A sample identified as "Warbex pour-on," expected to contain 13.2% famphur, and bovine tissue samples from 2 heifers that died after exhibiting signs of organophosphate intoxication were analyzed by gas chromatography/mass spectrometry (GC/MS). A product formulation problem was suspected because brain cholinesterase activities were depressed in both animals. Electron impact (EI) GC/MS of the pour-on revealed 9.7% famphur and an unidentified peak with approximately 76% of the peak area of the famphur. The unidentified peak showed a molecular ion at m/z 313, with a single Cl isotope cluster. Methane chemical ionization (MeCI) MS confirmed the molecular weight at 313 (1 Cl). A search on the molecular formula C9H17N3O3PSCl yielded a single match, isazophos. EI and MeCI GC/MS of reference isazophos confirmed the identity of the suspect peak. The concentration of isazophos in the pour-on was determined to be 6.0%. Famphur and isazophos were identified by their EI spectra and GC retention times in extracts of liver and brain from the 2 deceased animals. A GC/MS procedure utilizing selected ion monitoring (SIM) was developed for quantification of isazophos in liver, kidney, muscle, and fat of additional affected animals sacrificed at various times after exposure. Isazophos remained in animal tissues for as long as 94 days after topical exposure. Isazophos was present in fetal liver 70 days after exposure of the dam. High levels (6-3,500 ppm) of isazophos and famphur remained on the skin at 39 days postexposure.
Objective
To analyse maternal and fetal hair lead levels to assess chronic exposure. To evaluate if leaded petrol is associated with high levels of lead in the maternal and fetal hair.
A series of epidemiological studies showed high levels of lead to cause permanent fetal neurological damage. Maternal and fetal hair lead levels are shown to be low in countries using unleaded petrol. But many countries, particularly African continent, are still using leaded petrol.
Mother/baby pairs from centres in Nigeria, UK, Sudan and Cape Town were included in this study. Samples were taken within 3 days of delivery from the consented mothers and their babies. Lead level was analysed as per standard protocol in the same assay in Hull University by inductively coupled plasma mass spectrometry.
The results are shown in the table and are variable and indicate that petrol is not the only source of lead exposure. The Maternal: Fetal ratio varies and seems protective of high levels in the mother.
Table 1Abstract PF.31 Table
Centre
Maternal Hair Geometric mean(range) Ppm (parts per million)
Fetal Hair Geometric mean (range) ppm
Hull (United Kingdom)
1.5
1.4
Unleaded petrol
(0.41-5.44)
(0.26-5.9)
N=26
N=22
Ibadan
33.2
1.5
(Nigeria)
(0.76-355.4)
(0.98-3.6)
Leaded petrol
N=13
N=10
Khartoum
14.4
1.2
(Sudan)
(3.3-195.8)
(0.48-11.9)
Unleaded petrol
N=24
N=23
Cape Town A
5.1
0.24
(South Africa)
(0.20-44.0)
(0.01-3.04)
Leaded Petrol
N=30
n=27
Cape Town B
3.8
0.73
(South Africa)
(0.70-14.6)
(0.24-8.5)
Transition to Unleaded Petrol
N=30
N=25
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