (1 h/day on average) were regarded as a separate group. Questionnaires were obtained from 55 office staff (Group I = controls), 29 salesmen (II = salesmen), 72 blue collar workers (Ill = currently exposed), and 16 retired blue collar workers (IV = retired exposed)

Results and discussion

Results:

No irregularities were detected on the chest radiographs; in consequence, all radiographs were classified as 0/0 according to ILO criteria. In line with this finding, serum PIII-P levels were similar in the control and exposed groups.
All spirometric parameters, except FVC (forced vital capacity) were significantly lower in currently exposed workers (group III) than in controls (table 2). Differences were even more pronounced in the group of retired workers (group IV).
Airflow limitation (FEV1 ≤ 80%) was observed in 23 subjects, resulting in an incidence rate of 23/172 (13.4%). Cumulative dust exposure in the 16 workers with FEV1 ≤ 80% from groups III and IV was significantly higher compared to workers without airflow limitation (223.4 vs 112.5 gh/m3, p≤0.001).
The analysis of questionnaire data showed that dust exposure was significantly related to complaints of productive cough and chronic bronchitis.

Any other information on results incl. tables

Table 2: Average results of flow volume curves, impedance measurements, and serum P-III-P measurements in the four groups of workers.

Parameter	Group I		Group II		Group III		Group IV
	Office staff (control)		Salesmen		Current exposed		Retired exposed
	n = 55		n = 29		n = 72		n = 16
	Mean	SD	Mean	SD	Mean	SD	Mean	SD
Spirometry
FVC [%^a]]	109.5	10.9	110.4	11.4	107.3	11.5	109.0	16.4
FEV1 [%^a]]	99.0	11.8	100.2	12.5	93.4 *	15.6	93.4 *	22.7
FEV1/FVC ratio	74.2	7.2	74.0	7.5	70.4 *	9.3	66.4 *	8.2
PEF [%^a]]	98.8	13.2	102.2	15.5	93.2 *	17.6	88.9 **	23.1
MMEF [%^a]]	78.5	21.1	79.2	22.2	67.6 **	24.4	59.5 **	33.1
Impedance
R8 [hPa s/l]	2.26	0.56	2.22	0.57	2.42 *	0.97	2.85 **	1.38
FD [hPa s/l]	0.36	0.37	0.38	0.36	0.21 *	0.63	-0.28 *	0.78
X8 [hPa s/l]	0.04	0.20	0.05	0.21	-0.11 *	0.51	-0.47 *	1.06
f0 [hPa s/l]	8.17	1.90	8.16	1.82	9.63 *	4.4	12.62 *	7.9
Blood
Serum P-III-P levels	50.9	9.39	47.34	8.01	46.92	8.52	46.04	9.14

Significantly different from control (Group I) at * p<0.05 ** p<0.01

^a]Spirometric parameters as % predicted of European Community of Coal and Steel (ECCS) reference values.

Applicant's summary and conclusion

Conclusions:

This study shows that working populations exposed to clay (with amorphous diatomaceous earth) is not at an increased risk to develop pneumoconiosis. The main respiratory effect of the dust observed was airflow limitation with or without chronic bronchitis. No discrimination between the effects of total dust and respirable silica could be made.

Executive summary:

The occurrence of pneumoconiosis and airflow limitation in 172 male workers from 5 potato sorting plants (55 controls, 29 salesman with low exposure, 72 currently exposed, 16 retired exposed) exposed to inorganic dust high in diatomaceous earth was investigated.

No pneumoconiotic abnormalities were detected in by chest radiography in any worker. In line with this finding, serum PIII-P levels, as marker for fibrotic activity, were similar in the control and exposed groups. Nearly all spirometric parameters were significantly lower in currently exposed workers and even more so in retired workers compared to controls. The observed airflow obstruction was dose related to dust exposure.