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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: 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.Metabolites of DEP and DnBP were measured in these samples and extrapolated to parent phthalate intakes, corrected for background and hood air exposures.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

Box plots displaying the uptakes (μg) of DEP and DnBP, corrected for uptakes occurring outside the chamber and from hood air, normalized by measured chamber air concentrations during each exposure experiment (μg/m3; Table 1), for exposures without a hood (total) and exposures with a hood (dermal), and for the differences between these two uptakes (inhalation). Boxes extend from the 25th to the 75th percentile, horizontal lines represent the median, and whiskers indicate the 10th and 90th percentiles. The symbols indicate individual results for each of the six participants (P1–P6).
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f3: Box plots displaying the uptakes (μg) of DEP and DnBP, corrected for uptakes occurring outside the chamber and from hood air, normalized by measured chamber air concentrations during each exposure experiment (μg/m3; Table 1), for exposures without a hood (total) and exposures with a hood (dermal), and for the differences between these two uptakes (inhalation). Boxes extend from the 25th to the 75th percentile, horizontal lines represent the median, and whiskers indicate the 10th and 90th percentiles. The symbols indicate individual results for each of the six participants (P1–P6).

Mentions: Total uptake of DEP and DnBP estimated from urinary metabolite levels. As described in “Methods,” the total uptake of DEP and DnBP can be back-calculated from the concentrations of their metabolites in a participant’s urine samples. Figure 3 displays box plots of the net uptakes (micrograms) of DEP and DnBP, corrected for background and hood air uptakes, and normalized by their measured air concentrations during each exposure experiment (micrograms per cubic meter, Table 1). Separate box plots are displayed for exposures without a hood (total), exposures with a hood (dermal), and the differences between these two uptakes (inhalation). The median value for dermal uptake of DEP is slightly higher than that for its inhalation intake [4.0 vs. 3.8 μg/(μg/m3 air)]. The median value for dermal uptake of DnBP is about 80% of that for its inhalation intake [3.1 vs. 3.9 μg/(μg/m3 air)].


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)

Box plots displaying the uptakes (μg) of DEP and DnBP, corrected for uptakes occurring outside the chamber and from hood air, normalized by measured chamber air concentrations during each exposure experiment (μg/m3; Table 1), for exposures without a hood (total) and exposures with a hood (dermal), and for the differences between these two uptakes (inhalation). Boxes extend from the 25th to the 75th percentile, horizontal lines represent the median, and whiskers indicate the 10th and 90th percentiles. The symbols indicate individual results for each of the six participants (P1–P6).
© Copyright Policy - public-domain
Related In: Results  -  Collection

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

f3: Box plots displaying the uptakes (μg) of DEP and DnBP, corrected for uptakes occurring outside the chamber and from hood air, normalized by measured chamber air concentrations during each exposure experiment (μg/m3; Table 1), for exposures without a hood (total) and exposures with a hood (dermal), and for the differences between these two uptakes (inhalation). Boxes extend from the 25th to the 75th percentile, horizontal lines represent the median, and whiskers indicate the 10th and 90th percentiles. The symbols indicate individual results for each of the six participants (P1–P6).
Mentions: Total uptake of DEP and DnBP estimated from urinary metabolite levels. As described in “Methods,” the total uptake of DEP and DnBP can be back-calculated from the concentrations of their metabolites in a participant’s urine samples. Figure 3 displays box plots of the net uptakes (micrograms) of DEP and DnBP, corrected for background and hood air uptakes, and normalized by their measured air concentrations during each exposure experiment (micrograms per cubic meter, Table 1). Separate box plots are displayed for exposures without a hood (total), exposures with a hood (dermal), and the differences between these two uptakes (inhalation). The median value for dermal uptake of DEP is slightly higher than that for its inhalation intake [4.0 vs. 3.8 μg/(μg/m3 air)]. The median value for dermal uptake of DnBP is about 80% of that for its inhalation intake [3.1 vs. 3.9 μg/(μg/m3 air)].

Bottom Line: 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.Metabolites of DEP and DnBP were measured in these samples and extrapolated to parent phthalate intakes, corrected for background and hood air exposures.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