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Transdermal Uptake of Diethyl Phthalate and Di(n-butyl) Phthalate Directly from Air: Experimental Verification.

Weschler CJ, Bekö G, Koch HM, Salthammer T, Schripp T, Toftum J, Clausen G - Environ. Health Perspect. (2015)

Bottom Line: For DEP, the median dermal uptake directly from air was 4.0 μg/(μg/m(3) in air) compared with an inhalation intake of 3.8 μg/(μg/m(3) in air).For DnBP, the median dermal uptake from air was 3.1 μg/(μg/m(3) in air) compared with an inhalation intake of 3.9 μg/(μg/m(3) in air).For other semivolatile organic compounds (SVOCs) whose molecular weight and lipid/air partition coefficient are in the appropriate range, direct absorption from air is also anticipated to be significant.

View Article: PubMed Central - PubMed

Affiliation: Environmental and Occupational Health Sciences Institute, Rutgers University, Piscataway, New Jersey, USA.

ABSTRACT

Background: Fundamental considerations indicate that, for certain phthalate esters, dermal absorption from air is an uptake pathway that is comparable to or greater than inhalation. Yet this pathway has not been experimentally evaluated and has been largely overlooked when assessing uptake of phthalate esters.

Objectives: This study investigated transdermal uptake, directly from air, of diethyl phthalate (DEP) and di(n-butyl) phthalate (DnBP) in humans.

Methods: In a series of experiments, six human participants were exposed for 6 hr in a chamber containing deliberately elevated air concentrations of DEP and DnBP. The participants either wore a hood and breathed air with phthalate concentrations substantially below those in the chamber or did not wear a hood and breathed chamber air. All urinations were collected from initiation of exposure until 54 hr later. Metabolites of DEP and DnBP were measured in these samples and extrapolated to parent phthalate intakes, corrected for background and hood air exposures.

Results: For DEP, the median dermal uptake directly from air was 4.0 μg/(μg/m(3) in air) compared with an inhalation intake of 3.8 μg/(μg/m(3) in air). For DnBP, the median dermal uptake from air was 3.1 μg/(μg/m(3) in air) compared with an inhalation intake of 3.9 μg/(μg/m(3) in air).

Conclusions: This study shows that dermal uptake directly from air can be a meaningful exposure pathway for DEP and DnBP. For other semivolatile organic compounds (SVOCs) whose molecular weight and lipid/air partition coefficient are in the appropriate range, direct absorption from air is also anticipated to be significant.

No MeSH data available.


Related in: MedlinePlus

Net amount of MEP and MnBP excreted by each of the six participants (P1–P6) from the time exposure began until 54 hr later. No adjustments were made to the values.
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f2: Net amount of MEP and MnBP excreted by each of the six participants (P1–P6) from the time exposure began until 54 hr later. No adjustments were made to the values.

Mentions: Net amount of metabolite excreted over time. For each participant, Figure 2 shows the net amount of MEP and MnBP excreted from the time exposure began until 54 hr later (no corrections have been made to the values). As anticipated, there is participant-to-participant variability. However, for all participants there is substantial excretion of MEP and MnBP when they are exposed while wearing hoods (i.e., when exposure from chamber air is primarily via the dermal pathway). The net amount of MEP excreted when the participants were wearing hoods is roughly half that excreted when not wearing hoods; for MnBP, the fraction is somewhat less than half. It is also apparent from these plots that, during the initial 12 hr, the excreted amounts of both MEP and MnBP increased faster when participants were not wearing hoods than when wearing hoods.


Transdermal Uptake of Diethyl Phthalate and Di(n-butyl) Phthalate Directly from Air: Experimental Verification.

Weschler CJ, Bekö G, Koch HM, Salthammer T, Schripp T, Toftum J, Clausen G - Environ. Health Perspect. (2015)

Net amount of MEP and MnBP excreted by each of the six participants (P1–P6) from the time exposure began until 54 hr later. No adjustments were made to the values.
© Copyright Policy - public-domain
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4590762&req=5

f2: Net amount of MEP and MnBP excreted by each of the six participants (P1–P6) from the time exposure began until 54 hr later. No adjustments were made to the values.
Mentions: Net amount of metabolite excreted over time. For each participant, Figure 2 shows the net amount of MEP and MnBP excreted from the time exposure began until 54 hr later (no corrections have been made to the values). As anticipated, there is participant-to-participant variability. However, for all participants there is substantial excretion of MEP and MnBP when they are exposed while wearing hoods (i.e., when exposure from chamber air is primarily via the dermal pathway). The net amount of MEP excreted when the participants were wearing hoods is roughly half that excreted when not wearing hoods; for MnBP, the fraction is somewhat less than half. It is also apparent from these plots that, during the initial 12 hr, the excreted amounts of both MEP and MnBP increased faster when participants were not wearing hoods than when wearing hoods.

Bottom Line: For DEP, the median dermal uptake directly from air was 4.0 μg/(μg/m(3) in air) compared with an inhalation intake of 3.8 μg/(μg/m(3) in air).For DnBP, the median dermal uptake from air was 3.1 μg/(μg/m(3) in air) compared with an inhalation intake of 3.9 μg/(μg/m(3) in air).For other semivolatile organic compounds (SVOCs) whose molecular weight and lipid/air partition coefficient are in the appropriate range, direct absorption from air is also anticipated to be significant.

View Article: PubMed Central - PubMed

Affiliation: Environmental and Occupational Health Sciences Institute, Rutgers University, Piscataway, New Jersey, USA.

ABSTRACT

Background: Fundamental considerations indicate that, for certain phthalate esters, dermal absorption from air is an uptake pathway that is comparable to or greater than inhalation. Yet this pathway has not been experimentally evaluated and has been largely overlooked when assessing uptake of phthalate esters.

Objectives: This study investigated transdermal uptake, directly from air, of diethyl phthalate (DEP) and di(n-butyl) phthalate (DnBP) in humans.

Methods: In a series of experiments, six human participants were exposed for 6 hr in a chamber containing deliberately elevated air concentrations of DEP and DnBP. The participants either wore a hood and breathed air with phthalate concentrations substantially below those in the chamber or did not wear a hood and breathed chamber air. All urinations were collected from initiation of exposure until 54 hr later. Metabolites of DEP and DnBP were measured in these samples and extrapolated to parent phthalate intakes, corrected for background and hood air exposures.

Results: For DEP, the median dermal uptake directly from air was 4.0 μg/(μg/m(3) in air) compared with an inhalation intake of 3.8 μg/(μg/m(3) in air). For DnBP, the median dermal uptake from air was 3.1 μg/(μg/m(3) in air) compared with an inhalation intake of 3.9 μg/(μg/m(3) in air).

Conclusions: This study shows that dermal uptake directly from air can be a meaningful exposure pathway for DEP and DnBP. For other semivolatile organic compounds (SVOCs) whose molecular weight and lipid/air partition coefficient are in the appropriate range, direct absorption from air is also anticipated to be significant.

No MeSH data available.


Related in: MedlinePlus