reply to post by yellowsnow
Wired page does not provide methodology.
Full study from your pubmed.gov abstract: www.sciencedirect.com...
Eggs of fish or snails were transferred to 50 ml plastic Petri dishes containing different solutions of PtCl2 (platinum standard solution of 1000
μg/ml in 2% HCl, Ultra Scientific, Wesel, Germany) with the following nominal concentrations: 0.1, 1, 10, 50, 100 and 200 μg/l PtCl2 and the control
First, PtCl2 != Pt particulates from catalytic converter.
Second, 1000 ug = 1e-3 g
Moles PtCl2 = 195 + 71 = 1e-3 / 266 = 0.00000376 per ml
1 ml = 0.001 dm^-3
:. [PtCl2] = 0.00000376 / 0.001 = 3.76e-3 M (mol dm^-3)
That's the standard level of PtCl2 (not related to car exhaust) which embryonic organisms were exposed to, they used several multiples of this
including a 1/10 conc. solution and a 10x conc. solution (for comparison, see smoking while pregnant vs smoking in adulthood) while atmospheric levels
of Pt from car exhaust are [not found, trace, evidently orders of magnitude less than those used in this study].
The above calculations are only relevant if we assume Pt particulates in the air from car exhaust are at least partially PtCl2, which you're assuming
in your OP. (They're not.)
Guardian article is misleading - see convergent evolution. Examples of convergent evolution of interest: Cactaceae
On that note, study indicates hypersensitivity of M. cornuarietis
while showing no effect on D. rerio
3.2. Genotoxicity of PtCl2 in D. rerio
Comet assay data revealed no genotoxic hazard of the tested PtCl2 concentrations in cells derived from D. rerio (Fig. 2).
3.3. Genotoxicity of PtCl2 in M. cornuarietis
In contrast to the results obtained for D. rerio, PtCl2 revealed a considerable genotoxic hazard potential for M. cornuarietis. Except for the lowest
tested concentration of 0.1 μg/l PtCl2, tail moments of Pt-exposed snail cells were significantly higher than controls (Fig. 3). With rising
concentration of PtCl2 up to 100 μg/l, an increasing tail moment was observed in cells of M. cornuarietis. Medians of the tail moments of cells of M.
cornuarietis exposed to 50 and 100 μg/l PtCl2 were in the same order of magnitude or even slightly higher than the tail moments of the positive
controls. Only the tail moments recorded for snails exposed to the highest tested concentration of 200 μg/l PtCl2 were, though elevated above
negative control levels, significantly lower than after exposure to 100 μg/l PtCl2 (Fig. 3).
Your sources are unrelated to your claims.
Even if your sources were related to your claims, methodology is not comparable with reality.
Reasons for (not necessity of) use of catalytic converters is well documented, environmental implications mainly, environmental implications may be
suspect but that is not the point of this thread.
edit on 14-1-2013 by Dispo because: (no reason given)