Registration Dossier

Diss Factsheets

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

Constituent 1
Chemical structure
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.