Dermal Exposure Assessment Of Polycyclic Aromatic Hydrocarbons
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Int Arch Occup Environ Health (1999) 72: 528±532
Ó Springer-Verlag 1999
ORIGINAL ARTICLE
P. Sartorelli á A. Cenni á G. Matteucci á L. Montomoli M. T. Novelli á S. Palmi
Dermal exposure assessment of polycyclic aromatic hydrocarbons: in vitro percutaneous penetration from lubricating oil
Received: 7 January 1999 / Accepted: 10 July 1999
Abstract Objectives: Percutaneous penetration of polycyclic aromatic hydrocarbons (PAHs) is aected by various factors connected to exposure conditions. The nature of the matrix, such as that of oil, can strongly aect their percutaneous penetration. Risk assessment should consider these eects. We examined the eect of matrix on percutaneous penetration of PAHs, particularly that of lubricating oil. Methods: The test apparatus consisted of an in vitro static diusion cell system using full-thickness monkey (Cercopithecus aetiops) skin as the membrane and saline solution with gentamycin sulfate and 4% bovine serum albumin as receptor ¯uid. Chemical analysis of PAHs in the samples obtained from cells was carried out by inverse-phase HPCL, and the results were read by spectro¯uorimetry. Results: Comparing the penetration of 13 PAHs from a lubricating oil and from acetone solution with arti®cial sweat resulted in a signi®cantly slower passage from the oil matrix for acenaphthene, anthracene, phenanthrene, ¯uoranthene, naphthalene, pyrene, ¯uorene (MannWhitney U test, P < 0.05). No signi®cant dierences in the passage were found for chrysene because, in the test with oil, its concentration was very often below the detection limit. For benzo[a]anthracene, benzo[b]¯uoranthene, benzo[k]¯uoranthene, and benzo[a]pyrene it was possible to demonstrate a passage through the skin only when compounds were applied in acetone solution with arti®cial sweat. Conclusions: The results of the study
P. Sartorelli (&) á A. Cenni á L. Montomoli á M.T. Novelli Istituto di Medicina del Lavoro, UniversitaÁ degli Studi di Siena, Via dei Tu® 1, I-53100 Siena, Italy e-mail: [email protected] Tel.: +39-577-586755; Fax: +39-577-586159 G. Matteucci Biocine Sclavo, Via Fiorentina 1, I-53100 Siena, Italy S. Palmi Dipartimento di Medicina del Lavoro, ISPESL, Via Urbana 167, I-00184 Roma, Italy
suggest the necessity of dermal penetration data relevant for risk assessment, obtained under experimental conditions similar to the real exposure conditions. Key words Dermal exposure á Percutaneous penetration á Polycyclic aromatic hydrocarbons á Risk assessment
Introduction It is well known that percutaneous penetration of chemicals is strongly aected by the vehicle [2, 10]. Dermal exposure to polycyclic aromatic hydrocarbons (PAHs) can occur by deposition of vapors and particles or by splashing of oils. These are very common occurrences at workplaces. The nature of the matrix can aect percutaneous absorption of PAHs. Risk assessment should consider these eects. A dierent dermal bioavailability of benzo[a]pyrene (BaP) from that of acetone or mineral oils of varying viscosity has been found [4]. When BaP was applied to mouse skin in acetone, the degree of epidermal DNA and protein adduct formation was about 15±20 times greater than that observed when a low-viscosity oil was used as vehicle. However, when applied in oils of varying viscosity only a twofold difference was seen across the whole viscosity range. We studied the eect of matrix on percutaneous penetration of PAHs and in particular from lubricating oil, using an in vitro diusion system.
Methods The test apparatus consisted of a static diusion cell system (catalogue no. FDC 400, Crown Glass, N.J., USA) kept at a constant temperature of 37 °C so that the skin surface temperature was 32 °C. The exposure area was 1.77 cm2 (diameter 1.5 cm). Fullthickness monkey (Cercopithecus aetiops) skin from the abdomen was used as the membrane. Comparative in vivo and in vitro studies have demonstrated that percutaneous absorption through monkey skin is similar to that in man [5, 11, 12]. Monkeys were
529 sweat to simulate real conditions of exposure at the workplace. Arti®cial sweat is a liquid with characteristics similar to those of human sweat. Its composition is the following: 2.5 g sodium acid phosphate, 0.2 g triolein, 2 drops of Tween 85, water up to 1 l, pH 5.2 with hydrogen chloride [9]. As oil we used a commercial synthetic lubricator for engines. Chemical analysis demonstrated that it does not contain PAHs over the detection limit. Barrier integrity after applying 30 ll acetone solution was checked using the [3H]H2O passage through human cadaver skin in two cells. Using this technique previously described in literature [1], we measured a normal percentage of absorption of water (£0.29%) after 20 min, ®nding no apparent eects of this dose of acetone on skin permeability. Analysis of PAHs in the samples obtained from cells was carried out by puri®cation with acetonitrile in the presence of NaCl, followed by inverse-phase HPCL on a LC-PAH Supelchem column (25 cm long, 4.6 mm i.d., 5 lm grain size) eluted with an acetonitrile-water gradient. The results were read with a Shimadzu RF 551 programmable excitation and emission wavelength spectro¯uorimeter. The coecient of variation of the analytical method was 10.8% and the detection limits of the various substances were (in nanomoles per liter): naphthalene 25.8, acenaphthene 1.67, ¯uorene 7.5, phenanthrene 2.80, anthracene 0.56, pyrene 0.49, benzo[a]anthracene 1.32, and chrysene 0.45. All statistical analysis was performed with the SPSS software package (SPSS, Chicago, Ill., USA).
Table 1 Applied concentration and physicochemical properties of tested polycyclic aromatic hydrocarbons Applied nmol/cm2 Naphthalene 160.0 Acenaphthene 120.0 Fluorene 23.1 Anthracene 15.1 Phenanthrene 12.1 Pyrene 9.3 Benzo[a]anthracene 8.5 Chrysene 6.5 Benzo[b]¯uoranthene 16.5 Benzo[k]¯uoranthene 6.3 Benzo[a]pyrene 6.1 Dibenzo[a,h]anthracene 7.5 Benzo[g,h,i]perilene 6.9
Molecular weight
Log P
Melting point
128.2 154.2 166.2 178.2 178.2 202.3 228.3 228.3 252.3 252.3 252.3 278.4 276.3
3.40 3.92 4.18 4.50 4.60 5.18 5.61 5.91 6.12 6.84 6.50 6.50 7.10
81.0 95.0 115.5 216.4 100.5 150.4 160.7 253.8 168.3 215.7 178.1 266.6 278.3
previously killed to produce poliovirus vaccine. Skin samples were frozen and stored for few days. The receiving liquid was a saline solution with gentamycin sulfate and 4% bovine serum albumin. Liposoluble substances such as PAHs have also previously been found to diuse well with this receptor [7]. Ten 1-ml samples in 48 h were drawn for each cell. A mixture of 13 PAHs (Table 1) was applied without occlusion at the same concentration in 30 ll acetone solution (six cells) and dispersed in a lubricating oil (seven cells). Using a small volume of acetone, the volatile solvent evaporates leaving a ®lm of chemical on the surface if the skin. Then we added some drops of arti®cial Table 2 Kp values (cm/h), steady-state ¯uxes (nmol cm2 h)1) and lag time (h) of the tested compounds (mean SD) applied in a lubricating oil
The results were expressed as ¯ux at steady state Kp (obtained dividing absorption ¯ux values at steady state Kp
Naphthalene Acenaphthene Fluorene Anthracene Phenanthrene Pyrene Benzo[a]anthracene Chrysene Benzo[b]¯uoranthene Benzo[k]¯uoranthene Benzo[a]pyrene Dibenzo[a,h]anthracene Benzo[g,h,i]perilene a
Table 3 Kp values (cm/h), steady state ¯uxes (nmol cm2 h)1) and lag time (h) of the tested compounds (mean SD) applied in acetone solution with arti®cial sweat
Results
Flux
(1.87 (1.72 (1.64 (0.93 (0.50 (0.17 ±a (0.22 ±a ±a ±a ±a ±a
1.31) 1.76) 1.66) 0.98) 0.28) 0.04)
´ ´ ´ ´ ´ ´
)3
10 10)3 10)3 10)3 10)3 10)3
0.12) ´ 10)3
0.2189 0.2432 0.0355 0.0112 0.0035 0.0003
0.0008
4.86 8.37 5.70 17.55 15.15 13.38 ±a 26.12 ±a ±a ±a ±a ±a
7.99 3.44 3.02 4.73 3.10 8.91
3.34
Below the detection limit
Flux
Kp Naphthalene Acenaphthene Fluorene Anthracene Phenanthrene Pyrene Benzo[a]anthracene Chrysene Benzo[b]¯uoranthene Benzo[k]¯uoranthene Benzo[a]pyrene Dibenzo[a,h]anthracene Benzo[g,h,i]perilene a
0.2740 0.2255 0.0363 0.0120 0.0060 0.0015 ±a 0.0015 ±a ±a ±a ±a ±a
Lag time
Below the detection limit
(6.31 (7.80 (6.56 (3.97 (2.63 (4.13 (1.72 (0.57 (0.09 (0.09 (0.23 ±a ±a
2.49) 4.10) 5.33) 2.82) 0.74) 4.36) 2.60) 0.43) 0.04) 0.04) 0.20)
´ ´ ´ ´ ´ ´ ´ ´ ´ ´ ´
)3
10 10)3 10)3 10)3 10)3 10)3 10)3 10)3 10)3 10)3 10)3
1.0107 0.9684 0.1455 0.0526 0.0319 0.0387 0.0142 0.0035 0.0014 0.0006 0.0014 ±a ±a
Lag time
0.3981 0.5996 0.1138 0.0297 0.0089 0.0416 0.0215 0.0025 0.0006 0.0002 0.0012
1.18 2.34 4.23 12.85 10.95 24.46 27.14 23.79 22.46 23.80 31.21 ±a ±a
0.01 2.31 3.99 7.18 7.62 2.68 8.28 2.25 21.12 25.70 10.81
530
Fig. 1 Cumulative percutaneous penetration of acenaphthene applied in two dierent vehicles
Fig. 3 Cumulative percutaneous penetration of chrysene applied in two dierent vehicles
by the concentration of substance applied) and lag-time mean values SD. Comparing Kp values of compounds tested under the two dierent conditions (Table 2) resulted in a signi®cantly slower passage from the oil matrix for acenaphthene, anthracene, phenanthrene, ¯uoranthene, naphthalene, pyrene, ¯uorene (Mann-Whitney U test, P < 0.05). No signi®cant dierences in the passage were found for chrysene because, in the test with oil, very often its concentration was below the detection limit. For benzo[a]anthracene, benzo[b]¯uoranthene, benzo[k]¯uoranthene, benzo[a]pyrene it was possible to demonstrate a passage through the skin only when compounds were applied in acetone solution with arti®cial
sweat. Figures 1±7 compare percutaneous penetration of 7 PAHs applied in the two dierent vehicles.
Fig. 2 Cumulative percutaneous penetration of anthracene applied in two dierent vehicles
Fig. 4 Cumulative percutaneous penetration of phenanthrene applied in two dierent vehicles
Discussion Our experiment demonstrated a slower penetration through the skin of PAHs included in the oil matrix than the same compounds at the same concentrations in acetone solution with arti®cial sweat. This should be due to the liposolubility of PAHs and their consequent af®nity with oily liquids. This could lead to an overestimation of dermal exposure in workers exposed to lubricating oils. The results of the study suggest the necessity of dermal penetration data relevant for risk assessment,
531
Fig. 5 Cumulative percutaneous penetration of ¯uorene applied in two dierent vehicles
obtained under experimental conditions similar to the real exposure conditions. Factors such as short exposures with non-steady-state conditions, chemicals included in various vehicles (matrix and solvents) or solid can aect percutaneous penetration. According to literature, the penetration from solids is very low [13, 14]. The percutaneous penetration of seven PAHs, contained in two dierent types of carbon and at the same concentration in acetone solution with arti®cial sweat, has been compared using static ambered cells, full thickness monkey skin, and human plasma as the receptor and chemical analysis [3]. Results show no percutaneous penetration of PAHs contained in the two types of carbon (their concentration in the receptor ¯uid was under detection limits) with a passage through the skin of the compounds when they were in dierent vehicles (acetone solution with arti®cial sweat). Even the presence of solvents in commercial formulations can change penetration rates of chemicals [8].
Fig. 7 Cumulative percutaneous penetration of pyrene applied in two dierent vehicles
It is well known that properly conducted in vitro experiments can predict the in vivo absorption rate with reasonable approximation, but in vitro experimental conditions should be carefully controlled. To understand the dermal uptake of chemicals bound to soil, dust, oil, water, and solvents, etc. information on the pure substance is helpful, but additional factors must also be considered. Those factors can be easily reproduced and controlled in in vitro experiments. An attempt to establish international guidelines for in vitro percutaneous penetration studies was made in 1996 by the OECD [6]. However, these guidelines have not been accepted in all places, and now the OECD is reconsidering them. On the other hand, the Percutaneous Penetration Subgroup of the Dermal Exposure Network in the European Union is elaborating an international research proposal in this ®eld. The aim of this research is to produce in vitro penetration data that are suciently reliable and standardized as to be acceptable for regulatory purposes. Acknowledgements This research was carried out in collaboration with Istituto Superiore per la Prevenzione e la Sicurezza del Lavoro (ISPESL), Rome, Italy.
References
Fig. 6 Cumulative percutaneous penetration of naphthalene applied in two dierent vehicles
1. Bronaugh RL, Stewart RF, Simon M (1986) Methods for in vitro percutaneous absorption studies. VII. Use of excised human skin. J Pharm Sci 75: 1094±1097 2. Bronaugh RL, Franz TJ (1986) Vehicle eects on percutaneous absorption: in vivo and in vitro comparisons with human skin. Br J Dermatol 115: 1±11 3. FoaÁ V, Elia G, Schiavulli N, Sartorelli P, Sciarra G, Cenni A, Novelli MT, Mangani F, Cecchetti G, Iachetta R (1998) The non bioavailability of carcinogenic polycyclic aromatic hydrocarbons contained in coal dust. Medicina del Lavoro (Milano) 89: 68±77
532 4. Ingram AJ, Phillips JC (1993) The dermal bioavailability of radiolabelled benzo(a)pyrene from acetone or from oils of diering viscosity, assessed by DNA and protein binding. J Appl Toxicol 13: 25±32 5. Moody RP, Franklin CA, Ritter L, Maibach HI (1990) Dermal absorption of the phenoxy herbicides 2,4-D, 2,4-D amine, 2,4D isooctyl, and 2,4,5-t in rabbits, rats, rhesus monkeys, and humans: a cross-species comparison. J Toxicol Environ Health 29: 237±245 6. OECD (1996) Dermal delivery and percutaneous absorption: in vitro method. OECD guideline for the testing of chemicals ± proposal for a new guideline. OECD, Paris 7. Sartorelli P, Aprea C, Cenni A, Matteucci G, Novelli MT, Sciarra G (1995) In vitro percutaneous absorption of phenanthrene through monkey skin. Medicina del Lavoro (Milano) 86: 34±39 8. Sartorelli P, Aprea C, Bussani R, Novelli MT, Orsi D, Sciarra G (1997) In vitro percutaneous penetration of methyl-parathion from a commercial formulation through the human skin. Occup Environ Med 54: 524±525 9. Sciarra G, Angotzi G (1984) Studio della cessazione del di (2-etilesil) ftalato da ®nte pelli in PVC (abstract in
10.
11. 12.
13.
14.
English). Giornale Italiano Medicina del Lavoro (Pavia) 6: 235±238 Twist JN, Zatz JL (1989) Interaction of vehicles with model skin membranes in the permeation process. In: Bronaugh RL, Maibach HI (eds) Percutaneous absorption. Dekker, New York, pp 147±173 Wester RC, Maibach HI (1975) Percutaneous absorption in the rhesus monkey compared to man. Toxicol Appl Pharmacol 32: 394±447 Wester RC, Maibach HI (1989) In vivo animal models for percutaneous absorption. In Bronaugh RL, Maibach HI (eds) Percutaneous absorption. Dekker, New York, pp 221±238 Wester R, Bucks DAW, Maibach HI (1993) Percutaneous absorption of contaminants from soil. In Wang RGM, Knaak JB, Maibach HI (eds) Health risk assessment. CRC, London, pp 147±148 Yang JJ, Roy TA, Krueger AJ, Neil W, Mackerer CR (1989) In vitro and in vivo percutaneous absorption of benzo(a)pyrene from petroleum crude-forti®ed soil in the rat. Bull Environ Contam Toxicol 43: 207±214
Ó Springer-Verlag 1999
ORIGINAL ARTICLE
P. Sartorelli á A. Cenni á G. Matteucci á L. Montomoli M. T. Novelli á S. Palmi
Dermal exposure assessment of polycyclic aromatic hydrocarbons: in vitro percutaneous penetration from lubricating oil
Received: 7 January 1999 / Accepted: 10 July 1999
Abstract Objectives: Percutaneous penetration of polycyclic aromatic hydrocarbons (PAHs) is aected by various factors connected to exposure conditions. The nature of the matrix, such as that of oil, can strongly aect their percutaneous penetration. Risk assessment should consider these eects. We examined the eect of matrix on percutaneous penetration of PAHs, particularly that of lubricating oil. Methods: The test apparatus consisted of an in vitro static diusion cell system using full-thickness monkey (Cercopithecus aetiops) skin as the membrane and saline solution with gentamycin sulfate and 4% bovine serum albumin as receptor ¯uid. Chemical analysis of PAHs in the samples obtained from cells was carried out by inverse-phase HPCL, and the results were read by spectro¯uorimetry. Results: Comparing the penetration of 13 PAHs from a lubricating oil and from acetone solution with arti®cial sweat resulted in a signi®cantly slower passage from the oil matrix for acenaphthene, anthracene, phenanthrene, ¯uoranthene, naphthalene, pyrene, ¯uorene (MannWhitney U test, P < 0.05). No signi®cant dierences in the passage were found for chrysene because, in the test with oil, its concentration was very often below the detection limit. For benzo[a]anthracene, benzo[b]¯uoranthene, benzo[k]¯uoranthene, and benzo[a]pyrene it was possible to demonstrate a passage through the skin only when compounds were applied in acetone solution with arti®cial sweat. Conclusions: The results of the study
P. Sartorelli (&) á A. Cenni á L. Montomoli á M.T. Novelli Istituto di Medicina del Lavoro, UniversitaÁ degli Studi di Siena, Via dei Tu® 1, I-53100 Siena, Italy e-mail: [email protected] Tel.: +39-577-586755; Fax: +39-577-586159 G. Matteucci Biocine Sclavo, Via Fiorentina 1, I-53100 Siena, Italy S. Palmi Dipartimento di Medicina del Lavoro, ISPESL, Via Urbana 167, I-00184 Roma, Italy
suggest the necessity of dermal penetration data relevant for risk assessment, obtained under experimental conditions similar to the real exposure conditions. Key words Dermal exposure á Percutaneous penetration á Polycyclic aromatic hydrocarbons á Risk assessment
Introduction It is well known that percutaneous penetration of chemicals is strongly aected by the vehicle [2, 10]. Dermal exposure to polycyclic aromatic hydrocarbons (PAHs) can occur by deposition of vapors and particles or by splashing of oils. These are very common occurrences at workplaces. The nature of the matrix can aect percutaneous absorption of PAHs. Risk assessment should consider these eects. A dierent dermal bioavailability of benzo[a]pyrene (BaP) from that of acetone or mineral oils of varying viscosity has been found [4]. When BaP was applied to mouse skin in acetone, the degree of epidermal DNA and protein adduct formation was about 15±20 times greater than that observed when a low-viscosity oil was used as vehicle. However, when applied in oils of varying viscosity only a twofold difference was seen across the whole viscosity range. We studied the eect of matrix on percutaneous penetration of PAHs and in particular from lubricating oil, using an in vitro diusion system.
Methods The test apparatus consisted of a static diusion cell system (catalogue no. FDC 400, Crown Glass, N.J., USA) kept at a constant temperature of 37 °C so that the skin surface temperature was 32 °C. The exposure area was 1.77 cm2 (diameter 1.5 cm). Fullthickness monkey (Cercopithecus aetiops) skin from the abdomen was used as the membrane. Comparative in vivo and in vitro studies have demonstrated that percutaneous absorption through monkey skin is similar to that in man [5, 11, 12]. Monkeys were
529 sweat to simulate real conditions of exposure at the workplace. Arti®cial sweat is a liquid with characteristics similar to those of human sweat. Its composition is the following: 2.5 g sodium acid phosphate, 0.2 g triolein, 2 drops of Tween 85, water up to 1 l, pH 5.2 with hydrogen chloride [9]. As oil we used a commercial synthetic lubricator for engines. Chemical analysis demonstrated that it does not contain PAHs over the detection limit. Barrier integrity after applying 30 ll acetone solution was checked using the [3H]H2O passage through human cadaver skin in two cells. Using this technique previously described in literature [1], we measured a normal percentage of absorption of water (£0.29%) after 20 min, ®nding no apparent eects of this dose of acetone on skin permeability. Analysis of PAHs in the samples obtained from cells was carried out by puri®cation with acetonitrile in the presence of NaCl, followed by inverse-phase HPCL on a LC-PAH Supelchem column (25 cm long, 4.6 mm i.d., 5 lm grain size) eluted with an acetonitrile-water gradient. The results were read with a Shimadzu RF 551 programmable excitation and emission wavelength spectro¯uorimeter. The coecient of variation of the analytical method was 10.8% and the detection limits of the various substances were (in nanomoles per liter): naphthalene 25.8, acenaphthene 1.67, ¯uorene 7.5, phenanthrene 2.80, anthracene 0.56, pyrene 0.49, benzo[a]anthracene 1.32, and chrysene 0.45. All statistical analysis was performed with the SPSS software package (SPSS, Chicago, Ill., USA).
Table 1 Applied concentration and physicochemical properties of tested polycyclic aromatic hydrocarbons Applied nmol/cm2 Naphthalene 160.0 Acenaphthene 120.0 Fluorene 23.1 Anthracene 15.1 Phenanthrene 12.1 Pyrene 9.3 Benzo[a]anthracene 8.5 Chrysene 6.5 Benzo[b]¯uoranthene 16.5 Benzo[k]¯uoranthene 6.3 Benzo[a]pyrene 6.1 Dibenzo[a,h]anthracene 7.5 Benzo[g,h,i]perilene 6.9
Molecular weight
Log P
Melting point
128.2 154.2 166.2 178.2 178.2 202.3 228.3 228.3 252.3 252.3 252.3 278.4 276.3
3.40 3.92 4.18 4.50 4.60 5.18 5.61 5.91 6.12 6.84 6.50 6.50 7.10
81.0 95.0 115.5 216.4 100.5 150.4 160.7 253.8 168.3 215.7 178.1 266.6 278.3
previously killed to produce poliovirus vaccine. Skin samples were frozen and stored for few days. The receiving liquid was a saline solution with gentamycin sulfate and 4% bovine serum albumin. Liposoluble substances such as PAHs have also previously been found to diuse well with this receptor [7]. Ten 1-ml samples in 48 h were drawn for each cell. A mixture of 13 PAHs (Table 1) was applied without occlusion at the same concentration in 30 ll acetone solution (six cells) and dispersed in a lubricating oil (seven cells). Using a small volume of acetone, the volatile solvent evaporates leaving a ®lm of chemical on the surface if the skin. Then we added some drops of arti®cial Table 2 Kp values (cm/h), steady-state ¯uxes (nmol cm2 h)1) and lag time (h) of the tested compounds (mean SD) applied in a lubricating oil
The results were expressed as ¯ux at steady state Kp (obtained dividing absorption ¯ux values at steady state Kp
Naphthalene Acenaphthene Fluorene Anthracene Phenanthrene Pyrene Benzo[a]anthracene Chrysene Benzo[b]¯uoranthene Benzo[k]¯uoranthene Benzo[a]pyrene Dibenzo[a,h]anthracene Benzo[g,h,i]perilene a
Table 3 Kp values (cm/h), steady state ¯uxes (nmol cm2 h)1) and lag time (h) of the tested compounds (mean SD) applied in acetone solution with arti®cial sweat
Results
Flux
(1.87 (1.72 (1.64 (0.93 (0.50 (0.17 ±a (0.22 ±a ±a ±a ±a ±a
1.31) 1.76) 1.66) 0.98) 0.28) 0.04)
´ ´ ´ ´ ´ ´
)3
10 10)3 10)3 10)3 10)3 10)3
0.12) ´ 10)3
0.2189 0.2432 0.0355 0.0112 0.0035 0.0003
0.0008
4.86 8.37 5.70 17.55 15.15 13.38 ±a 26.12 ±a ±a ±a ±a ±a
7.99 3.44 3.02 4.73 3.10 8.91
3.34
Below the detection limit
Flux
Kp Naphthalene Acenaphthene Fluorene Anthracene Phenanthrene Pyrene Benzo[a]anthracene Chrysene Benzo[b]¯uoranthene Benzo[k]¯uoranthene Benzo[a]pyrene Dibenzo[a,h]anthracene Benzo[g,h,i]perilene a
0.2740 0.2255 0.0363 0.0120 0.0060 0.0015 ±a 0.0015 ±a ±a ±a ±a ±a
Lag time
Below the detection limit
(6.31 (7.80 (6.56 (3.97 (2.63 (4.13 (1.72 (0.57 (0.09 (0.09 (0.23 ±a ±a
2.49) 4.10) 5.33) 2.82) 0.74) 4.36) 2.60) 0.43) 0.04) 0.04) 0.20)
´ ´ ´ ´ ´ ´ ´ ´ ´ ´ ´
)3
10 10)3 10)3 10)3 10)3 10)3 10)3 10)3 10)3 10)3 10)3
1.0107 0.9684 0.1455 0.0526 0.0319 0.0387 0.0142 0.0035 0.0014 0.0006 0.0014 ±a ±a
Lag time
0.3981 0.5996 0.1138 0.0297 0.0089 0.0416 0.0215 0.0025 0.0006 0.0002 0.0012
1.18 2.34 4.23 12.85 10.95 24.46 27.14 23.79 22.46 23.80 31.21 ±a ±a
0.01 2.31 3.99 7.18 7.62 2.68 8.28 2.25 21.12 25.70 10.81
530
Fig. 1 Cumulative percutaneous penetration of acenaphthene applied in two dierent vehicles
Fig. 3 Cumulative percutaneous penetration of chrysene applied in two dierent vehicles
by the concentration of substance applied) and lag-time mean values SD. Comparing Kp values of compounds tested under the two dierent conditions (Table 2) resulted in a signi®cantly slower passage from the oil matrix for acenaphthene, anthracene, phenanthrene, ¯uoranthene, naphthalene, pyrene, ¯uorene (Mann-Whitney U test, P < 0.05). No signi®cant dierences in the passage were found for chrysene because, in the test with oil, very often its concentration was below the detection limit. For benzo[a]anthracene, benzo[b]¯uoranthene, benzo[k]¯uoranthene, benzo[a]pyrene it was possible to demonstrate a passage through the skin only when compounds were applied in acetone solution with arti®cial
sweat. Figures 1±7 compare percutaneous penetration of 7 PAHs applied in the two dierent vehicles.
Fig. 2 Cumulative percutaneous penetration of anthracene applied in two dierent vehicles
Fig. 4 Cumulative percutaneous penetration of phenanthrene applied in two dierent vehicles
Discussion Our experiment demonstrated a slower penetration through the skin of PAHs included in the oil matrix than the same compounds at the same concentrations in acetone solution with arti®cial sweat. This should be due to the liposolubility of PAHs and their consequent af®nity with oily liquids. This could lead to an overestimation of dermal exposure in workers exposed to lubricating oils. The results of the study suggest the necessity of dermal penetration data relevant for risk assessment,
531
Fig. 5 Cumulative percutaneous penetration of ¯uorene applied in two dierent vehicles
obtained under experimental conditions similar to the real exposure conditions. Factors such as short exposures with non-steady-state conditions, chemicals included in various vehicles (matrix and solvents) or solid can aect percutaneous penetration. According to literature, the penetration from solids is very low [13, 14]. The percutaneous penetration of seven PAHs, contained in two dierent types of carbon and at the same concentration in acetone solution with arti®cial sweat, has been compared using static ambered cells, full thickness monkey skin, and human plasma as the receptor and chemical analysis [3]. Results show no percutaneous penetration of PAHs contained in the two types of carbon (their concentration in the receptor ¯uid was under detection limits) with a passage through the skin of the compounds when they were in dierent vehicles (acetone solution with arti®cial sweat). Even the presence of solvents in commercial formulations can change penetration rates of chemicals [8].
Fig. 7 Cumulative percutaneous penetration of pyrene applied in two dierent vehicles
It is well known that properly conducted in vitro experiments can predict the in vivo absorption rate with reasonable approximation, but in vitro experimental conditions should be carefully controlled. To understand the dermal uptake of chemicals bound to soil, dust, oil, water, and solvents, etc. information on the pure substance is helpful, but additional factors must also be considered. Those factors can be easily reproduced and controlled in in vitro experiments. An attempt to establish international guidelines for in vitro percutaneous penetration studies was made in 1996 by the OECD [6]. However, these guidelines have not been accepted in all places, and now the OECD is reconsidering them. On the other hand, the Percutaneous Penetration Subgroup of the Dermal Exposure Network in the European Union is elaborating an international research proposal in this ®eld. The aim of this research is to produce in vitro penetration data that are suciently reliable and standardized as to be acceptable for regulatory purposes. Acknowledgements This research was carried out in collaboration with Istituto Superiore per la Prevenzione e la Sicurezza del Lavoro (ISPESL), Rome, Italy.
References
Fig. 6 Cumulative percutaneous penetration of naphthalene applied in two dierent vehicles
1. Bronaugh RL, Stewart RF, Simon M (1986) Methods for in vitro percutaneous absorption studies. VII. Use of excised human skin. J Pharm Sci 75: 1094±1097 2. Bronaugh RL, Franz TJ (1986) Vehicle eects on percutaneous absorption: in vivo and in vitro comparisons with human skin. Br J Dermatol 115: 1±11 3. FoaÁ V, Elia G, Schiavulli N, Sartorelli P, Sciarra G, Cenni A, Novelli MT, Mangani F, Cecchetti G, Iachetta R (1998) The non bioavailability of carcinogenic polycyclic aromatic hydrocarbons contained in coal dust. Medicina del Lavoro (Milano) 89: 68±77
532 4. Ingram AJ, Phillips JC (1993) The dermal bioavailability of radiolabelled benzo(a)pyrene from acetone or from oils of diering viscosity, assessed by DNA and protein binding. J Appl Toxicol 13: 25±32 5. Moody RP, Franklin CA, Ritter L, Maibach HI (1990) Dermal absorption of the phenoxy herbicides 2,4-D, 2,4-D amine, 2,4D isooctyl, and 2,4,5-t in rabbits, rats, rhesus monkeys, and humans: a cross-species comparison. J Toxicol Environ Health 29: 237±245 6. OECD (1996) Dermal delivery and percutaneous absorption: in vitro method. OECD guideline for the testing of chemicals ± proposal for a new guideline. OECD, Paris 7. Sartorelli P, Aprea C, Cenni A, Matteucci G, Novelli MT, Sciarra G (1995) In vitro percutaneous absorption of phenanthrene through monkey skin. Medicina del Lavoro (Milano) 86: 34±39 8. Sartorelli P, Aprea C, Bussani R, Novelli MT, Orsi D, Sciarra G (1997) In vitro percutaneous penetration of methyl-parathion from a commercial formulation through the human skin. Occup Environ Med 54: 524±525 9. Sciarra G, Angotzi G (1984) Studio della cessazione del di (2-etilesil) ftalato da ®nte pelli in PVC (abstract in
10.
11. 12.
13.
14.
English). Giornale Italiano Medicina del Lavoro (Pavia) 6: 235±238 Twist JN, Zatz JL (1989) Interaction of vehicles with model skin membranes in the permeation process. In: Bronaugh RL, Maibach HI (eds) Percutaneous absorption. Dekker, New York, pp 147±173 Wester RC, Maibach HI (1975) Percutaneous absorption in the rhesus monkey compared to man. Toxicol Appl Pharmacol 32: 394±447 Wester RC, Maibach HI (1989) In vivo animal models for percutaneous absorption. In Bronaugh RL, Maibach HI (eds) Percutaneous absorption. Dekker, New York, pp 221±238 Wester R, Bucks DAW, Maibach HI (1993) Percutaneous absorption of contaminants from soil. In Wang RGM, Knaak JB, Maibach HI (eds) Health risk assessment. CRC, London, pp 147±148 Yang JJ, Roy TA, Krueger AJ, Neil W, Mackerer CR (1989) In vitro and in vivo percutaneous absorption of benzo(a)pyrene from petroleum crude-forti®ed soil in the rat. Bull Environ Contam Toxicol 43: 207±214
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