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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

Dermal and inhalation uptakes from chamber air, corrected for uptakes occurring outside the chamber and from hood air, and normalized by chamber air concentrations and body weight plotted against the age of the six participants.
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f4: Dermal and inhalation uptakes from chamber air, corrected for uptakes occurring outside the chamber and from hood air, and normalized by chamber air concentrations and body weight plotted against the age of the six participants.

Mentions: Differences with age. In Figure 4, the normalized dermal and inhalation uptakes from air (micrograms of uptake/kilogram body weight per microgram per cubic meter of air) are plotted against the age of the participants. The older the participant, the higher were the dermal uptakes of both DEP and DnBP from air. Based on this limited sample of six, the impact of age is surprisingly strong. The uptake of DEP by the 66-year-old is five times greater than that of the 27-year-old, while the uptake of DnBP is seven times greater. The inhalation pathway also shows increasing uptake with increasing age for DnBP, but the trend is less pronounced for DEP. In the case of the dermal uptake, Spearman’s correlation coefficients (ρ) between uptake and age are 0.9856 (p = 0.0003) and 1.0 (p = 0.0000) for DEP and DnBP, respectively; in the case of the inhalation uptake, ρ = 0.0286 (p = 0.9572) for DEP and ρ = 1.0 (p = 0.0000) for DnBP.Although their power is weak, these correlation coefficients support expectations based on visual inspection of Figure 4. They indicate that the trend for increased dermal uptake with increasing age is significant for DEP and DnBP, whereas the trend for increased inhalation uptake is significant for DnBP, but not DEP.


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)

Dermal and inhalation uptakes from chamber air, corrected for uptakes occurring outside the chamber and from hood air, and normalized by chamber air concentrations and body weight plotted against the age of the six participants.
© Copyright Policy - public-domain
Related In: Results  -  Collection

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

f4: Dermal and inhalation uptakes from chamber air, corrected for uptakes occurring outside the chamber and from hood air, and normalized by chamber air concentrations and body weight plotted against the age of the six participants.
Mentions: Differences with age. In Figure 4, the normalized dermal and inhalation uptakes from air (micrograms of uptake/kilogram body weight per microgram per cubic meter of air) are plotted against the age of the participants. The older the participant, the higher were the dermal uptakes of both DEP and DnBP from air. Based on this limited sample of six, the impact of age is surprisingly strong. The uptake of DEP by the 66-year-old is five times greater than that of the 27-year-old, while the uptake of DnBP is seven times greater. The inhalation pathway also shows increasing uptake with increasing age for DnBP, but the trend is less pronounced for DEP. In the case of the dermal uptake, Spearman’s correlation coefficients (ρ) between uptake and age are 0.9856 (p = 0.0003) and 1.0 (p = 0.0000) for DEP and DnBP, respectively; in the case of the inhalation uptake, ρ = 0.0286 (p = 0.9572) for DEP and ρ = 1.0 (p = 0.0000) for DnBP.Although their power is weak, these correlation coefficients support expectations based on visual inspection of Figure 4. They indicate that the trend for increased dermal uptake with increasing age is significant for DEP and DnBP, whereas the trend for increased inhalation uptake is significant for DnBP, but not DEP.

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