Introduction:
Dermal absorption involves the uptake of substances through the skin. It may be physical, chemical, or biological. These substances, when absorbed, may have harmful effects on the body, causing organ damage and other systemic toxicity.
Skin is the topmost layer and the primary defender against external assaults. The stratum corneum, the first layer of the skin, acts as a barrier preventing any injury. But in certain cases, materials may be absorbed through the skin if:
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The skin’s integrity is lost.
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The molecular weight of the materials is less than that of the skin’s permeability.
Due to occupational exposure, dermal penetration may significantly affect the individual’s health and capacity to perform at work. Common side effects of dermal absorption are direct and mostly involve the skin. However, more severe systemic complications can arise from the chemicals absorbed into the bloodstream. General awareness about this issue is still lacking.
What Is Dermal Penetration?
Percutaneous or dermal penetrationis the movement of compounds through the skin.
It can occur in three forms:
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Penetration - Here, the compound enters a particular layer, for example, the stratum corneum.
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Permeation - Here, the compounds enter from one layer to another.
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Resorption - The compound is taken into the lymph or blood vessels of the vascular system.
After contact with the skin, certain compounds may enter the body by penetrating the subsequent layers of the skin through the bloodstream. In addition to liquids, even gasses may be absorbed by the skin.
What Amplifies Dermal Penetration?
The speed with which compounds move through the different layers of skin is called ‘flux’ or ‘dermal penetration rate.’ The following factors affect the penetration rate:
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In the affected skin region and its condition, thicker areas such as palms and feet have lower permeability due to the cornified layer.
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Genetic predisposition such as age, gender, and skin moisture content. The substances can also be stored in the superficial layer and slowly seep into the skin.
What Happens During a Dermal Penetration?
The human body typically can tolerate up to a certain limit. The body has defense mechanisms to eliminate the toxins from the body.
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It may enter the liver through the bloodstream, where it is detoxified. It may be converted to smaller toxins that could be utilized by the body, or it may be eliminated.
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The kidney eliminates waste products from the body through urine.
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Toxins may also be removed through feces, sweat, and exhalation.
However, the body might not be able to eliminate all the chemicals; the longer the body is exposed to them, the more harmful effects they will cause.
What Are the Adverse Effects of Dermal Penetration?
The effects of dermal penetration can be:
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Direct - Effects at the point of contact, such as drying, pigmentation, and chloracne.
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Systemic - Chemicals enter the body and cause health problems at different locations. This may be in a specific organ or the entire body.
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Sensitization - The individual exposed may become vulnerable to a certain chemical to which he was exposed, and further exposure will cause an allergic reaction. This can also include airway obstruction.
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Combined - Exposure may cause multiple health problems.
Chemicals or other substances absorbed can cause damage to specific organs such as the liver, kidney, and bladder. Toluene and xylene are known to cause liver and kidney damage.
Chemicals that can penetrate through the skin may affect:
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Immune system.
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Nervous system.
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Respiratory pathway.
Certain chemicals may even have targeted an organ:
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Methanol can lead to blindness.
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Nitrobenzene exposure through the skin can affect the central nervous system.
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Lead affects the central nervous system, kidneys, and red blood cells.
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Isocyanates may give rise to an allergic response.
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Chloroform may cause tumors in the liver and kidney.
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Pesticides and herbicides are common causes of central nervous system impairment. Pesticides can cause impairment to leukemia, lymphoma, prostate cancer, stillbirth (death or loss of newborn before or during delivery), and infertility.
What Are the Limitations in Tackling Dermal Penetration?
The fundamental problem which is responsible for the increased harmful effects of dermal absorption, especially in the workplace, is the lack of awareness. There is little or no data available on the harmful effects of each chemical, as there is a lack of research in that area. There is also very little report of work-related exposure as most individuals consider the side effects a part of their job. Therefore, a system should be established to encourage reporting and follow-up.
How to Prevent Harmful Side Effects?
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Monitoring of the exposure and follow-up assessment will reduce the side effects significantly.
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Preventive measures include elimination and substitution. Eliminate the product that causes systemic effects and substitute it with less harmful substances.
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A physical barrier is used in the uppermost layer. The stratum corneum is the most basic and effective approach.
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Skin-care products that help in the regeneration of the skin layer, or those that help in the healing, will, in turn, have a preventive effect on dermal absorption.
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At the same time, skin care products that include emulators that enhance absorption should be avoided to prevent transdermal uptake of chemicals.
How to Prevent Exposure at the Workplace?
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Minimizing skin contact.
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Control of spillage and easier cleaning mechanisms for spillage.
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Use of tools instead of hands.
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Safety maintenance at regular intervals.
Using personal protective equipment (PPE) should be a mandate when these precautions are not easy. Protective gloves and boots also help significantly reduce the impact.
A toolkit has been developed to assess the extent of the hazardous substances that can be dermally absorbed. This is called RISKOFDERM. This helps the people exposed to such chemicals reduce their exposure or use appropriate safety equipment.
Conclusion:
Lack of awareness of the implications of workplace exposure and dermal absorption is the primary factor for the increased incidence of harmful effects of skin penetration. The workers must be made aware; the risk should be identified and managed to prevent systemic complications. Proper training and the use of protective equipment can reduce the impact considerably. Controlling the exposure can be done by modifying the process to eliminate chemical exposure, adding adequate ventilation, maintaining healthy skin, and modifying work practices.
