Human skin is bombarded by environmental, chemical and pharma-physiological insults. At a young age, these attacks may seem imperceptible, but they contribute to skin aging. Using potentially irritating or skin-incompatible ingredients in daily-use home care, laundry and personal care products can cause increscent damage, due to a cascading array of inflammatory responses. This poses both a technical dilemma and a marketing opportunity: to formulate innovative skin care products to protect skin from these topically adversarial factors. While the use of such formulations by aging consumers may alleviate visible and perceptible inflictions, their regular use at a young age can lead to problems.


The challenges posed by environmental factors include pollutants (oxides of carbon, sulfur, and nitrogen, ozone and free radicals), electromagnetic waves (UV and others), and airborne toxic chemicals (pesticides, chemical sprays and hydrocarbons). Pharma-physiological factors include the use of certain drugs and medical treatments (such as chemotherapy and radiation) to cure physical ailments. Epidemiologically, there is a link between poor air quality and topical and other systemic diseases.¹ Even a loud noise can cause enough stress to retard wound healing!²


Repeated exposure to certain chemicals that may be present innocuously in a daily use product can cause multiple chemical sensitivity (MCS). MCS, or idiopathic environmental intolerances (IEI), is a non-specific chronic medical condition attributed to low-level exposures to commonly used chemicals and certain biologic or physical agents.


Among systemic ailments caused by airborne antagonists, it is well known that the contents of cigarette smoke negatively affect sperm count, seminal plasma and other fertility factors. Smoking increases the presence of reactive oxygen species (ROS), resulting in oxidative stress (OS), which has devastating effects on cellular biology, including sperm viability and morphology, and impairs sperm function, hence reducing male fertility.³


Similarly, tobacco smoke compounds exert a deleterious effect on the process of ovarian follicle maturation. Cigarette smoking comprises every system involved in the reproductive process.⁴ Even passive smoking during childhood and adolescence can lead to infertility and abortion in adulthood.⁵ Inhalation of tobacco smoke in childhood results in equal occurrence of COPD for active and passive smokers.⁶


Airborne pollen is a major culprit for causing topical allergy and hay fever symptoms. Ragweed and birch pollen, for example, cause hay fever and allergic rhinoconjunctivitis.⁷ Long-term exposure to ambient air pollution is associated with cardiopulmonary diseases.⁸


Airborne sulfur dioxide (SO₂) exposure has a direct correlation to mortality and morbidity. Nitrogen dioxide (NO₂) exposure from gas cooking causes respiratory symptoms and decreases lung function in children. When carbon monoxide (CO) in the lungs binds with blood hemoglobin it forms carboxyhemoglobin, which impairs the oxygen transport. CO exposure leads to hypoxia, neurological deficits and neurobehavioral changes. Acute effects of ozone (O₃) include pulmonary function decrements, aggravation of pre-existing respiratory diseases and excess mortality.⁹


The above examples illustrate some of the damage caused by airborne antagonists to internal organs. How do these invisible culprits damage visible beauty?  There seems to be link between the extrinsic and intrinsic ailments caused by atmospheric culprits such as UV, free radicals, ROS, CO, NO­₂, SO₂ and O₃.


Extrinsic skin aging results from chronic exposure to solar radiation and tobacco smoke. Chronic exposure to ultraviolet light, as a component of sunlight, is a major cause of environmentally-induced aging of the skin. Other environmental factors for premature skin aging include longer wavelength radiation in the visible light region and in the short-wave infrared radiation region. The particulate and gaseous components of air pollution are known to significantly contribute to skin aging.¹⁰


Social Behavior and Skin Aging

The particulate matter of cigarette smoke is composed of thousands of chemicals. Cigarette smoke condensate is known to increase the production of MMP-2, MMP-14 and TIMP-2. Smoking leads to extrinsic skin aging. Traffic pollution is also associated with extrinsic skin aging. Thus, in preventive skin aging strategies the long-term exposure towards air pollution merits serious attention.¹¹ Impact of exposure to particulates present in traffic-soot on skin aging, pigment spots, and wrinkles has recently been reported. An increase in soot and particles from traffic was associated with 20% more pigment spots on forehead and cheeks.¹²
Atmospheric antagonists can cause their harmful affects via their impact on the function of key enzymes and biocatalysts within the human body. In a study, exposure to roadside particulate matter (PM) pollutants led to an increase in cytokine levels. Lung mRNA levels of antioxidant/phase II detoxifying enzymes decreased by exposure to the PM. It was also observed that metals present in PM are largely responsible for the observed pulmonary inflammation and oxidative stress. For a treatment strategy, simultaneous activation of the antioxidant defense response may protect against such oxidative damage.¹³


Metals extracted from roadway traffic PM emissions promote reactive oxygen species (ROS) production and cause antioxidant response element (ARE) promoter activation. ARE is a cis-acting enhancer sequence found in the promoter region of many genes encoding antioxidant and Phase II detoxification enzymes/proteins. In response to oxidative stress, regulatory proteins such as NRF1, NRF3 and BACH1 bind to AREs and compete for binding with NRF2. NRF2 mediates a transcriptional network of responsive genes that modulate in vivo mechanisms against oxidative damage and reactive electrophiles.¹⁴ In practical terms, anthropogenic air pollution has been shown to cause resistance to antibiotics by microbes.¹⁵


At Home, Work and Play

Every day, the body is exposed to undesirable physical and chemical agents that can cause ailments from deadly cancer to unsightly skin aging. The improper use of household cleaners such as ammonia, chlorine bleach and hydrogen peroxides, as well as the use of wood-burning stoves and fireplaces, can lead to the formation of damaging atmospheric antagonists. Even chlorinated drinking water can be unsafe.¹⁶


Elsewhere, studies have shown that toxic chlorinated gases are produced in the headspace of washing machines when hypochlorite-containing bleach is used. Laundry bleaching has also been implicated in contributing dissolved organochlorine compounds to municipal wastewater. Formation of organochlorine compounds increases at higher wash temperature. These studies also suggest that residual hypochlorite remains in fabric after laundering with bleach, presenting the possibility of direct and sustained dermal contact with reactive chlorine, thus identifying a new risk factor for the use of chlorine bleach.¹⁷


The bleaching of hair with hydrogen peroxide exhibited epidermal thinning, sub-epidermal vesicle formation, and disruption of extracellular matrix of the skin.¹⁸ Chlorine molecules, formed from the decomposition of chlorine bleach and chlorination of swimming pools, are known to produce reactive chlorine species (RCS) upon their exposure to UV.¹⁹


Inadvertent mixing of ammonia and sodium hypochlorite (chlorine bleach) in home cleaning can lead to the formation of chlorine and chloramine gas, which are strong irritants that can cause skin tissue damage and severe respiratory irritation.²⁰



IAQ and Wood Burning

Most people around the world rely on biomass for cooking fuel, kerosene and coal for heat, and wood-burning fireplaces for comfort. Biomass combustion releases a considerable amount of incomplete combustion products, including PM and polycyclic aromatic hydrocarbons (PAH). The results of an indoor air quality measurements in six houses equipped with wood burning stoves or fireplaces revealed the average, the maximum and the lowest values of PM concentration that were 68.6 μg/m³, 350.7 μg/m³ and 16.8 μg/m³, respectively. The average benzo[a]pyrene (BaP) concentration was 9.4 ng/m³: the maximum and the minimum values being 24.0 ng/m³ and 1.5 ng/m³, respectively.²¹ 


Germany regulates outdoor emissions from wood burning. However, the indoor release of combustion products is rarely considered. Wood burning fireplaces were tested in private homes between November 2012 and March 2013. The indoor air quality was monitored before, during and after operation. The following parameters were measured: ultra-fine particles (5.6-560nm), fine particles (0.3-20μm), PM, NO_x, CO, CO_­2, formaldehyde, acetaldehyde, volatile organic compounds (VOCs) and BaP. Researchers found that wood-burning fireplaces are potential sources of indoor air contaminants, especially ultra-fine nano-particles and BaP.²²


Human exposure to combustion emissions, including the associated airborne fine particles and mutagenic and carcinogenic constituents (e.g., PAH, nitro-PAH), have been studied in populations in Europe, America, Asia and third-world countries. Bioassay studies of particulate air pollution have identified mutagenic and carcinogenic PAH, nitrated PAH, nitro-lactones, and lower molecular weight compounds from cooking. These components may also cause oxidative and DNA damage that can lead to reproductive, cardiovascular and topical disorders.²³


Exposure to high levels of PM in pregnancy has shown a 19% increased risk of pre-term birth. This exposure may in part contribute to the higher preterm birth rates in urban areas.²⁴ Exposure to air pollution, nitrogen dioxide and PM during pregnancy and during the first year of life has been associated with autism.²⁵


Relative to skin aging, particulate and gaseous components of air pollution, whether in-home or outdoors, are significant contributors.²⁶ In a recent study outdoor air pollution exposure from traffic and industry was linked to an increased risk of skin aging in Caucasian women. Indoor air pollution exposure caused by the use of fuels like coal has been shown to increase the risk of skin aging in Chinese women.²⁷


Air pollutants, PM and PAH enter the skin via nanoparticles (present in atmospheric pollutants) and generate quinones, which are redox-cycling chemicals that produce ROS. The PM increases the amount of ROS that triggers the upregulation of metalloproteinases that leads to extrinsic aging and skin pigmentation. The incidence of disorders of facial hyperpigmentation, specifically melasma, is increasing in India and South East Asia due to pollution antagonists.²⁸ PAC exposure (from coal tar) enhances the level of oxidative stress and genotoxic damage and thus contributes to skin aging process.²⁹


Sun, Sea, Sand and Skin

Beachgoers exposed to sun and sea for prolonged periods of time without the benefit of  environmental protection develop dry, rough skin wrinkles and fine lines. The perils of UV are well documented. The use of certain sunscreens, which can protect skin from ravages of sunlight, can also deposit peroxy and hydroxy radicals along with their photolysis fragments on skin. The same sunscreen agents in the presence of air, moisture and UV can produce these. For example, titanium dioxide composites are used as UV filters in sun care products combined with organic compounds such as butyl methoxydibenzoyl methane (avobenzone) and octyl methoxycinnamate (OMC) to improve the function of the sunscreen. In a study, the photolysis of avobenzone and OMC caused by the photocatalytic TiO_­2 nano composites (NCs) was investigated. NCs promoted the photolysis of OMC to the greatest extent.³⁰


TiO_­2 and zinc oxide (ZnO) are the primary inorganic physical sun blockers. TiO­_­2 is more effective in the UVB range and ZnO in the UVA range, so a combination of these particles assures broad-spectrum protection. For aesthetics, micronized TiO­_­2 and ZnO are getting replaced by TiO­_­2 and ZnO nanoparticles (NPs). Skin exposure to NP-containing sunscreens leads to incorporation of these NPs in the stratum corneum. Both sunscreens and NPs induce (photo)cyto- and genotoxicity and have been sporadically observed in viable skin layers especially with long-term exposures.³¹  However, conflicting results have also been reported.³² Regardless of NP safety, environmental pollution and damage to aquatic life caused by organic sunscreens remains a concern.³³ Clearly, there is a need for safer sunscreens that ensure optimal photo-protection with minimal photolytic decomposition and skin damaging byproduct formation.


Sulfates and Nitrates

Airborne sulfate and nitrate PM pose significant health risks. A reduction in sulfate and nitrate PM has been shown to improve public health.³⁴ Should consumers be concerned about sulfates, preservatives, and antibacterial agents in common hand soap and body wash products?


Consumers exposed to disinfectants, soaps, detergents and latex via their need to wash their hands frequently, especially those working in healthcare, are prone to hand/forearm dermatitis and sensitization to formaldehyde and p-phenylenediamine.³⁵  Glutaraldehyde, a disinfectant of choice for sterilizing medical and dental equipment, has many toxic side-effects, including the ability to induce allergic contact dermatitis.³⁶


In one study, 25 subjects washed hands and forearms with a neutral soap four times a day, for two minutes each time, for two weeks. Skin roughness and skin hydration were determined on the forearms. For skin roughness, silicon imprints were taken from the stratum corneum and assessed with a 3D skin analyzer for depth of the skin relief. For skin hydration measurements were taken with a corneometer. Washing hands led to a gradual increase of skin roughness from 100 (baseline) to a maximum of 108.5 after 9 days. Skin hydration was gradually decreased after washing hands from 79 (baseline) to 65.5 after 14 days.³⁷


A double blind, 24-hour randomized study assessed the irritation potential of four hand soaps. The effect on skin barrier function of repeated hand washing for two weeks was determined by assessing transepidermal water loss (TEWL), epidermal hydration and a visual assessment using the Hand Eczema Severity Index (HECSI). All products resulted in a significantly higher irritation compared with the no-treatment control.³⁸ Standardized methodology to test hand wash products for their skin irritation potential has been developed.³⁹ Skin-cleansing products containing syndets or amphoteric surfactants compared with standard soap and water washing improved skin dryness and demonstrated skin-protecting effects.⁴⁰


One caveat: certain ingredients used in skin care and other topical products have been labeled harsh, allergenic, toxic, “politically incorrect,” or unsuitable for use. Several preservatives have been condemned, leading to an explosion of “preservative-free” products. “Fragrance-free,” “emulsifier-free” and “all-natural ingredients” are other marketing jargon. These terms might suggest that preservatives, fragrances, emulsifiers, and other ingredients serve no practical function, are superfluous for product quality, and should be omitted. While this is obviously not the case, neither is the obverse—leading to an unresolved scientific controversy. It is undeniable that ingredients and their concentration used in skin care and other topical products must be carefully selected to maintain the overall stability and effectiveness of the product without causing undesirable side effects.⁴¹


Lessons from Ancient Cultures

KISS—Keep It Simple and Safe—has been practiced by the ancient cultures. Today, consumers are calling for the same. Here are some examples.


Kajal, a liniment made by mixing oil soot (“activated” carbon) and vegetable oil or ghee (butter heated until solids separate out, then removing pale yellow fat and cooling it). In India, it is used as eyeliner for tips of eyelids (just below eyelashes), which serves to beautify the eye-zone including eyebrows. Concurrently, the carbon particles absorb and trap any airborne pollutants or debris from eyeballs with the movement of every blink.


Ubtan, a pasty mixture of gram (chickpea) flour, water and oil (usually mustard oil) is applied on skin as a thin layer, left to dry for a few minutes, then rubbed off. It cleanses the skin from all unwanted deposits and dead cells, while concurrently moisturizing it as well. Antioxidants, such as powdered turmeric and ginger, can also be included. The facial beauty of a bride is further enhanced by ubtan application and mehendi decoration just before any wedding ceremony. Babies in rural India, in general, are not washed with soap or detergents, but cleansed with ubtan. Good health practices start at birth.


Mehendi (henna leaves) has been used by many ancient cultures for body art (temporary tattoo) and coloring of gray hair. Modern henna can impart auburn or black tints.


The application of various forms of clay and mud preparations to purify and beautify skin is still widely practiced. Of course, the benefits of botanical preparations continue to be reaped in rural Asia, Africa and the Americas. Native Americans continue to use indigenous botanicals for their health and beauty.⁴²


Relative to botanicals used by native people, Moringa oleifera was used to treat ailments by the Romans, Greeks and Egyptians. It has been cultivated from India to Oceania, Latin America, Africa and tropical Asia. The importance of peptides in skin care, especially in the protection of cells from oxidative stress and functional elegance of mitochondria, are well recognized.⁴³ A peptide fragment obtained from Moringa oleifera  was recently discovered. In a screening test, low concentrations of this peptide effectively killed bacteria such as Pseudomonas aeruginosa and Streptococcus pyogenes without displaying a toxic effect on human red blood cells.⁴⁴ An extract from this plant has shown inhibitory action against apostosis and ROS formation.⁴⁵ The marriage of old ingredients with new technology may lead to safer antibacterial agents.


Simple, functional, accessible, preservative- and emulsifier-free, non-irritating, and inexpensive—consumers around the world need basic and simplistic products.


Formulation Challenges

For centuries, “dilution is the solution to pollution” was widely practiced. From the consumer’s point of view, the design of topical formulations that can both capture and deactivate any harmful airborne antagonists that contact the skin surface and prevent deeper entry into skin is highly desirable. But it can be impractical to trap and neutralize all antagonistic culprits via this method, the enemies that manage to penetrate the skin must be defanged.


It is now a well-recognized science that such internally invading antagonists can cause malfunction of several key enzyme systems within human body. The management of key enzyme systems that are affected by environmental antagonists, especially aspects relating to visible changes to human beauty, is a highly desirable consumer need. An outside/inside dual treatment scheme utilizing both topical and ingestible products can lead to the development of beauty-for-the-whole body personal care and nutritional formulations.


Zymotherapy (zymo: relating to enzymes) can address the management of enzyme dysfunctions responsible for inflammatory processes leading to skin aging and other topical afflictions. Inflammation, initiated by both intra- and extra-cellular oxidation processes that have been altered by external antagonists, is one of the key culprits for human aging. These oxidation mechanisms trigger various enzyme dysfunctions that imprint the onset of such inflammation.


Recent work has shown that certain antioxidant-related enzymes perform a protective action against environmentally-induced oxidative stress. Investigations of oxidative responses suggest that organs and tissues contain distinct antioxidant systems in mammals. This may form the basis for differential susceptibility to environmental antagonists. Understanding the pathways leading to the induction of antioxidant responses can enable development of strategies to protect against oxidative damage.⁴⁶


Developing consumer-focused, safer products for humanity and the planet require a long-term effort. The social, cultural, economic and political factors that can influence the path to success require multinational attention. Recognition of discovery and development by both public and private sector will hasten this progress.


Conclusion 

Imagine a skin lotion or cream that binds airborne antagonists and retains them without their deeper penetration into skin, while concurrently permitting the transfer of any beneficial ingredients composed in that product into skin. Consider a body cleanser that effectively removes the above trapped antagonists along with dirt, grime and discarded dead cells. Or, how about a  sunscreen that protects skin from UV without being absorbed into body or producing any harmful photo-fragmentation byproducts? Or maybe a laundry detergent that does not emit any unwanted effluent gases? These can become a reality in the near future offering new opportunities for businesses and providing prized products for consumer.

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About the Authors
Shyam Gupta is an international consultant in innovative skin and hair care ingredients and delivery systems with 100+ patents, patent applications, cosmetics publications and book chapters specializing in nature and science based formulations with enhanced efficacy and consumer-appreciated performance attributes.
More info: shyam@biodermresearch.com; biodermresearch.com

John Stanek is direcror of research and development at CoValence Laboratories; his primary responsibility is to research new technologies leading to new product concepts.
More info: jstanek@covalence.com

Melinda Wochner is the chief marketing officer at CoValence Laboratories. Her primary responsibilities are to oversee the company’s website, press page, social media campaigns, tradeshows, creative and industry writing, private label products, in addition to being a member of the AZ District Export Council.

More info: melinda@covalence.com; covalence.com


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