Registration Dossier

Administrative data

Endpoint:
health surveillance data
Type of information:
experimental study
Adequacy of study:
disregarded due to major methodological deficiencies
Reliability:
3 (not reliable)
Rationale for reliability incl. deficiencies:
other: Does not meet important study design or analytical criteria. Co-expsoure to cobalt, chromium, and other substances not accounted for in analyses.
Cross-reference
Reason / purpose:
reference to other study

Data source

Reference
Reference Type:
publication
Title:
Effect of nickel and chromium exposure on buccal cells of electroplaters
Author:
Qayyum S, Ara A, Usmani JA
Year:
2011
Bibliographic source:
Toxicology and Industrial Health; 28(1):74-82

Materials and methods

Endpoint addressed:
genetic toxicity
Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
Male individuals were exposed to nickel and evaluated for genotoxic damage, such as micronuclei induction and other anomalies.

Test material

Reference
Name:
Unnamed
Type:
Constituent

Method

Type of population:
occupational
Details on study design:
Cohort of 150 male subjects; age 18-35 years old (mean age of 25.85 years)

Subjects were divided into 3 groups: Group I (controls), Group II (subchronic exposure; electroplaters for <10 years), and Group III (chronic exposure; electroplaters for 10 or more years)

Subjects completed a questionnaire about the nature and duration of their work, smoking and drinking habits, medical history, and symptomatology list of common symptoms associated with skin, respiratory tract, and dental problems. Smokers, drinkers, tobacco chewers were eliminated from the study.

5 ml of blood was collected from each patient every morning and plasma was isolated.

Nickel concentrations were estimated with atomic absorption spectrophotometry (wavelength of 232 nm).

Epithelial (buccal) cells were obtained from the cheeks of each subject, then fixed and stained on slides. The micronuclei test was scored according to the criteria detailed in Fenech et al (2003). The nuclear anomalies were scored according to the criteria detailed in Tolbert et al (1992).

Results and discussion

Results:
Group III (electroplaters with over 10 years of exposure) had the highest concentration of plasma nickel (significant difference) and the highest frequency of micronuclei in buccal cells (significant difference).

Karyorrhexis, karyolysis, binucleated cells, and enucleated cells were more significantly more frequent in Group III subjects.
There was no significant change in the frequency of pyknosis (pkynotic cells).

A significant positive correlation was observed between plasma nickel levels and the frequencies of micronuclei, karyorrhexis, karyolysis, binucleated cells, and enucleated cells. There was no significant correlation with pyknosis (pkynotic cells).

Applicant's summary and conclusion

Executive summary:

Study was rated by an independent reviewer.