Reaction mass of cerium dioxide and lanthanum oxide and lanthanum fluoride

Direct observations: clinical cases, poisoning incidents and other

Administrative data

Endpoint:

direct observations: clinical cases, poisoning incidents and other

Type of information:

other: occupational surveillance report

Adequacy of study:

supporting study

Study period:

November 1967 / December 1968

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Well documented clinical report

Data source

Reference

Reference Type:

publication

Title:

[Pneumoconiosis due to cerium] (article in French)

Author:

Nappée J, Bobrie J, Lambard D

Year:

1972

Bibliographic source:

Arch Mal Prof. 33(1): 13-8

Materials and methods

Study type:

clinical case study

Endpoint addressed:

repeated dose toxicity: inhalation

Test guideline

Qualifier:

no guideline required

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Cerium oxide or Cerox

IUPAC Name:

Cerium oxide or Cerox

Method

Type of population:

occupational

Subjects:

- Number of subjects exposed: 2
- Sex: Male
- Age: 62 years old (subject 1) / 59 years old (subject 2)
- Race: Not specified
- Demographic information: 15 years in cerium oxide preparation, smoker (20 cigarettes/day) (subject 1) / 11 years in cerium oxide preparation, smoking status not provided
- Known diseases: None (suject 1) / Past ulcer on right leg (subject 2)
- Other: Workers in a plant in the region of La Rochelle (France) in an extraction workshop

Ethical approval:

not applicable

Route of exposure:

inhalation

Reason of exposure:

intentional, occupational

Exposure assessment:

not specified

Examinations:

Pulmonary examination, cardiac examination (one worker), bone radiography, bronchoscopy, bronchial anatomopathology (biopsy), respiratory functional exploration, clinical biology

Medical treatment:

None

Results and discussion

Clinical signs:

No relevant clinical sign reported

Results of examinations:

Cerium oxide pneumoconiosis was diagnosed in two workers exposed to cerium oxide by inhalation for 11 or 15 years in an extraction workshop of this rare earth. The level of exposure was unknown. This pneumoconiosis practically did not modify the respiratory function. It rather appeared only as a pulmonary overload of cerium oxide which is opaque to X-rays.

Any other information on results incl. tables

Table: Results of examinations in the two workers

 

	Subject 1	Subject 2
Pulmonary examination	Normal auscultation – Pulmonary radiography for 3 years from November 1967 show constant reticulo-nodulation in the whole lungs. No mediastinal lymphoadenopathy.	Normal auscultation – Pulmonary radiography for 2 years from December 1968 show 2-3 mmdiameter pulmonary nodules in both lungs, more particularly basal left lung. No hilum lymphoadenopathy.
Cardiac examination	Normal (electrical and clinical) - blood pressure 14 -8	Normal (electrical and clinical) - blood pressure 16-9
Bone radiography	Normal	Normal
Bronchoscopy	Bronchitis aspect (mucosa more red than normal and a few non-purulent secretions)	Bronchial spasms, red and inflamed mucosa, with mucous secretions
Bronchial anatomopathology	Ciliated cylindrical epithelium interrupted on a portion by a malpighian metaplasia, going back to the cylindrical type afterwards. Chorion particularly rich in seromucous glands, surrounded by lymphocytic infiltration, without specific arrangement.	Malpighian metaplasia in a really localised aera of the bronchial mucosa epithelium. Discrete inflammatory infiltration in superficial chorion, with quite dense collagenous sclerosis. Attributed to chronic inflammatory lesions without specific etiology.
Respiratory functional exploration	Slight restriction (around 30%) – No sign of obstruction or distension –Normalblood gaz	Slight restriction (around 30%) – No sign of obstruction or distension –Normalblood gaz
Clinical biology	Positive tuberculosis intradermo reaction – Negative search for tuberculosis agent – Metopyrone test: negative – Other clinical biology tests: normal	Positive tuberculosis intradermo reaction – Negative search for tuberculosis agent – Metopyrone test: negative – Other clinical biology tests: normal

Applicant's summary and conclusion

Conclusions:

Cerium oxide pneumoconiosis was diagnosed in two workers exposed to cerium oxide by inhalation for 11 or 15 years in an extraction workshop of this rare earth. The level of exposure was unknown. This pneumoconiosis practically did not modify the respiratory function. It rather appeared only as a pulmonary overload of cerium oxide which is opaque to X-rays.