H
harkonsen8 Dec 2023 17:23Hello everyone,
We have cast asphalt screed throughout the house dating back to the 1970s.
We had a laboratory analysis done as a precaution concerning PAHs.
Parameter Measurement
Naphthalene mg/kg <0.05
Acenaphthylene mg/kg <0.05
Acenaphthene mg/kg <0.05
Fluorene mg/kg 0.077
Phenanthrene mg/kg 0.24
Anthracene mg/kg 0.056
Fluoranthene mg/kg 0.45
Pyrene mg/kg 0.32
Benzo(a)anthracene mg/kg 0.16
Chrysene mg/kg 0.21
Benzo(b)fluoranthene mg/kg 0.17
Benzo(k)fluoranthene mg/kg 0.063
Benzo(a)pyrene mg/kg 0.13
Dibenz(a,h)anthracene mg/kg <0.05
Benzo(ghi)perylene mg/kg 0.15
Indeno(1,2,3-cd)pyrene mg/kg 0.059
Total PAHs EPA mg/kg 2.1
Phenol index mg/l <0.01
As I understand it, these values are acceptable or roughly what you would expect for PAH levels in bitumen.
According to the literature, bitumen usually contains between 2.5 and 100 mg/kg PAHs, and cast asphalt screed around 0.1 to 7 mg/kg, assuming a bitumen content of about 6–8% in the cast asphalt screed.
What do you think, should the floor be removed?
We have cast asphalt screed throughout the house dating back to the 1970s.
We had a laboratory analysis done as a precaution concerning PAHs.
Parameter Measurement
Naphthalene mg/kg <0.05
Acenaphthylene mg/kg <0.05
Acenaphthene mg/kg <0.05
Fluorene mg/kg 0.077
Phenanthrene mg/kg 0.24
Anthracene mg/kg 0.056
Fluoranthene mg/kg 0.45
Pyrene mg/kg 0.32
Benzo(a)anthracene mg/kg 0.16
Chrysene mg/kg 0.21
Benzo(b)fluoranthene mg/kg 0.17
Benzo(k)fluoranthene mg/kg 0.063
Benzo(a)pyrene mg/kg 0.13
Dibenz(a,h)anthracene mg/kg <0.05
Benzo(ghi)perylene mg/kg 0.15
Indeno(1,2,3-cd)pyrene mg/kg 0.059
Total PAHs EPA mg/kg 2.1
Phenol index mg/l <0.01
As I understand it, these values are acceptable or roughly what you would expect for PAH levels in bitumen.
According to the literature, bitumen usually contains between 2.5 and 100 mg/kg PAHs, and cast asphalt screed around 0.1 to 7 mg/kg, assuming a bitumen content of about 6–8% in the cast asphalt screed.
What do you think, should the floor be removed?
“Fear is a poor advisor!” – at least that’s the common saying.
In this case, however, it is true.
The analyses apparently conducted on the mastic asphalt screed for PAHs (polycyclic aromatic hydrocarbons) reveal nothing whatsoever about the emission of pollutants.
The reasoning behind this:
Mastic asphalt is a bitumen-bound mixture modified with minerals.
In the analysis, part of the sample to be tested is dissolved in an organic solvent, so that the components contained within the bitumen type are also present in the solution.
These can then be analyzed qualitatively, quantitatively, or semi-quantitatively for their content.
The possible initial error in the investigation was assuming that all components, and thus all substances, are emitted into the indoor air.
For example, if one were to analyze masonry mortar or a piece of concrete in the same way, pollutants such as chromium and possibly arsenic might be detected.
However, since nobody gnaws on screed or concrete and ingests it, the substances are inert — that is, present but firmly bound in the matrix.
And this is exactly the case with PAHs in bitumen types used or applied in mastic asphalt!
So if, in overzealousness or due to heightened health concerns, someone wants to learn about PAHs in living spaces, an indoor air analysis would have been the correct approach.
Only if a noticeable concentration (of whatever substance) is then measured would one start looking for the source.
And that source is not always what first “catches the eye”!
----------------
Best regards, KlaRa
In this case, however, it is true.
The analyses apparently conducted on the mastic asphalt screed for PAHs (polycyclic aromatic hydrocarbons) reveal nothing whatsoever about the emission of pollutants.
The reasoning behind this:
Mastic asphalt is a bitumen-bound mixture modified with minerals.
In the analysis, part of the sample to be tested is dissolved in an organic solvent, so that the components contained within the bitumen type are also present in the solution.
These can then be analyzed qualitatively, quantitatively, or semi-quantitatively for their content.
The possible initial error in the investigation was assuming that all components, and thus all substances, are emitted into the indoor air.
For example, if one were to analyze masonry mortar or a piece of concrete in the same way, pollutants such as chromium and possibly arsenic might be detected.
However, since nobody gnaws on screed or concrete and ingests it, the substances are inert — that is, present but firmly bound in the matrix.
And this is exactly the case with PAHs in bitumen types used or applied in mastic asphalt!
So if, in overzealousness or due to heightened health concerns, someone wants to learn about PAHs in living spaces, an indoor air analysis would have been the correct approach.
Only if a noticeable concentration (of whatever substance) is then measured would one start looking for the source.
And that source is not always what first “catches the eye”!
----------------
Best regards, KlaRa
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