Cutaneous exposure modeling

Cutaneous exposure modeling This approach utilizes statistical and deterministic methods to aid in estimating the amount of pesticide deposited on the skin. One conceptual model of cutaneous exposure (Schneider et a ., 1999) divides the worker s environment into six compartments the. source, air, surface contatniiiaiit layer, outer clothing layer, inner clothing layer, and. skin. The following transport processes then characterize movement of the chemical within the environment emission, deposition, resuspension/evaporation, transfer. 

Cutaneous exposure may be selected to simulate the main route of human exposure and as a model for induction of skin lesions. During skin absorption, the chemical applied is transferred from the outer surface of the skin through the homy layer, the epidermis, the comeum, and into the systemic circulation. Absorption of chemicals through the skin is time-dependent, and this can be demonstrated by the application of occlusive bandages to prevent loss of the test material from the application site. Solid chemicals and chemicals soluble in secretions of the skin may dissolve in the secretions to a variable extent. 

The IPPSF model offers many unique advantages. First, it allows confirmation that cutaneous exposure to a penetrating molecule actually occurred. Second, it allows quantitation of this exposure and subsequent correlation to severity of toxicity observed. Finally, it would allow the development of linked toxicokinetic-toxico-dynamic models to be developed, which should shed insight into the mechanisms of cutaneous toxicity. 

The physicochemical approach to the prediction of transdermal absorption kinetics described In this paper offers a promising stategy for the estimation of cutaneous exposure risk. The model Is conceptually straightforward yet sensitive to the biology of skin and to the chemical and physical properties of the penetrant. Human, In vivo, penetration data for a diverse array of absorbing molecules have been... 

Smith, K.J., Casillas, R., Graham, J., Skelton, H.G., Stemler, F., Hackley, B.E., Jr. (1997a). Histopathologic features seen with different animal models following cutaneous sulfur mustard exposure. J. Dermatol. Sci. 14 126-35. 

Interpretation of urinary excretion data following topical application Is presented for 9 compounds. It Is shown that the model has predictive potential based upon recognized cutaneous biology and penetrant physical chemistry, In particular the diffusive and partitioning properties of the substrate. Refinements and developments of the approach (e.g., to multiple exposure and competitive surface removal situations) are Indicated and discussed. 

Halkier-Sorensen L, Thestrup-Pedersen K (1991) The relationship between skin surface temperature, transepidermal water loss and electrical capacitance among workers in the fish processing industry comparison with other occupations. A field study. Contact Dermatitis 24 345-355 Halkier-Sorensen L, Menon GK, Elias PM, Thestrup-Pedersen K, Feingold KR (1995) Cutaneous barrier function after cold exposure in hairless mice a model to demonstrate how cold interferes with barrier homeostasis among workers in the fish-processing industry. Br J Dermatol 132 391-401... 

The behavior of HF on the anatomic structures of the skin can be described with this model, with exposure conditions similar to cutaneous splash conditions. It can be applied to HF concentrations up to 70 %, a high concentration representative of the concentration used in industry. 

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