Cobalt hydroxide oxide

Health surveillance data

Administrative data

Endpoint:

health surveillance data

Type of information:

experimental study

Adequacy of study:

disregarded due to major methodological deficiencies

Reliability:

other: Any kind of reliability rating is not considered to be applicable, since human health surveillance data, epidemiological studies, field studies and case reports are not conducted/reported according to standardised guidelines

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

The references contained in this summary entry represent monitoring data of the general population with very limited value for risk assessment purposes, due to the following reasons. The reported data suffer either from a lack of statistical relevance (low number of samples), inadequacy of the analytical method or lack plausibility; not considered relevant or reliable for risk assessment purposes.

Data source

Reference

Reference 1

Reference Type:

publication

Title:

Essential trace metal in man: Cobalt

Author:

Schroeder, H. A. et al.

Year:

1967

Bibliographic source:

J. Chronic Dis. 20, 869-890

Reference 2

Reference Type:

publication

Title:

Metal concentrations in human lung tissue, with special references to age, sex, cause of death, emphysema and contamination of lung tissue

Author:

Takemoto, K. et al.

Year:

1991

Bibliographic source:

Int. Arch. Occup. Environ. Health 62, 579-586

Reference 3

Reference Type:

publication

Title:

Trace elements in human tissue, Part II. Adult subjects from the United States

Author:

Tipton, I.H.; Cook, M.

Year:

1963

Bibliographic source:

Health Phys. 9, 103-145

Reference 4

Reference Type:

publication

Title:

The Cobalt Content of Human Body

Author:

Yamagata, N.

Year:

1962

Bibliographic source:

J. Radiat. Res. 3, 4-8

Materials and methods

Study type:

other: monitoring

Endpoint addressed:

basic toxicokinetics

Test guideline

Qualifier:

no guideline available

Principles of method if other than guideline:

STUDY 1:“normal” background cobalt tissue levels in human autopsy material from non-exposed individuals STUDY 2:Analysis of cobalt concentrations in 1,438 human lung autopsy samples from JapanSTUDY 3:Analysi of cobalt as a trace element as "background" in human tissue samples from spontaneously deceased individuals (n=150)STUDY 4:Normal background cobalt tissue levels in human autopsy samples (n=14)

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Cobalt

EC Number:

231-158-0

EC Name:

Cobalt

Cas Number:

7440-48-4

Molecular formula:

Co

IUPAC Name:

cobalt(2+)

Method

Type of population:

general

Details on study design:

STUDY 1: Foods, feeds and human tissue from three autopsies were analysed for cobalt by atomic absorption spectrophotometry.STUDY 2: Cobalt was analysed in lung tissue from autopsy samples of individuals, who had suffered from a wide range of illnesses, by atomic absorption spectrometry. STUDY 3: Tissue samples of 150 subjects were collected, prepared and spectrographical and statistical analysed for 27 variables.STUDY 4: Spectrophotometric analyses have been made of common cobalt in the human tissue and organs from autopsies.

Results and discussion

Results:

STUDY 1:Cobalt was analysed in three autopsy samples from the US with concentrations ranging from 0.01-0.4 ug/g (wet weight). In samples from a total of 348 subjects from both the US and abroad, cobalt levels were close to or below detection limit.STUDY 2:Cobalt was analysed in lung tissue from individuals who had suffered from a wide range of illnesses. Median lung cobalt levels were 0.18 ug/g (dry weight), with a 95th percentile of 0.9 ug/g. Cobalt levels did not vary with age, sex or severity of lung emphysema, for example.STUDY 3:Cobalt was analysed in a wide range of tissues, but was below detection limit in all cases, due to a lack in sensitivity of the analytical method.STUDY 4:The authors claim that cobalt was detected in autopsy samples from Japan at concentrations ranging from 1-77 ug/g (wet weight), with highest concentrations in bone. These data are not plausible, since they are three orders of magnitude higher than other published data (which are reported in ug/g).