Trilead bis(carbonate) dihydroxide

Sensitisation data (human)

Administrative data

Endpoint:

sensitisation data (humans)

Type of information:

experimental study

Adequacy of study:

other information

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Acceptable, well-documented publication which meets basic scientific principles

Data source

Reference

Reference Type:

publication

Title:

Pulmonary retention of lead: an experimental study in man

Author:

Morrow PE, Beiter H, Amato F & Gibb FR

Year:

1980

Bibliographic source:

Environmental Research 21(2):373-384

Materials and methods

Type of sensitisation studied:

respiratory

Study type:

study with volunteers

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

After brief, mouthpiece exposures, 17 subjects were followed by serial counting with a thoracic array of 12 2-in. scintillation detectors and two 2-in. leg counters, all coupled to single channel analyzers.

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Lead hydroxide

EC Number:

243-310-3

EC Name:

Lead hydroxide

Cas Number:

19783-14-3

Molecular formula:

H2O2Pb

Method

Type of population:

general

Ethical approval:

confirmed and informed consent free of coercion received

Subjects:

- Number of subjects exposed: 2 groups of 4 and 5 persons each
- Sex: men
- Age: mean 26.5 (24-37)
- Other: mean weight 65.9 kg (55-86.4), mean height 1.75 m (1.65-1.85)

Clinical history:

Young adults having no history of pulmonary disease

Route of administration:

inhalation

Details on study design:

TYPE AND DETAILS OF TEST(S) USED
- Lung function measurements: standard respiratory mouthpiece, deszigned so that the aerosol volume breathed was continuously measured using a recording integrator (Linear Instruments, Model 252A)
- Other: the exposure duration was predicated on the assumption that 100% deposition would occur

Results and discussion

Results of examinations:

The average aerosol deposition occuring in the nine lead hydroxide exposures was 26% (SD = 8). This resulted in 1.9 µCi 203Pb (0.7-3.2) and ~3 (1-5) micrograms of lead being deposited in the respiratory system of the average subject.
The measured (effective) halftime for retention of 950min (15.8h) for indicates a biological retention halftime of 22.6 h. Thus the correction factor reduces the biological half time approximately 40% (13.6 vs 22.6).

Any other information on results incl. tables

Urban air studies indicate atmospheric lead aerosol has a MMAD between 0.18 and 0.6 µm

Applicant's summary and conclusion

Conclusions:

The collective evidence supports the view that atmospheric lead is rapidly and completly absorbed from the human lungs.